A recent Greenpeace India report, published at the beginning of 2017, shows that air pollution results in 1.2 million deaths every year in the country – Delhi being the most polluted. Continuous exposure to high levels of pollution can lead to long-term heath effects like chronic respiratory disease, lung cancer and even cause damage to the brain. A group of researchers, from the University of Washington School of Public Health, have now found a strong link between exposure to bad quality air and higher incidence of heart disease.

According to their findings which are a part of the Multi-Ethnic Study of Atherosclerosis, an ongoing US study examining the lifestyle factors that predict the development of cardiovascular disease, exposure to high levels of air pollution may increase the risk of heart disease by lowering the levels of high-density lipoprotein (HDL), commonly known as the “good” cholesterol. Imagine this, you are breathing in and breathing out the same toxic air every second. It is bound to have some impact on your physical health.

For the study, 6,654 middle-aged and older US adults from diverse ethnic backgrounds were examined. It was seen that people living in areas with high levels of traffic-related air pollution had lower HDL levels. Moreover, exposure to high particulate matter over a period of three months was associated with a a lower HDL particle number. These changes in the HDL levels may appear even after a brief exposure to air pollution, the authors noted. Further, it was seen that men and women responded to air pollutants differently. While HDL levels fell when faced with higher pollution exposure for both sexes, the magnitude was greater in women.

Low levels of good cholesterol can be an indicator of heart disease. Low levels of good cholesterol may be often accompanied by increased triglyceride levels which is bad for your heart. Pollution can also cause inflammatory effects in the heart which can lead to blood vessel rupture causing high blood pressure or even heart failure.