Coronavirus outbreak: Under lockdown, Mumbai witnesses cleaner air

There was a 45 per cent drop in concentration of NOx this month, as compared to March 2018 and 2019. (File/Representational Image)

Mumbai saw clean air on Monday as the lockdown due to COVID-19 kept cars off the road and improved air quality. Researchers at the System of Air Quality Forecasting and Research (SAFAR) have said there has been considerable reduction in the levels of nitrogen oxide (NOx) — an irritant gas released during fuel combustion and in high concentrations can cause inflammation in the airways.

According to the SAFAR report released on March 23, there has been a reduction in the levels of NOx in Pune (15 per cent), Mumbai (30 per cent) and Ahmedabad (53 per cent) this year. Maximum decline is found in Ahmedabad, followed by Mumbai and Pune. According to the report, NOx, which was not showing any reduction, has started to indicate a significant declining trend now after a sudden spike on March 18, due to mild dust lifting. On the day of the Janata Curfew, i.e, March 22, NOx declined by 30 per cent as compared to previous days. Maximum decline of NOx levels were seen in Andheri at 25 per cent, followed by Borivali, the western suburbs of Mumbai.

There was a 45 per cent drop in concentration of NOx this month, as compared to March 2018 and 2019. A drop in concentration of PM 2.5 (which is used to calculate air quality index) was also recorded. On Sunday, Mumbai recorded an AQI of 68, which falls in the satisfactory category. The city has been recording ‘satisfactory’ AQI since March 20 this year.