GUWAHATI, Dec 4 - Is Guwahati going the Delhi way? As the national capital struggles to cope with severe levels of toxic air pollution, there is some alarming news for Guwahatians as well.Black carbon levels in the city atmosphere are on the rise and this may have severe consequences on the respiratory health of children and elderly as an immediate impact, a study by a team from IIT Guwahati has indicated.
The IIT team conducted a year-long monitoring of black carbon at ten locations in Guwahati.
At the Lachit Nagar point, the daily average black carbon concentration during winter (December-February) was found to be 19 microgram per cubic metre and the maximum recorded concentration during the season was up to 62 microgram per cubic metre. During the post monsoon period (September-November), the concentration was 15 and 47 respectively.
“The levels observed in Guwahati are alarming and increasing, indicating the contribution of diesel vehicles more. Black carbon is a short-lived climate pollutant. As compared with the carbon dioxide it has a low residence time of about one week,” Dr Sharad Gokhale, Professor of Environmental Engineering at the Department of Civil Engineering, IIT Guwahati, told The Assam Tribune.
Black carbon concentrations change with seasons drastically. In monsoon, it has decreased by about 47 per cent as compared to the values observed in the winter season, which is considered to be the worst season for air pollution.
It has also been observed that black carbon constitutes about 30 to 40 per cent share in the daily average PM2.5 (particulate matter 2.5) levels.
“We have been monitoring the levels at Ground Water Board (Lokhra), College of Veterinary Science (Khanapara), PCBA (Bamunimaidam), Sanjevani Hospital (Maligaon), Vishwaratna Hotel (Paltan Bazaar), IIT Guwahati campus and Uzanbazar. So far we have the data ready for Lachit Nagar location. Once we analyse the data for other locations, the spatial scenario of black carbon over the city will be clear,” he added.
Among the vehicles, diesel-driven vehicles which are the main cause of black carbon have a share of about 26 per cent in the traffic fleet nearby Lachit Nagar location along GS Road. Autorickshaws, which are mostly diesel-driven, occupy a larger share. Apart from that, other heavy and light diesel-driven vehicles also contribute to black carbon and to the overall PM2.5 levels significantly, the study has observed.
Every month around 5,000 new vehicles are added to the city roads. According to the District Transport Office here, as many as 62,281 new vehicles were registered in the office last year. The number of vehicles on the city roads currently could be over 10 lakh.
Senior environmental scientist at the Pollution Control Board, Assam, Manoj Saikia too blamed the phenomenon on the vehicular pollution.
“The roads in the city are not scientific. The roads are small and clogged, resulting in slow movement of vehicles and frequent halts which cause more vehicular pollution. Moreover, the greenery in and around the city, which absorbs the toxic gases, is depleting. It is time the government and the stakeholders adopted a multi-pronged approach, or else the city will become another Delhi,” he added.
