Peer Review

science report and need a sample draft to help me learn.

Guidelines for Offering Feedback
Be mindful of your tone as you respond to your peer’s writing : There’s certainly no need to go overboard with niceties, but consider integrating a couple of positive comments for things that seem to be working well, especially at the beginning of your comments. You might want to use language such as: “I like how you . . .” or “I’m impressed by. . . .” Essentially, think about ways to achieve something like the balance between being honest and congenial that you’d aim for if you were talking face – to – face. A tone that works particularly well is one that is both friendly and supportive.
Ask questions : Your job as a reviewer is not to fix the paper, but rather to help your classmate understand how the writing affects readers. Given this approach, it can be very helpful to ask questions, just as you might do if you were talking face – to – face. It will be helpful for the writer to reflect on these questions when making writing choices.
Questions about claims. You might ask, “What in the readings or evidence prompted you to develop this claim? Why are you interested in this aspect of the topic? How does the evidence support your claim? How many pieces of evidence do you have (and does the quantity of evidence say anything about the strength of that evidence)? Do you have additional evidence that isn’t included in this draft?”
Questions about evidence. If the writer needs more evidence, you might say that you would like to hear more about a particular point, that you didn’t understand a certain point, and/or that you have additional unanswered questions.
Questions about organization. If you think a certain paragraph doesn’t belong, you can describe your response as a reader; for example, “When I got to this paragraph, I wondered what it was doing here – it seemed like you had been talking about A, but all of a sudden, here’s this paragraph about B! Can you help your reader understand how this paragraph should fit in?” The student may need better transitions, or may have left out something important that will clarify matters, or he or she may see that the paragraph doesn’t really belong. But let the writer make those decisions – if you say, “Take that one out!” you are making the writing decision for her/him.
Questions about sentence structure. How might you help your classmate learn to revise a sentence without changing it? Make up a similar sentence and carry out your revisions on it, explaining what the problem is, what options there are for revising it, and why you selected the option you did. Offer several different options, not just one, so that the writer sees that he/she has many choices.
Questions about word choice. Ask why the writer chose the word; tell what the word means to you and why it seems odd to you in this context. You could say, for example, “In your opening paragraph, I wonder how you chose the word ‘bellicose.’ When I read this word, I think of someone who is aggressive and warlike; is that what you meant?”
Look for patterns: When addressing sentence – level issues, loo k for patterns of error, rather than going through the draft and pointing out errors in the order in which they occur. The same sort of big – picture reflection will be helpful with non – sentence – level issues, too. If you notice wordiness, see how often it occurs; if you see one transition that troubles you, check out the others. You can then try to offer the writer new ideas about this general issue, instead of just commenting on one sentence here and another one there.
Beware of taking over : Avoid the following, as easy and tempting as they may be:
Revising the writer’s thesis or claim
Presenting new evidence for the writer to include
Rewriting individual sentences
Telling the writer to use a different word (and suggesting what the new word should be)
Telling the writer to remove a paragraph or to move it to a specific place
Organize your comments: Consider outlining or clearly grouping your comments, realizing that a certain approach may work well in one instance, but not necessarily another. Here are some strategies:
Organize your comments by first addressing the writer’s concerns (in an orderly way) and then moving on to additional concerns you noticed.
Emphasize the more significant writing issues (such as how effective the claim is, how powerful the evidence) at the beginning of your feedback, and ending with more minor issues (word choice, spelling errors, etc.).
Make your comments chronologically: Make sure to note specific paragraphs or sentences where problems occur; for example, you could say, “In the second paragraph of page 3, you. . . .”
Consider your language choices: Because your classmate isn’t with you and you can’t see her/his reactions, be sure to write in a respectful and fairly neutral style. It’s important to avoid evaluative claims; instead of saying, “Your paper is really successful,” it would be more appropriate to say, “After seeing your presentation of the evidence, I was convinced of your argument.” Be especially careful about anything that might sound overly harsh, offensive, or patronizing.
Make your organization explicit: If you are responding in writing, consider simple visual strategies (bullet points, numbering, boldface, etc.) to keep your content clear and to emphasize your main points. If you are recording your comments, you may want to use language such as: “First I’ll make some suggestions related to your organization. Second, I will discuss ways you might make your claims more effective. Finally, since you asked about commas, I will point out a few places where you make the same error and include a link to a handout that should help.”
Know the limitations of this type of work : In the time you spend with this paper (roughly an hour), you may find that you could discuss a large number of different writing issues. Keep in mind, however, that your classmate may be overwhelmed (and dismayed) if presented with a list of fifteen things to look at or work on. Therefore, it is essential that you prioritize your comments. Use signals such as, “If you only had time to work on one thing, I think you could increase clarity the most by considering. . .” or “The three areas that gave me the most trouble as a reader were. . . .”
Emphasize the fact that you are just one reader: Keep in mind for yourself, and emphasize for the writer, that you are just one a reader; consider prefacing your comments with phrases such as, “As one reader. . . ” or “From my perspective. . . ” You are not offering the definitive summary of what does and does not work in the paper.
Components of your peer review:
Your peer review must contain the following sections. I recommend that you work on a word document, and once you are ready to submit your peer review, you can paste it on the comments section or you can upload the file as an attachment to the comment. Please see here how to submit a peer review on CanvasLinks to an external site.. You don’t have to fill out any rubric, just answer the questions below and post them as a comment or upload them as a document. Your answers should be long enough to provide the author enough information on how to improve the paper, you should follow the guidelines listed above. Your peer review must include the following sections:
Summary: Start with the positive. Give a brief summary of what you liked about the paper and the things the author did well.If there are major issues with the paper, indicate those afterwards.
Content & Development: Is the thesis clearly stated and well developed? Is the topic and depth of content appropriate for this audience (biology seniors)? Are the ideas well supported by evidence, is there enough support provided? Are there enough details provided or is the information vague? Does the introduction provide enough background about the topic and state why the topic is relevant? Do the conclusions summarize the main takeaway from the paper and how it relates to the bigger picture?
Organization: Does the abstract follow the guidelines provided? Is the paper clearly focused and organized around a central theme with no digressions? Is there a clear progression in the topic for each section of the paper? Are the ideas within each section organized in a logical way that takes into account the background of the audience, usually starting with the most general ideas followed by more specific information?
Language: Is the paper concise, free of words, sentences or paragraphs that don’t add new information? Is each sentence informative and communicates just one idea per sentence? Are the paragraphs well organized, with the main idea of the paragraph stated at the beginning and supported by the following sentences? There are no quotes and all the information has been paraphrased into the author’s own words?
Conventions: Is every fact accompanied by a citation for the source? Is every source cited in the text fully referenced in the reference section? Does the format of the in-text citations and the reference section follow the reference guidelines? Is every reference listed in the reference section also cited in-text? Are the figures and tables cited in the text telling the reading when they are being referenced? Does each figure and table have a number, title and caption written in the author’s own words? Is every section heading labeled by a descriptive title?
Conclusion: End your review with positive words for the author, encouraging them to take on the work that is left.
Please make sure that all of the components for the peer review are added! I attached the two papers that need to be peer reviewed. Thank you!
