Air quality: New WHO norms, now almost entire India polluted
While a PM2.5 concentration of 25 micrograms per cubic metre in a 24-hour period was considered safe earlier, the WHO has now said that a concentration of over 15 micrograms is not safe. https://indianexpress.com/article/india/air-quality-new-who-norms-now-almost-entire-india-polluted-7528266/23 Sept 2021 

The new guidelines take into account several scientific studies in recent years that have suggested that air pollution is much more damaging to human health than earlier known. By WHO’s own estimates, nearly 7 million deaths every year can now be attributed to diseases that are a direct cause of air pollution.

The new air quality guidelines mean that nearly entire India would be considered a polluted zone for most of the year. But India is not alone. By WHO’s own admission, more than 90 per cent of the world’s population lived in areas which did not meet its 2005 pollution standards. With the norms now being made even more stringent, this proportion would go up.