Kiln Eco-

India's construction sector contributes about six per cent to her Gross Domestic Product. In the Tenth Five-year Plan currently unfolding, that figure is likely to go up. The plan envisages massive construction activity across the country. Over 60 per cent of the total plan outlay is likely to be spent on construction components alone. Question is: how many bricks does that translate into?

Says Rakesh Verma, of the All India Bricks and Tiles Manufacturers Association (aibtmf), "According to the data provided by our state associations, there are nearly 60,000 kilns operating all over the country." But this is a guesstimate. And how many bricks do these turn out? He cannot say. "The production capacity of a brick-manufacturing unit depends upon how big the ghera (area of the circle around its chimney) is. A big kiln with a comparatively bigger ghera produces more than 30,000 bricks every day. Medium and small kilns produce 20,000 and 10,000 per day respectively," he informs. Beyond this generality, no calculation exists of how many of the 60,000 kilns fall into these categories.

It is an informal economy, after all. Says Rajesh Kumar Gupta, who owns a kiln on the road that runs from Aligarh to Mathura in western Uttar Pradesh, "If you want to install a bhatta (brick kiln) , you will need at least 20 bigha s of land. This will cost between Rs 7 lakh to Rs 10 lakh, depending upon the rate of the land in a particular area. Rs 3 lakh to Rs 4 lakh are needed to install a pakki chimney. Rs 2 lakh to Rs 3 lakh we keep to give to labour as advance. There are other miscellaneous expenses, such as the cost of fuel." Rs 12 lakh to Rs 17 lakh in all, a sizeable amount. Who would invest such a sum if the returns weren't better?

Bigger the kiln, it seems, the more the profit. As Sanjeev Kumar Singh, president, Mathura Brick Kiln Association, says, "If you have a kiln with a bigger production capacity, you can make more profit because you will produce more bricks with the same quantity of coal." He undercuts himself immediately. "What if your stocks are not sold for a week, where would you store them? Ultimately you will sell them below the market price and incur a loss."

Shyam Singh runs a small kiln in district Bulandshahar. The unit runs on a 25-day cycle producing nearly 6.5 lakh bricks. "The business is profitable if the cycle completes perfectly and no fuel or labour problem occurs," he says. "But a problem may occur on any of the two ends (putting mud bricks in, taking made bricks out during the burning), or the pathiaya (the mud brick maker) runs away. Besides losing our advance given to labour, we also run into loss because this interrupts completion of the circle. In such a case, production stops, for there is no mud-brick to burn. We have to pay the money to those who worked but don't earn anything."

Singh's lament notwithstanding, brickmaking is whiplash business for 7-8 months in a year -- September to April in north India. Avoiding the monsoon, the kilns furiously produce various grades of bricks. " Avval and doyam, two better-quality bricks, are used in building and priced high: Rs 1,500 to Rs 1,700 per thousand bricks," informs Hari Om, another Bulandshahar kiln-owner. "The price of Soyam and talsa, two inferior-quality bricks used in foundations, remains between Rs 1,000 to Rs 1,200 per thousand bricks. Chatka is of the worst quality. Used in road construction, it is priced around Rs 900." Prices rise during the monsoon, or when demand outstrips supply, or when policy threatens to upset the unorganised cart. This happened in late 2004: " aibtmf called for a nation-wide strike in October last year against the flyash notification that forces us to mix flyash in bricks," says Verma. "Production stopped for nearly three-and-a-half months. In December, the price of a thousand bricks reached Rs 2,700, the highest ever."

But soil
But soil, particularly topsoil at a depth of one to one-and-a-half metres, is not simply the physical material on Earth's surface: probably its most important component is the living organisms within it. Healthy soil contains extremely large numbers: a typical arable soil -- precisely the kind used to make bricks -- may contain 100 million bacteria/gramme. The rhizosphere, the thin layer immediately next to a plant root, typically has 1 million bacteria/gramme. Also, in one gramme of healthy soil there can be 15,000 to 20,000 different species of bacteria. Fungi are also very important -- especially mycorrhiza, which form close associations with plant roots. One kilometre of fungal hyphae have been detected in one gramme of soil.

Does not the land used to extract clay from lose, then, its microbial diversity, thus reducing its fertility and regenerative capacity? Kiln-owners agree that the land on which the kiln is located becomes completely unusable. Soil science bears this out. The burning process used to fire clay bricks changes soil chemistry and soil biology. The heat penetrates the soil up to a few centimetres. As a result, bacterial and fungal populations decrease immediately -- and substantially -- in the top 2.5 centimetre of the soil. Repeated burning permanently diminishes bacterial populations by more than 50 per cent and also decreases soil respiration. Similarly, long-term burning reduces total nitrogen and carbon and the potentially mineralised nitrogen content in the 0-15 cm soil layer.

But kiln-owners also argue that the land used to extract clay can be reclaimed. Disagrees J M Bhatnagar, deputy director and head, clay products division, Central Building Research Institute: "It takes years to reclaim that land. Bricks are made out of argillaceous mass (like clay), which are largely hydrous alumina silicate systems. These hydrous alumina silicates are the weathering product of rock mass, which takes hundreds to thousands of years in transforming to its present usable form. "It (the topsoil) is almost non-renewable," says Dilip Biswas, ex-chairperson, Central Pollution Control Board, Delhi. According to Biswas, it takes about 100 to 400 years to form the 10 millimetres of the topsoil; 30 millimetres of topsoil takes as much as 3,000 years to 12,000 years to form.

In March 2005
The Technology Information, Forecasting & Assessment Council -- tifac, an autonomous body under the department of science and technology, promotes use of flyash in bricks to save topsoil -- in a national seminar on building components made a presentation which shows that the current annual requirement of bricks in India is 150 billion. This means digging up nearly 300 million tonnes of topsoil: a mass stripping of around 20,234 hectares of agricultural land goes in brick manufacturing every year. But the actual damage could be more than what tifac has estimated (see box: Lump sum).

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).