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Lead occurs naturally in the environment at very low levels. Relatively high level sources of lead occur in older paint (modern paint does not contain lead), and pre-1980 car exhaust (the lead from exhaust is ultimately deposited on the ground in dust which children play in). Other sources exist such as pewter pitchers and dinnerware, birdshot, and fishing weights.
In the past, toothpaste tubes were made of lead and condensed milk cans were soldered with lead. This has been corrected. Lead can also be found in drinking water from homes whose copper pipes were soldered with lead solder. New building codes require lead free solder.
Infants and children most at risk are those living in pre-sixties housing where paint often contained led. These children, when small, often ingest paint chips or dust from lead based paint. Soil in cities with high traffic density may contain high levels of lead from car exhaust.
There are few clear cut symptoms of lead poisoning. Very high levels may lead to an acute encephalopathy. Low levels of lead are thought to be detrimental to mental development and have been implicated in decreased IQ and mental functioning. Hard evidence for this, however, is still questionable. Anemia with lead poisoning is common.
Specific symptoms are nebulous but hyperirritability, aggressive behavior, decreased appetite and energy, poor sleeping, headaches, constipation, and loss of recently acquired developmental skills. Abdominal cramping may be present.
In severe intoxication lead encephalopathy develops with vomiting, staggering gait, motor weakness from peripheral neuropathy, seizures, and coma.
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