In a study that ran from January to December 2016, the monitoring station of the System of Air Quality and Weather Forecasting And Research (SAFAR) recorded that the average volume of PM1 is 49, 46, and 20 micrograms per cubic metre during winter, summer and monsoon months. (Representational Image)
Substantial presence of PM1, an extremely fine particulate matter measuring less than 1 micron, that can penetrate into the cardiovascular stream and predispose people to heart diseases, has been observed in areas around Lodhi Road.
PM1 in urban pollution is mainly due to vehicular combustion and its presence has been noted in central Delhi, which sees a considerable flow of traffic. In comparison to Mumbai, Delhi also has higher PM1 levels across seasons.
PM1 is finer and more harmful than PM 2.5 and PM 10 — the most common particulate matter found in the city’s air in terms of volume. There is also “no permissible standard” specified for PM1 globally. In other words, safe standards of PM1 have not been defined yet, in the absence of which its potentially harmful effects have not been documented.
In a study that ran from January to December 2016, the monitoring station of the System of Air Quality and Weather Forecasting And Research (SAFAR) recorded that the average volume of PM1 is 49, 46, and 20 micrograms per cubic metre during winter, summer and monsoon months. “PM1 particles are so light that they stay suspended in the air longer compared to coarser ones and hence the probability of inhaling them is relatively higher,” the study states.
The report is based on data from one monitoring station in Delhi and 10 stations’ “average data” in Mumbai. “Mumbai level is as high as Delhi in winter as combination of high salty humidity and low temperature leaves them suspended longer in Mumbai,” the SAFAR study states. The average volume of PM1 in Mumbai is 40, 22, and 8 micrograms per cubic metre during winter, summer and monsoon.
Centre for Science and Environment’s Anumita Roychowdhury said a profile taken of particulate matter emitted by diesel vehicles will reveal that “more than 90 per cent would measure less than 1 micron” and the tinier particles come from combustion sources.
“Globally, governments are focusing on control measures at the source level of these particles to eliminate them as far as possible,” she said. “It comes down to controlling the number of vehicles plying on the road, encouraging people to opt for public transport and using cleaner fuel.” She said the introduction of BS-VI emission standards in 2020 will go a long way in addressing PM1 levels.
