Even small increases in NO2 levels could be linked to heightened risk of heart and respiratory death

The findings suggest a need to revise and tighten the current air quality guidelines, and to consider stricter regulatory limits for nitrogen dioxide concentrations.

Nitrogen dioxide (NO₂) is a common air pollutant formed by burning fuel for things like transport, power and industrial processes.

It is measured in micrograms (one-millionth of a gram) per cubic meter of air or µg/m³. World Health Organization (WHO) air quality guidelines currently recommend that nitrogen dioxide levels should not exceed an annual average of 40 40 µg/m³.

Many studies have reported the effects of short term exposure to NO₂ on health, but most have been based on small samples, covered limited geographical areas, or used different study designs, so results are inconsistent.

To address this uncertainty, a team of international researchers set out to investigate the short term associations between NO₂ and total, cardiovascular, and respiratory deaths across multiple countries/regions worldwide.

Their findings are based on daily concentrations of nitrogen dioxide from 398 cities in 22 low to high income countries/regions over a 45-year period (1973 to 2018).

Regards

Jun Ray

Assistant Mnaging Editor

Environmental Toxicology and Studies Journal