Decay of endocrine-disrupting chemicals in aerobic and anoxic groundwater.

Biodegradation and adsorption of selected endocrine-disrupting chemicals (EDCs), namely oestrogens (E2 and EE2) and phenolic compounds (BPA, 4-t-OP and 4-n-NP), in aquifer materials was investigated in the laboratory in order to understand the behaviour and fate of these chemicals associated with reclaimed water during managed aquifer recharge. Biodegradation experiments were conducted in microcosms with aquifer material and groundwater mixture, or with aquifer material and effluent mixture in the presence of glucose under both aerobic and anoxic conditions. All five selected compounds were degraded by microorganisms in both types of aquifer material-water mixtures under aerobic and anoxic conditions. Under aerobic conditions, EE2 was found to degrade faster in the aquifer material supplemented with effluent with a half-life of 15 days compared with that of 26 days in the aquifer material and groundwater microcosm. No significant difference between the two aquifer material-water mixtures was found for the other four compounds with half-lives ranging between 0.2 and 4.1 days. Under anoxic conditions, however, little biodegradation was observed for the selected EDCs except for E2, which degraded in the aquifer material in the presence of both water types.

Smell perception during early pregnancy: no evidence of an adaptive mechanism.

OBJECTIVE: It has been suggested that nausea and vomiting in pregnancy is an evolutionary adaptive mechanism to avoid the ingestion of potentially harmful foods. It has also been suggested that the mechanism that triggers nausea and vomiting in pregnancy may be olfaction and that olfactory senses are invoked to provide this protection. This study aimed to test this theory in a systematic design. DESIGN: Cross sectional study. SETTING: The antenatal department of a maternity hospital in the north of England. SAMPLE: Three groups of participants: pregnant women (n= 55), non-pregnant women (n= 42) and men (n= 48). METHODS: Sensitivity was tested towards the odours of six standard stimuli (half safe and half associated with potentially harmful compounds). MAIN OUTCOME MEASURES: Odour rating of likeness, strength and pleasantness. RESULTS: Pregnant women rated safe and odours with potentially harmful compounds differently but not more so than men or non-pregnant women. There was no evidence that pregnancy changed the olfactory processes from the non-pregnant state and only slight differences between pregnant women and men were recorded. CONCLUSIONS: There was no evidence that olfactory processes had undergone any adaptation during pregnancy. The ability to differentiate safe from potentially harmful compounds was common to all three groups studied.