AIR POLUTION AND HEART DISEASE

Air pollution is contamination of air by harmful gasses and particulate matters. Gaseous phase of pollutants are mainly composed of ozone, volatile and semi volatile organic compounds. Particulate matter (PM) fraction of air pollution is measured by particles contained per cubic meter of air(mg.m3). They are broadly categorized by diameter of the particulate matter and it falls broadly in three categories –     <10 mm (thoracic particles [PM10]), <2.5 mm (fine particles [PM2.5]), and <0.1 mm (ultrafine particles). Health effect of PM on body depends on PM size as PM2.5 and smaller particles penetrate the lung alveoli and enter into blood stream producing adverse health effects. It leads to hardening of blood vessels, increase coagulability therefore increase chances of clot formation and altered electrical activity leading to increase cardiac arrhythmia.

            Air quality guideline of(AQG) WHO recommends exposure limit of <10 mg/m3 for annual levels and <20 mg/m3 for daily levels. However  more than 90% of the global population is exposed to levels exceeding AGQ and situation is far more worse in Asian countries particularly China and India where majority of urban population exposure routinely exceeds 35 mg/m3. 

            In number of studies it have been found that chronic exposure to air pollution is associated with atherosclerotic diseases. The relative risk of heart attack increases by 2.5% and stroke by 1% per 10 mg/m3 thereby significantly increasing public heath burden. Air pollution also leads to increased risk of heart failure by 2.1%, diabetes/insulin resistance by 29% and cardiac arrhythmia by 0.89% besides host of other respiratory, renal and neurological diseases. Acute exposure to particulate air pollutants leads to  69% increase in cardiovascular deaths. Further risk of ischemic

heart disease, heart failure, arrhythmias, and cardiac arrest increased 8~18% for every 10.5 μg/m3 in PM2.5  in a study involving large population of young population. 

There are numerous studies that reports similar results reinforcing  the impact PM2.5 on public health. Cardiovascular disease caused by air pollution has now emerged as worldwide important critical health problems. 

Eating a healthy, balanced diet with plenty of fruit and vegetables could help protect from the adverse impacts of air pollution. Increase  physically activity may also help in reducing pollution impact. Increased awareness level regarding air pollution levels also helps in reducing the problem. Wearing a face mask may protect against the effects of air pollution but effectiveness has not been proven yet.