Heart Disease And Air Pollution: What's The Link?

Air pollution is a complex mixture of gases, liquids, and particulate matter. It has been linked to adverse health effects such as respiratory and cardiovascular diseases. Short-term exposure to air pollution can increase the risk of heart attack, stroke, arrhythmias, and heart failure in susceptible people, such as the elderly or those with pre-existing medical conditions. Long-term exposure to air pollution is associated with the development and progression of atherosclerosis, a buildup of plaque in the coronary artery that can affect heart health and increase the likelihood of cardiovascular events like heart attack and stroke.

Fine particulate matter (PM2.5)

PM2.5 is a major component of air pollution and has been linked to a range of adverse health effects, particularly for those with pre-existing heart conditions. Research has shown that exposure to PM2.5 can increase the risk of cardiovascular events such as heart attacks and stroke, and can lead to increased mortality in people with heart disease. Long-term exposure to PM2.5 has also been associated with premature ageing of blood vessels and a more rapid buildup of calcium in the coronary artery, which restricts blood flow to the heart and increases the likelihood of cardiovascular events.

The American Heart Association has issued an announcement on the effects of particulate air pollution, including PM2.5, on cardiovascular disease. Studies have found that for every 10 µg/m3 increase in PM2.5, the risk of cardiovascular death increases. Additionally, short-term exposure to PM2.5 has been associated with increased hospital admissions for heart-related issues, particularly in those with pre-existing heart disease.

People with chronic heart disease may experience symptoms such as chest tightness or pain in the chest, neck, or shoulder after exposure to PM2.5. Overall, PM2.5 is a significant contributor to cardiovascular disease and can have detrimental effects on those with existing heart conditions. It is important for individuals, especially those with heart disease, to monitor air quality and take precautions when particle pollution levels are high.

Nitrogen oxides

In recent years, researchers have found a strong link between long-term exposure to nitrogen oxides and an increased risk of cardiovascular disease. A 2022 review of multiple studies found that elevated levels of NO2 were strongly associated with heart and lung harm. This is supported by a decade-long study, the Multi-Ethnic Study of Atherosclerosis Air Pollution Study (MESA Air), which found that long-term exposure to NO2 at levels close to the National Ambient Air Quality Standards (NAAQS) can prematurely age blood vessels and contribute to a more rapid buildup of calcium in the coronary artery. This buildup of calcium restricts blood flow to the heart and other major blood vessels, increasing the likelihood of cardiovascular events such as heart attacks and strokes.

The MESA Air study also found a direct link between air pollution exposure and plaque buildup, with healthy individuals exposed to air particle pollution over the long term experiencing accelerated cases of atherosclerosis. This buildup of plaque in the walls of the arteries can result in blood clots, which can block blood flow and lead to serious cardiovascular events.

Overall, the evidence suggests that nitrogen oxides, particularly nitrogen dioxide, play a significant role in exacerbating existing cardiovascular disease and increasing the risk of developing the disease. While air quality standards and emissions reductions have helped drive down nitrogen dioxide emissions in recent years, it remains a pressing issue for individuals with heart disease and other vulnerable populations.

Outdoor particle pollution

Research has shown that short- and long-term exposure to outdoor particle pollution is linked to an increased risk of heart attacks and other forms of heart disease. Individuals with chronic heart disease may experience symptoms such as chest tightness or pain in the chest, neck, or shoulder after exposure to fine particulate matter. The evidence is particularly strong for the impact of outdoor particle pollution on those with underlying cardiovascular conditions. Exposure to increased concentrations of PM2.5 over a few hours to weeks can trigger cardiovascular disease-related heart attacks and even death. Longer-term exposure can lead to an increased risk of cardiovascular mortality and decreased life expectancy.

Particle pollution is a serious health concern, especially for those with pre-existing heart conditions. It is important to monitor air quality and take measures to reduce exposure to outdoor particle pollution, especially for vulnerable individuals. Understanding the harmful effects of particle pollution can help inform preventive measures and policies to protect public health.

Indoor air pollution

Fine particulate matter (PM2.5) is of particular concern for indoor air pollution. Sources of indoor PM2.5 include tobacco smoke, cooking activities like frying and broiling, burning candles or oil lamps, and operating fireplaces and fuel-burning space heaters. Exposure to PM2.5 has been linked to increased cardiovascular morbidity and mortality, with studies showing associations between PM2.5 exposure and decreased heart rate variability, elevated blood pressure, and increased risk of specific acute cardiovascular diseases such as myocardial infarction, ischemic stroke, and heart failure.

Additionally, indoor air pollutants like nitrogen dioxide and sulfur dioxide have been associated with increased cardiovascular morbidity, hospitalization, and mortality. For example, studies have shown a positive association between nitrogen dioxide concentration and hospital emergency transports for ischemic heart diseases.

Overall, indoor air pollution poses a significant risk to cardiovascular health, and understanding its harmful effects can help develop preventive measures and regulatory actions to improve indoor air quality and protect heart health.

Wildfire smoke

Several studies have linked smoke exposure from wildfires to an increased risk of sudden cardiac arrest and a higher volume of visits to emergency rooms for cardiovascular disease-related causes. A 2020 study found that exposure to heavy smoke during wildfires raised the risk of out-of-hospital cardiac arrests by up to 70%. The risk was higher among men, women, adults aged 35-64, and in communities with lower socioeconomic status.

Another study found that exposure to wildfire smoke was associated with increased rates of emergency room visits for breathing trouble, ischemic heart disease, irregular heart rhythm, heart failure, pulmonary embolism, and stroke. The increase was most notable for adults aged 65 and older.

People with underlying cardiovascular disease risk factors may be at risk for an acute cardiovascular event when exposed to wildfire smoke. It is important to recognise the signs of a heart attack or stroke and seek immediate medical attention if experiencing serious symptoms.

The adverse health effects of wildfire smoke exposure are more pronounced among vulnerable populations, including the elderly, pregnant women, and those with pre-existing cardiovascular conditions. Fine particles from wildfire smoke can penetrate indoors and elevate indoor particle pollution concentrations. Therefore, it is recommended to stay indoors with doors and windows closed during wildfires and use high-efficiency air filters or seek other shelter if necessary.

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