Lead

Lead and its compounds have been used in countless ways for thousands of years, despite the equally long history of knowledge about the dangers of lead. Exposure to lead-containing goods and the environmental contamination from their manufacture and [Page 590]use produces considerable mortality and morbidity among workers, children, and the general public. Lead's toxicity appears to have no threshold for harm: Blood-lead levels (BLLs) < 10µg/dl (well below those associated with clinical symptoms of lead poisoning) are associated with neurological deficits in children, while slightly elevated BLLs are implicated in increased rates of hypertension and kidney disease in adults. At higher BLLs, clinical signs of lead poisoning appear, including chronic or acute gastrointestinal symptoms and neurological conditions ranging from palsies to paralysis and encephalopathy.