Lead is a metal with no known biological benefit to humans. Lead poisoning also known as Plumbism occurs when there is increased accumulation of lead in the body, usually slowly, over a period of months or years. This leads to the damage of various body systems including the kidneys, the nervous and reproductive systems.
In Nigeria, Lead poisoning is more prevalent in the North. Lead Poisoning in Zamfara State claimed the lives of hundreds of children in the first few months of 2010. This resulted from the gold mining practices the villagers embarked on during that period. The lead from the gold rocks stuck to their clothes of the miners and they went home to their children who also got exposed to the lead by touching the contaminated mining materials.
Lead poisoning is primarily a problem of children under the age of 6 years partly because they tend to put things in their mouth and also because they manifest symptoms earlier than older children and adults at the same blood level.
Lead is imbibed by inhalation or oral consumptions. House paints and environmental dusts are the commonest sources.
House Paints- they peel off from the wall and emit lead into the environment which is then inhaled. This is more common with paints that were used before 1978.
Storage batteries- Industrial workers are usually exposed to this.
Water sources- More common in old houses where lead pipes are used to convey water.
Contaminated soil, especially in regions where mining is a major source of income. This constitutes lead dust in the environment.
Children’s paint sets and art supplies (check labels).
Dinnerware and lead solders used for can food cans.
Currently the CDC defines elevated blood levels as any level equal to or above 10 microgram per deciliter. Symptoms are worse in children especially the unborn and with increasing blood lead levels. They include-
1. Abdominal pain and cramping
4.Difficulty in sleeping
7.Low appetite and weakness
8 Loss of previously acquired developmental skills in children.
9.In very high amounts, there could be vomiting, staggering, muscle weakness, seizures or coma which could lead to death. These occur more commonly with sudden exposure to very high levels of lead.
The possible complications of lead poisoning include kidney damage, hearing impairment and reduced IQ which is worse in very young children and in people with marginal IQ. The neurological complications of lead poisoning tend be more permanent in children, even after the exposure to lead had ceased.
The best treatment for lead poisoning is its prevention. However, if lead is detected to be very high (above 44 microgram per deciliter), a chelation therapy is instituted. This is a process of filtering lead out of the blood stream. Chelation is saved for those with very high values of lead in the blood because of the many complications associated with the process including a depletion of essential body nutrients.
Preventive methods include the following:
• The avoidance of possible sources of lead exposure and screening people who are at risk of lead poisoning.
• People who live in old houses should check for the lead concentration by using a lead kit. If it shows high levels, the houses should be renovated and re-painted with lead-free paints. It is important that children be evacuated from the building prior to the renovation as the breaking-down process often leads to emission of high levels of lead which can be inhaled.
• People who use lead pipes should have them changed, or should allow water run from the pipes for at least 10minutes before they collect for boiling and drinking.
• People who live in areas where the soil is highly contaminated by lead can minimize exposure by wet mopping their floors instead of sweeping and dry mopping. Children should be stopped from playing on bare soil and their hands and face washed frequently.
• Also, diets rich in Iron, Calcium, Zinc and low in fat have been found to reduce the gut absorption of lead for any given exposure
• Children and pregnant women who are at risk or are suspected to have lead poisoning should be screened early to avoid complications as these may be difficult to reverse after they are established.
• Enforcement of occupational health hazards preventive measures.
• Water treatment.
• Removal of lead solder from food cans.
-By Dr Chioma Oputa