Endocrine disrupting compounds in streams in Israel and the Palestinian West Bank: Implications for transboundary basin management.

Endocrine disrupting compounds (EDCs) frequently enter surface waters via discharges from wastewater treatment plants (WWTPs), as well as from industrial and agricultural activities, creating environmental and health concerns. In this study, selected EDCs were measured in water and sediments along two transboundary streams flowing from the Palestinian Authority (PA) into Israel (the Zomar-Alexander and Hebron-Beer Sheva Streams). We assessed how the complicated conflict situation between Israel and the PA and the absence of a coordinated strategy and joint stream management commission influence effective EDC control. Both streams receive raw Palestinian wastewater in their headwaters, which flows through rural areas and is treated via sediment settling facilities after crossing the 1949 Armistice Agreement Line. Four sampling campaigns were conducted over two years, with concentrations of selected EDCs measured in both the water and the sediments. Results show asymmetrical pollution profiles due to socio-economic differences and contrasting treatment capacities. No in-stream attenuation was observed along the stream and in the sediments within the Palestinian region. After sediment settling in treatment facilities at the Israeli border, however, significant reductions in the EDC concentrations were measured both in the sediments and in the water. Differences in sedimentation technologies had a substantial effect on EDC removal at the treatment location, positively affecting the streams' ability to further remove EDCs downstream. The prevailing approach to addressing the Israeli-Palestinian transboundary wastewater contamination reveals a narrow perspective among water managers who on occasion only take local interests into consideration, with interventions focused solely on improving stream water quality in isolated segments. Application of the "proximity principle" through the establishment of WWTPs at contamination sources constitutes a preferable strategy for reducing contamination by EDCs and other pollutants to ensure minimization of public health risks due to the pollution of streams and underlying potable groundwater.

A simple model for estimating the concentrations of natural estrogens in raw wastewater.

This study provides a tool for predicting the concentrations of the natural estrogens (NEs) estrone, 17ß-estradiol and estriol in raw wastewater (WW). Data characterizing the biochemical oxygen demand (BOD), NE concentrations, and discharges of raw sewage to wastewater treatment plants (WWTPs) were collected from various publications and used in the model formulation. A strong correlation was found between the log transformed BOD and the log transformed estrone load (r2=0.84, n=61), the log transformed 17ß-estradiol load (r2=0.89, n=52) and the log transformed estriol load (r2=0.80, n=40). The models are reasonably accurate when compared to the measured concentrations and slightly better than previous modeling efforts. The relative amounts of data falling within ±50% error were 67% for estrone, 63% for 17ß-estradiol, and 55% for estriol. Because the model was developed from a wide array of WWTPs from five continents, it is universal and can be used for projecting concentrations of NEs from a wide range of mixed domestic and industrial sources, but may be less precise when sources contain high levels of NEs or BOD (e.g., WW from dairy farms and food processing plants). The model is expected to improve our ability to predict the fate of NEs in WWTPs and in the receiving environment, which currently relies on estimating the concentrations of NEs in raw wastewater. Its application is especially valuable since direct measurement of NEs in raw WW is expensive and practically impossible in many developing countries due to the lack of expertise and funds.

Occurrence and fate of endocrine disrupting compounds in wastewater treatment plants in Israel and the Palestinian West Bank.

Israel and its Palestinian neighbors constitute a unique venue for evaluating the treatment efficiency and potential environmental risks of endocrine disrupting compounds (EDCs) in wastewater treatment plants (WWTPs), because of their physical proximity yet contrasting societal dynamics. Israel primarily relies on advanced tertiary sewage treatment and recycles over 85% of its treated wastewater, while in the Palestinian Authority (PA), there is only secondary treatment levels at WWTPs and reuse is minimal (<1%). To evaluate the extent of EDC occurrence and treatment efficiency, we conducted four sampling campaigns over two consecutive years, and measured the concentrations of selected EDCs in raw wastewater (WW), treated WW and sludge in six WWTPs in Israel, as well as in two Palestinian plants. Low concentrations of bisphenol A, octylphenol and triclosan measured in the raw WW in the Palestinian WWTPs reflected the relatively modest industrial activity and consumption habits as compared to the westernized consumer patterns in Israel. On the other hand, hormone concentrations in raw WW were higher in the Palestinian WWTPs than those in the Israeli WWTPs, presumably because of a dilution effect associated with a higher water per capita consumption among Israelis. Despite these differences in raw WW concentrations, the removal efficiency in all advanced WWTPs was relatively high when compared to averages reported internationally.