The World Health Organization issued new guidelines on air pollution Wednesday that dramatically reduce the levels of particulate matter (PM) and other pollutants linked to a range of diseases.

These illnesses include heart disease, lung cancer, stroke, and respiratory diseases including asthma.

“Since WHO’s last 2005 global update, there has been a marked increase of evidence that shows how air pollution affects different aspects of health,” said the global health body. Air pollution is implicated in some 7 million premature deaths each year, more than 90% of them in developing countries.

A 2018 report found that every child on the African continent was exposed to more particulate matter than even the previous guidelines called for.

“It hits people in low- and middle-income countries the hardest,” said WHO chief Dr. Tedros Adhanom Ghebreyesus. “I urge all countries and all those fighting to protect our environment to put them to use to reduce suffering and save lives.”

The new guidelines set lower exposure standards for ozone, nitrogen dioxide and sulfur dioxide, as well as particulate matter (PM). WHO said particles with a diameter of 10 microns or less (PM10) can enter and lodge deep inside the lungs, but even smaller particles can enter the blood system. These PM2.5 particles contribute to lung cancer and other illnesses.

With PM2.5, WHO researchers say almost 80% of deaths could be avoided if existing air pollution levels were reduced to those found in the updated guidelines.

WHO also said it’s clear that individuals don’t make decisions for industry, which accounts for pollution from factories, transport and power facilities. But everyone is encouraged to act for change on air pollution and other climate-related issues.

Image: WHO/Gates Foundation file