Guwahati, Nov 19 (IANS): A large chunk of the population in Assam is breathing toxic air, with Guwahati topping the chart of the highest polluted cities in the state and also having one of the highest black carbon emissions in the country.

The idea of clear blue skies and clean air in this part of the country is in danger as a result of the ongoing problem of air pollution in Assam and other northeastern states, according to a new warning from the Delhi-based Centre of Science and Environment.

Assam's five non-attainment cities -- Guwahati, Nagaon, Silchar, Sivasagar and Nalbari -- have been identified by the National Air Quality Monitoring Programme (NAMP). These cities' pollution levels are higher than the recommended air quality guidelines.

Accordingly, the National Clean Air Programme (NCAP) has been initiated to develop action plans to bring down the fine particulate matter (like PM10 and PM2.5) by 20-30 per cent within a stipulated time frame.

An emission inventory study has been initiated for Guwahati city, wherein the contribution of pollutants from different sectors like commercial, transportation, domestic and industrial sources shall be estimated.

Black carbon is just next to carbon dioxide in global warming potential and has an effect on global climate.

Rajarshi Sharma, a research scholar of the Air & Noise Research Lab of IIT Guwahati headed by Prof. Sharad Gokhale, studied emission levels of black carbon and found that fossil fuel burning (from transportation, industries, kerosene lamps for lighting in residential use) is responsible for about 60 per cent of black carbon emission, while biomass burning (from firewood for residential use, cropland burning, forest fires, slash burning) contribute to about 40 per cent.

The total emission of black carbon is about 19.38 Gigagram (Gg) during 2018-19, of which 3.38 Gg is from Kamrup Metropolitan district only, which is also the highest black carbon emitting district.

The unplanned and open burning of solid waste disposal within the municipal boundary is the other factor hurting Guwahati. The quantity of harmful chemicals and black carbon released by burning waste materials is something that most people are unaware of.

According to a state government official, Guwahati has one of the highest levels of black carbon pollution in the world, which is concerning.

In a study conducted close to Guwahati's metropolitan highways, Ardhendu Shekhar Chaudhury, another researcher from IIT-G, discovered that the average amount of black carbon present at the breathing level during the winter is roughly 32 micrograms per cubic meter.

Prof Gokhale told IANS that the air pollution scenario in Assam is not as grave as Delhi today but is certainly alarming as the levels of fine particles are rising.

“There is a need for public awareness of its harmful health effects and practically adaptable solutions to reduce the particle levels and minimize the damage to human health as well as the climate of the region,” he added.

In the hills and valleys of the northeastern states, the high levels of air pollution brought on by widespread motorization, traffic jams, and the usage of solid fuel are creating a public health emergency. Even worse, despite a slow worsening in air quality, little public attention has been drawn to it as of yet.

The wintertime air pollution in Guwahati is on par with that of several other Uttar Pradesh cities. Even smaller cities have substantial levels of pollution.

According to Parthankar Choudhury, a professor of ecology and environmental science at Assam University in Silchar, the amount of particle matter in the ambient air has been increasing over time.

“More research projects need to be carried out on the respiratory distress and other health ailments caused due to air pollution,” he added.

In the present scenario, various construction works are going on in and around Guwahati, which may be responsible for the increase in concentrations of PM10.

However, this increase is temporary in nature because, after the completion of the construction works, e.g., a flyover, the vehicle flow will be smooth with less congestion which will eventually lead to lesser pollutant levels in the long run.