Exposure to environmentally relevant concentrations of Bisphenol-A linked to loss of visual lateralization in adult zebrafish (Danio rerio).

Weak, but environmentally relevant concentrations of contaminants can have subtle, yet important, impacts on organisms, which are often overlooked due to the lack of acute impacts and the timing of exposure. Thus, recognizing simple, non-invasive markers of contamination events is essential for early detection and addressing the effects of exposure to weak environmental contaminants. Here, we tested whether exposure to an environmentally relevant concentration of Bisphenol-A (BPA), a common and persistent contaminant in aquatic systems, affects the lateralization of adult zebrafish (Danio rerio), a widely used model organism in ecotoxicology. We found that 73.5% of adult zebrafish displayed a left-side bias when they approached a visual cue, but that those exposed to weak BPA (0.02 mg/L) for 7 days did not exhibit laterality. Only 47.1% displayed a left-side bias. We found no differences in activity level and visual sensitivity, motor and sensory mechanisms, that regulate lateralized responses and that were unaffected by weak BPA exposure. These findings indicate the reliability of laterality as a simple measure of contaminant exposure and for future studies of the detailed mechanisms underlying subtle and complex behavioral effects to pollutants.

Determining the connectivity of tribal communities to wastewater treatment facilities for use in environmental contamination and exposure assessments by wastewater-based surveillance.

BACKGROUND: Limited information is available on the connectivity of Tribal communities to wastewater treatment facilities (WWTFs). This is important for understanding current sanitation infrastructure which drives public health and community construction, knowledge of potential routes of exposure through lack of infrastructure and/or discharging facilities, and opportunities to assess community health through wastewater-based surveillance (WBS). OBJECTIVES: The objective of this work was to assess current wastewater infrastructure for 574 Federally Recognized Indian Tribes (FRITs) in the United States (US) to determine the number and location of facilities on or adjacent to Tribal reservations and Off-Reservation Trust Lands, with the goal of determining the feasibility of employing wastewater-based surveillance within these communities and to identify areas with inadequate sanitation infrastructure. METHODS: Here, we identified available National Pollutant Discharge Elimination System (NPDES) wastewater discharge permits in the Environmental Protection Agency's Environmental Compliance History Online database to assess proximity to and within spatial boundaries of Tribal lands. These data were coupled to race data and tribal spatial boundary information from the US Census Bureau. RESULTS: 94 FRITs have registered NPDES permits within Tribal boundaries including a total of 522 facilities. 210 of these are American Indian (AI)-serving (>50% AI) with the ability to reach 135,000 AI-people through the wastewater network to provide community health assessments via WBS. Of the remaining facilities, 153 predominantly serve non-Tribal populations raising concerns about infrastructure placement and indigenous sovereignty. 523 FRITs were identified as without permitted discharging WWTFs, which may suggest inadequate or alternative infrastructure. IMPACT STATEMENT: Here, multiple data sources including permit information from the Environmental Protection Agency's National Pollution Discharge Elimination System and US Census Bureau data were used to determine the number of wastewater treatment facilities on or adjacent to Tribal lands and how many community members were connected to those municipal systems. This information was used to assess which Tribal communities may be a viable option for wastewater public health surveillance techniques and were used to answer supplemental questions related to basic sanitation and environmental justice concerns.

Nationwide geospatial analysis of county racial and ethnic composition and public drinking water arsenic and uranium.

There is no safe level of exposure to inorganic arsenic or uranium, yet recent studies identified sociodemographic and regional inequalities in concentrations of these frequently detected contaminants in public water systems across the US. We analyze the county-level association between racial/ethnic composition and public water arsenic and uranium concentrations from 2000-2011 using geospatial models. We find that higher proportions of Hispanic/Latino and American Indian/Alaskan Native residents are associated with significantly higher arsenic and uranium concentrations. These associations differ in magnitude and direction across regions; higher proportions of non-Hispanic Black residents are associated with higher arsenic and uranium in regions where concentrations of these contaminants are high. The findings from this nationwide geospatial analysis identifying racial/ethnic inequalities in arsenic and uranium concentrations in public drinking water across the US can advance environmental justice initiatives by informing regulatory action and financial and technical support to protect communities of color.

