Dietary intake of lead among Japanese farmers.

More than 1,000 24-h duplicates of food consumed were collected from farmers in 49 nonpolluted regions in Japan during the winter and summer seasons of 1977-1981. The samples were analyzed for lead to assess dietary intake. The dietary intake distributed log-normally in both winter and summer. The geometric mean (GM) (geometric standard deviation [GSD]) for winter samples was 38.2 micrograms/d (1.94) for males (N = 381) and 32.8 micrograms/d (1.91) for females (N = 711). A seasonal variation was detected in females but not in males. The findings on regional differences in dietary intake were inconclusive. The levels observed were lower than most values reported in the literature. The low dietary intake levels were in agreement with the low blood lead levels found among the subjects, which may reflect of Japan's decision in 1975 to withdraw alkyl lead from automobile gasoline. No significant correlation could be established between dietary intake and blood lead levels when GMs for the study regions were compared, or when dietary intake and blood lead levels were compared in 555 nonsmoking and nondrinking females who were between 30 and 59 y of age. It is estimated that 2-4 micrograms of lead is absorbed daily from the diet (i.e., food and water), and 0.1-1 micrograms is absorbed via respiration, and that cigarette smoking and alcohol consumption may increase lead absorption.