Threat of heart attacks on the rise due to intense heat and polluted air conditions
A new study, published in July 2023, has shed light on the potential impact of extreme heat and wildfire smoke on cardiovascular health. The research, which assessed the effects of heat and particulate matter (PM) based on typical temperatures in Jiangsu province, reveals a concerning increase in the risk of heart attacks due to this synergy.
The combined effect of extreme heat and air pollution from wildfires significantly increases the risk of heart attacks. This is primarily due to the promotion of cardiovascular stress through inflammation, oxidative stress, and vascular dysfunction. Exposure to fine particulate matter (PM2.5) from wildfire smoke notably raises cardiovascular mortality and hospitalizations, with risk effects peaking within days after exposure.
For every 1 µg/m³ increase in wildfire PM2.5, cardiovascular mortality rises by about 0.9% in the following seven days. Wildfire smoke air pollution triggers inflammation and oxidative stress, damaging blood vessels and increasing atherosclerosis, which can precipitate heart attacks.
Heat extremes, such as during heatwaves that often accompany wildfires, exacerbate the cardiovascular burden by increasing metabolic demand and stressing the heart, compounding the harmful effects of air pollution. Studies have observed increased emergency room visits for heart attacks on days with poor air quality due to wildfire smoke, particularly among vulnerable groups like the elderly and people with pre-existing heart or lung conditions.
There may be a lag effect of several days between exposure and cardiovascular events, consistent with the progressive biological impact of both pollutants and heat on the cardiovascular system. Vulnerable populations include the very young, elderly, those with metabolic diseases (e.g., diabetes, obesity), and people with chronic pulmonary or heart diseases.
The study projects a 162% increase in cardiovascular deaths due to extreme heat by the middle of the century in a hypothetical scenario where the U.S. has successfully lowered greenhouse gas emissions. However, if only minimal action to reduce emissions is undertaken, the researchers say cardiovascular deaths could increase by as much as 233%.
The fine particles discussed in the article are called PM, which stands for "particulate matter, 2.5 micrometers or smaller." These tiny particles can reach places in the human body that larger particles cannot, potentially leading to inflammatory responses.
To mitigate the risks associated with extreme heat and wildfire smoke, it is essential to stay informed about local air quality and take necessary precautions. Real-time information regarding the amount of PM in the air can be found on the United States government's AirNow website or through free AirNow apps for iOS and Android phones. On hot days with high PM, staying indoors as much as possible, using air conditioning, and wearing an N95 face mask can help limit the ability of PM to enter the body.
It is also crucial to stay hydrated during extreme heat, as the body loses water through sweating to cool itself. Regular cool-air breaks in air-conditioned areas and wearing light and loose clothes, including wide-rim hats, can help manage extreme heat.
Dr. Rakesh Ghosh, an epidemiologist at the Institute for Health & Aging in the School of Nursing at the University of California, San Francisco, stated that humans are resilient and can acclimatize to different temperatures. However, it is important to remember that extreme heat and wildfire smoke pose significant risks to cardiovascular health, particularly for at-risk groups.
The increase in cardiovascular deaths will disproportionately affect non-Hispanic Black individuals and older adults, according to the study authors. As such, public health protection during wildfire events that coincide with heat waves is of utmost importance. Be aware of heat-related illnesses such as heat cramps, heat exhaustion, and heat stroke, and seek immediate help in an emergency.
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- Extreme heat and wildfire smoke, in tandem, significantly enhance the risk of heart attacks through inflammation, oxidative stress, and vascular dysfunction.
- The study unveils an exacerbated cardiovascular burden due to heat extremes, such as during heatwaves, as they increase metabolic demand and stress the heart.
- For every 1 µg/m³ increase in wildfire PM2.5, cardiovascular mortality rises by approximately 0.9% within seven days.
- Fine particulate matter (PM2.5) from wildfire smoke contributes to cardiovascular mortality and hospitalizations by damaging blood vessels, increasing atherosclerosis, and sparking heart attacks.
- Heat-related events, particularly among vulnerable groups like the elderly, the very young, and those with pre-existing heart or lung conditions, result in increased emergency room visits for heart attacks.
- The synergy between extreme heat and air pollution from wildfires will lead to a 162% increase in cardiovascular deaths in a hypothetical scenario with reduced greenhouse gas emissions by mid-century.
- If minimal action is taken to curb emissions, the increase in cardiovascular deaths could reach as high as 233%.
- The study warns that the fine particles in question, PM, are 2.5 micrometers or smaller and can reach sensitive areas within the human body, causing inflammation.
- To safeguard against health risks from extreme heat and wildfire smoke, it is necessary to stay informed about local air quality, stay hydrated, and take necessary precautions, such as avoiding outdoor activity and wearing an N95 face mask.
- Climate change, in the form of heatwaves and wildfires, disproportionately affects non-Hispanic Black individuals and older adults, calling for heightened public health protection during these events.
- As global temperatures rise, it becomes increasingly crucial to prioritize health and wellness, including mental and physical fitness, nutrition, and lifestyle choices, to build resilience against climate change-related health impacts.
