TEST SERIES 
Date : 23 Sep 2021
WHO GLOBAL AIR QUALITY GUIDELINES
Tags :WHO GLOBAL AIR QUALITY GUIDELINES
- The World Health Organisation (WHO) released stringent air quality guidelines, lowering the recommended levels of pollutants that can be considered safe for human health.
- 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.
- The recommended levels of six most common air pollutants — PM2.5, PM10, ozone, nitrogen dioxide, sulphur dioxide , and carbon monoxide – have all been revised downwards from the existing norms that have been in place since 2005.
- PM2.5 and PM10 refer to particulate matters of sizes 2.5 microns or less, and 10 microns and less, respectively (micron is one millionth of a metre), and are the most common pollutants, as well as causes of respiratory diseases.
- The new air quality guidelines mean that nearly entire India would be considered a polluted zone for most of the year. Over 95 per cent of India’s population already lived in areas where pollution levels were higher than WHO’s 2005 norms.
- 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.
