Air Pollution Takes its Toll

Disease pattern of out patient department of Shishu
(Children) Hospital shows that respiratory problems related
to air pollution tops the list. Manzoor Hussain writes

AIR pollution can affect the health of all human, regardless of age, but the greatest impact is likely to be among urban children. Increased urbanisation and rapid industrialisation in developing countries is causing a virtual epidemic of diseases related to air pollution among younger children. Most children who live in large cities in the developing world breathe air that is equivalent of smoking two packs of cigarette a day.

Respiratory disease is now the leading cause of deaths in children worldwide and air pollution in the developing world is responsible for at least 50 million cases of chronic cough. Children living in cities in developing countries face double jeopardy from both living in poverty and from exposures to degraded environment. Many children in cities in developing countries already suffer from hunger, malnutrition and infections, and do not have access to basic medical care. Air pollution only worsens their burden by aggravating diseases like bronchitis, asthma and other lung diseases. Medical practitioners have not been trained to relate specific illness or symptoms with air quality problems. So, connection between environmental causes and health effect is not easy to arrive at.

Dhaka city is the capital of Bangladesh, where about nine million people live in an area of 1353 sk and over thousand immigrants join to swell the population of Dhaka for livelihood everyday from different parts of the country. Fifty-five per cent of the inhabitants live under the absolute poverty line and standard of living of about 2.5 million slum dwellers is precariously low in Dhaka city.

There is considerable evidence that the present level of atmospheric contaminants that exist in Dhaka is sufficient to cause discomfort or significantly impair child health. Sky of Dhaka gets overcast with smoke that forms due to uncontrolled emission of exhaust from 70-80 per cent of the total 175 thousand automobiles operating in the city.

From automobile emission - about 3,700 tonnes of suspended particles are added to the air of Dhaka yearly. Hundreds of brick kilns around the city are also belching smoke in the atmosphere. It is claimed that the density of lead in the air of Dhaka is the highest in the world and about 50 tonnes of lead is being mixed with air annually. Studies showed that children have blood lead level in excess of WHO guidelines in Dhaka.

Children of Dhaka are more at risk than the adults because their bodies are still developing. The lung of a child grows most rapidly in the first two years of life. They also tend to absorb pollutants more readily than adults do and retain them in the body for longer period of time.

Because, their breathing rates are substantially higher than the adults and the children are exposed to greater levels of pollutants. Children with diet deficient of micro-nutrients have also weaker immune system. For this reason children below six are highly vulnerable to the toxic effects of air pollution.

On an average of 450 to 500 patients attend at the Out-patient Department including emergency room of Dhaka Shishu (Children) Hospital for treatment. Out of them, 350 to 400 patients attend for medical consultation. Disease pattern of out patient department of Dhaka Shishu Hospital shows that respiratory problems topped the list. Even ARI prevention programme launched in 1990 could not reduce the hospital attendance due to ARI in Dhaka. From November to February 1998, 52 per cent of total 13,025 patients were suffering from ARI and 33 per cent had wheezing who attended the out patient department of Dhaka Shishu Hospital.

Long term low level exposure to pollutants in the environment depresses immune system. The same may be responsible for vague undesirable illnesses. Common complaints of headaches, sneezing, coughing, nausea, fatigue, skin rashes, irritation of noses, throat and eye, and difficulty in concentration may be nature's way of informing us that there is a problem in the air quality. The ill effect of air pollution is most obvious during acute episodes of unusually high pollution. So, connection between environmental cause and health effect is not easy to arrive at when the children are exposed to long term low-level exposure to the pollutants.

As little data is available — pediatricians are beginning to realise that cumulative effect of long-term exposure to low level pollutants may, infact, be responsible for those vague undesirable illnesses or symptoms. Important pollutants and their effect on child-health is briefly discussed below:

Emission of smoke from motorised vehicle is the main culprit for impairing health status of a child. Smoke inhalation alters lung function resulting in chronic symptoms and significantly decrease performance endurance. Immediate effect of smoke inhalation causes headache, vertigo, burning sensation of the eyes, sneezing, nausea, tiredness, cough etc. Long term effect of chronic smoke inhalation may cause asthma, recurrent respiratory tract infection, wheezy bronchitis, bronchitis, triggers asthma attacks. The effects are manifestations of body response to irritant materials present in the smoke that interfere with lung functions.

Sub-clinical toxicity has been reported in dense traffic situation. Symptoms consist of headache, lethargy, nausea, vomiting and depressed sensorium. Carbon monoxide gas combines with hemoglobin to form carboxy-haemoglobin, which fails to carry oxygen and results in tissue anoxia (lack of oxygenation).

Children below six of Dhaka city are exposed to lead poisoning due to use of leaded petrol in the vehicle. Studies in USA indicate that 5 per cent to 15 per cent of their children have increased lead absorption. We need such studies to understand our situation. Lead poisoning is actually a chronic disorder that may be punctuated by acute episodes. We do not know the exact incidence. The clinical diagnosis tends not to be suspected until the onset of nervous system symptoms or evidence of sideroblastic anemia in the blood film.

Chronic lead poisoning may present as non-specific development delay, behavioural and attention disorder or a peripheral neuropathy where weakness begins in the foot muscles. Mild sensory loss may accompany. Eventually hand muscles are affected. General symptoms include apathy, decreased play, clumsiness and intermittent vomiting.

The dust particles in the air collect bio-aerosols (microscopic living organisms or fragments of living thing). Bio-aerosols floating about our homes consists of viruses, bacteria, mold spores, fungi, yeast, animal and insect allergens, pieces of dead skin, microscopic dust mites and their excrement. Breathing these various elements all the time obviously puts pressure on our immune systems. Allergies, asthma, colds and flue are some of the health effects of these pollutants. Bio-aerosols can cause severe health problems during December to March period when total suspended particulate level of air of Dhaka remains high. During this period incidence of respiratory problems sharply rises among the children of Dhaka.

The recent increasing trend of the incidences of respiratory disease in Dhaka signals the acute necessity of combating air pollution in a befitting manner. Lead is a serious environmental pollutants. One can hope for cleaner air if persons in policy making positions recognise the problem like leaded gasoline and move quickly to enforce strict emission standards for automobiles; only then children will be able to breathe improved air.

We are pitifully behind the time — not just scientifically and technologically but more potentially in our ability to grasp the true nature of the problem in time. This time, if we fail to face the challenge of air pollution then there will be a man made disaster — the cost of morbidity will be unbearable for both the families and the nation.

—BCAS Feature

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