Lead and child safety came into sharp focus recently when high levels of lead were discovered in children toys.
This served to highlight the need for continued public health education on the health risk associated with lead.
Lead is toxic heavy metal that disrupts essential enzymatic processes at a molecular level leading to changes in cell function and eventual cell death.
Lead intoxication is a preventable medical condition and proactive measures should be put in place to reduce, eliminate and prevent lead from entering the environment, food chain and man. These effective measures require effective legislation and enforcement.
Recommendations on ways to reduce lead intoxication are discussed and possible modes of treatment are presented. Key words: lead, lead intoxication, public health education, public health
The Problem The public health safety of lead recently came into focus when children toys from two manufacturers were recalled due to high levels of lead.
Lead is a heavy metal that exists in three forms; elemental, inorganic and organic. It is used in the manufacture of paints, batteries, household chemicals, cosmetics and other chemicals and items. According to the National Health and Nutrition Examination Survey found that the US population has an overall prevalence of lead of 0.7 % for the period 1999 to 2002.
Children are particularly susceptible to lead poisoning since they are often exposed to contaminated environments such as old buildings containing lead particles and playground soils and dust.
It was found that Black children were more often exposed to lead intoxication, followed by Mexican-American and White children. This trend resulted because Black children were living in building constructed before 1978 and which in most cases probably had lead chips and dust from lead paint. Additionally, it is a customary habit that children under the age of 6 years tend to put their hands in their mouths. This habit has resulted in the ingestion of lead into the body.
The oral route is therefore the major route of entry for lead in children under the age of 6 years.
Other routes of entry of lead into the body include the nose, eyes and skin. In addition, adults may experience occupational hazards for lead that may be significant in fields such as electrical, printing, ammunitions, plumbing, and the automobile industries.
Lead is extremely toxic and once internalized via ingestion and/or absorption it can create havoc in the body, disrupting bodily systems, causing unconsciousness, paralysis and eventual death. Lead intoxication is preventable and measures must be put in place to reduce, eliminate or prevent lead from getting into the food chain, and to maintain clean and sanitary environments free from lead pollutants. The only way this can be done is through effective education, development of policies, practices and effective legislation and enforcement.
The purpose of this paper is to review the current information on lead and to present information on ways to identify sources, reduce and treat lead intoxication, thereby providing public health education, and protecting the public's health.
Molecular pathophysiology of lead toxicity:
Lead interacts with electon donars such as sulfhydryl groups and interferes with enzymatic processes. It also interacts with cations such as calcium, iron and zinc and sodium-potassium adenosine triphosphate pump, thus resulting in altered cellular and mitochondrial fragility. It also inhibits pyrimidine-5-nucleotidase and hence impairs nucleotide functions. These molecular changes result in the decreased production of ATP for energy, maintenance and repair, ionic imbalance and cell death.
Sources of lead:
Permissible Exposure Limit for lead:
50 Ug per m3 per 8 hours according to OSHA requirements.
What is the critical level for lead in the blood?
10 Ug per dL of lead according to CDC recommendation.
Who are at the greatest risk for lead poisoning?
Children are at the greatest risk for lead poisoning since they represent a highly vulnerable group by virtue of their rapid developing bodily systems. Their immature and fragile bodily systems are often sites of target for heavy metals and toxins that serve to disrupt these systems and cause havoc leading to growth abnormalities, mental retardation, immune deficiency, blood disorders, endocrine disorders, brain and CNS abnormalities, liver and heart dysfunction.
The exploring and inquisitive nature of children makes them particularly vulnerable to environmental toxins. Since most children under the age of six, put almost every thing they come into contact with in their mouths. They are more likely to play in contaminated environments and consume unintentionally lead containing food and water.
In addition, aged, pregnant, and immunocompromised individuals also belong to or can be classified as vulnerable groups and may be adversely affected by lead intoxication often leading to coma, shortening of life expectancy and death.
Some symptoms associated with lead poisoning? Nausea. Vomiting. Hearing loss. Stomach cramps. Constipation. Sleeping problems. Fatigue. Depression. High blood pressure. Moodiness. Headache. Joint or muscle pain. Anemia. Decreased sex drive. Spontaneous abortion. Preterm delivery. Stillbirth. Increased infant mortality. Reproductive problems. Learning disabilities. Behavioral abnormalities. Seizures. Coma. Liver problems. Urinary problems. Kidney problems. Endocrine problems. Brain and CNS problems. Blood and immune system complications.
What can be done to prevent lead poisoning?
Lead is a heavy metal that has become ubiquitous in the environment either through the indiscriminate dumping of car batteries near houses and in water-courses, use of lead paint in toys, drugs, cosmetics or the consumption of tainted foods.
Once lead enters the body and approaches or exceeds 10 Ug/dL of lead in the blood, it then begins to interfere with the molecular machinery of the cell leading to the decreased production of ATP, increased intracellular toxicity, decreased cellular functions and cell death. These changes often manifest itself as symptoms of lead intoxication.
Lead intoxication is a preventable disorder and proactive measures should be aimed at reducing, eliminating or preventing lead from entering the environment, food chain and man.
Current treatment regimes involve the use of chelating agents, garlic and foods such as vitamin C, calcium, zinc, milk and dairy products, meat and seafoods, fruits and vegetables in the right proportions.