Environment

After abuse

A kiln is a blot on the village landscape

DTE Staff

After abuse

Workers stack unfired bricks.< (Credit: Vikas parashar /CSE)Laments Surendra Kumar, a resident of village Parsotigarhi in district Mathura, "Every morning we find a layer of black particles on our rooftop and in our fields. Our clothes become blackish within 4-5 hours. Black particles collect in our nostrils." His village is not the only one finding it difficult to cope with growing pollution in the area. The informal brick industry is the third largest consumer of coal in the country, after power plants and the steel industry. Says Mahesh Sharma, a kiln-owner near Imaliya village, district Bulandshahar, "It's actually the cost and consumption of the coal that decides the rates of bricks and our profit margins." But coal contributes heavily to the particulate emissions kilns are notorious for (see box: Jet black smoke).

Rubber's the choice
Kilns also use biomass, primarily rice husk. But what really causes the black smoke to spew from chimneys is the use of rubber as a fuel. Kiln owners use rubber and waste oil as fuel because production capacities have grown, and coal doesn't suffice. At least in eastern Uttar Pradesh, the demand is so high that rubber scrap dealerships have emerged as a viable profession. Says R K Sharma, an Aligarh rubber scrap dealer, "A quintal of rubber scrap costs Rs 300 to Rs 400, much cheaper than coal. It's a good fuel because it burns for a longer time". It's collected locally, but "Sometimes we bring rubber tyres all the way from Lucknow and even from West Bengal."

Rubber burns better because its calorific value -- 9,000 kilo Calorie/kg -- is higher than that of coal, about 70 per cent that of crude oil. But rubber contains 25 per cent extender oils derived from benzene, 25 per cent styrene (a derivative of benzene) and 25 per cent 1,3 butadiene. Both benzene and 1,3 butadiene are suspected human carcinogens. In short, tyres are not made to be burnt. Tyre incineration emits toxic heavy metals including mercury, lead, chromium, beryllium, cadmium and arsenic. A 1997 us Environment Protection Agency (epa) report on burning tyres for fuel found that a paper mill that burned tyres as just 2 per cent of its fuel had:

20 per cent increase in mercury emissions

179 per cent increase in hexavalent chromium emissions

20 per cent increase in benzene emissions

Burning tyres releases large amounts of the metal zinc, leading to increase in fine particulate matter related to respiratory and cardiac disease. Kilns lack state-of-the-art particulate controls needed to capture this fine soot. Burning tyres also releases dioxin, recognised by us epa in 1985 as the most potent human-made carcinogen known. Dioxin does not break down in the environment but builds up in the food chain, concentrating in meat and dairy products.

Are brick kilns regulated? The Central Pollution Control Board (cpcb) has set two kinds of standards, one for chimney height and the other for emissions. The first was drafted in 1987, to put a stop to the (then) prevalent practice of using movable chimneys. A 1993 Food and Agricultural Organisation of the United Nations estimated that there were in India nearly 100,000 brick kilns, out of a total of 115,000, that were using movable chimneys. The idea was to put paid to the problem that movable chimneys had: its emissions do not disperse, because of its lesser height. "Existing moving chimney Bull's trench kilns shall be dispensed with by December 31, 1987 and no new moving chimney kilns shall be allowed to come up", says the 1987 law. But the brick industry, a powerful lobby, got the implementation of these standards delayed. The time limit to weed moving chimneys out was extended twice: to June 30, 1999 and then to June 30, 2000. In 1996, cpcb stipulated emission standards for kilns (see table: For particulates only). But limits are set only for particulate matter. What about kilns that use rubber, as in Ardaspur village in western Uttar Pradesh. In any case, cpcb can only make standards. So who regulates even for the limited standards? No one knows.

The net effect? "The yield has declined drastically in the area, as the temperature has risen. Dew formation has decreased due to the heavy pollution in the area. Now in morning, we find a layer of black particles on our crops leaves instead of dew that we used to get earlier," says Surendra.

Though cpcb and State Pollution Control Board officials have a fair idea of damage caused by these units, action is taken only when courts intervene (see box: Like a tonne of bricks).

For particulates only
CPCB emission standards for kilns

Size Kiln capacity Maximum limit particulate
matter concentration (mg/Nm3)
Small Less than 15,000 bricks per day  (less than 15 ft trench width) 1,000
Medium 15,000-30,000 bricks per day  (15-22 ft trench width) 750
Large More than 30,000 bricks per day  (more than 22 ft trench width) 750