Unseen Passage 2

INDOOR POLLUTANTS

1.      Call it a blessing or a curse of Mother Nature, we have to breathe in over 10,000 litres of air in a day (more than four million litres in a year) to remain alive. By making it essential for life, God has wished that we try to keep the air we breathe clean. Everyone can see the food that is not clean and perhaps refrain from eating it, but one cannot stop breathing even if one can feel the air to be polluted.

2.      Several harmful and noxious substances can contaminate the air we breathe. Generally, much is said and written about outdoor air pollution, most of which is due to vehicular and industrial exhausts.

3.      Given the fact that most of us spend over 90% of our time indoors, it is most important to recognise that the air we breathe in at home or in offices can be polluted. It can be a cause of ill-health. Air pollutants that are generally present in very low concentrations can assume significance in closed ill-ventilated places.

4.      The indoor air pollution can lead to allergic reactions and cause irritation to the skin, the eyes and the nose. But as is logical to assume, the brunt of insult by pollutants is borne by the lungs. It can lead to the development of fresh breathing problems, especially in those who have allergic tendencies, or it can worsen the existing respiratory illnesses like asthma and bronchitis.

5.      There can be several sources of indoor air pollution. Tobacco smoke is one of the most important air pollutants in closed places. “Passive smoking” or environmental tobacco smoke (ETS) pollution can lead to all the harmful effects of tobacco smoking seen in the smokers in their non-smoking companions. ETS as a health hazard has been unequivocally proven and is also getting social recognition now. One can occasionally see signs displaying the all-important message: “Your smoking is injurious to my health” in offices and homes. The children of smoking parents are among the worst affected persons.

6.      The exposure of young children to ETS leads to increased respiratory problems and hospital admissions as compared to non-exposed children. Several studies, including those done at the PGI, have shown an increased risk of lung cancer among women exposed to passive smoking. ETS also worsens the existing lung diseases like asthma and bronchitis. It may be responsible for the development of asthma in children.

7.      The next most important source of indoor air pollution is the allergens. House dust mites (HDM) are very small insects not visible to the naked eye and are the commonest source of allergy in the house. They are ubiquitous and thrive in a warm and moist atmosphere. They breed very fast and are very difficult to eradicate. Modem houses present ample breeding spaces for them in the form of carpets, curtains, mattresses, pillows, etc.

8.      Exposure to HDM can be prevented by the frequent washing of linen and by encasing the mattresses and pillows in a non-permeable cover. Pets form an important part of life for some of us. But they can add plenty of allergens to our indoor atmosphere. Cats are notorious for doing this. Fine particles from feline fur can remain stuck to the upholstery and carpets for a long time* even after the removal of the animal and lead to the worsening of asthma and skin allergies. Fortunately, owing to religious and social customs cats are not very popular pets in India. Dogs, however, are quite popular and can be as troublesome. Pets should be kept out of the bedrooms and washed frequently. To remove the fur particles one has to use vacuum cleaners as the ordinary broom and mop are not effective.

9.      Moulds, fungi and several other microorganisms thrive in damp conditions and can lead to allergies as well as infections. Humidifiers in the air-conditioning plants provide an ideal environment for certain types of bacteria and have led to major outbreaks of pneumonia. It is important to clean regularly the coolers, air-conditioners and damp areas of the house such as cupboards, lofts, etc to minimise this risk.

10. Toxic gases can also pollute the indoor environment. Biomass fuels (wood, cowdung, dried plants) and coal, if burned inside, can lead to severe contamination by carbon monoxide (CO): The poor quality of stoves and other cooking or heating appliances that cause incomplete combustion of LPG can also lead to the emission of CO or nitrogen dioxide.

Formaldehyde (a gas) can be released from adhesives that are used for fixing carpets, upholstery and also in making plywood and particleboard.

11. The gases are very toxic in high concentrations as may be encountered during industrial accidents, but even in very minimal amounts, as may be prevalent in homes and offices, they can cause irritation to the skin or the eyes, rashes, headache, dizziness and nausea. Improving the ventilation is an important preventive measure, besides trying to eliminate the source that may not be always feasible.

12. Other indoor pollutants are toxic chemicals like cleansing agents, pesticides, paints, solvents and inferior-quality personal-care products, especially aerosols. Very old crumbling pipes, boilers, insulation or false roofing can also be important sources. Asbestos is a hazardous product that can cause cancer in humans.

13. It is important to realise that the air we breathe at home may not be clean always andwe must try to eliminate the source of pollution. We should give due consideration to ventilation.

Answer the following questions briefly

(a) What is essential for our life? How?

(b) Why should we pay attention to the quality of air we breathe indoor?

(c) Name eight important sources of indoor air pollution.

(d) What do you understand by ETS? How is it harmful? Give two instances.

(e) How can the risk of allergies be minimised?

(f) How can the toxic gases pollute the indoor environment?