4 research outputs found
Transcriptome signatures of wastewater effluent exposure in larval zebrafish vary with seasonal mixture composition in an effluent-dominated stream
Wastewater treatment plant (WWTP) effluent-dominated streams provide critical habitat for aquatic and terrestrial organisms but also continually expose them to complex mixtures of pharmaceuticals that can potentially impair growth, behavior, and reproduction. Currently, few biomarkers are available that relate to pharmaceutical-specific mechanisms of action. In the experiment reported in this paper, zebrafish (Danio rerio) embryos at two developmental stages were exposed to water samples from three sampling sites (0.1 km upstream of the outfall, at the effluent outfall, and 0.1 km below the outfall) during base-flow conditions from two months (January and May) of a temperate-region effluent-dominated stream containing a complex mixture of pharmaceuticals and other contaminants of emerging concern. RNA-sequencing identified potential biological impacts and biomarkers of WWTP effluent exposure that extend past traditional markers of endocrine disruption. Transcriptomics revealed changes to a wide range of biological functions and pathways including cardiac, neurological, visual, metabolic, and signaling pathways. These transcriptomic changes varied by developmental stage and displayed sensitivity to variable chemical composition and concentration of effluent, thus indicating a need for stage-specific biomarkers. Some transcripts are known to be associated with genes related to pharmaceuticals that were present in the collected samples. Although traditional biomarkers of endocrine disruption were not enriched in either month, a high estrogenicity signal was detected upstream in May and implicates the presence of unidentified chemical inputs not captured by the targeted chemical analysis. This work reveals associations between bioeffects of exposure, stage of development, and the composition of chemical mixtures in effluent-dominated surface water. The work underscores the importance of measuring effects beyond the endocrine system when assessing the impact of bioactive chemicals in WWTP effluent and identifies a need for non-targeted chemical analysis when bioeffects are not explained by the targeted analysis
Health Indicators of a Cohort of Midwest Farmers: Health Outcomes of Participants in the Certified Safe Farm Program
Occurrence and Spatiotemporal Dynamics of Pharmaceuticals in a Temperate-Region Wastewater Effluent-Dominated Stream: Variable Inputs and Differential Attenuation Yield Evolving Complex Exposure Mixtures
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