Requirements:
George Dimov 1 The Impact of Severe Droughts Brought on by Climate Change on Biodiversity Abstract: In this impactful study, the authors delved into the escalating problem of severe droughts intensified by climate change and their profound implications on biodiversity. The motivation behind this research lay in understanding the intricate relationships between extreme drought events, altered ecological interactions, and the subsequent repercussions on plant and terrestrial animal species. The critical question addressed was how these droughts reshape habitats, behaviors, and population dynamics, necessitating proactive conservation strategies in the face of environmental challenges. The main contribution of this paper to the scientific community lies in revealing the intricate web of connections between drought intensity, habitat loss, and altered ecological behaviors. Through meticulous research and analysis, the study uncovered that severe droughts not only lead to habitat destruction but also induce significant behavioral shifts in animals, influencing migration patterns, feeding habits, and reproductive strategies. These behavioral changes, in turn, have far-reaching effects on plant pollination, seed dispersal, and overall ecosystem health. The key findings of this research highlight the urgency of adopting holistic conservation approaches. Habitat restoration, water resource management, and community engagement emerged as pivotal strategies in mitigating the adverse effects of severe droughts. Moreover, the integration of climate change projections and ecological forecasting into conservation practices was underscored as a vital step. Predictive modeling can identify vulnerable areas, enabling targeted interventions and adaptive management strategies, thereby enhancing the resilience of ecosystems against drought-induced stressors. In conclusion, this study not only provides valuable insights into the complex interactions between severe droughts and biodiversity but also offers practical recommendations for conservationists, policymakers, and researchers. By comprehensively understanding these intricate relationships, stakeholders can develop informed strategies, ensuring the preservation of the delicate balance of life on Earth amidst the challenges posed by climate change-induced droughts. The take-home message of this research is clear: proactive, interdisciplinary, and technology-informed conservation measures are paramount in safeguarding biodiversity in our changing world.
George Dimov 2 Introduction: In the intricate tapestry of Earth’s ecosystems, the delicate balance between flora and fauna is continuously challenged by environmental perturbations. Among these challenges, the intensifying impact of climate change-induced extreme droughts stands as a formidable force, reshaping the landscapes upon which countless species depend. The scientific community has long recognized the importance of understanding the intricate relationship between extreme drought and biodiversity. Drought events are not isolated incidents but rather pivotal ecological events that influence various aspects of natural systems. As climate change accelerates, the urgency to comprehensively explore the effects of extreme drought on biodiversity becomes increasingly paramount Historically, droughts have been recognized as natural phenomena shaping ecosystems, yet the intensification of these events due to climate change has heightened their significance. The increasing frequency and severity of extreme droughts have far-reaching consequences on plant and terrestrial animal life. Drought-induced stress challenges the adaptability of both plants and animals, leading to shifts in species composition and habitat availability. Understanding these changes is not just a scientific pursuit; it is crucial for our ability to preserve the intricate web of life that sustains our planet’s ecosystems. Previous studies, as indicated by a plethora of scientific research have highlighted the multifaceted impacts of extreme drought on biodiversity. These studies have delved into altered adaptations in plant species, habitat loss and fragmentation in animal populations, and the intricate interplay between ecological interactions under drought-induced stress. The consequences of extreme droughts are not isolated to immediate habitat alterations; they permeate through ecosystems, influencing behavior, population dynamics, and, ultimately, the overall biodiversity of affected regions. This research paper embarks on a detailed exploration of these phenomena, aiming to decipher the mechanisms through which extreme drought reshapes biodiversity. By investigating the interconnectedness of plant and terrestrial animal ecosystems under the stress of extreme drought, this study seeks to unravel the complexities of their responses. The ultimate goal is to shed light on the pivotal role of droughts in driving ecological changes, emphasizing the urgency of comprehensive conservation strategies. Through this exploration, the study not only contributes to the existing body of knowledge but also provides crucial insights necessary for
George Dimov 3 informed environmental management practices in the face of our changing climate. In essence, this research illuminates how extreme drought, through mechanisms such as increased fire frequency, leads to profound alterations in biodiversity, emphasizing the necessity for adaptive and proactive conservation measures to preserve the intricate balance of life on Earth. Impact of Severe Droughts on Plant Biodiversity: Severe droughts, intensified by climate change, constitute a significant ecological challenge, profoundly impacting plant biodiversity, leading to biodiversity loss, altered adaptations, and ecosystem disruptions. The connection between extreme droughts and altered ecological interactions underscores the urgency of understanding this phenomenon. Liu et al. (2020) studied the effects of decadal experimental drought and climate extremes on vegetation growth in Mediterranean forests and shrublands. Their research illuminated the intricate relationship between prolonged drought periods and heightened stress levels among plant populations. This stress manifests in various ways, notably through reduced photosynthetic activity, diminished growth rates, and increased vulnerability to diseases. Consequently, plant communities experience disrupted life cycles and weakened reproductive success, leading to alterations in species composition and plant community dynamics (Liu et al., 2020). This research underscores the critical role of droughts in triggering a cascade of events that significantly impact plant biodiversity, aligning with the thesis statement emphasizing the intricate connections between drought intensity, fire occurrences, and biodiversity alterations. In response to severe droughts, plants undergo significant adaptations to cope with water scarcity, a phenomenon extensively studied by Hao and Chu (2022) in terrestrial bryophytes in southern China. These adaptations range from morphological changes, such as altered root structures to enhance water absorption, to physiological modifications like reduced stomatal conductance to minimize water loss (Hao & Chu, 2022). Some species exhibit dormancy or altered reproductive strategies to conserve energy during prolonged dry periods. These adaptations, while crucial for short-term survival, might become insufficient in the face of escalating and prolonged drought events. Plants’ ability to adapt, once a testament to their resilience, is increasingly challenged, leading to shifts in species composition and biodiversity. Understanding these adaptive mechanisms is vital for predicting the long-term impact of severe droughts on plant communities.
George Dimov 4 Ecosystem disruptions caused by severe droughts extend beyond individual plant species. Wang et al. (2010) examined the sustained drought impact on vegetation ecosystems in southwest China, emphasizing the far-reaching consequences on ecosystem structure and functioning. Drought-induced stress not only weakens plant vitality but also disrupts intricate relationships within ecosystems. Reduced vegetation cover affects soil stability, leading to increased erosion and altered nutrient cycling (Wang et al., 2010). Consequently, these disruptions impact other organisms reliant on stable ecosystems, triggering shifts in animal populations, microbial communities, and overall ecosystem health. The intricate interdependencies within ecosystems highlight the widespread consequences of severe droughts, indicating the urgent need for comprehensive conservation strategies that consider the entire ecosystem. Figure 1 shows the change in the remote sensing monitoring of vegetation from the sustained drought in Yunnan, Guangxi, Sichuan, Guangxi, Chonqing, and Guizhou regions of Southwest China. Table 1 shows the numerical representations of the monthly changes in the data for each of the previously mentioned regions in Southwest China. Figure 2 shows a visual representation of the ecological impact of the drought based on the variation of vegetation of each of the regions in Southwest China from August 2009 – March 2010 throughout the sustained drought. Normal phenology, the study of recurring plant and animal life cycle events, forms the basis of ecosystem stability. However, severe droughts disrupt these patterns, leading to unprecedented changes in phenological events. Lewinska et al. (2018) investigated drought impacts on phenology and green biomass production in alpine mountain forests in South Tyrol, emphasizing the disruption in phenological events due to prolonged water scarcity. Plants, under normal conditions, follow predictable phenological patterns, crucial for synchronization with pollinators and optimal environmental conditions for growth. Severe droughts, however, lead to phenological mismatches, where flowering, fruiting, or leaf shedding occur at inappropriate times. These disruptions create imbalances within ecosystems, affecting the availability of resources and disrupting ecological relationships, further emphasizing the complexity of severe drought impacts on plant biodiversity (Lewinska et al., 2018). In summary, severe droughts have multifaceted consequences on plant biodiversity, extending from altered ecological interactions to disruptions in adaptive mechanisms and ecosystem-wide disturbances. These impacts,
