Exceed US Environmental Protection Agency Research Articles

Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS).

It is hypothesized that environmental contamination by per- and polyfluoroalkyl substances (PFAS) defines a separate planetary boundary and that this boundary has been exceeded. This hypothesis is tested by comparing the levels of four selected perfluoroalkyl acids (PFAAs) (i.e., perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)) in various global environmental media (i.e., rainwater, soils, and surface waters) with recently proposed guideline levels. On the basis of the four PFAAs considered, it is concluded that (1) levels of PFOA and PFOS in rainwater often greatly exceed US Environmental Protection Agency (EPA) Lifetime Drinking Water Health Advisory levels and the sum of the aforementioned four PFAAs (Σ4 PFAS) in rainwater is often above Danish drinking water limit values also based on Σ4 PFAS; (2) levels of PFOS in rainwater are often above Environmental Quality Standard for Inland European Union Surface Water; and (3) atmospheric deposition also leads to global soils being ubiquitously contaminated and to be often above proposed Dutch guideline values. It is, therefore, concluded that the global spread of these four PFAAs in the atmosphere has led to the planetary boundary for chemical pollution being exceeded. Levels of PFAAs in atmospheric deposition are especially poorly reversible because of the high persistence of PFAAs and their ability to continuously cycle in the hydrosphere, including on sea spray aerosols emitted from the oceans. Because of the poor reversibility of environmental exposure to PFAS and their associated effects, it is vitally important that PFAS uses and emissions are rapidly restricted.

Variations of radon and airborne particulate matter near three large phosphogypsum stacks in Florida.

Approximately 1 billion tons of phosphogypsum (PG), a by-product of the fertilizer industry, are currently stacked in Florida. PG emits radon gas, which is a risk factor for lung cancer and can also increase particulate matter (PM) associated non-cancer mortality in exposed individuals. We measured concentrations of atmospheric radon and particulate matter near PG stacks and their short-term variations at different distances to estimate exposures in nearby communities. Specifically, we measured atmospheric levels of radon, and mass concentrations of PM1, PM2.5, and PM10, and number concentrations of PM0.3, PM0.5, PM1, PM2.5, PM5, and PM10 near three large PG stacks in Florida. Atmospheric radon was collected at distances of 2.5, 5.0, and 7.5 miles downwind from three large PG stacks using charcoal-based kits and measured by liquid scintillation counting. A professional radon monitor was used to take 24-h-average radon reading at 5.0 miles from each stack for comparison purposes. The median (IQR) radon levels were 0.325 (0.150, 0.675), 0.150 (0.150, 0.650), and 0.500 (0.150, 0.700) pCi/L at 2.5, 5, and 7.5 miles, respectively. The median (IQR) PM2.5 levels were 5 (4, 6), 5 (3, 7), and 5 (2, 9) µg/m3 at 2.5, 5, and 7.5 miles, respectively. Non-parametric Kruskal-Wallis test could not detect any association between radon or PM levels and distances (2.5-7 miles) from PG stacks. With scintillation counting, median radon levels detected were above the US Environmental Protection Agency (EPA) recommended standard in some of the sites; however, much higher levels were detected through the more advanced digital monitor. PM2.5 levels were below the US-EPA 24-h average national ambient air quality standard in the study area. We conclude that ambient radon levels near PG stacks could exceed US EPA recommended outdoor standards and do not vary within a short distance from the sources, implying similar exposures in nearby communities.

