Air pollution in India

Air pollution in India is quite a serious issue with the major sources being fuel wood and biomass burning, fuel adulteration, vehicle emission and traffic congestion. In autumn and winter months, large scale crop residue burning in agriculture fields - a low cost alternative to mechanical tilling - is a major source of smoke, smog and particulate pollution. India has low per capita emissions of greenhouse gases but the country as a whole is the third largest after China and the United States. A 2013 study on non-smokers has found that Indians have 30% lower lung function compared to Europeans.

The Air (Prevention and Control of Pollution) Act was passed in 1981 to regulate air pollution and there have been some measurable improvements. However, the 2013 Environmental Performance Index ranked India 155 out of 178 countries

Fuel wood and biomass burning is the primary reason for near-permanent haze and smoke observed above rural and urban India, and in satellite pictures of the country. Fuel wood and biomass cakes are used for cooking and general heating needs. These are burnt in cook stoves known as chullah or chulha piece in some parts of India. These cook stoves are present in over 100 million Indian households, and are used two to three times a day, daily. As of 2009, majority of Indians still use traditional fuels such as dried cow dung, agricultural waste, and firewood as cooking fuel.

This form of fuel is inefficient source of energy, its burning releases high levels of smoke, PM10 particulate matter, NO_x, SO_x, PAHs, polyaromatics, formaldehyde, carbon monoxide and other air pollutants. Some reports, including one by the World Health Organization, claim 300,000 to 400,000 people die of indoor air pollution and carbon monoxide poisoning in India because of biomass burning and use of chullahs. The air pollution is also the main cause of the Asian brown cloud which is delaying the start of the monsoon. Burning of biomass and firewood will not stop, unless electricity or clean burning fuel and combustion technologies become reliably available and widely adopted in rural and urban India.

India is the world's largest consumer of fuel wood, agricultural waste and biomass for energy purposes. From the most recent available nationwide study, India used 148.7 million tonnes coal replacement worth of fuel wood and biomass annually for domestic energy use. India's national average annual per capita consumption of fuel wood, agri water and biomass cakes was 206 kilogram coal equivalent.

In 2010 terms, with India's population increased to about 1.2 billion, the country burns over 200 million tonnes of coal replacement worth of fuel wood and biomass every year to meet its energy need for cooking and other domestic use. The study found that the households consumed around 95 million tonnes of fuel wood, one-third of which was logs and the rest was twigs. Twigs were mostly consumed in the villages, and logs were more popular in cities of India.^[14]

The overall contribution of fuel wood, including sawdust and wood waste, was about 46% of the total, the rest being agri waste and biomass dung cakes. Traditional fuel (fuel wood, crop residue and dung cake) dominates domestic energy use in rural India and accounts for about 90% of the total. In urban areas, this traditional fuel constitutes about 24% of the total.

Fuel wood, agricultural waste and biomass cake burning releases over 165 million tonnes of combustion products into India's indoor and outdoor air every year. To place this volume of emission in context, the Environmental Protection Agency (EPA) of the United States estimates that fire wood smoke contributes over 420,000 tonnes of fine particles throughout the United States – mostly during the winter months. United States consumes about one-tenth of fuel wood consumed by India, and mostly for fireplace and home heating purposes. EPA estimates that residential wood combustion in the USA accounts for 44 percent of total organic matter emissions and 62 percent of the PAH, which are probable human carcinogens and are of great concern to EPA. The fuel wood sourced residential wood smoke makes up over 50 percent of the wintertime particle pollution problem in California. In 2010, the state of California had about the same number of vehicles as all of India.

India burns tenfold more fuel wood every year than the United States, the fuel wood quality in India is different than the dry firewood of the United States, and the Indian stoves in use are less efficient thereby producing more smoke and air pollutants per kilogram equivalent. India has less land area and less emission air space than the United States. In summary, the impact on indoor and outdoor air pollution by fuel wood and biomass cake burning is far worse in India.

A United Nations study finds firewood and biomass stoves can be made more efficient in India. Animal dung, now used in inefficient stoves, could be used to produce biogas, a cleaner fuel with higher utilization efficiency. In addition, an excellent fertilizer can be produced from the slurry from biogas plants. Switching to gaseous fuels would bring the greatest gains in terms of both thermal efficiency and reduction in air pollution, but would require more investment. A combination of technologies may be the best way forward.

Between 2001 and 2010, India has made progress in adding electrical power generation capacity, bringing electricity to rural areas, and reforming market to improve availability and distribution of liquified cleaner burning fuels in urban and rural area. Over the same period, scientific data collection and analysis show improvement in India's air quality, with some regions witnessing 30 to 65% reduction in NO_x, SO_x and suspended particulate matter. Even at these lower levels, the emissions are higher than those recommended by the World Health Organization. Continued progress is necessary.

Scientific studies conclude biomass combustion in India is the country's dominant source of carbonaceous aerosols, emitting 0.25 teragram per year of black carbon into air, 0.94 teragram per year of organic matter, and 2.04 teragram per year of small particulates with diameter less than 2.5 µm. Biomass burning, as domestic fuel in India, accounts for about 3 times as much black carbon air pollution as all other sources combined, including vehicles and industrial sources.

The author of this article is Assistant Professor, Pioneer Institute, Indore