What is the single largest source of air pollution exposure in India? You would be perhaps surprised to find that the answer, with a near consensus in the published scientific literature, is neither transportation nor stubble burning.

Poor air quality is one of the leading five health risks worldwide, along with high blood pressure, tobacco smoking, diabetes and being overweight. In 2015, it contributed to nearly 8% of all deaths worldwide. Long-term exposure to polluted air has been linked to respiratory infections, chronic obstructive pulmonary disease, stroke, heart attack and lung cancer. It is justifiably called ‘passive outdoor smoking’.

Original Source

Nitrogen oxides, released from fossil fuel use and other combustion processes, affect air quality and climate. From the mid-1990s onward, nitrogen dioxide (NO2) has been monitored from space, and since 2004 with relatively high spatial resolution by the Ozone Monitoring Instrument. Strong upward NO2 trends have been observed over South and East Asia and the Middle East, in particular over major cities.

Air pollution can cause a widespread haze in the Arctic. A study of the lower atmosphere there suggests that haze particles might take up free radicals, and so extend the lifetime of air pollutants in the region.