Lead poisoning

Lead poisoning was one of the earliest occupational diseases to be recorded - the Greek physician Hippocrates (c.370 BC) described a case in a man mining the metal. Even today, there have been cases of entire families, including pets, being poisoned during the removal of lead-based paint from their homes.

Lead is absorbed into the body through the lungs or the mouth and is a cumulative poison, being stored in the bone tissue. Early symptoms of lead poisoning are tiredness, headache, aching bones and muscles, forgetfulness, loss of appetite and sleep disturbance. One tell-tale sign is a blue line on the gums. This is followed by constipation and attacks of intense pain in the abdomen, called lead colic.

As more lead is absorbed into the body, paralysis sets in. This affects the radial nerve in particular, causing 'wrist drop'. In the final stages, the victim suffers convulsions, coma, delirium and possibly death.

Children are more susceptible to lead poisoning than adults and may suffer permanent neurological damage. Lead can damage the human foetus, so pregant women should not work with lead.

Full-blown cases of lead poisoning are rare today, because of better hygiene practices in industry. However, people working in occupations such as radiator repair, battery manufacture, lead soldering, engine reconditioning, and non-ferrous smelting and casting need to be under medical surveillance and have blood lead level tests to monitor the amount of lead in their bodies.

A house painter affected by chronic lead poisoning. Wasted muscles and wrist drop are tell-tale symptoms of lead poisoning.

Animals can be affected by lead poisoning, particularly when lead-based paint is stripped from older houses. This photo shows lead palsy affecting the right forepaw of a cat.

Radiator repair is an industry where workers may be exposed to lead fumes. Ventilation is designed to draw the fumes away from the worker.