Lead pollution was evaluated in 216 individuals working in 10 garages on the Island of Funen, Denmark and related to data from biochemical and medical examinations. Clinical symptoms were recorded by means of a questionnaire. Increased blood test lead levels were foun in 59% with 9% having above 80 microgram lead/100 ml (3-86mumol/1) whole blood. Mechanics in eight out of ten garages had significantly increased blood lead levels. A decrease in delta-aminolevulinic acid dehydratase (ALAD) activity was associated with increased blood lead levels but the latter were not related to haematological changes, tobacco consumption or to length of service in the trade. Particulate lead air pollution was not the sole cause of increased blood lead levels. Raised lead values were maximal among diesel engine workers who are exposed to high pressure-resistant lubricants containing lead naphthenate. As these workers complained of skin damage, lead absorption may have occurred through the skin. Assay of lead content showed 9290 ppm in gear oil and 1500-3500 ppm in used motor oils. The data are discussed in relation to the occupational risks in auto repair shops.