Lead exposure patterns and parameters for monitoring lead absorption among workers in Singapore.

A study was carried out among 1414 workers in 14 industries in Singapore to determine the extent of their exposure to lead and their lead absorption. High-level exposure situations found included secondary lead smelting, followed by mixing of lead salt stabilizers and lead storage battery manufacture. Other exposure situations included those relating to lead welding, print shop, wire splicing, leaded paint manufacture, fire-fighting and soldering. Early cases of lead absorption could not be detected by clinical signs alone. Other parameters such as blood lead and delta-aminolaevulinic acid dehydratase had to be used. There was good correlation between a rise in blood lead and a fall in delta-aminolaevulinic acid dehydratase levels.