As per World Health Organization (WHO) standards, the daily average level of PM2.5 should not be more than 10ug/m3 and aggregated annual mean 25ug/m3 in a day.
However, for the past one week the level of PM2.5 in Lahore remained between 450-500ug/m3, which is extraordinary high.
PM2.5 refers to atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometers, which is about 3 percent the diameter of a human hair.
Why Are PM2.5 Dangerous?
According to Bliss Air, since they (PM 2.5) are so small and light, fine particles tend to stay longer in the air than heavier particles. This increases the chances of humans and animals inhaling them into the bodies. Owing to their minute size, particles smaller than 2.5 micrometers are able to bypass the nose and throat and penetrate deep into the lungs and some may even enter the circulatory system.
Studies have found a close link between exposure to fine particles and premature death from heart and lung disease. Fine particles are also known to trigger or worsen chronic disease such as asthma, heart attack, bronchitis and other respiratory problems.
According to a report in The News, as per WHO standards, aggregated annual mean should be 25ug/m3 in a day whereas as per a gazette notification of the Punjab government, the daily limit of PM2.5 is 15ug/m3 and aggregated annual mean 35ug/m3 per day.