Dietary exposure to xenoestrogens in New Zealand

Abstract

Continuing evidence of the feminising effects of xenoestrogens on a range of wildlife species increases the need to assess the human health risk of these estrogen mimics. We have estimated the exposure of New Zealand males, females and young men to a range of naturally occurring and synthetic xenoestrogens found in food. Only estrogenic compounds that act by interaction with the estrogen receptor have been included. Theoretical plasma estrogen activity levels were derived from estrogen exposure estimates and estrogenic potency data. Theoretical plasma levels were compared with published data for specific xenoestrogens. There was surprisingly close agreement. Xenoestrogenicity from dietary intake was almost equally attributed to naturally occurring and synthetic xenoestrogens. Relative contributions for a male, for example were isoflavones (genistein and daidzein) (36%) and bisphenol A (34%) with smaller contributions from alkyl phenols (18%) and the flavonoids (phloretin and kaempferol) (12%). It is suggested that dietary xenoestrogens might have a pharmacological effect on New Zealand males and postmenopausal women, but are unlikely to be significant for pre-menopausal women.

The E-screen test and the MELN gene-reporter assay used for determination of estrogenic activity in fruits and vegetables in relation to pesticide residues

“…Applying the factor used by Thomson (Thomson et al, 2003), the EEQ plasma levels obtained would result in an estimate of 0.7-0.9 ng EEQ/L, a level that is not likely to be of health significance for the population, confirming the results of our previous study . However, it is also feasible that total daily intake of EDCs might exceed our estimate due to possible contributions from as-yetundetermined EDCs in foods and beverages (Guenter et al, 2002;Muncke et al, 2009;Stanford et al, 2010;Wagner et al, 2011) and from other environmental sources (Takamura-Enya et al, 2003).…”

“…To obtain rough estimates of the dietary intake of EEQs Thomson et al, 2003), the following assumptions were made: the total absorption of dietary EEQs is given by the values calculated in this study (0.070 ± 0.016 µg/100 g and 0.090 ± 0.017 µg/100 g by the E-screen test and MELN gene-reporter assay, respectively); the mean intake of fruits and vegetables in the European population is 335 g/day (Boffetta et al, 2010); a human blood volume of 5 L; the EEQ half-life was not considered; and the body can be represented by a single-compartment pharmacokinetic model (although this assumption is clearly not correct).…”

Bisphenol A in canned foods in New Zealand: An exposure assessment

“…In a previous assessment evaluating dietary exposure to a range of oestrogenic compounds that may be found in food, Thomson et al (2003) estimated that BPA accounted for about 35% of all oestrogenicity from food. This former assessment was based on very limited overseas concentration data for BPA and an estimated exposure of 4 mg day…”

Probabilistic assessment of aggregate risk for bisphenol A by integrating the currently available environmental data

“…The difference in the mean daily BPA exposure at 1.03 lg/kg-day and 3.4 lg/ kg-day could be attributed to exposures from beverages and canned and packaged foods. The estimated BPA exposures from canned foods were reported ranging from (Thomson et al 2003;Lim et al 2009;USFDA 2009;AFSSA 2010). Compared with exposures from various routes, BPA intakes from canned food could be very significant, but was not considered in this study since the objective of this study was to assess the aggregate health risk caused by BPA exposures through environmental media.…”