Dietary exposure to mercury and its relation to cytogenetic instability in populations from “La Mojana” region, northern Colombia

Fish consumption and chronic exposure to low doses of mercury (Hg) seems to activate several molecular mechanisms leading to carcinogenic and/or teratogenic processes. However, Hg genotoxic effects on humans are not completely described. In the present study, we assessed cytogenetic damage in isolated human peripheral lymphocytes using the cytokinesis-block micronucleus cytome assay (CBMN-Cyt), micronucleus formation with anti-kinetochore antibody (CREST staining), levels of total Hg in hair (T-Hg), fish consumption, and estimated Hg dose. The study comprised 39 non-exposed, and 73 residents from La Mojana region, an area with a well-documented Hg contamination. Data showed a significant increase in micronuclei (MNBN), nucleoplasmic bridges (NPB), and necrotic and apoptotic cell frequencies in residents of “La Mojana.” The overall mean T-Hg level in hair for exposed residents was 1.12 ± 0.94 mg kg−1 and 0.15 ± 0.05 in individuals from the reference area. Approximately 40% of analyzed individuals showed T-Hg levels that exceeded US Environmental Protection Agency (USEPA) reference dose. Increased T-Hg levels in hair were related to increased MNBN frequencies and high fish consumption. Other cellular markers, such as necrotic and apoptotic cell frequencies, were also correlated with high fish intake and T-Hg contents. Results of the CREST staining demonstrated that in vivo exposure to Hg induces genetic instability by chromosome fragment loss (clastogenic). Additionally, a high average intake of some fish species, particularly with carnivorous habits like Caquetaia kraussii, Hoplias malabaricus, and Sorubin cuspicaudus, seems to increase MNBN frequencies significantly.

Trends in neonicotinoid pesticide residues in food and water in the United States, 1999\u20132015

BackgroundNeonicotinoids are a class of systemic insecticides widely used on food crops globally. These pesticides may be found in “off-target” food items and persist in the environment. Despite the potential for extensive human exposure, there are limited studies regarding the prevalence of neonicotinoid residues in foods sold and consumed in the United States.MethodsResidue data for seven neonicotinoid pesticides collected between 1999 and 2015 by the US Department of Agriculture’s Pesticide Data Program (PDP) were collated and summarized by year across various food commodities, including fruit, vegetable, meat, dairy, grain, honey, and baby food, as well as water to qualitatively describe and examine trends in contamination frequency and residue concentrations.ResultsThe highest detection frequencies (DFs) for neonicotinoids by year on all commodities were generally below 20%. Average DFs over the entire study period, 1999–2015, for domestic and imported commodities were similar at 4.5%. For all the samples (both domestic and imported) imidacloprid was the neonicotinoid with the highest overall detection frequency at 12.0%. However, higher DFs were observed for specific food commodity-neonicotinoid combinations such as: cherries (45.9%), apples (29.5%), pears (24.1%) and strawberries (21.3%) for acetamiprid; and cauliflower (57.5%), celery (20.9%), cherries (26.3%), cilantro (30.6%), grapes (28.9%), collard greens (24.9%), kale (31.4%), lettuce (45.6%), potatoes (31.2%) and spinach (38.7%) for imidacloprid. Neonicotinoids were also detected in organic commodities, (DF < 6%). Individual commodities with at least 5% of samples testing positive for two or more neonicotinoids included apples, celery, and cherries. Generally, neonicotinoid residues on food commodities did not exceed US Environmental Protection Agency tolerance levels. Increases in detection trends for both finished and untreated water samples for imidacloprid were observed from 2004 to 2011.ConclusionsAnalysis of PDP data indicates that low levels of neonicotinoids are present in commonly-consumed fruits and vegetables sold in the US. Trends in detection frequencies suggest an increase in use of acetamiprid, clothianidin and thiamethoxam as replacements for imidacloprid. Given these findings, more extensive surveillance of the food and water supply is warranted, as well as biomonitoring studies and assessment of cumulative daily intake in high risk groups, including pregnant women and infants.

