July 13, 1998

Safe in the house? The air indoors can be more dangerous than inhaling India's toxic urban smog.

By Samar Halarnkar

Geeta Khanna doesn't get out much. Once a week to the movies and three times a week to the market for vegetable shopping in Delhi's Punjabi bastion of New Rajinder Nagar. These trips outdoors are the only break from domestic pastimes like television, knitting and cooking. Khanna, 34, is comfortable with her traditional home-alone, middle-class existence, safe -- so she believed -- from the poisonous air of one of the world's most polluted cities.

Today, she holds a wet chunni to her mouth, a home-made filter, as she tries to stay away from the fumes of spices popping and crackling in hot oil. Near the gas stove in her smoky, claustrophobic kitchen ventilated by a solitary TV-sized window, lies a bronchodilator -- emergency help for the asthma she developed six months ago. Husband Pradeep, an insurance salesman, is a frequent bronchitis sufferer, the result of trundling along for seven years on a scooter through a haze of pollution. "I thought I would be safe at home, but I seem to be no better than him," says Khanna, before she's choked by a fit of wheezing and coughing.

Don't be deluded into believing that the housewife has it any better. Don't be deluded into believing home is an end-of-the-day refuge from the ravages of pollution. Home, as researchers and dismayed families are discovering, is no haven: indeed, the air indoors is often much worse than the toxic soup you breathe outdoors. Here's a simple test. Take a look at the blackened blades of fans. Your lungs are similarly blackening with layers of microscopic dust and soot particles, capable of triggering everything from plain headaches to asthma to severe respiratory problems.

"We're finding that people who stay indoors have as much of a problem with respiratory illnesses as people outdoors," says Dr Rohit Chawla, senior consultant in respiratory medicine at Delhi's Indraprastha Apollo Hospital. "Indoor-air pollution is a neglected, lesser known kind of pollution," explains Dr S.R. Kamat, a thoracic physician who pioneered pollution and health studies in Mumbai. "It's often unnoticed and therefore dangerous."

There are no detailed studies yet on the health risks of indoor air, but there is no longer any doubt that poorly ventilated homes and even offices can be cauldrons of toxic pollutants. The indications are diverse but clear:

Suspended particulate matter (SPM) in most Delhi homes are more than 100 per cent above safe levels, the result of the intense concentration of vehicle and factory exhausts, dust and cooking in the confines of concrete homes, says a study of middle-class homes conducted for the Council of Scientific and Industrial Research by Nandita Shukla, an environmental scientist.

Carbon dioxide -- not itself a pollutant but an indicator of pollutants trapped in badly ventilated spaces -- levels are up to two-and-a-half times higher than the outside, says a survey of 288 public spaces (hotels, offices and health clubs) carried out in Delhi by the local chapter of the American Society of Heating, Refrigeration and Air-conditioning Engineers.

Providing clean air indoors is becoming big business. The once non-existent market for room air purifiers, is estimated at Rs 25 crore today and growing at an annual rate of 20 to 25 per cent. From June, a South Korean company is also offering India's first air conditioner with an in-built air purifying system.

There are three main reasons for the poisonous indoors: poorly designed and ventilated Indian houses, leaky gas cylinders in the kitchen and the polluted air outdoors. "The main problem with indoor air is outdoor air," says Purushottam Khanna, director of the National Environmental Engineering Research Institute. Take your pick: the air in India's metropolitan cities is so harmful that it is equivalent to smoking 10 to 20 cigarettes every day; more than 40,000 people die prematurely each year from urban air pollution; and the number of people with respiratory diseases and asthma has roughly doubled in the '90s.

This poison soup creeps indoors and gathers in increasing concentration in houses without a free flow of air, unlike the outdoors where it has space to disperse. "Pollutants come in but they don't go out," say Chawla. Shukla's study found that the worst time indoors was at night when SPM levels soared. Worse, "most particulate matter at home is respirable, so the damage it can cause is greater," she says.

Kitchens in middle-class homes are major hotspots. Data from Mumbai show that kitchens with LPG cylinders as the primary fuel revealed higher concentrations of SPM, sulphur dioxide and nitrogen oxide (both causes of bronchial problems, cough and eye irritations) than kitchens using kerosene. This is because burners don't use all the gas released from the cylinders. The gas, not enough to cause a fire, "hangs" in the air after extended use and mixes with fumes from traffic and cigarettes.

Air-conditioned rooms are comparative oases when it comes to particulate matter, but when the machines' filters are not cleaned regularly -- which is usually the case in India -- they can become hotbeds of moulds, viruses and bacteria. And if you decide to smoke in an air-conditioned space, be prepared to either inject carcinogens into yourself and others in the room at a rate that is 10 to 50 times more than normal inhalation.

So are we doomed at home? It need not be so. Your best bet to escape the hell indoors is simply to make sure air flows freely through the house. It is important to ensure that houses are designed properly with large windows, high roofs if possible, and a clear flow of air from one end to the other. Of course, if you already live in a modern matchbox, just make sure that the house is aired as much as possible, particularly the kitchen, where exhausts are a must.

Purifiers do clean up particulate matter and other pollutants but are effective mainly in a limited, closed area, particularly in an air-conditioned room. Doctors, however, say that the effect of purifiers on the overall health of people ranges from limited to negligible; outside the room and house, the assault continues relentlessly. Home may indeed be where the heart is -- only it's the lungs you should start worrying about.

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