KOLKATA: A much-awaited study to detect the source of air pollution and quantify the amount of contaminents in Kolkata and Howrah has finally been commissioned by the West Bengal Pollution Control Board (WBPCB). Source apportionment studies have already been done for Delhi, Bengaluru, Mumbai, Chennai, Pune and Kanpur.
The two-year study will commence by April, once 14 new automatic air pollution measurement stations are installed — seven in Kolkata, five in Howrah and one each in Kalyani and Hooghly. The National Engineering & Energy Research Institute (Neeri) will collect samples, analyze them and do a modelling to identify and quantify sources like emission from vehicles, dust from construction, chemicals released by industry and so on.
"PCB has been monitoring the city's ambient air for over two decades. But since a majority of equipment is manual that functions twice a week, data collection was inadequate to identify areas with high pollution levels. This is needed to plan strategies and develop action plan to scientifically combat air pollution. Each machine, costing Rs 25 lakh, will record fine particlate matter (PM10 and PM2.5). The molecular marker will detect 12 other parameters," WBPCB chairman Kalyan Rudra told TOI.
Neeri scientist DipankarMajumdar said his team had already identified various sources like industry, biomass cookstoves used in slums and roadside eateries, LPG in urban households and restaurants, the two CESC power plants close to the city, open burning of biomass and waste, road dust, large sewage canals and small open drains, construction activities, petrol pumps and storage facilities, incinerator, hot mix plants, brick kilns and construction debris. He has also mapped out zones. For instance, industry is located in Howrah, Taratala and Kasba.
"What the study will do is quantify how much is each source responsible for poisoning the air we breathe so that remedial measures can be chalked out. The study will continue for at least 12 months to take into account data collected across seasons as ambient air quality has a wide seasonal variance," Majumdar pointed out.
This year, PM levels have been close to Delhi, even surpassing it on several days. This is cause for worry as air quality monitoring data in Kolkata, while above the permissible limit all through the year except three months in summer/monsoon, it is way below Delhi. Kolkata's proximity to the sea and river as well as the wind patterns contribute to the supression of particulate matter," said Rudra.