Implementing wastewater monitoring on American Indian reservations to assess community health indicators.

Healthcare access and health-related information for American Indian/Alaska Native (AIAN) communities is often limited. A potential solution to acquire additional population level health data is through wastewater-derived measurements, a method termed wastewater-based epidemiology (WBE), however, due to often remote locations with rudimentary wastewater infrastructure, the feasibility of implementing WBE on an AIAN reservation is unclear. In this study, we i) performed a preliminary assessment of percent connectivity of the top 10 most populous tribal reservations using available wastewater treatment facility information from the Environmental Protection Agency Enforcement and Compliance History Online database and satellite imagery, and ii) performed a sampling campaign on a select tribal reservation to measure common WBE indicators of health and behavior. Results indicate that, on average, approximately 81 ± 23% of tribal residents are connected to some form of aggregated wastewater collection system. On the sampled reservation, 6 communities comprising 7500 people were sampled across 160 km of reservation land using active samplers successfully deployed within the sewer network upstream of terminal lagoon systems. Results showed detectable levels of 7 opioids, 1 opioid maintenance medication, 5 stimulants, 1 hallucinogen, and chemical indicators of alcohol, nicotine, caffeine, and an over-the-counter cough suppressant. These results illustrated the feasibility in implementing WBE in rural and remote communities where information on community health may be lacking.

Co-occurring Environmental Stressors have Emerging Impacts on Sensory-Motor Behavior.

Anthropogenic activities often lead to alterations in the natural environment via multiple routes. Simultaneous occurrence of interacting environmental perturbations may influence animals via more complex pathways than when being exposed to environmental stressors discretely. In our study, we investigated the interactive effects of poor visual environment and exposure to an environmentally realistic concentration of a common contaminant on the behavior of larval zebrafish, Danio rerio. Specifically, we tested the sensory-motor behavior of zebrafish larvae by exposing them to low-light conditions and a low concentration of bisphenol-A (BPA) for 7 days postfertilization. We found that zebrafish exposed to both BPA and low-light conditions had significantly weaker response to a moving-visual cue. However, those exposed to only one of these treatments did not have altered response to visual cues. Since the response to a moving, visual cue involves locomotion, we also examined the distance they traveled as a proxy for activity level of individuals across treatments. However, the distance traveled by individuals did not significantly differ across treatments, suggesting that the differences in response are linked to visual sensory pathways. Here, we emphasize that the adverse effects of environmental stressors, particularly of those that occur at environmentally relevant concentrations, may emerge only when they co-occur with another environmental stressor. These findings highlight the need to incorporate multiple environmental stressors to comprehensively assess impacts that human activities have on behavioral strategies of animals.

Engineered proteoliposome transporter for treatment of cesium contaminated water.

Radioactive cesium (137Cs) released from nuclear power plants and nuclear accidents continues to be a worldwide concern, and its removal from water remains a difficult problem. Here, we present the development of an innovative method to remove Cs+ present at low concentrations in water. To achieve this, a proteoliposome transporter was engineered, composed of a membrane-bound potassium uptake protein, Kup from E. coli, which was reconstituted into a liposome vesicle. Cs+ removal (10-100 µg/L) was demonstrated by incubating the constructed proteoliposome in lab-fortified water, followed by ultracentrifugation to remove captured Cs+. Inductively coupled plasma mass spectrometry (ICP-MS) results from testing water spiked with 100 µg/L Cs+ revealed that adding increasing volumes of proteoliposome solution (containing 0.015-1.2 mg of Kup membrane transporter) resulted in 0.29-12.7% removal in a linear fashion. Proteoliposome addition (containing 0.015-0.3 mg of Kup membrane transporter) to water spiked with 10 µg/L Cs+ resulted in 0.65-3.43% removal, while removal by protein-free liposomes was negligible at 0.03%. These results suggest that Kup transporters inserted into the liposomes are mainly responsible for the removal efficiencies. Consequently, a desired removal efficiency can be achieved by adding a higher volume of constructed proteoliposome and subsequently higher mg of Kup transporter to the contaminated water. This provides new insight on the effectiveness and applicability of proteoliposome transporters, and an alternative and a novel contribution to emerging technologies in removing cesium or other metal contaminants undergoing transmembrane transport.

