A recent study published in the American Heart Association's journal Circulation has unveiled the worrisome impact of climate change on human health.
Researchers analysing more than 200 000 heart attack deaths in a Chinese province discovered that soaring temperatures and high levels of fine particulate matter in the air significantly double the risk of heart attack fatalities.
The study highlights that the combination of extreme heat and air pollution poses the greatest danger, with women and older adults being particularly vulnerable.
The research emphasises the urgency to address climate change and its detrimental effects on public health.
The study reveals that extreme heat and cold and high levels of fine particulate matter air pollution are all significantly associated with an increased risk of death from heart attacks.
However, the most severe risk is observed during days when extreme heat and high pollution levels coexist. Two-day heat waves with heat indexes above the 90th percentile raise the risk of a fatal heart attack by 18%, while four-day heat waves with heat indexes above the 97.5th percentile escalate the risk by 74%.
During four-day heat waves with fine particulate pollution levels surpassing 37.5 micrograms per cubic metre, the risk is twice as high.
The senior author and associate professor of epidemiology at Sun Yat-sen University, Yuewei Liu, says extreme temperature events are becoming more frequent, longer and more intense, raising concerns about their impact on health.
Researchers analysed more than 200 000 heart attack deaths between 2015 and 2020 in a Chinese province that experiences four distinct seasons and a range of temperatures and pollution levels.
The presence of fine particulate matter in the air, a widespread environmental issue, further exacerbates the adverse effects of extreme temperatures on cardiovascular health.
Urgent action is needed to address climate change and air pollution to protect vulnerable populations from the escalating dangers to heart health.
Exposure to excessive heat can have wide-ranging impacts on anyone, from the direct effects of heat on the body to the worsening of existing conditions.
In hotter than-normal conditions, the body can experience rapid heat gain that compromises its ability to regulate temperature, resulting in heat cramps, heat exhaustion, heatstroke and hyperthermia, according to the World Health Organization.
The study serves as a reminder that the consequences of climate change extend beyond the environment, directly affecting human well-being.
The identified risks to heart health underline the urgent need for measures to mitigate and adapt to climate change on local and global scales.
Policymakers, health professionals, and communities must work collaboratively to reduce greenhouse gas emissions, enhance air quality, and develop strategies to protect the most vulnerable individuals from the health impacts of a rapidly changing climate.
Despite their small size of less than 2.5 micrometres, fine particulates — mostly associated with car exhaust, factory emissions or wildfires — can be inhaled deep into the lungs and irritate the lungs and blood vessels around the heart, the news release explains.
“Our findings provide evidence that reducing exposure to both extreme temperatures and fine particulate pollution may be useful to prevent premature deaths from heart attack, especially for women and older adults,” said Liu.