Vadose zone transport of natural and synthetic estrogen hormones at Penn state's "Living Filter" wastewater irrigation site

The increase in endocrine-disrupting compounds in the environment has generated research focused on the behavior of these compounds in natural soil and water ecosystems. To understand how estrogens behave in the soil environment as a result of 25+ yr of wastewater irrigation, soils from Penn State's "Living Filter" wastewater irrigation site were extracted and analyzed for two natural estrogens (17β-estradiol and estrone) and one synthetic estrogen (17α-ethynylestradiol). Soil estrogen concentrations were compared for two independent variables: type of land cover and sampling time. Soils were sampled from cropped and forested land areas, and soils were sampled 2 d and 3 wk after a single 12-h effluent irrigation event. A nonirrigated control site was sampled to provide natural background data. For 17β-estradiol, the nonirrigated mean concentration was 0.68 ± 0.11 ng cm^-3, and the irrigated values, including samples from both land areas and time frames, ranged from 0.99 ± 0.11 to 1.82 ± 0.69 ng cm^-3. For estrone, the nonirrigated mean concentration was 2.36 ± 0.22 ng cm^-3, and the irrigated values, including samples from both land areas collected and time frames, ranged from 2.18 ± 0.20 to 6.24 ± 3.14 ng cm^-3. The 17α-ethynylestradiol nonirrigated mean concentration was 0.47 ± 0.40 ng cm^-3. The irrigated values, including samples from both land areas and time frames, ranged from 0.25 ± 0.06 to 1.37 ± 0.39 ng cm^-3. This study found that time of sampling, land cover, and irrigation can affect estrogen concentrations in soils, resulting in levels that exceed natural background and require improvements in management practices.