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Climate Science


Commuters make their way along a busy road amid heavy smog conditions in Amritsar, India.

On Wednesday, the World Health Organization, or WHO, published an update to its air quality guidelines — the international rubric that sets non-binding standards for safe levels of air pollution for the world’s countries. The update, which is the organization’s first since 2005, says that air pollution, alongside climate change, is one of the biggest environmental threats to human health. It sets higher standards for almost every pollutant the organization monitors. Adhering to these new guidelines, the WHO said, “could save millions of lives.” 

In the 16 years since the WHO last updated its air quality guidelines, evidence of the harms of indoor and outdoor pollutants has only grown. The new report notes that exposure to air pollutants causes 7 million premature deaths each year. In children, air pollution can slow lung growth, fuel respiratory infections, and exacerbate asthma. In adults, premature deaths due to air pollution often present as heart disease and stroke, though research is beginning to suggest that diabetes and neurodegenerative conditions are also linked to bad outside air quality. 

The new guidelines set levels for six pollu... Read more

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