George Dimov 5 supported by extensive scientific research, emphasize the urgency of devising holistic conservation strategies to safeguard plant biodiversity in the face of escalating climate-induced drought events. Understanding the intricacies of these impacts is paramount for informed decision-making, aiding conservation efforts, and promoting the resilience of plant ecosystems in the changing climate scenario. Impact of Severe Droughts on Terrestrial Animal Biodiversity: Severe droughts, intensified by climate change, are fundamentally reshaping animal biodiversity by disrupting habitats and altering ecological interactions, leading to habitat loss, altered behavior, and altered population dynamics. Clark et al. (2016) conducted an extensive study on the impacts of increasing drought on forest dynamics, structure, and biodiversity in the United States, providing a foundational understanding of these profound effects. The relationship between extreme drought and altered ecological interactions serves as a critical focal point in comprehending the intricate mechanisms through which animal biodiversity is influenced. Droughts heighten stress on ecosystems, leading to increased vulnerability among plant species. This heightened stress reverberates throughout the food chain, impacting herbivorous and carnivorous animals alike. Additionally, droughts exacerbate the frequency of forest fires, resulting in habitat destruction. As habitats shrink, animal populations are forced into smaller, fragmented areas, leading to increased competition for resources and, often, a decline in overall biodiversity (Clark et al., 2016). These impacts underscore the imperative for studying the interconnected dynamics between drought intensity, habitat loss, and altered ecological interactions. One of the most immediate and visible consequences of severe droughts is habitat loss and fragmentation, an issue extensively explored in studies like Peterson et al. (2021). Drought-induced changes in vegetation cover directly translate to alterations in animal habitats. Areas that were once lush and habitable transform into arid, inhospitable environments. Moreover, the scarcity of water sources further exacerbates the challenges for aquatic and semi-aquatic species. For terrestrial animals, the shrinking habitats result in fragmentation, isolating populations and restricting their movements. Fragmented habitats can lead to genetic isolation, reducing genetic diversity and adaptive potential among species. The loss of connectivity between habitats also hinders migration patterns and disrupts predator-prey relationships (Peterson et al., 2021). As a
George Dimov 6 consequence, animal populations face increased stress, limited resources, and higher predation risks, all of which contribute to declines in biodiversity. Droughts have profound effects on animal behavior, reshaping the strategies and patterns crucial for survival, a phenomenon thoroughly investigated by Cayuela et al. (2016). In response to dwindling resources, animals often alter their behavior, migration routes, and feeding habits. Nocturnal species may become diurnal to avoid daytime heat, while others might travel longer distances in search of water and food (Cayuela et al., 2016). Breeding behaviors, such as courtship rituals and nesting practices, are also influenced. These behavioral changes have broader ecological implications, affecting interactions with other species, plant pollination, and seed dispersal. Moreover, altered behaviors may lead to increased human-wildlife conflicts as animals venture closer to human settlements in search of sustenance. Understanding these behavioral shifts is critical for predicting species’ responses to changing environmental conditions and devising appropriate conservation strategies. Severe droughts influence population dynamics, leading to fluctuations in animal numbers and, in some cases, population declines. Baldwin et al. (2013) explored the impacts of inundation and drought on eukaryote biodiversity in semi-arid floodplain soils, shedding light on the intricate relationships between moisture levels and microbial diversity. Similarly, animal populations are intricately connected to environmental moisture. Reduced water sources and food availability lead to declines in reproduction rates and increased mortality (Baldwin et al., 2013). Small populations become vulnerable to extinction, especially if the drought events are prolonged. Additionally, the stress of drought conditions weakens animals, making them more susceptible to diseases and predation. These factors compound, leading to cascading effects on entire ecosystems. Understanding the population dynamics of various animal species in the face of drought-induced stressors is vital for predicting the long-term impacts on biodiversity and implementing targeted conservation measures. Conservation Strategies and Future Outlook: Severe droughts, intensified by climate change, pose a significant threat to biodiversity by increasing the frequency of forest fires and disrupting ecological interactions. Amidst these challenges, effective habitat conservation strategies are crucial to safeguarding biodiversity. Brown et al. (2022) examined the utilization of the Conservation Standards Framework to
George Dimov 7 address climate change effects on biodiversity and ecosystem services, providing essential insights into comprehensive conservation approaches. Conservation efforts must begin with a thorough understanding of the ecosystems at risk (Brown et al., 2022). This framework emphasizes the importance of assessing ecosystem vulnerabilities, determining conservation targets, and designing interventions tailored to specific contexts. By integrating climate change projections, conservationists can identify areas most susceptible to drought-induced stressors, enabling proactive planning and targeted interventions. Incorporating this framework into conservation practices equips professionals with a systematic methodology to counter the adverse effects of droughts, aligning with the thesis statement highlighting the need for adaptive strategies against intensified drought events. Despite the existence of conservation strategies, challenges persist in mitigating drought-induced biodiversity loss. Muralikrishnan et al. (2022) explored climate change-induced drought impacts and adaptation measures in semi-arid pastoral and agricultural watersheds, shedding light on the complexities of conservation efforts. Habitat degradation and resource scarcity intensify competition among species, exacerbating vulnerability during droughts (Muralikrishnan et al., 2022. Conservation strategies often involve habitat restoration, water resource management, and community engagement. These interventions, while vital, require significant financial and human resources. Implementing such strategies necessitates collaboration between governments, NGOs, and local communities. Additionally, awareness campaigns and education initiatives are crucial to fostering a sense of environmental stewardship, empowering communities to actively participate in conservation efforts. Overcoming these challenges demands innovative approaches that balance ecological sustainability with socioeconomic considerations, ensuring the resilience of ecosystems against drought-induced stressors. Looking to the future, innovative conservation approaches are imperative to bolster the resilience of habitats affected by droughts. Sternberg et al. (2015) employed an expert assessment approach to evaluate the impacts of climate change on biodiversity in Israel, emphasizing the need for adaptive management strategies. Future conservation efforts must consider evolving climate patterns and anticipate emerging challenges. Utilizing predictive modeling and ecological forecasting, conservationists can identify potential refuge habitats, aiding species’ migration and adaptation (Sternberg et al., 2015). Furthermore, integrating
George Dimov 8 traditional ecological knowledge with scientific research enhances the understanding of ecosystem dynamics, enabling the development of culturally sensitive and community-based conservation approaches. Embracing technological advancements, such as remote sensing and artificial intelligence, enhances monitoring and assessment capabilities, facilitating timely interventions. By adopting a forward-looking perspective, conservation strategies can proactively address future climate-induced uncertainties, ensuring the persistence of biodiversity amidst the escalating challenges posed by droughts intensified by climate change. Conclusion: In conclusion, the extensive review of scientific research presented in this paper sheds light on the intricate and multifaceted impacts of severe droughts intensified by climate change on biodiversity. The findings underscore the urgency of understanding the interconnected dynamics between extreme drought events, altered ecological interactions, habitat loss, and population dynamics. The patterns revealed in various studies highlight the vulnerabilities of both plant and terrestrial animal species, emphasizing the critical need for proactive conservation strategies. One of the intriguing aspects of these findings is the complex web of interactions between drought intensity, habitat loss, and altered ecological behaviors. The research indicates that severe droughts not only lead to habitat destruction but also trigger behavioral shifts in animals, impacting their migration patterns, feeding habits, and reproductive strategies. These behavioral changes, in turn, have cascading effects on plant pollination, seed dispersal, and overall ecosystem health. Understanding these intricate connections provides valuable insights into the mechanisms driving biodiversity alterations in the face of climate-induced droughts. The implications of these findings for the field of biodiversity conservation are profound. Firstly, it emphasizes the importance of holistic conservation strategies that consider not only individual species but entire ecosystems. Conservation efforts need to address habitat restoration, water resource management, and community engagement to mitigate the adverse effects of severe droughts. Secondly, the research highlights the significance of integrating climate change projections and ecological forecasting into conservation practices. Predictive modeling can identify vulnerable areas, enabling targeted interventions and adaptive management strategies. Looking to the future, the field of biodiversity research is heading towards more interdisciplinary collaborations. Integrating traditional ecological knowledge with cutting-edge
George Dimov 9 scientific research enhances our understanding of ecosystem dynamics and fosters culturally sensitive conservation approaches. Additionally, advancements in technology, such as remote sensing and artificial intelligence, offer new avenues for monitoring and assessment, facilitating timely and data-driven conservation interventions. In summary, the findings presented in this paper underscore the urgency of proactive and adaptive conservation measures in the face of escalating climate-induced drought events. By comprehensively understanding the intricate relationships between severe droughts and biodiversity, conservationists can develop informed strategies to preserve the delicate balance of life on Earth. As we move forward, interdisciplinary collaborations, technological advancements, and community engagement will play pivotal roles in shaping the future of biodiversity conservation amidst the challenges posed by climate change-induced droughts. Figures and Tables: Table 1: Remote Sensing Monitoring Results of Southwest China
George Dimov 10
George Dimov 11 Table. 1. Monthly change in the remote sensing monitoring data of vegetation from the sustained drought in the Yunnan, Guangxi, Sichuan, Guangxi, Chonqing, and Guizhou regions of Southwest China (Adapted from Wang et al., 2010). Fig. 1: Change in the remote sensing monitoring of vegetation from the sustained drought in various regions of Southwest China Fig. 1. Line graph of the change in the remote sensing monitoring of vegetation from the sustained drought in the Yunnan, Guangxi, Sichuan, Guangxi, Chonqing, and Guizhou regions of Southwest China based on the data in Table 1 (Adapted from Wang et al., 2010). Fig. 2: Variation of vegetation in the Yunnan, Guangxi, Sichuan, Guangxi, Chonqing, and Guizhou regions in Southwest China from August 2009 – March 2010 throughout the sustained drought
George Dimov 12 Fig. 2. A visual representation of the ecological impact of the drought based on the variation of vegetation of each in the Yunnan, Guangxi, Sichuan, Guangxi, Chonqing, and Guizhou regions in Southwest China from August 2009 – March 2010 throughout the sustained drought. (Adapted from Wang et al., 2010).
