Lead-poisoning hampers intellectual growth
PRIMARY testing of 250 gm of Pran brand of turmeric powder imported from Bangladesh was done in a private laboratory in New York after one consumer complained of falling sick after taking the powder. The test revealed that the powder had lead levels as high as 28 to 42 parts per million (ppm), a totally unacceptable levels for human health. The US Food and Drug Administration banned marketing of the product in America.
Following the recall of the turmeric powder from American chain stores, BSTI conducted tests on the powder and detected 40 to 58 parts per million (ppm) of lead, which far exceeds the permissible limit of 2.5 ppm set by it. BSTI has temporarily suspended Pran's turmeric powder processing and marketing licence.
The lead threat to the population, especially to children, is far worse than was thought earlier. Many developed nation had banned leaded paint and water pipes as far back as 1920s, and started to phase out leaded gasoline in the 1970s. Many lead pipes have been replaced either with copper or non-toxic materials.
Studies conducted over the last 20 years suggest that ingesting the lead equivalent of three granules of sugar a day can impair development and may make children less intelligent. Even the dust created by a lead-painted window can be toxic to children. This makes lead a health risk from the crumbling city apartments to suburban houses which were once thought to be relatively safe from lead contamination.
Reports reveal that 30 years ago authorities believed that children were safe with up to 40 micrograms of lead in each deciliter of blood. The safe level has slowly fallen since the US Centre for Disease Control (CDC) issued new warnings alerting doctors that anything higher than 10 mg/dL can be harmful to children. The CDC recommendation urges all children to be tested for lead as part of their regular health checkups.
In our country, the main sources of lead include leaded gasoline, lead smelting, coal combustion, lead-based paint, and pipes of lead-based solder in water supply system.
Vehicular lead emissions also accumulate in the soil and enter the food chain. Much to citizens' concern, health officials have not been trained to recognise the symptoms of lead poisoning, particularly in children, which are as banal as stomach aches, constipation and vomiting.
Scientific evidence shows that lead retards mental and physical development of children causing reading and learning disabilities, hearing loss, respiratory problems, hyperactivity and lack of concentration, even at low levels of exposure. The upper respiratory tract of humans cannot stop passage of the fine particles and thus they are deposited in the lungs and eventually enter the blood stream. Children represent the highest risk group due to their propensity to ingest significant quantities of contaminated dust and soil. Adults are more susceptible to lead exposure through inhalation.
Recent studies have linked even low blood-lead levels to a host of problems associated with the brain and nervous systems including IQ loss, aggressiveness, hyperactivity, reduced attentiveness, hearing loss, slow reflex, slow growth and problems with balance.
We do not know how many children in our country are suffering from lead poisoning because even the big cities lack the facilities for testing blood-lead levels in children. We have woken up to the danger arising from lead only very recently. The administration has to be careful about the dangers that lead poses. And it has to make all-out efforts to control the threat from lead, the most abundant heavy metal from earth's crust.
In our country, the government has never taken the threat to seriously, evidenced by the fact that it has never urged the general public to have their children tested for blood lead. The problem is most severe where lead pipes have been laid in zones with "soft" or highly acidic water, which can accelerate the leaching of lead particles. Neither the government nor the general public should be harbouring any impression that lead poisoning has disappeared, because no one talked about it. And because no one suspected it, no one looked for it and so no one found it. Experts say that the moment a child complains of stomach pains and headaches, becomes hyperactive without any ostensible reason, and is inattentive in school, he should be tested for blood-lead level.
It may be a very extensive and expensive measure to clean up old residues of lead. A cheaper approach is prevention through substituting zinc for lead in plastic pipes and cables. Sweden is following that path. The result is that Swedish children show few cases of lead poisoning. In our country, we don't simply have the money to retool for large scale production of unleaded gasoline. Even then we might adopt some measures that are hardly costly.
Physicians have recommended some home-spun measures to keep kids and adults away from lead exposure. Parents should roll up car windows while travelling with children. Let tap water run for a while before using it -- so that any accumulated lead can wash out. These measures can help reduce exposure substantially. But one can never escape lead absorption or exposure through these measures, so state-level measures are obviously needed.
The writer is a columnist of The Daily Star. E-mail: [email protected]
Comments