Estimated daily intake and hazard quotients and indices of phthtalate diesters for young danish men

Because of wide exposure to phthalates, we investigated whether simultaneous exposure to several phthalates reached levels that might cause adverse antiandrogenic effects. Thirty three healthy young Danish men each delivered three 24-h urine samples during a three months period. The daily intakes of the sum of di-n-butyl and di-iso-butyl phthalate, di(2-ethylhexyl) phthalate, di-iso-nonyl phthalate, and butylbenzyl phthalate were estimated based on urinary excretion of the metabolites. Based on a hazard quotient (HQ) of the individual phthalate (i.e., the ratio between the daily intake and an acceptable level of exposure), a hazard index (HI) for each man was calculated as the sum of HQs for the individual phthalates. All men were exposed to all phthalates during the urine collection periods. Median HIs were all below 1 (i.e., below an acceptable cumulative threshold) ranging from 0.11 to 0.17 over the three different sample collections. Of the 33 men, 2 men had HIs above 1 in one of their three samples, indicating that occasionally the combined exposure to the investigated phthalates reached a level that may not be considered safe. Besides the phthalates investigated here, humans are exposed to numerous other chemicals that also may contribute to a cumulative antiandrogenic exposure.