George Dimov 13 References: Baldwin, D. S., Colloff, M. J., Rees, G. N., Chariton, A. A., Watson, G. O., Court, L. N., Hartley, D. M., Morgan, M. J., King, A. J., Wilson, J. S., Hodda, M., & Hardy, C. M. (2013). Impacts of inundation and drought on eukaryote biodiversity in semi-arid floodplain soils. Molecular Ecology, 22(6). https://doi.org/10.1111/mec.12190 Brown, M. B., Morrison, J. C., Schulz, T. T., Cross, M. S., Püschel-Hoeneisen, N., Suresh, V., & Eguren, A. (2022). Using the Conservation Standards Framework to Address the Effects of Climate Change on Biodiversity and Ecosystem Services. In Climate (Vol. 10, Issue 2). https://doi.org/10.3390/cli10020013 Cayuela, H., Arsovski, D., Bonnaire, E., Duguet, R., Joly, P., & Besnard, A. (2016). The impact of severe drought on survival, fecundity, and population persistence in an endangered amphibian. Ecosphere, 7(2). https://doi.org/10.1002/ecs2.1246 Clark, J. S., Iverson, L., Woodall, C. W., Allen, C. D., Bell, D. M., Bragg, D. C., D’Amato, A. W., Davis, F. W., Hersh, M. H., Ibanez, I., Jackson, S. T., Matthews, S., Pederson, N., Peters, M., Schwartz, M. W., Waring, K. M., & Zimmermann, N. E. (2016). The impacts of increasing drought on forest dynamics, structure, and biodiversity in the United States. In Global change biology (Vol. 22, Issue 7). https://doi.org/10.1111/gcb.13160 Hao, J., & Chu, L. M. (2022). Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China. Journal of Forestry Research, 33(5). https://doi.org/10.1007/s11676-021-01443-4 Lewinska, K. E., Ivits, E., Schardt, M., & Zebisch, M. (2018). Drought impact on phenology and green biomass production of alpine mountain forest-Case study of South Tyrol 2001-2012 inspected with MODIS time series. Forests, 9(2). https://doi.org/10.3390/f9020091
George Dimov 14 Liu, D., Zhang, C., Ogaya, R., Estiarte, M., & Peñuelas, J. (2020). Effects of decadal experimental drought and climate extremes on vegetation growth in Mediterranean forests and shrublands. Journal of Vegetation Science, 31(5). https://doi.org/10.1111/jvs.12902 Muralikrishnan, L., Padaria, R. N., Choudhary, A. K., Dass, A., Shokralla, S., Zin El-Abedin, T. K., Abdelmohsen, S. A. M., Mahmoud, E. A., & Elansary, H. O. (2022). Climate change-induced drought impacts, adaptation and mitigation measures in semi-arid pastoral and agricultural watersheds. Sustainability (Switzerland), 14(1). https://doi.org/10.3390/su14010006 Peterson, E. K., Jones, C. D., Sandmeier, F. C., Arellano Rivas, A. P., Back, C. A., Canney, A., Fender, J., Gomez, M., Gorski, J., Heintzelman, N., Healey, K., Kester, M., Klinger, D., Liao, A., Varian-Ramos, C. W., & Heuvel, B. Vanden. (2021). Drought influences biodiversity in a semi-arid shortgrass prairie in southeastern Colorado. Journal of Arid Environments, 195. https://doi.org/10.1016/j.jaridenv.2021.104633 Sternberg, M., Gabay, O., Angel, D., Barneah, O., Gafny, S., Gasith, A., Grünzweig, J. M., Hershkovitz, Y., Israel, A., Milstein, D., Rilov, G., Steinberger, Y., & Zohary, T. (2015). Impacts of climate change on biodiversity in Israel: an expert assessment approach. Regional Environmental Change, 15(5). https://doi.org/10.1007/s10113-014-0675-z Wang, W., Wang, W. J., Li, J. S., Wu, H., Xu, C., & Liu, T. (2010). The impact of sustained drought on vegetation ecosystem in southwest China based on remote sensing. Procedia Environmental Sciences, 2. https://doi.org/10.1016/j.proenv.2010.10.179
1 Extreme Heat Threatens Cardiovascular Health Bryan Souza BSC 4931 Professor Steven Oberbauer
2 Abstract The body’s cardiovascular system is influenced by various factors, one of them being extreme temperatures. As climate change becomes more prominent around the world, the prevalence of extreme heat events is surging. While the impact of extreme heat on cardiovascular health is known, a full understanding of the specific diseases affected, the impact on diverse demographics, and the extent to which it contributes to cardiovascular deaths is lacking. This review dives into the effects of extreme heat on distinct cardiovascular diseases, analyzes its varying impacts on demographic groups, and determines its significance when it comes to causing cardiovascular deaths. The findings show that extreme heat is responsible for the increasing prevalence of a plethora of diseases, the most common amongst all studies being ischemic heart disease. The demographic groups that were most impacted were women and people over the age of 65, but all groups were affected to some degree. Cardiovascular mortality was shown to be substantially affected by extreme heat events on a global scale; also, cardiovascular morbidity was proven to account for an increase in years of life lost when periods of extreme heat are occurring. All in all, extreme heat showed to have a strong effect in each aspect that was reviewed. Precautionary measures should be taken to reduce the impact of extreme heat such as increasing intake of water, acquiring some type of air conditioning, and reducing exposure to the hot temperatures. Introduction When it comes to the health of specific body areas, few are as influenced as the cardiovascular system. Cardiovascular health is impacted by a multitude of factors with the most notable in society being physical activity and diet. However, one factor that has become just as impactful is extreme temperature. With climate change causing extreme temperatures on both ends of the spectrum, it is certain that these extremes are detrimental to cardiovascular health. As the global warming phenomenon continues, extreme heat is becoming more common all throughout the world which in turn, is negatively impacting cardiovascular health globally. Although it is well-documented that extreme heat does negatively affect cardiovascular health, there are questions regarding the extent of that effect. To state that cardiovascular health worsens with extreme heat conditions does not detail which aspects of cardiovascular health it affects, or if the role it plays in cardiovascular health is acute, chronic, or fatal. More so, it is important to consider if and how demographic factors such as age, location, and sex are affected
3 differently by extreme heat. Completing the previously mentioned analyses will provides a basis for how to judge the trend of increasing mortalities related to cardiovascular issues, possibly allowing to create a correlation between the former and extreme heat. Therefore, this review article will assess the following: the effects that extreme heat has on specific cardiovascular diseases, how it affects different demographics in the population, and if it is responsible for the increase in cardiovascular mortality. Effects on Specific Cardiovascular Diseases Extreme heat is responsible for worsening cardiovascular health, but it is important to study which issues are most affected by this phenomenon. Cardiovascular health issues are plentiful and affect a plethora of people on a regular basis, some being more serious than others. With extreme heat, these issues become more intense and it is common for an increase for hospitalizations to occur during periods of extremely hot temperatures. A study conducted in New York City during the months of June through August between the years of 1991 and 2004 compiled data on hospitalizations related to cardiovascular and respiratory diseases (Lin et al., 2009). The study used this data to determine if the extreme heat during those months causes an increase in hospitalizations for cardiovascular or respiratory purposes, as well as to discover which diseases are most affected by the hotter temperatures. Figure 1. The 3-day moving average for hospitalizations related to cardiovascular and respiratory diseases when the heat index is above the threshold of 32¡C. Demographic variables of the patients and their diagnoses were also recorded. (Adapted from Lin et al., 2009).
