Noxious NO2 levels rise in Mumbai

Mumbai: Mumbai's air has seen an increased amount of nitrogen dioxide (NO2) pollutants, confirms the environment status report prepared by the Brihanmumbai Municipal Corporation (BMC). The report highlighted the fact that since 2015, NO2 emissions were caused mainly from vehicular and industrial pollution. Moreover, at various places, the levels recorded were beyond permissible limits.

According to the report, NO2 levels were recorded between 62 and 76mg/m3, which exceeds the standard limit of 40mg/m3. Worli recorded the highest NO2 level followed by Andheri (73), Bhandup and Khar (62). The Asian Age had last year carried a report by the Centre for Science and Environment (CSE), which stressed on the increase of NO2 levels in the city’s air and sought measures to curb industrial and vehicular pollution.

“Increasing levels of NO2 is a grave concern for Mumbai as it is already struggling with increasing PM2.5 levels, as stated in a WHO report. Both of them are now beyond permissible limits, which is bad for Mumbai. Moreover, when NO2 increases, it leads to an increase in ozone concentration, which is a precursor for formation of ozone,” said Sunil Dahiya, senior campaigner for the NGO, Greenpeace India..

Experts have highlighted the fact that increased levels could be due to increase in private vehicles in the city along with unchecked emission from  petro-chemical industries. Increased NO2 in the city could lead to regular coughing, sore throat, among other respiratory problems. The air quality was also assessed in terms of Sulphur Dioxide (SO2) and Ammonia (NH3) pollutants, which were recorded below the annual permissible limits. But  the levels were higher than those recorded between 2016 and 2017. The annual average PM2.5 and PM10 were recorded as high as 67 and 111 in BKC since last year.

“The increased PM2.5, NO2 and SO2 levels reveal an immediate need to control pollution from industries especially those in petro-chemical refineries,” he said.