Lead is a very toxic substance that can build up in the body and affect virtually every organ and bodily function. Lead poisoning is usually a chronic disorder and may not present with any acute symptoms. Whether acute symptoms are present or not, lead poisoning eventually leads to permanent and irreversible damage such as cognitive impairment, kidney dysfunction and peripheral neuropathy.
Children under the age of six years are especially susceptible to the harmful effects of lead poisoning, which can damage neurons while the nervous system develops. Acute lead poisoning in children may initially lead to symptoms such as poor concentration span and irritability. Cerebral swelling may then develop causing repeated vomiting, seizures and eventually coma. Chronic lead poisoning can cause learning disability, behavioural disorders, delayed development and anemia.
In adults, lead poisoning may lead to headaches, behavioral changes, abdominal pain and neuropathy. Women may experience a loss of sex drive and are at risk of infertility, while men may suffer from erectile dysfunction and have a low sperm count and abnormal sperm.
Both children and adults are at risk of developing anemia since lead interferes with the formation of hemoglobin.
In cases of suspected lead poisoning, a doctor will ask questions and perform a physical examination and simple blood test. As the symptoms of lead poisoning can be caused by many other illnesses, it can be difficult to diagnose the condition. In the US, screening programs are available to check children’s blood lead level if they are expected to be at risk of lead poisoning. Paints containing lead and dust contaminated with lead from paint chips in older houses (built before 1978, when leaded paints were banned) are the most common causes of lead poisoning in children. Contaminated air, soil and water are other sources. Therefore, whether or not a child requires screening partly depends on where the child lives and how old their home is, along with other risk factors.
Occupational exposure to lead can occur in battery manufacture, pottery production, bronzing, glass making, pipe cutting, smelting, soldering and roofing. When adults are working in environments where they may be exposed to lead, companies are usually expected to provide testing for lead poisoning.
The first step for treating any degree of lead poisoning is to eliminate the source from the environment. If this is not possible, it may be possible to reduce the likelihood that the source will cause any future problems. For example, it may sometimes be preferred to seal in lead paint rather than remove it. Local health departments can provide advice on how to reduce lead in the home.
For people with relatively low levels of lead, avoiding further exposure may be sufficient to bring the blood lead level down. For people with higher levels, treatment may be recommended. Chelation therapy may be advised, which involves taking a medication that binds with lead and is then removed from the body through urinary excretion. Children may receive chelation therapy at lower blood lead levels than adults do.
If a patient’s blood lead level is higher than 45 μg/dL, one or more of three drugs may be prescribed, but usually the drug used is ethylenediaminetetraacetic acid (EDTA).
Reviewed by Catherine Shaffer, M.Sc.