4 The data is shown in Figure 1. This figure shows this data over a 3-day moving average, meaning that these diagnoses are a result of exposure to extreme heat that could have occurred up to 3 days prior to the patient being admitted to the hospital. In the figure, the exposure to extreme heat is described as apparent temperature above the threshold of 32¡C. It is important to note that apparent temperature is defined as the temperature that it feels like, instead of the actual temperature reading. Apparent temperature includes the added effects of humidity on the temperature. Humidity is shown to augment the impact of extreme heat as there were more hospitalizations on days of extreme heat with high relative humidity than low relative humidity (Lin et al., 2009). The data in Figure 1 shows that there is an overall 1.41% increase in hospitalizations for cardiovascular disease for each degree Celsius that the apparent temperature is above the threshold. Of the listed cardiovascular diseases, cardiac dysrhythmia and ischemic heart disease experienced increases in hospitalizations due to extreme heat, while cerebrovascular diseases, hypertension, and heart failure saw decreases (Fig. 1). There are many meta-analyses that also state that ischemic heart disease is severely affected by extreme heat; however, these meta-analyses also include a study done in Germany that showed an increased risk of myocardial infarctions because of extreme heat (Chaseling et al., 2021). Table 1. Table depicting excess emergency department visits for cardiovascular and cerebrovascular diseases in North Carolina during extreme heat events. Asterisks mean that the more than 60% of patients were 65 and older. (Adapted from Fuhrmann et al., 2015).
5 Another study took place in North Carolina in which three extreme heat events were analyzed for their impact on cardiovascular health. As per the data compiled from the study that is shown in Table 1, there were increases of 3.5% or higher for the totality of cardiovascular diseases across all three events (Fuhrmann et al., 2015). All of the specific diseases displayed an excess of visits in at least one extreme heat period, with the majority having it in all three. The specific diseases with the highest number of excess visits were hypotension, acute myocardial infarction, heart failure, and ischemic heart disease (Table 1). This relates to the meta-analysis of the study in Germany as it serves as another example of myocardial infarction being more frequent as a result of extreme heat. Moreover, this explains how hypertension in the study done in New York City decreased as its opposite, hypotension, experienced drastic increases during the events in North Carolina. Hot temperatures cause blood vessels to expand which would mean there is less pressure in those vessels when blood is rushing through it. Meanwhile, cold temperatures cause vessels to constrict so there’s more pressure in the vessels when blood is passing. There is consistency within the research that diseases such as cardiac dysrhythmia, ischemic heart disease, hypotension, and myocardial infarction are worsened by extreme heat. There also exists data that extreme heat can reduce the risks of other diseases, most notably hypotension and cerebrovascular diseases. Generally, extreme heat impacts cardiovascular health negatively; but, not all aspects of cardiovascular health are affected equally. Effects on Different Demographics Extreme heat does not affect everyone the same way. Age, sex, ethnicity, and living situation should all be taken into consideration when looking into what effects extreme heat had on the person. The most telling demographical difference tends to be age, as the elderly will more likely be affected by extreme heat than younger people. This is a result of the body weakening with age and becoming more susceptible to risk factors that are detrimental to health. When a person gets older, the ability for their body to dissipate heat decreases and their body temperatures deviate more in extreme temperatures than when they were younger. An average group of elders (ages 55-73) will experience a greater increase of body temperature by 0.5¡C than a group of young adults (19-28) (Kenny et al., 2016). This increased body temperature is a key factor in worsening cardiovascular health. It causes “attenuated sweat gland outputs, reduced blood flow to the skin, smaller increases in cardiac outputs, and less redistribution of
6 blood flow from the splanchnic and renal circulations” which all increase the risk of cardiovascular diseases and mortality for elders (Achebak et al., 2019). Figure 1 also shows that as the age group gets older, there is a greater increase of cardiovascular hospitalizations per ¡C above the threshold (Fig. 1). The aging process of the body places the cardiovascular health of elders at much more risk than younger people when under extreme heat. Different sexes also feel the effects of extreme heat differently. In the study done in New York City, there was a 1.76% increase in male hospitalizations and 1.06% increase in female hospitalizations (Fig. 1). Physiological differences in thermoregulation seems to be the most likely explanation for this. Women tend to sweat less than men and need higher temperatures than men in order to start sweating, meaning their bodies cooldown process is less effective than that of their counterparts (Achebak et al., 2019). The lack of sweating will cause women to retain more heat and under periods of extreme heat, this is counterproductive. Figure 2. Minimum mortality temperature for cardiovascular diseases (Adapted from Achebak et al., 2019.)
7 Figure 2 strengthens the fact that women are more affected by extreme heat than men by showing how the minimum mortality temperature for cardiovascular diseases is generally lower for women than for men. Besides the graph of the age group 60-74, women were consistently suffering from mortality due to cardiovascular diseases at lower temperatures (Fig. 2). The graph of age 60-74 is likely to be an outlier in the data as all other results show it to be as such. An individual’s background can also play a role in how their cardiovascular health is affected by extreme heat. Figure 1 shows an example of this as the Hispanic population of New York City experienced a greater percentage of hospitalizations for cardiovascular diseases than the non-Hispanic population. This perspective on how extreme heat affects these demographics differently is yet to be studied further, but there are more studies that prove its effects are unique to each background. This is noticeable in a study conducted in the Northern Territory of Australia in which researchers examined the prevalence of cardiac diseases (ischemic heart disease and heart failure) in indigenous and non-indigenous people during periods of extreme heat. This was done by recording daily hospital admissions for five public hospitals in the Northern Territory between 1992 and 2011. The results showcase that extreme heat caused a greater impact on the cardiovascular health of indigenous people than that of non-indigenous people, with the greatest impact being on indigenous women between 25 and 64 years old (Webb et al., 2014). This group experienced a 32% increase in hospitalizations for ischemic heart disease and the overall group of indigenous people experienced a 17% increase, greater than all percentages of non-indigenous groups (Webb et al., 2014). The results did not mention heart failure with extreme heat as the researchers believe the dilation of vessels in hot temperatures would help alleviate the workload on the heart. Although that is a valid statement, the data present in Table 1 says otherwise as extreme heat caused an increase in visits to emergency departments for heart failure (Table 1). If heart failure were to be improved by vasodilation, the increase because of extreme heat demonstrated in Table 1 should be a decrease instead. It is integral that all effects of extreme heat on cardiovascular health are considered for diseases instead of focusing on a singular one. Effects on Mortality Considering the effects of extreme heat on specific cardiovascular diseases, it is reasonable to assume there are similarities when it comes to cardiovascular mortality. The increasing cases and severity of the diseases eventually lead to mortalities from those diseases.
