Environmental factors affecting antipyrine metabolism in London factory and office workers.

1 Measurements of antipyrine clearance in saliva have been made in 128 London factory and office workers. 2 Mean antipyrine clearance in 56 Asian immigrants was 40% slower than in 72 White subjects. 3 Although dietary differences existed between the two groups, analysis of their effect independently of race was impossible since all but one of the vegetarians were Asian and the non-vegetarians were nearly all White. 4 In the White subjects, use of the oral contraceptive reduced clearance by 38% in women, while cigarette smoking increase clearance by 38% in men.