As the city celebrated Deepavali on Wednesday, few among those merrily bursting fire crackers would have realised that air pollution rose to unusually high levels, noise exceeded permissible limits and thick smog shrouded residential areas and roads.
Respirable suspended particulate matter (RSPM) touched 1423 microgram/cubic metre at Arumbakkam. The permissible limit is 100 microgram/cubic metre.
According to K.Karthikeyan, Member-Secretary, Tamil Nadu Pollution Control Board, the burning of crackers was intensive from 6 p.m. to 8.15 p.m. and it resulted in RSPM levels varying from 39.08 microgram/cubic metre and 1423 microgram/cubic metre in Arumbakkam.
The Board had installed air and noise monitoring facilities at five locations — Sowcarpet, Triplicane, Ayanavaram, T.Nagar and Nungambakkam for Deepavali. Though the amount of sulphur dioxide came down, the RSPM level did not. The TNPCB had conducted 24-hour ambient noise level and ambient air quality surveys in the city before and on Deepavali day.
As far as noise levels were concerned, they had exceeded limits in the five places where the survey had been done.
Mr. Karthikeyan said that Ayanavaram, which recorded 85.2 db in the 24 hour period ending 6 p.m. on Wednesday, was the noisiest. However, as residents stopped bursting crackers after 10 p.m. and because of the rain, the levels of pollution came down considerably. The noise level in Nungambakkam, 85.1 db, Triplicane was 80.1 db, Sowcarpet 77.6 db and T.Nagar 71.5 db. As per the norm, the permissible noise level in residential areas is 45 db during night time, 55 db during day and in commercial areas it is 55 db during night and 65 db during day. “At Arumbakkam, we used a continuous digital ambient air quality monitoring system provided by the Chennai Petroleum Corporation Ltd. this year. Sulphur dioxide levels varied from 29.5 to 70.09 microgram/cubic metre against National Ambient Air Quality (NAAQ) standards of 60 microgram/cubic metre. The level of Nitrogen Oxides was 86.42 microgram/cubic metre as against NAAQ standard of 50 microgram/cubic metre,” he said.
Prasanna Kumar Thomas, consultant respiratory physician, Apollo Clinic, and Fortis Malar Hospital, said some patients suffering from asthma were admitted on Thursday due to aggravation caused by the smog. “During every Deepavali we get cases with coughs, colds and fevers. It is the particulate matter that causes the problem and not the fog.”