Persistence and fate of 17beta-estradiol and testosterone in agricultural soils.
Steroidal hormones are constantly released into the environment by man-made and natural sources. The goal of this study was to examine the persistence and fate of 17beta-estradiol and testosterone, the two primary natural sex hormones. Incubation experiments were conducted under aerobic and anaerobic conditions using [4-(14)C]-radiolabeled 17beta-estradiol and testosterone. The results indicated that 6% of 17beta-estradiol and 63% of testosterone could be mineralized to (14)CO(2) in native soils under aerobic conditions. In native soils under anaerobic conditions, 2% of testosterone and no 17beta-estradiol was methanogenized to (14)CH(4). Essentially, no mineralization of either testosterone or 17beta-estradiol to (14)CO(2) occurred in autoclaved soils under aerobic or anaerobic condition. Results also indicated that 17beta-estradiol could be transformed to an unidentified polar compound through abiotic chemical processes; however, 17beta-estradiol was only oxidized to estrone via biological processes. The TLC results also indicated that testosterone was degraded, not by physical-chemical processes but by biological processes. Results also indicated that the assumed risks of estrogenic hormones in the environment might be over-estimated due to the soil's humic substances, which can immobilize majority of estrogenic hormones, and thereby reduce their bioavailability and toxicity.
Fan
Zhaosheng
Z
Department of Soil Science, North Dakota State University, Fargo, ND 58105, USA.
Casey
Francis X M
FX
Hakk
Heldur
H
Larsen
Gerald L
GL
D000332:Aerobiosis; D000383:Agriculture; D000693:Anaerobiosis; D001578:Benzopyrans / Q000032:analysis; D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D006812:Humic Substances / Q000032:analysis; D008697:Methane / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
D001578:Benzopyrans; D006812:Humic Substances; D012989:Soil Pollutants; C001861:humin; D002245:Carbon Dioxide; D013739:Testosterone; D004958:Estradiol; D008697:Methane; C005023:fulvic acid