When enemies lurk within the house
Animal dander, molds, dust, mites and other biological substances threaten our health
Muneera Parbeen

Some of the common symptoms that are seen in an average household in our country include exacerbation of asthma (recognised infectious disease), conjunctival inflammation, recurrent fevers (also called allergic fevers), chest tightness and coughs and sneezes.Awareness about these kinds of indoor pollution need to be created in order to educate people to take steps to rid themselves of it. A little care will go a long way to a long and healthy life.

Shumaila has a sudden tendency to develop a cold. She falls sick without any warning, and spends a major part of any month with coughs, sneezing and watery eyes. Her mother is tired of her daughter's inability to cure a cold, and takes special care to ensure that she doesn't take cold baths and that she has adequate intake of vitamin C to keep the cold at bay. However, her problem doesn't get any better.

Take for example the other day when Shumaila's mum was dusting the house. Instead of lending her a hand, Shumaila was in bed, coughing and sneezing and the mother though sympathetic was actually a bit angry that every time she went on a spring cleaning session, her daughter fell sick and was unable to help.

A simple visit to a doctor to treat Shumaila's allergy to metals however shed light onto this lingering problem that had bothered her for so long. Her doctor after hearing about the frequent spells of her reaction took a few tests and revealed the secret behind her illness. On further investigation it was found that Shumaila was having the allergic reactions to the dust and moulds in her house. The problem was aggravated on days when her mother dusted the house, when she always used to fall sick because of increase in the pollutants that affected her breathing and set off a natural allergic reaction to it.

It's not only dust and molds are the only factors that pose a health risk within the houses of our country. Biological air pollutants are found to some degree in every home, school, and workplace. Sources include outdoor air and human occupants who shed viruses and bacteria, animal occupants (insects, other arthropods, mammals) that shed allergens, and indoor surfaces and water reservoirs where fungi and bacteria can grow. A number of factors allow biological agents to grow and be released into the air.

This is especially true of a climate where there is high relative humidity, and that encourages house dust mite populations to increase and allows fungal growth on damp surfaces.

Mite and fungus contamination can be caused by flooding, continually damp carpet (which may occur when carpet is installed on poorly ventilated room floors), inadequate exhaust of bathrooms, or kitchen-generated moisture. Appliances such as humidifiers, dehumidifiers, air conditioners, and drip pans under cooling coils (as in refrigerators), support the growth of bacteria and fungi.

The common problems that lead to the above becoming a reason for cause in our country is lack of knowledge regarding these. Bathrooms are poorly ventilated in countries as ours, not very hygienic in their build-up, or use -- there are too many old buildings, too little access to sunlight and lack of ventilation.

Components of mechanical heating, ventilating, and air conditioning (HVAC) systems may also serve as reservoirs or sites of microbial amplification. These include air intakes near potential sources of contamination such as standing water (potholes on roads, ponds and ditches during the rainy season), organic debris or bird droppings (aplenty in gardens, roads and fields), or integral parts of the mechanical system itself, such as various cooling coils, or condensate drain pans. Dust and debris may be deposited in the duct work or mixing boxes of the air handler.

Biological agents in indoor air are known to cause three types of human disease: infections, where pathogens invade the human tissues; hypersensitivity diseases, where specific activation of the immune system causes disease; and toxicosis, where biologically produced chemical toxins cause direct toxic effects. In addition, exposure to conditions conducive to biological contamination (e.g., dampness, water damage) has been related to nonspecific upper and lower respiratory symptoms.

Some of the common symptoms that are seen in an average household in our country include exacerbation of asthma (recognised infectious disease), conjunctival inflammation, recurrent fevers (also called allergic fevers), chest tightness and coughs and sneezes.

Awareness about this kinds of indoor pollution need to be created in order to educate people to take steps to rid themselves of it. A little care will go a long way to a long and healthy life.

Source : The Daily Star, Dhaka, December 7, 2001