LETHAL LEAD

It is well-known that the environment in which a person lives determines to a considerable extent the status of health of that individual. This is more so in the case of children, who are more vulnerable and sensitive to harmful environmental factors than are adults.

The air they breathe, the food they ingest, the water they drink, the dust and other things they touch, the toys they play with, the care they get from caregivers, parental disharmony, and even what they see on TV can affect their physical and mental well being.

Harmful environmental exposures can occur in a variety of settings - at home, in schools and while playing outdoors. However, it is at home where they live most of their young lives that they get exposed to many potential hazards. Some such environmental exposures are what trigger asthma in children. These can be in the form of pet dander and saliva, mould, second hand tobacco smoke, dust and dust mites and even the ubiquitous cockroach.

Not all asthmatic children have the same "triggers". The fact remains that childhood asthma is one of the most common chronic diseases and a leading cause of disability among children. A majority of children with asthma have significant allergies to these environmental triggers. Reducing contact with asthma triggers, especially at home, can help prevent asthma attacks.

Playtime is an important part of a child's life. But it is also when they can get exposed to many environmental hazards. Dust and soil contaminated with residual lead from leaded petrol is a major hazard. Although the exact magnitude of this problem in Sri Lankan children is not well documented, it is an undeniable fact that the prevalence of lead poisoning could well be a problem in the absence of adequate safeguards against exposure to deteriorating lead-based household paint and consumption of water contaminated with lead from plumbing in old homes.

Lead exposure could also occur with some toys with either metallic lead in them or simply painted with lead-based paint, and parental occupations involving lead such as in archaic printing presses that still use lead in type setting. Parents can unknowingly poison their children by taking home lead dust from such work places.

While the symptoms of asthma such as wheezing and cough are well known to parents, it is not so with childhood lead poisoning. Lead poisoning can cause a wide range of symptoms from minor discomforts like loss of appetite, constipation, vomiting, abdominal pain etc, to much more serious convulsions, coma and even death if the condition remains untreated. The lead poisoned child may be excessively tired, cranky, hyperactive, or lose interest in playing.

Lead poisoning could also reduce intelligence and attention span thereby significantly lowering the educational performance of the child. It may also cause reading and learning disabilities, loss of hearing, and delay a child's standing, walking and talking.

Asbestos is a fibrous mineral that is widely used in building construction materials such as roofing and ceiling sheets which most house builders in Sri Lanka use for economic reasons and convenience. The tiny asbestos fibres can easily penetrate tissues if inhaled or swallowed and can remain in the body for many years. Prolonged accumulation of these fibres in the lungs can lead to scarring of lung tissue and diminished breathing capacity. This results in symptoms such as breathlessness, tiredness, persistent cough etc. However, signs and symptoms usually don't appear until years after exposure. Needless to say, children living in such homes are exposed to this environmental hazard.

Another environmental poison that has not attracted much attention in Sri Lanka but nevertheless affects mainly children and women of childbearing age is mercury. At a time when the construction of two coal-fired power plants in Norochcholai and Trincomalee have been planned to solve Sri Lanka's impending power crisis, a paragraph on mercury poisoning would not be out of place here.

Coal-burning power plants are known to be a primary source of atmospheric mercury. When such mercury falls back to the sea or earth from where it can get washed away into large bodies of water such as rivers and lakes, bacteria transforms it into highly toxic methylmercury. Contaminated plankton, shellfish and other small fish have insignificant amounts of mercury. But when larger fish consume their prey, the small doses add up as stores lodged in their tissues. Consumption of these larger fish can cause poisoning in humans.

Although, it could be argued that the presence of fluoride in drinking water should not be discussed here as an environmental problem affecting children on account of its proven ability to prevent dental caries, it is worth mentioning at least in passing. The large numbers of children living in and around the North Central Province who have dark brownish stained teeth are in that unfortunate situation due to the presence of excessive amounts of fluoride in their drinking water. This condition known as "fluorosis" is not seen in children in other parts of the country. It is ironical that in some communities, fluoride has to be added to community water supplies to bring the fluoride content to an optimal level that has been found to be very effective in preventing tooth decay.

On a similar note, it may be mentioned that the high prevalence of iodine deficiency disorders especially in areas with a high rainfall such as Kalutara and its environs has been attributed to the leaching away of naturally occurring iodine in the soil. Iodine deficiency disorders affect both adults and children. The condition called "cretinism" occurs in infants and children and is due to lack of thyroid hormone. Cretinism causes very serious retardation of physical and mental development.

It usually results from a congenital defect like the absence of the thyroid gland, presence of only a rudimentary gland, or inability of the gland to produce the thyroxine hormone. However, it can develop later if there is a lack of iodine in the diet, or if the thyroid is diseased or surgically removed. As mentioned before, lack of iodine in the diet could well be due to leaching away of iodine in the soil by rainwater.

To end this article on a more positive note, I was happy to read in newspapers recently that the incidence of iodine deficiency disorders in Sri Lanka has come down drastically. This downward trend has been attributed to the increasing use of iodised salt by the population at large in recent years. If these reports are correct, it gives me great satisfaction as a person who was actively involved in promoting the use of iodised salt as a staff member of UNICEF in Colombo in the early nineties. Working with D.B. Nihalsinghe, then of Telecine Ltd. and Ms. Sandya Salgado of Grants Advertising, it was quite a challenge to plan and implement a mass media campaign with the objective of moving Sri Lankan housewives away from the traditional "Lunu Polkatta" (coconut shell containing rock salt) and getting them to use powdered iodised salt in its place.

(The writer is attached to the Department of Health and Environmental Control, South Carolina, USA)