8 This applies to many different diseases on a global scale. A meta-analysis compiled of research from 1957 to 2002 studied how public health is impacted by extreme heat and one finding was that an increase in average daily temperature by 10¡F corresponded to a 2.6% increase for cardiovascular mortality in North America (Cheng & Su, 2010). The disease most responsible for this increase was ischemic heart disease which is reasonable considering how it was consistently one of the most affected diseases by extreme heat. Figure 3. Maps of total number of extreme-heat days and average monthly cardiovascular mortality rates per county in the US from 2008 to 2017 (Adapted from Khatana et al., 2022). A study conducted in the United States from 2008 to 2017 wanted to determine the extent to which extreme heat affects cardiovascular mortality. Data was collected between the months of May and September, which consisted of county-level information on days that the heat index was greater than or equal to 90¡F. The monthly cardiovascular rate was calculated with the number of deaths of adults 20 years and older due to cardiovascular diseases per month. Figure 3 represents the data in the two maps, the left one representing the total of extreme heat days per county and the right one being the average monthly cardiovascular mortality rates per county. The counties that make up the second and third tertiles of extreme heat days also make up many of the counties in the second and third tertiles of the monthly cardiovascular mortality rates (Fig. 3). Each additional day of extreme heat increased the monthly cardiovascular mortality rates by 0.12% (Khatana et al., 2022). Furthermore, these extreme heat days were responsible for approximate 5,958 extra deaths due to cardiovascular disease (Khatana et al., 2022). Extreme heat in the United States is shown to increase the rate of cardiovascular
9 mortality, with some regions of the United States (mostly southern and central) being more at risk than others. Additionally, similar results have been gathered outside of the United States. Studies conducted in China show that extreme heat causes a significant increase in mortality resulting from coronary heart diseases (Tian et al., 2012). These increases were greater amongst women and the elderly, showcasing additional examples of the effects on different demographics. Whether in the United States or anywhere else in the world, there is proof of the increase in the occurrence of mortality due to cardiovascular diseases. Also, there is the issue of morbidity when it comes to cardiovascular health. Instead of losing a life, morbidity describes the amount of years lost in life because of a risk factor. In the situation that extreme heat is a factor, morbidity is drastically affected. Table 2. Years of Life Lost as a Result of Heat Waves in Brisbane, Australia from 1996-2004 (Adapted from Huang et al., 2012). Cardiovascular morbidity was studied in Brisbane, Australia during periods of extreme heat called heat waves over the years of 1996 to 2004. When a heat wave was 2 days or longer, the effects augmented greatly as years of life lost reached a peak of 235 for a 4-day heat wave (Huang et al., 2012). Years of life lost is calculated based on the age the death occurred and how much longer their life expectancy at that age (Huang et al., 2012). From cardiovascular diseases during that time period, over 200,000 years of life were lsot (Huang et al., 2012). Now, there is the implication that the cardiovascular disease is the sole purpose of why that person did not reach their life expectancy. This is a shortcoming as that is merely an estimate with uncertainty that it would happen; however, there is undoubtable truth that the extreme heat caused the cardiovascular diseases to worsen and lead to premature deaths. Conclusion In conclusion, the impact of extreme heat on cardiovascular health is significant in a negative manner. The extremely high temperatures have massive effects on various cardiovascular diseases, with the most affected being ischemic heart disease. All demographics
10 of a population are at some type of risk in these conditions, but especially the elderly, women, and native people. The rate of cardiovascular deaths increases substantially because of extreme heat and many people suffer from losing years of life when exposed to periods of extreme heat. It is important to understand the effects of extreme heat on cardiovascular health so that the appropriate medical actions can be taken. Doing so will decrease the severity of the cardiovascular risks from extreme heat. Precautionary measures like drinking more water, reducing exposure to heat, and using a form of air conditioning are all ways to make extreme heat less effective. Considering how cardiovascular health is already influenced by many other factors, it would be beneficial to limit the impact of one of the more detrimental factors in extreme heat.
11 References Achebak H, Devolder D, & Ballester J (2019). Trends in Temperature-related Age-specific and Sex-specific Mortality From Cardiovascular Diseases in Spain: a National Time-series Analysis. Lancet Planet Health 3(7): 297-306. Chaseling GK, Iglesies-Grau J, Juneau M, Nigam A, Kaiser D, & Gagnon D (2021). Extreme Heat and Cardiovascular Health- What a Cardiovascular Health Professional Should Know. Canadian Journal of Cardiology 37(11): 1828-1836. Cheng X & Su H (2010). Effects of Climatic Temperature Stress on Cardiovascular Diseases. European Journal of Internal Medicine 21(3): 164-167. Fuhrmann CM, Sugg MM. Konrad CE, & Waller A (2015). Impact of Extreme Heat Events on Emergency Department Visits in North Carolina (2007–2011). Journal of Community Health 41(1): 146-156. Huang C; Barnett AG; Wang X, Tong S (2012). Effects of Extreme Temperatures on Years of Life Lost for Cardiovascular Deaths: A Time Series Study in Brisbane, Australia. Circulation: Cardiovascular Quality and Outcomes 5(5): 609-614. Kenny GP, Poirier MP, Metsios GS, Boulay P, Dervis S, Friesen BJ, Malcolm J, Sigal RJ, Seely AJE, Flouris AD (2017). Hyperthermia and cardiovascular strain during an extreme heat exposure in young versus older adults. Temperature 4(1): 79-88. Khatana SAM, Werner RM, Groeneveld PW (2022). Association of Extreme Heat and Cardiovascular Mortality in the United States: A County-Level Longitudinal Analysis From 2008 to 2017. Circulation 146(3): 249-261. Lin S, Luo M, Walker RJ, Liu X, Hwang S, Chinery R (2009). Extreme High Temperatures and Hospital Admissions for Respiratory and Cardiovascular Diseases. Epidemiology 20(5): 738-746. Tian Z, Li S, Zhang J, Kaakkola JJK, Guo Y (2012). Ambient temperature and coronary heart disease mortality in Beijing, China; a time series study. Environmental Health 11(56): 1-7. Webb L, Bambrick H, Tait P, Green D, & Alexander L (2014). Effect of Ambient Temperature on Australian Northern Territory Public Hospital Admissions for Cardiovascular Disease among Indigenous and Non-Indigenous Populations. International Journal of Environmental Records and Public Health 11(2): 1942-1959.
