Suchergebnisse

The presence of trace organic chemicals (TOrCs) in municipal biosolids in the U.S. has received considerable attention by the public and scientific community over the last several years. Of particular concern is whether the presence of TOrCs in biosolids results in significant risks to public health and the environment upon land application of the biosolids. While the U.S. Environmental Protection Agency has evaluated the risks associated with dioxins present in biosolids-amended soils, to date, no other TOrCs, particularly those of emerging concern, have been subjected to complete risk assessments with respect to the land application of municipal biosolids. This study identified the scientific data gaps that should be filled if appropriate risk assessments are to be conducted. The focus of this effort was to compile data from published peer-reviewed literature that addresses the occurrence, mobility, persistence, bioaccumulation, toxicity, and microbial impacts of biosolids-borne TOrCs in soils. In addition, an evaluation of the current modeling approaches employed to evaluate the risks of biosolids-borne TOrCs was conducted

AbstractPer- and polyfluoroalkyl substances (PFASs) are today considered important constituents of the continuously growing substance group of persistent contaminants of emerging environmental concern (PCEC). Here, we report for the first time the concentrations of 12 relevant PFASs in 28 marine water samples from the Saudi Arabian coastal waters of the Red Sea. The sum levels of 12 PFASs (Σ12PFAS) in surface seawater ranged from <LOQ to 956 ngL−1. For the reference background site of this study, Σ12PFAS levels ranged from <LOQ to 10.9 ng/L. The highest PFAS levels have been found in Al-Arbaeen and Al-Shabab, two lagoons continuously receiving treated sewage effluents. PFHxA, PFHxS, and 6:2 FTS were the most prevalent PFASs with relatively high concentrations. Discharge of municipal and industrial wastewaters is considered an important source of PFASs. The pattern of PFASs observed here suggests that the usage of PFAS-containing aqueous film-forming foams (AFFFs) is a potential additional source for these compounds in Al-Arbaeen and Al-Shabab lagoons. However, a systematic elucidation of local PFASs sources is needed. Contamination of the Red Sea waters with PFASs poses a potential imminent risk to the marine environment of the Red Sea and ultimately may even affect the health of human consumers through the consumption of local seafood.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are a chemical class widely used in industrial and commercial applications because of their unique physical and chemical properties. Between 2013 and 2016 PFAS were detected in public water systems and private wells in El Paso County, Colorado. The contamination was likely due to aqueous film forming foams used at a nearby Air Force base. OBJECTIVE: To cross-sectionally describe the serum concentrations of PFAS in a highly exposed community, estimate associations with drinking water source, and explore potential demographic and behavioral predictors. METHODS: In June 2018, serum PFAS concentrations were quantified and questionnaires administered in 213 non-smoking adult (ages 19–93) participants residing in three affected water districts. Eighteen PFAS were quantified and those detected in >50% of participants were analyzed: perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA) and perfluoroheptane sulfonate (PFHpS). Unadjusted associations were estimated between serum PFAS concentrations and several predictors, including water consumption, demographics, personal behaviors and employment. A multiple linear regression model estimated adjusted associations with smoking history. RESULTS: Study participants' median PFHxS serum concentration (14.8 ng/mL) was approximately 12 times as high as the U.S. national average. Median serum concentrations for PFOS, PFOA, PFNA and PFHpS were 9.7 ng/mL, 3.0 ng/mL, 0.4 ng/mL and 0.2 ng/mL, respectively. Determinants of PFHxS serum concentrations were water district of residence, frequency of bottled water consumption, age, race/ethnicity, and smoking history. Determinants of serum concentrations for the other four PFAS evaluated included: water district of residence, bottled water consumption, age, sex, race/ethnicity, smoking history, and firefighter or military employment. CONCLUSIONS: Determinants of serum concentrations for multiple PFAS, including ...

AbstractAdsorption of perfluoroalkyl acids (PFAAs) by granular activated carbon (GAC) was evaluated in bench‐, pilot‐, and full‐scale studies to determine effects of PFAA characteristics and background organic matter on carbon use rates. Rapid small‐scale column tests (RSSCTs) were conducted according to the proportional diffusivity (PD) design to assess their suitability to predict full‐ or pilot‐scale GAC performance. PFAA removal from groundwater (GW) and coagulated surface water (SW) was studied with two sub‐bituminous coal‐based GACs. In batch tests conducted with pulverized GAC, the GACs performed similarly in GW, but the GAC with the larger mesopore volume was more effective for PFAA removal from SW. In column tests, carbon use rates decreased with increasing PFAA chain length and were lower for GW (total organic carbon [TOC] = 0.7 mg/L) than for SW (TOC = 2.0–2.7 mg/L). The volume of SW that could be treated to 10% or 50% PFAA breakthrough was about 50–60% of the volume of GW that could be treated when comparing pilot‐scale data for SW with full‐scale data for GW. Consistent differences in PFAA adsorption capacity were not observed for empty bed contact times of 13 and 26 min in full‐scale adsorbers treating GW. The PD‐RSSCT simulating PFAA removal from GW consistently overpredicted full‐scale adsorption capacity, on average by ~70%. Using a carbon use rate of <25 mgGAC/Lwater treated) as a criterion for the feasibility of GAC treatment, full‐ and pilot‐scale GAC adsorber data suggest that GAC is a viable treatment option (carbon use rate < 25 mgGAC/Lwater treated) for perfluoroalkylcarboxylic acids with six or more carbon atoms in SW and five or more carbon atoms in GW. For perfluoroalkyl sulfonic acids, GAC treatment is viable for compounds containing four or more carbons based on results obtained with both SW and GW.