NEW DELHI: Delhi's air pollution levels are among the worst in the world but new research is pointing at something even more worrying. A government agency that recently started monitoring the most dangerous class of particulate pollutants — ultrafine particulate matter or PM1 — found its levels to be quite high even in the low-pollution pre-monsoon season in comparatively cleaner locations of the city such as central Delhi's Lodhi Road.
PM1 is the tiniest class of pollution particles. Studies show it's the primary cause of pollution-linked incidence of cardiovascular disease. Much finer than PM2.5, PM1 particles can easily penetrate very deep into the lungs or enter the blood stream.
Currently, no safe standards have been set for PM1. Yet, there are several reasons why experts are ringing the alarm bells on the pollutant's levels in Delhi. According to monitoring agency SAFAR, PM1 levels on certain days had peaked to 70 micrograms per cubic metre, higher than even the national safe standard for PM2.5, which is 60mg/m3.
PM1 is a fraction of PM2.5 emissions but SAFAR scientists say their levels should be extremely low or none because of their health implications. "On most days, the proportion of PM1 is about 35% of the PM2.5 emissions but on Thursday it was more than 50% of PM2.5 emissions. This shows that people are breathing in ultrafine particles that have serious health impacts," said GufranBeig, project director, SAFAR.
PM1 levels remain high even in wet weather because rain doesn't wash away very fine particles, Beig said.
