Air pollution is a key risk factor for cardiovascular disease, and a major contributor to the global burden of disease. In 2019, an estimated 6.7 million deaths, or 12 percent of all deaths worldwide, were attributable to outdoor or household air pollution. As many as half of these were due to cardiovascular disease. Air pollution also increases the risk of heart attack, stroke, diabetes and respiratory diseases.
“Even before the COVID-19 pandemic, air pollution was an issue of growing concern due to its impact on people’s health, although it was frequently overlooked as a risk factor for cardiovascular disease. COVID-19 has brought a new, deadly factor to the equation, and the time has come for the health community to speak up and take action.”
– Michael Brauer, Chair of the World Heart Federation Air Pollution Expert Group
Common sources of air pollution cut across many sectors and include residential energy for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry. Exposure to smoke from cooking fires causes 3.8 million premature deaths each year, mostly in low- and middle-income countries. Burning fuels such as dung, wood and coal in inefficient stoves or open hearths produces a variety of health-damaging pollutants, including particulate matter (PM), methane, carbon monoxide, polyaromatic hydrocarbons (PAH) and volatile organic compounds (VOC). Burning kerosene in simple wick lamps also produces significant emissions of fine particles and other pollutants.
Air pollution is a complex and dynamic mixture of numerous compounds in gaseous and particle form, originating from diverse sources, subject to atmospheric transformation and varying over space and time. Three common air pollutants, particulate matter (PM), ozone and nitrogen dioxide (NO2), are the focus of most monitoring programs, communication efforts, health impact assessments, and regulatory efforts.
Evidence for impacts on cardiovascular disease is most consistent for particulate matter, which is responsible for the vast majority of the disease burden via its impacts on ischemic heart disease, and stroke, as well as lung cancer, COPD, lower respiratory infections, Type 2 diabetes, pregnancy outcomes and related infant mortality. Ozone is mainly associated with exacerbation of respiratory disease, with COPD incidence and mortality and with metabolic effects. NO2 is often used as an indicator of traffic-related air pollution. Chronic exposure to NO2 is associated with incident childhood asthma while short-term variability is associated with exacerbation of asthma and increased daily mortality counts.