In silico binding of 4,4'-bisphenols predicts in vitro estrogenic and antiandrogenic activity.

Bisphenols, anthropogenic pollutants, leach from consumer products and have potential to be ingested and are excreted in waste. The endocrine disrupting effects of highly manufactured bisphenols (BPA, BPS, and BPF) are known, however the activities of others are not. Here, the estrogenic and androgenic activities of a series of 4,4'-bisphenols that vary at the inter-connecting bisphenol bridge were determined (BPA, BPB, BPBP, BPC2, BPE, BPF, BPS, and BPZ) and compared to in silico binding to estrogen receptor-alpha and the androgen receptor. Bioassay results showed the order of estrogenicity (BPC2 (strongest) > BPBP > BPB > BPZ > BPE > BPF > BPA > BPS, r2 = 0.995) and anti-androgenicity (BPC2 (strongest) > BPE, BPB, BPA, BPF, and BPS, r2 = 0.996) correlated to nuclear receptor binding affinities. Like testosterone and the anti-androgen hydroxyflutamide, bisphenol fit in the ligand-binding domain through hydrogen-bonding at residues Thr877 and Asn705, but also interacted at either Cys784/Ser778 or Gln711 through the other phenol ring. This suggests the 4,4'-bisphenols, like hydroxyflutamide, are androgen receptor antagonists. Hydrogen-bond trends between ERα and the 4,4'-bisphenols were limited to residue Glu353, which interacted with the -OH of one phenol and the -OH of the A ring of 17ß-estradiol; hydrogen-bonding varied at the -OH of ring D of 17ß-estradiol and the second phenol -OH group. While both estrogen and androgen bioassays correlated to in silico results, conservation of hydrogen-bonding residues in the androgen receptor provides a convincing picture of direct antagonist binding by 4,4'-bisphenols.

Development of a field enhanced photocatalytic device for biocide of coliform bacteria.

A field enhanced flow reactor using bias assisted photocatalysis was developed for bacterial disinfection in lab-synthesized and natural waters. The reactor provided complete inactivation of contaminated waters with flow rates of 50mL/min. The device consisted of titanium dioxide nanotube arrays, with an externally applied bias of up to 6V. Light intensity, applied voltage, background electrolytes and bacteria concentration were all found to impact the device performance. Complete inactivation of Escherichia coli W3110 (~8×10(3)CFU/mL) occurred in 15sec in the reactor irradiated at 25mW/cm(2) with an applied voltage of 4V in a 100ppm NaCl solution. Real world testing was conducted using source water from Emigration Creek in Salt Lake City, Utah. Disinfection of natural creek water proved more challenging, providing complete bacterial inactivation after 25sec at 6V. A reduction in bactericidal efficacy was attributed to the presence of inorganic and organic species, as well as the increase in robustness of natural bacteria.

Estrogen mimics induce genes encoding chemical efflux proteins in gram-negative bacteria.

Escherichia coli and Pseudomonas aeruginosa are gram-negative bacteria found in wastewater and biosolids. Spanning the inner and outer membrane are resistance-nodulation-cell division superfamily (RND) efflux pumps responsible for detoxification of the cell, typically in response to antibiotics and other toxicity inducing substrates. Here, we show that estrogenic endocrine disruptors, common wastewater pollutants, induce genes encoding chemical efflux proteins. Bacteria were exposed to environmental concentrations of the synthetic estrogen 17α-ethynylestradiol, the surfactant nonylphenol, and the plasticizer bisphenol-A, and analyzed for RND gene expression via q-PCR. Results showed that the genes acrB and yhiV were over-expressed in response to the three chemicals in E. coli, and support previous findings that these two transporters export hormones. P. aeruginosa contains 12 RND efflux pumps, which were differentially expressed in response to the three chemicals: 17α-ethynylestradiol, bisphenol-A, and nonylphenol up-regulated mexD and mexF, while nonylphenol and bisphenol-A positively affected transcription of mexK, mexW, and triC. Gene expression via q-PCR of RND genes may be used to predict the interaction of estrogen mimics with RND genes. One bacterial response to estrogen mimic exposure is to induce gene expression of chemical efflux proteins, which leads to the expulsion of the contaminant from the cell.