Balancing the budget of environmental estrogen exposure: the contribution of recycled water.

Estrogenic endocrine disrupting compounds (e-EDCs) are present in treated sewage and there is concern about estrogenicity of potable recycled water. However e-EDCs are also present in other environmental media and intake from water needs to be considered in relation to these other sources. The concentrations of 13 e-EDCs in foodstuffs and drinking water are reviewed, their predicted concentrations in recycled water are estimated, and the daily estrogenic intake as 17beta-estradiol equivalent (EEq) based on both in vitro and in vivo potencies is calculated as 1.39 and 9.65 microg EEq/d, respectively. Dietary intake accounts for more than 99.8% of that total, and more than 84.2% is due to phytosterols. Drinking 2 L of recycled water per day is expected to add 0.001 to 0.016 microg EEq/d based on in vitro and in vivo potencies, respectively. Exposure to e-EDCs in recycled water is therefore likely to be insignificant compared to current dietary intakes.