1 Extreme Heat Threatens Cardiovascular Health Bryan Souza BSC 4931 Professor Steven Oberbauer
2 Abstract The body’s cardiovascular system is influenced by various factors, one of them being extreme temperatures. As climate change becomes more prominent around the world, the prevalence of extreme heat events is surging. While the impact of extreme heat on cardiovascular health is known, a full understanding of the specific diseases affected, the impact on diverse demographics, and the extent to which it contributes to cardiovascular deaths is lacking. This review dives into the effects of extreme heat on distinct cardiovascular diseases, analyzes its varying impacts on demographic groups, and determines its significance when it comes to causing cardiovascular deaths. The findings show that extreme heat is responsible for the increasing prevalence of a plethora of diseases, the most common amongst all studies being ischemic heart disease. The demographic groups that were most impacted were women and people over the age of 65, but all groups were affected to some degree. Cardiovascular mortality was shown to be substantially affected by extreme heat events on a global scale; also, cardiovascular morbidity was proven to account for an increase in years of life lost when periods of extreme heat are occurring. All in all, extreme heat showed to have a strong effect in each aspect that was reviewed. Precautionary measures should be taken to reduce the impact of extreme heat such as increasing intake of water, acquiring some type of air conditioning, and reducing exposure to the hot temperatures. Introduction When it comes to the health of specific body areas, few are as influenced as the cardiovascular system. Cardiovascular health is impacted by a multitude of factors with the most notable in society being physical activity and diet. However, one factor that has become just as impactful is extreme temperature. With climate change causing extreme temperatures on both ends of the spectrum, it is certain that these extremes are detrimental to cardiovascular health. As the global warming phenomenon continues, extreme heat is becoming more common all throughout the world which in turn, is negatively impacting cardiovascular health globally. Although it is well-documented that extreme heat does negatively affect cardiovascular health, there are questions regarding the extent of that effect. To state that cardiovascular health worsens with extreme heat conditions does not detail which aspects of cardiovascular health it affects, or if the role it plays in cardiovascular health is acute, chronic, or fatal. More so, it is important to consider if and how demographic factors such as age, location, and sex are affected
3 differently by extreme heat. Completing the previously mentioned analyses will provides a basis for how to judge the trend of increasing mortalities related to cardiovascular issues, possibly allowing to create a correlation between the former and extreme heat. Therefore, this review article will assess the following: the effects that extreme heat has on specific cardiovascular diseases, how it affects different demographics in the population, and if it is responsible for the increase in cardiovascular mortality. Effects on Specific Cardiovascular Diseases Extreme heat is responsible for worsening cardiovascular health, but it is important to study which issues are most affected by this phenomenon. Cardiovascular health issues are plentiful and affect a plethora of people on a regular basis, some being more serious than others. With extreme heat, these issues become more intense and it is common for an increase for hospitalizations to occur during periods of extremely hot temperatures. A study conducted in New York City during the months of June through August between the years of 1991 and 2004 compiled data on hospitalizations related to cardiovascular and respiratory diseases (Lin et al., 2009). The study used this data to determine if the extreme heat during those months causes an increase in hospitalizations for cardiovascular or respiratory purposes, as well as to discover which diseases are most affected by the hotter temperatures. Figure 1. The 3-day moving average for hospitalizations related to cardiovascular and respiratory diseases when the heat index is above the threshold of 32¡C. Demographic variables of the patients and their diagnoses were also recorded. (Adapted from Lin et al., 2009).
4 The data is shown in Figure 1. This figure shows this data over a 3-day moving average, meaning that these diagnoses are a result of exposure to extreme heat that could have occurred up to 3 days prior to the patient being admitted to the hospital. In the figure, the exposure to extreme heat is described as apparent temperature above the threshold of 32¡C. It is important to note that apparent temperature is defined as the temperature that it feels like, instead of the actual temperature reading. Apparent temperature includes the added effects of humidity on the temperature. Humidity is shown to augment the impact of extreme heat as there were more hospitalizations on days of extreme heat with high relative humidity than low relative humidity (Lin et al., 2009). The data in Figure 1 shows that there is an overall 1.41% increase in hospitalizations for cardiovascular disease for each degree Celsius that the apparent temperature is above the threshold. Of the listed cardiovascular diseases, cardiac dysrhythmia and ischemic heart disease experienced increases in hospitalizations due to extreme heat, while cerebrovascular diseases, hypertension, and heart failure saw decreases (Fig. 1). There are many meta-analyses that also state that ischemic heart disease is severely affected by extreme heat; however, these meta-analyses also include a study done in Germany that showed an increased risk of myocardial infarctions because of extreme heat (Chaseling et al., 2021). Table 1. Table depicting excess emergency department visits for cardiovascular and cerebrovascular diseases in North Carolina during extreme heat events. Asterisks mean that the more than 60% of patients were 65 and older. (Adapted from Fuhrmann et al., 2015).
5 Another study took place in North Carolina in which three extreme heat events were analyzed for their impact on cardiovascular health. As per the data compiled from the study that is shown in Table 1, there were increases of 3.5% or higher for the totality of cardiovascular diseases across all three events (Fuhrmann et al., 2015). All of the specific diseases displayed an excess of visits in at least one extreme heat period, with the majority having it in all three. The specific diseases with the highest number of excess visits were hypotension, acute myocardial infarction, heart failure, and ischemic heart disease (Table 1). This relates to the meta-analysis of the study in Germany as it serves as another example of myocardial infarction being more frequent as a result of extreme heat. Moreover, this explains how hypertension in the study done in New York City decreased as its opposite, hypotension, experienced drastic increases during the events in North Carolina. Hot temperatures cause blood vessels to expand which would mean there is less pressure in those vessels when blood is rushing through it. Meanwhile, cold temperatures cause vessels to constrict so there’s more pressure in the vessels when blood is passing. There is consistency within the research that diseases such as cardiac dysrhythmia, ischemic heart disease, hypotension, and myocardial infarction are worsened by extreme heat. There also exists data that extreme heat can reduce the risks of other diseases, most notably hypotension and cerebrovascular diseases. Generally, extreme heat impacts cardiovascular health negatively; but, not all aspects of cardiovascular health are affected equally. Effects on Different Demographics Extreme heat does not affect everyone the same way. Age, sex, ethnicity, and living situation should all be taken into consideration when looking into what effects extreme heat had on the person. The most telling demographical difference tends to be age, as the elderly will more likely be affected by extreme heat than younger people. This is a result of the body weakening with age and becoming more susceptible to risk factors that are detrimental to health. When a person gets older, the ability for their body to dissipate heat decreases and their body temperatures deviate more in extreme temperatures than when they were younger. An average group of elders (ages 55-73) will experience a greater increase of body temperature by 0.5¡C than a group of young adults (19-28) (Kenny et al., 2016). This increased body temperature is a key factor in worsening cardiovascular health. It causes “attenuated sweat gland outputs, reduced blood flow to the skin, smaller increases in cardiac outputs, and less redistribution of
6 blood flow from the splanchnic and renal circulations” which all increase the risk of cardiovascular diseases and mortality for elders (Achebak et al., 2019). Figure 1 also shows that as the age group gets older, there is a greater increase of cardiovascular hospitalizations per ¡C above the threshold (Fig. 1). The aging process of the body places the cardiovascular health of elders at much more risk than younger people when under extreme heat. Different sexes also feel the effects of extreme heat differently. In the study done in New York City, there was a 1.76% increase in male hospitalizations and 1.06% increase in female hospitalizations (Fig. 1). Physiological differences in thermoregulation seems to be the most likely explanation for this. Women tend to sweat less than men and need higher temperatures than men in order to start sweating, meaning their bodies cooldown process is less effective than that of their counterparts (Achebak et al., 2019). The lack of sweating will cause women to retain more heat and under periods of extreme heat, this is counterproductive. Figure 2. Minimum mortality temperature for cardiovascular diseases (Adapted from Achebak et al., 2019.)
