| Popis: |
Municipal biosolids contain natural estrogens, e.g., 17ß-estradiol (E2) and estrone (E1), and synthetic estrogens, e.g., 17a-ethinylestradiol (EE2), which can be transported to receiving waters via runoff when land-applied as fertilizer. Previous studies have investigated estrogens in runoff from biosolids-amended fields but have not tracked changes in estrogenicity within this water over time. Microbial conversion of conjugated estrogens (a major portion of water-extractable estrogens) to parent forms may result in temporary increases in estrogenicity in natural water bodies. The present study measured aqueously extractable estrogens in simulated runoff generated using biosolids sourced from four municipal wastewater treatment facilities in Maryland. Estrogen analytes (E2 and E1) were quantified over 10 d periods in 80 L static simulated runoff mixtures (0.5 g biosolids L-1) by LC-MS/MS, and estrogenic activity was estimated using the bioluminescent yeast estrogen screen (BLYES) assay and the fathead minnow () vitellogenin (VTG) induction model. The effectiveness of pilot-scale in-vessel, aerated, turned (IVAT) composting to reduce or eliminate aqueously extractable estrogens in biosolids was also investigated. On arrival, only one of four biosolids had environmentally meaningful levels of aqueously extractable estrogens. Results indicate that estrogens/estrogenicity increased >6.5-fold during the first 6 d in an aqueous extract generated with that sample, as indicated both by BLYES quantitation of estrogenicity (0.8 to 5.6 ng EEQ L-1) and LC-MS/MS quantitation of estrone (13.8 to 93.0 ng L-1). Results also indicate that IVAT composting was effective at reducing or eliminating aqueously extractible estrogens in that biosolids sample. This study demonstrates the need for low-level detection of estrogens/estrogenicity in complex environmental media and validates the benefits of screening assays and fish models as complementary sensitive tools for environmental monitoring. Keywords: Biosolids, Compost, Estrogenicity, Fathead minnow, Microbial deconjugation, Vitellogenin. |
