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Published in Fall 2001
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Lead and children’s health
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Although the sources of potential lead toxicity in the western world have been significantly reduced in the last two decades, lead continues to be an important environmental health hazard to children, writes Irena Buka. Children are particularly susceptible to chronic low-dose exposure that may cause irreversible damage to their neurological development.
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By Irena Buka
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| Playgrounds in lead-polluted environments are hazards, not sanctuaries. |
Read related article: Mexico holds first national Workshop on Children's Health and the Environment
The effects of lead on children have been recognized medically for at least 100 years. Initially, only acute lead toxicity—causing headaches, abdominal pain and constipation, and eventually leading to vomiting and convulsions, unconsciousness and possibly death —was described. As late as the 1940s, it was believed that if children survived acute lead toxicity there would be no residual effects. However, as epidemiological and toxicological data grew it was realized that children who recovered from acute toxicity showed a high incidence of behavioral and learning disorders. Later studies in the 1970s and 1980s demonstrated that children with elevated levels of lead, but not to the extent of causing acute toxicity, had lower IQ scores, more language and speech difficulties, attention problems and behavioral problems.
Children, from the very beginning of fetal life, are more vulnerable than adults to lead exposure because of their rapid growth and development. They also have a higher metabolic rate and, per kilogram of body weight, take in more water and higher quantities of a smaller variety of foods. Small children are particularly vulnerable if their diet is low in calcium, protein, iron and vitamin C, because lead is absorbed into their body more rapidly in these conditions.
Lead binds to enzymes and alters the structure and function of many proteins, interfering with the action and purpose of many different types of cells in the body. These changes can cause permanent damage in the growing and developing organs, especially in the neurological system of children. The effects are very difficult to reverse.
Lead is taken into the body not only by ingestion but also by inhalation. Normal childhood behavior—crawling on the ground, playing in the dirt, putting their fingers in their mouths and eating dirt—exposes children to the danger of ingesting and inhaling lead, putting them in jeopardy where there are significant levels of lead dust. Children who live near a lead smelter or a plant making vehicle batteries may be at significant risk of lead toxicity.
The continuing threat posed by lead to the health and wellbeing of North American children was recognized by the CEC Council in the adoption of
Resolution 00-10, which identifies lead as one of the priorities for action.
In the western world significant measures have been undertaken in the last two decades to protect children from lead. Paint sold for indoor use and paint used on household furniture and children’s toys is now lead-free, and the removal of lead from gasoline has made a major impact on blood lead levels in children living in countries where only unleaded gasoline is available. But there are still many hazards.
Leaded paint is still used on the exterior surfaces of buildings (it makes the paint cling to surfaces better). As the paint wears away, cracks and chips, it falls into the soil around buildings. Children playing in such areas are particularly susceptible to lead toxicity.
Older homes contain furniture or fittings coated with leaded paint. They may also have water pipes, pipe soldering and fixtures containing lead. Lead may leach into water that stagnates in the pipes, particularly if it is warm and acidic. Lead solder may still be found in cans of food imported from other parts of the world. Lead-glazed ceramic ware and pottery and leaded crystal can contaminate food and drink. Certain folk remedies may contain lead—for example, Greta and Azarcon, used by Hispanic and Asian communities to treat stomach upset, and the red powder Pay Loo Ah, used to treat rash or fever. From time to time, miscellaneous goods such as imported costume jewelry and wax crayons have also been found to contain lead.
Children must rely on their adult caregivers to keep them in a safe environment to play, grow and develop. Measures such as washing the child’s hands before eating are important. Nutritional counseling is also extremely important in reducing the amount of lead that is absorbed into a small child’s body. Protecting children from environmental lead exposure rests not only in environmental control measures, but also in educating parents about sources of potential lead toxicity and how to avoid them.
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