7 Figure 2 strengthens the fact that women are more affected by extreme heat than men by showing how the minimum mortality temperature for cardiovascular diseases is generally lower for women than for men. Besides the graph of the age group 60-74, women were consistently suffering from mortality due to cardiovascular diseases at lower temperatures (Fig. 2). The graph of age 60-74 is likely to be an outlier in the data as all other results show it to be as such. An individual’s background can also play a role in how their cardiovascular health is affected by extreme heat. Figure 1 shows an example of this as the Hispanic population of New York City experienced a greater percentage of hospitalizations for cardiovascular diseases than the non-Hispanic population. This perspective on how extreme heat affects these demographics differently is yet to be studied further, but there are more studies that prove its effects are unique to each background. This is noticeable in a study conducted in the Northern Territory of Australia in which researchers examined the prevalence of cardiac diseases (ischemic heart disease and heart failure) in indigenous and non-indigenous people during periods of extreme heat. This was done by recording daily hospital admissions for five public hospitals in the Northern Territory between 1992 and 2011. The results showcase that extreme heat caused a greater impact on the cardiovascular health of indigenous people than that of non-indigenous people, with the greatest impact being on indigenous women between 25 and 64 years old (Webb et al., 2014). This group experienced a 32% increase in hospitalizations for ischemic heart disease and the overall group of indigenous people experienced a 17% increase, greater than all percentages of non-indigenous groups (Webb et al., 2014). The results did not mention heart failure with extreme heat as the researchers believe the dilation of vessels in hot temperatures would help alleviate the workload on the heart. Although that is a valid statement, the data present in Table 1 says otherwise as extreme heat caused an increase in visits to emergency departments for heart failure (Table 1). If heart failure were to be improved by vasodilation, the increase because of extreme heat demonstrated in Table 1 should be a decrease instead. It is integral that all effects of extreme heat on cardiovascular health are considered for diseases instead of focusing on a singular one. Effects on Mortality Considering the effects of extreme heat on specific cardiovascular diseases, it is reasonable to assume there are similarities when it comes to cardiovascular mortality. The increasing cases and severity of the diseases eventually lead to mortalities from those diseases.
8 This applies to many different diseases on a global scale. A meta-analysis compiled of research from 1957 to 2002 studied how public health is impacted by extreme heat and one finding was that an increase in average daily temperature by 10¡F corresponded to a 2.6% increase for cardiovascular mortality in North America (Cheng & Su, 2010). The disease most responsible for this increase was ischemic heart disease which is reasonable considering how it was consistently one of the most affected diseases by extreme heat. Figure 3. Maps of total number of extreme-heat days and average monthly cardiovascular mortality rates per county in the US from 2008 to 2017 (Adapted from Khatana et al., 2022). A study conducted in the United States from 2008 to 2017 wanted to determine the extent to which extreme heat affects cardiovascular mortality. Data was collected between the months of May and September, which consisted of county-level information on days that the heat index was greater than or equal to 90¡F. The monthly cardiovascular rate was calculated with the number of deaths of adults 20 years and older due to cardiovascular diseases per month. Figure 3 represents the data in the two maps, the left one representing the total of extreme heat days per county and the right one being the average monthly cardiovascular mortality rates per county. The counties that make up the second and third tertiles of extreme heat days also make up many of the counties in the second and third tertiles of the monthly cardiovascular mortality rates (Fig. 3). Each additional day of extreme heat increased the monthly cardiovascular mortality rates by 0.12% (Khatana et al., 2022). Furthermore, these extreme heat days were responsible for approximate 5,958 extra deaths due to cardiovascular disease (Khatana et al., 2022). Extreme heat in the United States is shown to increase the rate of cardiovascular
9 mortality, with some regions of the United States (mostly southern and central) being more at risk than others. Additionally, similar results have been gathered outside of the United States. Studies conducted in China show that extreme heat causes a significant increase in mortality resulting from coronary heart diseases (Tian et al., 2012). These increases were greater amongst women and the elderly, showcasing additional examples of the effects on different demographics. Whether in the United States or anywhere else in the world, there is proof of the increase in the occurrence of mortality due to cardiovascular diseases. Also, there is the issue of morbidity when it comes to cardiovascular health. Instead of losing a life, morbidity describes the amount of years lost in life because of a risk factor. In the situation that extreme heat is a factor, morbidity is drastically affected. Table 2. Years of Life Lost as a Result of Heat Waves in Brisbane, Australia from 1996-2004 (Adapted from Huang et al., 2012). Cardiovascular morbidity was studied in Brisbane, Australia during periods of extreme heat called heat waves over the years of 1996 to 2004. When a heat wave was 2 days or longer, the effects augmented greatly as years of life lost reached a peak of 235 for a 4-day heat wave (Huang et al., 2012). Years of life lost is calculated based on the age the death occurred and how much longer their life expectancy at that age (Huang et al., 2012). From cardiovascular diseases during that time period, over 200,000 years of life were lsot (Huang et al., 2012). Now, there is the implication that the cardiovascular disease is the sole purpose of why that person did not reach their life expectancy. This is a shortcoming as that is merely an estimate with uncertainty that it would happen; however, there is undoubtable truth that the extreme heat caused the cardiovascular diseases to worsen and lead to premature deaths. Conclusion In conclusion, the impact of extreme heat on cardiovascular health is significant in a negative manner. The extremely high temperatures have massive effects on various cardiovascular diseases, with the most affected being ischemic heart disease. All demographics
10 of a population are at some type of risk in these conditions, but especially the elderly, women, and native people. The rate of cardiovascular deaths increases substantially because of extreme heat and many people suffer from losing years of life when exposed to periods of extreme heat. It is important to understand the effects of extreme heat on cardiovascular health so that the appropriate medical actions can be taken. Doing so will decrease the severity of the cardiovascular risks from extreme heat. Precautionary measures like drinking more water, reducing exposure to heat, and using a form of air conditioning are all ways to make extreme heat less effective. Considering how cardiovascular health is already influenced by many other factors, it would be beneficial to limit the impact of one of the more detrimental factors in extreme heat.
11 References Achebak H, Devolder D, & Ballester J (2019). Trends in Temperature-related Age-specific and Sex-specific Mortality From Cardiovascular Diseases in Spain: a National Time-series Analysis. Lancet Planet Health 3(7): 297-306. Chaseling GK, Iglesies-Grau J, Juneau M, Nigam A, Kaiser D, & Gagnon D (2021). Extreme Heat and Cardiovascular Health- What a Cardiovascular Health Professional Should Know. Canadian Journal of Cardiology 37(11): 1828-1836. Cheng X & Su H (2010). Effects of Climatic Temperature Stress on Cardiovascular Diseases. European Journal of Internal Medicine 21(3): 164-167. Fuhrmann CM, Sugg MM. Konrad CE, & Waller A (2015). Impact of Extreme Heat Events on Emergency Department Visits in North Carolina (2007–2011). Journal of Community Health 41(1): 146-156. Huang C; Barnett AG; Wang X, Tong S (2012). Effects of Extreme Temperatures on Years of Life Lost for Cardiovascular Deaths: A Time Series Study in Brisbane, Australia. Circulation: Cardiovascular Quality and Outcomes 5(5): 609-614. Kenny GP, Poirier MP, Metsios GS, Boulay P, Dervis S, Friesen BJ, Malcolm J, Sigal RJ, Seely AJE, Flouris AD (2017). Hyperthermia and cardiovascular strain during an extreme heat exposure in young versus older adults. Temperature 4(1): 79-88. Khatana SAM, Werner RM, Groeneveld PW (2022). Association of Extreme Heat and Cardiovascular Mortality in the United States: A County-Level Longitudinal Analysis From 2008 to 2017. Circulation 146(3): 249-261. Lin S, Luo M, Walker RJ, Liu X, Hwang S, Chinery R (2009). Extreme High Temperatures and Hospital Admissions for Respiratory and Cardiovascular Diseases. Epidemiology 20(5): 738-746. Tian Z, Li S, Zhang J, Kaakkola JJK, Guo Y (2012). Ambient temperature and coronary heart disease mortality in Beijing, China; a time series study. Environmental Health 11(56): 1-7. Webb L, Bambrick H, Tait P, Green D, & Alexander L (2014). Effect of Ambient Temperature on Australian Northern Territory Public Hospital Admissions for Cardiovascular Disease among Indigenous and Non-Indigenous Populations. International Journal of Environmental Records and Public Health 11(2): 1942-1959.

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