EVALUATION OF THE THYROID DISRUPTING EFFECTS OF WATER FORM GUANTINGRESERVOIR, BEIJING

摘要

An improved yeast bioassay for rapid evaluation of thyroid hormone disruption at the level of thyroid receptor (TR) in water samples is used to evaluate the thyroid disrupting effects of water from Guanting Reservoir, Beijing. Antagonism was detected in all water samples and is expressed as AH equivalents (21.0±1.0-2147.2±48.1 μg/L). A solid phase extraction by C18 cartridges was used to separate the organic extracts, which eliminated more than 69.6% antagonistic activities, suggesting the organic pollutants may play a major role in the TR disruption activity of the water. After addition of ethylene diamine tetraacetic acid (EDTA, 30mg/L) to the residual water samples, the antagonistic activities decreased significantly, showing the metals might contribute to the TR antagonistic activity. The present study shows that the modified yeast bioassay can be used as a valuable tool for quantification of thyroid hormone disrupting effects in environmental water samples, moreover organic pollutants and heavy metals may contribute to the antagonistic TR activities in the water samples from Guanting Reservoir.