Assessment of Water Quality in Roof-Harvested Rainwater Barrels in Greater Philadelphia

A study of water quality parameters was conducted in 38 small-scale roof-harvested rainwater barrels (RHRB) located in urban and peri-urban Philadelphia, USA in winter (November–December) 2014 and summer (June–August 2016). Parameters included two fecal indicator bacteria (FIB) (Escherichia coli and Enterococcus spp.) measured using culture-based methods, eight potential enteric and opportunistic pathogens (Campylobacter jejuni, Acanthamoeba spp., Legionella spp., L. pneumophila, Naegleria fowleri, Pseudomonas aeruginosa, Mycobacterium avium and Mycobacterium intracellulare) measured using quantitative polymerase chain reaction (qPCR), and two metals (lead and zinc) using inductively coupled plasma mass spectrometry (ICP-MS). Fecal indicator bacteria were detected in greater than 60% RHRB samples and concentrations (up to &gt;103 per 100 mL) exceeded US Food and Drug Administration (USFDA) irrigation water quality standards. Among the enteric and opportunistic pathogens tested, 57.9, 44.7, 21.1, 18.4, 5 and 3% were PCR positive for Legionella spp., M. intracellulare, M. avium, Acanthamoeba spp., P. aeruginosa, and C. jejuni, respectively. N. fowleri and L. pneumophila were not detected in any sample. The concentrations of enteric and opportunistic pathogens ranged from 102 to 107 gene copies/L of barrel water. Lead and zinc were each observed in 88.5% of RHRB but the concentrations did not exceed US Environmental Protection Agency (USEPA) standards for irrigating produce, with the exception of one zinc observation (2660 µg/L). Based on these data, it appears that the risk associated with metals in RHRB is likely to be low, as these barrels are only used for gardening and non-potable purposes. However, risks due to fecal and opportunistic pathogens may be higher due to exposure to aerosols during gardening activities and produce consumed raw, and should be investigated further.

Suspended sediment supply dominated by bank erosion in a low-gradient agricultural watershed, Wildcat Slough, Fisher, Illinois, United States

The relative contributions from potential sediment sources to the suspended load of the Wildcat Slough, a headwater tributary in central Illinois, are estimated as a proxy for understanding sediment and nutrient transport in low gradient, intensively managed watersheds. Sediment and nutrient fluxes from agricultural areas to rivers have led to nitrate (NO3) concentrations that exceed US Environmental Protection Agency water quality standards and phosphorus (P) concentrations that promote algal growth, decreasing water quality across the state of Illinois. This study assesses contributions to the sediment load as a function of land use and channel morphology in Wildcat Slough, a low gradient, intensively managed 61.3 km2 (23.67 mi2) watershed in the Upper Sangamon River Basin of central Illinois, United States. Land use is dominated by row crop agriculture. Potential sediment sources include row crop fields, forest, floodplains, river banks, pastures, and grasslands. The majority of the stream is constrained within a deep, channelized ditch fed by tile drains. However, in the lowermost reaches, Wildcat Slough freely meanders and has established fluvial features including point bars and cut banks. A suite of tracers (delta carbon 13 [δ13C], phosphorus [P], magnesium [Mg], manganese [Mn], and carbon [C]) differ significantly between the potential sediment sources. An unmixing model uses the concentrations of the tracers in source samples and in suspended sediment collected during high discharge events to estimate the relative contribution from each source to the suspended load. The majority of suspended sediment was sourced from channel banks (40% to 65%) and forest (35% to 55%) with very little derived from the agricultural uplands (10% or less). The lack of sediment from uplands signifies a disconnect between the uplands and the channel, reflecting the low relief of the uplands and the dominance of tile drains in routing water to the channel. These findings suggest that efforts to limit the sediment-born nutrient load should focus on near-channel areas in meandering reaches. Best practices in similar landscapes may include installation of a buffer between meandering channel reaches and fertilized land, or limiting fertilizer application near channel banks, to diminish the inputs to the nutrient load via natural channel migration.

