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Exposure assessment of 17α‐ethinylestradiol in surface waters of the United States and Europe
Author(s) -
Hannah Robert,
D'Aco Vincent J.,
Anderson Paul D.,
Buzby Mary E.,
Caldwell Daniel J.,
Cunningham Virginia L.,
Ericson Jon F.,
Johnson Andrew C.,
Parke Neil J.,
Samuelian John H.,
Sumpter John P.
Publication year - 2009
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/08-622.1
Subject(s) - percentile , environmental science , ethinylestradiol , surface water , environmental chemistry , reference values , chemistry , statistics , mathematics , demography , environmental engineering , population , sociology , research methodology , medicine
An evaluation of measured and predicted concentrations of 17α‐ethinylestradiol in surface waters of the United States and Europe was conducted to develop expected long‐term exposure concentrations for this compound. Measured environmental concentrations (MECs) in surface waters were identified from the literature. Predicted environmental concentrations (PECs) were generated for European and U.S. watersheds using the GREAT‐ER and P h ATE™ models, respectively. The majority of MECs are nondetect and generally consistent with model PECs and conservative mass balance calculations. However, the highest MECs are not consistent with concentrations derived from conservative (worst‐case) mass balance estimates or model PECs. A review of analytical methods suggests that tandem or high‐resolution mass spectrometry methods with extract cleanup result in lower detection limits and lower reported concentrations consistent with model predictions and bounding estimates. Based on model results using P h ATE and GREAT‐ER, the 90th‐percentile low‐flow PECs in surface water are approximately 0.2 and 0.3 ng/L for the United States and Europe, respectively. These levels represent conservative estimates of long‐term exposure that can be used for risk assessment purposes. Our analysis also indicates that average concentrations are one to two orders of magnitude lower than these 90th‐percentile estimates. Higher reported concentrations (e.g., greater than the 99th‐percentile PEC of ∼1 ng/L) could result from methodological problems or unusual environmental circumstances; however, such concentrations are not representative of levels generally found in the environment, warrant special scrutiny, and are not appropriate for use in risk assessments of long‐term exposures.