Persistent organic pollutants (POPs) are ubiquitous in the environment and display the capacity to bioaccumulate in living organisms, constituting a hazard to both wildlife and humans. Although restrictions have been applied to prohibit the production of several POPs since the 1960s, high levels of these compounds can still be detected in many environmental and biological matrices, due to their chemical properties and significantly long half-lives. Some POPs can be passed from mother to the fetus and can gain entry to the central nervous system (CNS), by crossing the blood-brain barrier (BBB), resulting in significant deleterious effects, including neurocognitive and psychiatric abnormalities, which may lead to long-term socio-economic burdens.
View Article and Find Full Text PDFBatch leaching experiments were conducted to evaluate the release of forty per- and polyfluoroalkyl substances (PFAS) from sludge samples collected after thickening, anaerobic digestion, and dewatering processes at two wastewater treatment plants. The South District wastewater treatment plant (SDWWTP), which receives domestic wastewater and landfill leachate from a nearby landfill, and the Central District wastewater treatment plant (CDWWTP), which receives only domestic wastewater, were selected for this study. PFAS released into the aqueous phase were analyzed by sacrificial sampling after 1, 3, 7, 14, and 30 days.
View Article and Find Full Text PDFThis research was carried out in order to assess a baseline occurrence in Biscayne National Park, Florida, of four organic contaminants: the UV filters oxybenzone, dioxybenzone, and benzophenone, as well as the topical pain reliever benzocaine. A total of 35 samples were taken from five locations within the park, four near barrier islands, and one at a coral reef. Analyses were carried out using liquid chromatography coupled to high-resolution mass spectrometry.
View Article and Find Full Text PDFNon-targeted analysis (NTA) using high-resolution mass spectrometry allows scientists to detect and identify a broad range of compounds in diverse matrices for monitoring exposure and toxicological evaluation without a priori chemical knowledge. NTA methods present an opportunity to describe the constituents of a sample across a multidimensional swath of chemical properties, referred to as "chemical space." Understanding and communicating which region of chemical space is extractable and detectable by an NTA workflow, however, remains challenging and non-standardized.
View Article and Find Full Text PDFCarbon adsorbent fouling by dissolved organic matter (DOM) inhibits the ability of the widely-used rapid small-scale column test (RSSCT) to accurately predict the removal of organic micropollutants (OMP) from water by full-scale carbon adsorbers. Here, the adsorption of 11 short-chain per-/poly-fluoroalkyl substances (PFAS) from groundwater, surface water, and wastewater was examined in pilot columns as well as RSSCTs using constant diffusivity (CD) and proportional diffusivity (PD) designs. Neither the CD- or PD-RSSCT accurately predicted pilot adsorber breakthrough of PFAS using standard diffusional mass transfer models.
View Article and Find Full Text PDFProlonged work stress, as indicated by the effort-reward imbalance (ERI) model, jeopardizes health. Cortisol represents a candidate mechanism connecting stress to ill health. However, previous findings appear inconclusive, and recommendations were made to assess work stress at multiple time points and also to investigate ERI (sub-)components.
View Article and Find Full Text PDFThis ongoing survey reports the levels of persistent organic pollutants (POPs) in sea surface slicks collected on a global circumnavigation. Hydrophobic xenobiotic compounds such as POPs are known to accumulate on the sea surface in slicks at concentrations many fold greater than the underlying water column, raising concerns about the ecological impacts due to the high biological activity associated with this zone. Six different categories of POPs were reported: chlorobenzenes, hexachlorocyclohexanes, chlordane related compounds, organochlorine pesticides and other cyclodiene pesticides, DDTs and metabolites, and polychlorinated biphenyls.
View Article and Find Full Text PDFA superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction.
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