3 research outputs found
Occurrence and In Vitro Bioactivity of Estrogen, Androgen, and Glucocorticoid Compounds in a Nationwide Screen of United States Stream Waters
In
vitro bioassays are sensitive, effect-based tools used to quantitatively
screen for chemicals with nuclear receptor activity in environmental
samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid
receptor (GR) activity, along with a broad suite of chemical analytes,
in streamwater from 35 well-characterized sites (3 reference and 32
impacted) across 24 states and Puerto Rico. ER agonism was the most
frequently detected with nearly all sites (34/35) displaying activity
(range, 0.054–116 ng E2Eq L<sup>–1</sup>). There was
a strong linear relationship (<i>r</i><sup>2</sup> = 0.917)
between in vitro ER activity and concentrations of steroidal estrogens
after correcting for the in vitro potency of each compound. AR agonism
was detected in 5/35 samples (range, 1.6–4.8 ng DHTEq L<sup>–1</sup>) but concentrations of androgenic compounds were
largely unable to account for the in vitro activity. Similarly, GR
agonism was detected in 9/35 samples (range, 6.0–43 ng DexEq
L<sup>–1</sup>); however, none of the recognized GR-active
compounds on the target-chemical analyte list were detected. The utility
of in vitro assays in water quality monitoring was evident from both
the quantitative agreement between ER activity and estrogen concentrations,
as well as the detection of AR and GR activity for which there were
limited or no corresponding target-chemical detections to explain
the bioactivity. Incorporation of in vitro bioassays as complements
to chemical analyses in standard water quality monitoring efforts
would allow for more complete assessment of the chemical mixtures
present in many surface waters
Additional file 1 of A collaboratively produced model of service design for children and young people with common mental health problems
Additional file 1. Topic Guides
Tapwater Exposures, Effects Potential, and Residential Risk Management in Northern Plains Nations
In the United States (US), private-supply tapwater (TW)
is rarely
monitored. This data gap undermines individual/community risk-management
decision-making, leading to an increased probability of unrecognized
contaminant exposures in rural and remote locations that rely on private
wells. We assessed point-of-use (POU) TW in three northern plains
Tribal Nations, where ongoing TW arsenic (As) interventions include
expansion of small community water systems and POU adsorptive-media
treatment for Strong Heart Water Study participants. Samples from
34 private-well and 22 public-supply sites were analyzed for 476 organics,
34 inorganics, and 3 in vitro bioactivities. 63 organics and 30 inorganics
were detected. Arsenic, uranium (U), and lead (Pb) were detected in
54%, 43%, and 20% of samples, respectively. Concentrations equivalent
to public-supply maximum contaminant level(s) (MCL) were exceeded
only in untreated private-well samples (As 47%, U 3%). Precautionary
health-based screening levels were exceeded frequently, due to inorganics
in private supplies and chlorine-based disinfection byproducts in
public supplies. The results indicate that simultaneous exposures
to co-occurring TW contaminants are common, warranting consideration
of expanded source, point-of-entry, or POU treatment(s). This study
illustrates the importance of increased monitoring of private-well
TW, employing a broad, environmentally informative analytical scope,
to reduce the risks of unrecognized contaminant exposures