EVALUATION OF THE ESTROGENIC POTENCY OF NONYLPHENOL IN NON-OCCUPATIONALLY EXPOSED HUMANS

In this study, the estrogenic potency of 4-nonylphenol (NP) was estima ted: and a risk calculation for non-occupationally exposed humans was performed. The daily intake of non-occupationally exposed persons was estimated to be less than 0.16 mg/day. Risk estimates were based on th is daily intake and the relative potency of NP to 17 beta-estradiol. C omparison of this intake with the NOAEL derived from a 90-day subchron ic toxicity study in animals, results in a safety factor of about 2000 0. A safety margin of 3000 can be derived when comparing the resulting NP blood concentrations (calculated upon pharmacokinetic studies) wit h 17 beta-estradiol levels in the blood of adult males. Risk estimatio ns based on the daily intake of NP and the resulting organ concentrati ons (calculated upon the lipid content) compared with minimal estrogen ic cell effect concentrations result in a safety factor in the range o f 5000. In addition, the comparison of NP with genistein in human bloo d indicate a minor importance of nonylphenol. The results of this stud y show that the non-occupational exposure to NP does not pose an estro genic health risk to humans. (C) 1998 Elsevier Science B.V. All rights reserved.