Air pollution is broken down into ambient (outdoor) air pollution and indoor air pollution. This pollution comes from many sources, the majority of them a result of human activity:
the burning of fossil fuels, such as coal to generate electricity for homes and businesses, or petrol and diesel to power our cars, buses, ships and planes industrial processes, particularly from the chemical and mining industries are the source of air pollution.
In 2016, PM2.5 exposure reduced average global life expectancy at birth by approximately one year. Around seven million people die each year from exposure to polluted air, both indoor and outdoor. The three biggest killers attributable to air pollution are stroke (2.2 million deaths), heart disease (2.0 million) and lung disease and cancer (1.7 million deaths).
Air pollution doesn’t just kill, however. It also contributes to other illnesses, hampers development and causes mental health problems. One study found that ambient PM2.5 contributed to 3.2 million cases of diabetes in 2016.
Research from the United Nations Children’s Fund (UNICEF) shows that breathing in particulate air pollution can damage brain tissue and undermine cognitive development in young children – with lifelong implications. An estimated 17 million babies under one year old live in areas where air pollution is six times higher than safe limits.