The Effects of Slash Pile Burning on Soil and Water Macronutrients

Significant effects of slash pile burning on soil chemistry and water quality were observed in forested sites in the eastern Sierra Nevada Mountains of Nevada. Slash piles in upland and meadow sites were instrumented postburn with ceramic cup lysimeters, runoff collectors, and resin stakes (Plant Root Simulator™ probes) along transects from pile centers to unburned areas. Ash and soil samples also were collected along these transects. The pH and concentrations of most nutrients in the soil were highest in the centers of the piles. Larger piles had lower levels of total carbon and total nitrogen in the pile centers (indicative of high burn temperatures and volatilization) compared with smaller piles. There also were differences between meadow and non-meadow systems including higher soil NO3− and lower SO42− amounts in the meadow areas. Soil solution data indicated that peak concentrations exceeded US Environmental Protection Agency water quality standards for both NO2−-N and NO3−-N at all three sites and were 2.5 to 3 times the standards in two sites. Runoff solution peak concentrations also exceeded the standards but only in the meadow site.

Mineralogy and the release of trace elements from slag from the Hegeler Zinc smelter, Illinois (USA)

Slag from the former Hegeler Zn-smelting facility in Illinois (USA) is mainly composed of spinifex Ca-rich plagioclase, fine-grained dendritic or coarse-grained subhedral to anhedral clinopyroxenes, euhedral to subhedral spinels, spherical blebs of Fe sulfides, silicate glass, and less commonly fayalitic olivine. Mullite and quartz were also identified in one sample as representing remnants of the furnace lining. Secondary phases such as goethite, hematite and gypsum are significant in some samples and reflect surficial weathering of the dump piles or represent byproducts of roasting. A relatively rare Zn-rich material contains anhedral willemite, subhedral gahnite, massive zincite, hardystonite and a Zn sulfate (brianyoungite), among other phases, and likely represents the molten content of the smelting furnace before Zn extraction. The bulk major-element chemistry of most slag samples is dominated by SiO 2 , Al 2 O 3 , Fe 2 O 3 and CaO. The bulk composition of the slag suggests a high viscosity of the melt and the mineralogy suggests a high silica content of the melt. Bulk slag trace-element chemistry shows that the dominant metal is Zn with >28.4 wt.% in the Zn-rich material and between 212 and 14,900 mg/kg in the other slags. The concentrations of other trace elements reach the following: 45 mg/kg As, 1170 mg/kg Ba, 191 mg/kg Cd, 242 mg/kg Co, 103 mg/kg Cr, 6360 mg/kg Cu, 107 mg/kg Ni, and 711 mg/kg Pb. Zinc, as the dominant metal in the slags, is likely the most environmentally significant metal in these samples; Cd, Cu, and Pb are also of concern and their concentrations exceed US Environmental Protection Agency preliminary remediation goals for residential soils. Spinel was found to be the dominant concentrator of Zn for samples containing significant Zn (>1 wt.%); the silicate glass also contained relatively high concentrations of Zn compared to other phases. Zinc partitioned into the silicates and oxides in these samples is generally more resistant to weathering and therefore less leached when compared to the slag samples with lower bulk Zn concentrations where Zn is likely partitioned into volumetrically minor sulfides. This is confirmed by leachate tests that resulted in low leachate Zn concentrations for samples with Zn partitioned into spinel. In contrast, the concentrations of Zn and SO 4 are close to those expected from the dissolution of stoichiometric ZnS in leachates from samples in which the dominant host of Zn is suspected to be sulfides. The fact that Zn and other metals occur commonly as sulfides, which are more reactive than the silicates and oxides into which they dominantly partition according to other slag studies, indicates the Hegeler slag pile may be more of an environmental concern than other slag piles.

Assessment of the Microbial Quality of Water Offered to Captive Psittacine Birds

To investigate potential water-source microbes, 44 samples of water offered to individually caged psittacine birds were aseptically collected from 14 bird-owning households and evaluated for the presence of coliforms, Escherichia coli, heterotrophic bacteria, and Pseudomonas aeruginosa. No samples were positive for E. coli; however, 21 of 25 water samples (84%) from open containers and 7 of 19 samples (37%) from bottles exceeded US Environmental Protection Agency standards for coliforms. Fourteen of 24 open containers (58%) and 7 of 19 bottles (37%) grew heterotrophic bacteria that exceeded 500 colonies/ml. Pseudomonas aeruginosa was isolated from water samples from 1 open container and 1 bottle. These results suggest that potentially pathogenic bacteria can be found in water offered to companion psittacine birds. Additional studies are needed to assess whether these bacteria are clinically important causes of disease and to develop husbandry methods that will reduce contamination.

