Environmental impacts of the ultraviolet filter oxybenzone.

Organic UV filters are emerging contaminants with increasing evidence of their negative impact on environmental health and water quality. One of the most common and environmentally relevant organic UV filters is oxybenzone (OBZ). While much of the initial focus has been on investigating the interaction of OBZ with coral reefs, there have been several recent studies that indicate that organic UV filters are affecting other environmental endpoints, including marine animals, algae, and plants. OBZ has been found to bioaccumulate in marine animals such as fish and mussels and then potentially acting as an endocrine disruptor. In plants, exposure to OBZ has been associated with decreased photosynthesis, inhibited seed germination, and impaired plant growth. In this review, we summarize the current state of knowledge regarding the environmental impacts of OBZ and suggest potential future directions.

Monitoring coliphages to reduce waterborne infectious disease transmission in the One Water framework.

Coastal waters, surface waters, and groundwater are impacted by wastewater and stormwater discharges, as well as agricultural flows containing animal waste and nutrients. A One Water approach posits that components of the water system have overlapping and interactive impacts on other aspects of the system, for which a comprehensive approach to water management is needed to further inform public health decisions. Current frameworks for monitoring wastewater effluent and recreational surface waters include the measurement of fecal indicator bacteria. Although viral pathogens are likely to be transported further and can survive longer than bacterial pathogens, virus monitoring is not required for recreational waters. A scientific consensus is emerging that the use of bacterial indicators alone does not account for nor represent the health risks associated with viral pathogens due to the differences in the fate and transport of bacterial versus viral pathogens in wastewater treatment, surface water, and groundwater. Furthermore, it is likely that the public health risk associated with these waterborne pathogens is variable and diverse. For example, under drought conditions, effluents of urban water systems can comprise most of the dry weather flow in downstream waters, which are often used as sources of drinking water. This de facto reuse could increase viral risk for the end users of this water. A One Water approach will aid in protecting the health of the public from waterborne pathogens, regardless of where those pathogens entered the water system. In this review, we assert that monitoring for fecal indicator viruses can complement the monitoring of bacterial indicators, thereby improving public health protections. Bacteriophages have the strongest research foundation and correlation with viral pathogens along with some prediction power for risk to human health. Methods for detecting and quantifying coliphages are briefly summarized, as are challenges in the implementation of testing. Key knowledge gaps and research priorities are discussed so that the potential value and limitations of coliphage monitoring can be better addressed and understood.

Determining the effects of Class I landfill leachate on biological nutrient removal in wastewater treatment.

The disposal of landfill leachate is a chronic problem facing the municipal solid waste industry. The composition of landfill leachate is highly variable and often dependent on site-specific conditions. Due to the potentially disruptive impact on wastewater treatment processes, wastewater treatment plants (WWTP) are reluctant to accept landfill leachate for co-treatment. To improve the ability of WWTPs to screen the impact of landfill leachate and reduce landfill owners' cost of disposal, two bench scale methods were evaluated. First, six landfill leachates were screened with the specific oxygen uptake rate (SOUR) test, and second, the effect of leachate on the efficacy of activated sludge processes using lab scale sequencing batch reactors (SBRs) was determined with volumetric loading rates ranging from 5% to 20%. Results suggested that these tools can be used to estimate the impacts of leachate loading on biological processes. Both tools were able to identify loadings where biological activity was increased and inhibition of biological processes was minimized. The loading that maximized microbial activity was leachate specific and typically ranged from 5% to 10%. Taken together, these results suggest that improved landfill leachate screening and testing may improve outcomes at WWTPs by identifying a "Goldilocks" loading rate that increases biological activity. Nevertheless, our results also demonstrated that the effluent quality was degraded even at loading rates that increased biological activity. It is uncertain at this time if biological acclimation can remedy increased effluent nutrient mass loadings, suggesting further research is needed.

Natural Radiation in the Rocks, Soils, and Groundwater of Southern Florida with a Discussion on Potential Health Impacts.

Southern Florida is underlain by rocks and sediments that naturally contain radioactive isotopes. The primary origin of the radioactive isotopes is Miocene-aged phosphate deposits that can be enriched in uranium-238 and its daughter isotopes. Nodular phosphate containing radionuclides from the Miocene has been reworked into younger formations and is ubiquitous in southern Florida. When the nodular phosphate is exposed to groundwater with geochemical conditions favorable for its dissolution, uranium, radium, and radon may be released into the groundwater system. Uranium concentrations have been measured above the 30 µg/L drinking water standard at only one location in Lee County. Radium226/228 exceedances of the drinking water standard have been documented in numerous wells in Sarasota County. Indoor radon activities have exceeded the 4 piC/L guideline in five southern Florida counties. The exceedance of radioactivity standards in drinking water does not occur in municipal drinking water supplies, but rather only in some domestic self-supply wells. Health risks for exposure to radiation from domestic self-supply wells could be mitigated by testing of well water and, if necessary, switching to the use of a different aquifer or treatment process. While the risk of exposure to radon in indoor air in southern Florida is generally low, some areas are enriched in soil radon that migrates into structures, which could be addressed by improved ventilation.