Hexavalent chromium (Cr(VI)) in ambient airborne particulate matter (PM) is a known pulmonary carcinogen and may have both soluble and insoluble forms. The sum of the two forms is defined as total Cr(VI). Currently, there were no methods suitable for large-scale monitoring of total Cr(VI) in ambient PM. This study developed a method to measure total Cr(VI) in ambient PM. This method includes PM collection using a Teflon filter, microwave extraction with 3% Na2CO3-2% NaOH at 95°C for 60 minutes, and Cr(VI) analysis by 1,5-diphenylcarbazide colorimetry at 540 nm. The recoveries of total Cr(VI) were 119.5 ± 10.4% and 106.3 ± 16.7% for the Cr(VI)-certified reference materials, SQC 012 and SRM 2700, respectively. Total Cr(VI) in the reference urban PM (NIST 1648a) was 26.0 ± 3.1 mg/kg (%CV = 11.9%) determined by this method. The method detection limit was 0.33 ng/m3. This method and the one previously developed to measure ambient Cr(VI), which is soluble in pH ~9.0 aqueous solution, were applied to measure Cr(VI) in ambient PM10 collected from three urban areas and one suburban area in New Jersey. The total Cr(VI) concentrations were 1.05-1.41 ng/m3 in the winter and 0.99-1.56 ng/m3 in the summer. The soluble Cr(VI) concentrations were 0.03-0.19 ng/m3 in the winter and 0.12-0.37 ng/m3 in the summer. The summer mean ratios of soluble to total Cr(VI) were 14.3-43.7%, significantly higher than 4.2-14.4% in the winter. The winter concentrations of soluble and total Cr(VI) in the suburban area were significantly lower than in the three urban areas. The results suggested that formation of Cr(VI) via atmospheric chemistry may contribute to the higher soluble Cr(VI) concentrations in the summer.
Introduction: Perfluoronated chemicals (PFCs) are used in manufacturing stain resistant and water repellent consumer products and in firefighting foams at airports and military sites. They have been released into the environment inadvertently and when sprayed during firefighting scenarios and simulations. Due to their slow environmental degradation they have contaminated water supplies in multiple counties in the US potentially exposing more that 5 million people nationwide. The ground water in several communities in Gloucester County, NJ, particularly the municipal water in Paulsboro, was contaminated with perfluoro-n-nonanoic acid (PFNA) and perfluorooctoanic acid (PFOA). Since 2014, the water supplies have been filtered with activated charcoal. To assess the effectiveness of the water intervention program on reducing exposure to these PFCs, a convenience sample of 120 adult residents in the area have been recruited and twelve PFCs were measured in serum, household tap water, and household dust and a questionnaire administered as part of a CDC Biomonitoring grant.Results: The first visits have been completed and two more visits to each subject are planned approximately a year apart. Nine of the PFCs were routinely above the detection limits in the serum. The analyses of approximately half of the subjects have been completed, with the serum PFNA levels of the residents (5.9±9.5, median 3.3, maximum 60 µg/L) often exceeded the 95th% reported in the 2009-2010 NHANES levels for adults over 20 (3.94 (CI: 2.38-8.36)). The distribution of other PFCs serum levels were similar to that reported in NHANES. Water levels were below detection for all PFCs, indicative that the water intervention has effectively reduced the PFCs exposure through that route. PFCs were found in dust reflecting their use in consumer products. It is expected that the serum levels of PFNA will decline over the next few years if the drinking water was the main exposure source.
Epidemiologic studies consistently demonstrate an association between acute cardiopulmonary events and changes in air pollution; however, the mechanisms that underlie these associations are not completely understood. Oxidative stress and inflammation have been suggested to play a role in human responses to air pollution. The proteasome is an intracellular protein degradation system linked to both of these processes and may help mediate air pollution effects.
A commercial polyclonal plate ELISA was validated for the analysis of chlorpyrifos in fruits and vegetables. Produce was extracted by high speed homogenization 10 g of a homogeneous subsample in 20 ml of methanol for 3 min followed by clean‐up with C18 Sep‐Paks. All samples and standards were analyzed in 10% final methanol concentration. Reproducibility studies yielded per cent coefficients of variation (%CVs) from 2.1 to 20. Fruits and vegetables fortified at five different levels demonstrated percent recoveries ranging from 77 to 92 (%CVs of 4.0 to 14) for chlorpyrifos. A comparison of the analysis of 35 positive chlorpyrifos samples between ELISA and a gas chromatography‐atomic emission detector method indicated good agreement with a correlation coefficient of 0.967 and a slope of 0.9583.
This study aimed to characterize spatial/temporal variations of ambient volatile organic compounds (VOCs) using a community-scale monitoring approach and identify the main sources of concern in Paterson, NJ, an urban area with mixed sources of VOCs. VOC samples were simultaneously collected from three local source-dominated (i.e., commercial, industrial, and mobile) sites in Paterson and one background site in Chester, NJ (located ∼58 km southwest of Paterson). Samples were collected using the EPA TO-15 method from midnight to midnight, one in every sixth day over one year. Among the 60 analyzed VOCs, ten VOCs (acetylene, benzene, dichloromethane, ethylbenzene, methyl ethyl ketone, styrene, toluene, m,p-xylene, o-xylene, and p-dichlorobenzene) were selected to examine their spatial/temporal variations. All of the 10 VOCs in Paterson were significantly higher than the background site (p<0.01). Ethylbenzene, m,p-xylene, o-xylene, and p-dichlorobenzene measured at the commercial site were significantly higher than the industrial/mobile sites (p<0.01). Seven VOCs (acetylene, benzene, dichloromethane, methyl ethyl ketone, styrene, toluene, and p-dichlorobenzene) were significantly different by season (p<0.05), that is, higher in cold seasons than in warm seasons. In addition, dichloromethane, methyl ethyl ketone, and toluene were significantly higher on weekdays than weekend days (p<0.05). These results are consistent with literature data, indicating the impact of anthropogenic VOC sources on air pollution in Paterson. Positive Matrix Factorization (PMF) analysis was applied for 24-hour integrated VOC measurements in Paterson over one year and identified six contributing factors, including motor vehicle exhausts (20%), solvents uses (19%), industrial emissions (16%), mobile+stationery sources (12%), small shop emissions (11%), and others (22%). Additional locational analysis confirmed the identified sources were well matched with point sources located upwind in Paterson. The study demonstrated the community-scale monitoring approach can capture spatial variation of VOCs in an urban community with mixed VOC sources. It also provided robust data to identify major sources of concern in the community.
Prepared by UMDNJ-Robert Wood Johnson Medical School and Environmental and Occupational Health Sciences Institute and NJDEP, Division of Science, Research and Technology
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