Hydrogeology and hydrochemistry of a shallow alluvial aquifer, western Saudi Arabia

A hydrogeological and hydrochemical study was conducted on a shallow alluvial aquifer, Wadi Wajj, in western Saudi Arabia to assess the influence of protection measures on groundwater quality. The hydrochemistry was assessed up-gradient and down-gradient from potential contamination sources in the main city in dry and wet seasons prior to and after the installation of major drainage and wastewater facilities. Wadi Wajj is an unconfined aquifer where water is stored and transmitted through fractured and weathered bedrock and the overlying alluvial sediments. Natural recharge to the aquifer is about 5% of rainfall-runoff. Hydrochemistry of the aquifer shows temporal and seasonal changes as influenced by protection measures and rainfall runoff. Both groundwater and runoff showed similar chemical signature, which is mostly of chloride-sulfate-bicarbonate and sodium-calcium type. Groundwater downstream of the city, though of poorer quality than upstream, showed significant improvement after the installation of a concrete runoff tunnel and a wastewater treatment plant. Concentrations of many of the groundwater quality indicators (e.g., TDS, coliform bacteria, and nitrate) exceed US Environmental Protection Agency drinking-water standards. Heavy metal content is, however, within allowable limits by local and international standards. The chemical analyses also suggest the strong influence of stream runoff and sewage water on the groundwater quality.

Evaluation of repeated measurements of radon-222 concentrations in well water sampled from bedrock aquifers of the Piedmont near Richmond, Virginia, USA: Effects of lithology and well characteristics

Radon ( 222Rn) concentrations in 26 ground water wells of two distinct lithologies in the Piedmont of Virginia were measured to assess variation in ground water radon concentrations (GWRC), to evaluate differences in concentrations related to well characteristics, lithology, and spatial distributions, and to assess the feasibility of predicting GWRC. Wells were sampled in accordance with American Public Health Association Method 7500 Rn-B, with modifications to include a well shaft profile analysis that determined the minimum purge time sufficient to remove the equivalent of one column of water from each well. Statistically significant differences in GWRC were found in the Trssu (1482±1711 pCi/L) and Mpg (7750±5188 pCi/L) lithologies, however, no significant differences were found among GWRC at each well over time. Using multiple regression, 86% of the variability ( R 2) in the GWRC was explained by the lithology, latitudinal class, and water table elevation of the wells. The GWRC in a majority of the wells studied exceed US Environmental Protection Agency designated maximum contaminant level and AMCL. Results support modifications to sampling procedures and indicate that, in previous studies, variations in GWRC concentrations over time may have been due in part to differences in sampling procedures and not in source water.

Assessing Oregon's twenty-six coastal beach areas for recreational water quality standards

Water samples from 26 Oregon beaches were analyzed for Escherichia coli ( E. coli) and enterococci concentrations by the Oregon Department of Human Services (ODHS) Public Health Laboratory. Nine Oregon beaches exceeded US Environmental Protection Agency's (USEPA) single sample maximum density of 104 enterococci colony forming units (cfu) per 100 mL with levels ranging from 121 to 4325 most probable number (MPN)/100 milliliters (mL). Otter Rock at South Cove had the highest enterococci concentration at 4352 MPN/100 mL. The results from two Oregon beaches exceeded Oregon Department of Environmental Quality's (ODEQ) estuarine E. coli standard of 406 organisms/100 mL. Otter Rock at South Cove had the highest E. coli concentration at 1850 MPN/100 mL while Road's End had an E. coli density of 771 MPN/100 mL. Results of this study suggest that adopting USEPA's marine enterococci standard in lieu of the ODEQ's estuarine standard will lead to increased Oregon beach water standard failures.