Source apportionment of polychlorinated biphenyls in the sediment of the Newtown Creek superfund site.

Polychlorinated biphenyls (PCBs) are a primary contaminant of potential concern at the Newtown Creek superfund site. Measurements of PCBs in hundreds of samples of sediment (surface and cores) within Newtown Creek and at nearby reference locations were obtained from the Remedial Investigation (RI) databases. This data set was analyzed using Positive Matrix Factorization (PMF). A weight-of-evidence approach was used to attribute the PMF-generated fingerprints to sources. The PMF analysis generated eight factors (fingerprints or sources) that represent primary sources, such as Aroclors, as well as secondary sources, including the East River and Combined Sewer Outfalls (CSOs). In addition to the high-production volume Aroclors (1016/1242, 1248, 1254, and 1260), some less-widely used Aroclors (1232 and 1268) were found in Newtown Creek sediment. Aroclor 1268 is disproportionately abundant in the deepest sediments, while PCBs likely from CSOs are relatively more abundant in surface sediment.

PFAS in municipal landfill leachate: Occurrence, transformation, and sources.

To understand sources and processes affecting per- and polyfluoroalkyl substances (PFAS), 32 PFAS were measured in landfill leachate from 17 landfills across Washington State in both pre-and post-total oxidizable precursor (TOP) assay samples, using an analytical method that was the precursor to EPA Draft Method 1633. As in other studies, 5:3FTCA was the dominant PFAS in the leachate, suggesting that carpets, textiles, and food packaging were the main sources of PFAS. Total PFAS concentrations (Σ32PFAS) ranged from 61 to 172,976 ng/L and 580-36,122 ng/L in pre-TOP and post-TOP samples, respectively, suggesting that little or no uncharacterized precursors remained in landfill leachate. Furthermore, due to chain-shortening reactions, the TOP assay often resulted in a loss of overall PFAS mass. Positive matrix factorization (PMF) analysis of the combined pre- and post-TOP samples produced five factors that represent sources and processes. Factor 1 consisted primarily of 5:3FTCA (intermediate of 6:2 fluorotelomer degradation and characteristic of landfill leachate), while factor 2 was dominated by PFBS (degradant of C-4 sulfonamide chemistry) and, to a lesser extent, by several PFCAs and 5:3FTCA. Factor 3 consisted primarily of both short-chain PFCAs (end-products of 6:2 fluorotelomer degradation) and PFHxS (derived from C-6 sulfonamide chemistry), while the main component of factor 4 was PFOS (dominant in many environmental media but minor in landfill leachate, perhaps reflecting a production shift from longer to shorter chain PFAS). Factor 5, highly loaded with PFCAs, was dominant in post-TOP samples and therefore represented the oxidation of precursors. Overall, PMF analysis suggests that the TOP assay approximates some redox processes which occur in landfills, including chain-shortening reactions which yield biodegradable products.

Sources of polychlorinated biphenyls to Upper Hudson River fish post-dredging.

Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative, and toxic chemicals that are the dominant contaminant in the Upper Hudson River (UHR) in New York State where two General Electric (GE) plants historically discharged PCBs to the river. Portions of the UHR were dredged from 2009 to 2015 to address PCB contamination. In 2017, the first post-dredging survey of yearling feeder fish and sediment PCB contamination was conducted to establish a baseline for the recovery of the river. Prior analysis of the sediment data from the 2017 survey indicated that ∼2% of the PCBs in the surface sediment were higher in molecular weight than the formulation used by GE and therefore arose from non-GE sources. In this work, the fish PCB data from the 2017 survey were analyzed using Positive Matrix Factorization (PMF). Empirical Bayesian Kriging (EBK) was used to estimate PCB concentrations in the sediment at the locations where fish were collected. The results suggest that PCBs that are the products of microbial dechlorination bioaccumulate in the fish and represent 7% of the PCB mass in the fish data set. Further, the results suggest that about 13% of the PCBs in the fish may have come from non-GE sources. This is higher than the percentage of non-GE PCBs in the sediment, but can be explained by the higher molecular weight of the non-GE mixture which causes it to bioaccumulate more effectively than GE PCBs. Concentrations of the non-GE PCBs averaged about 240 ppb wet weight (whole body) in yearling feeder fish. The remedial goals range from 50 to 400 ppb ww in fillet for fish including piscivorous species that are likely to have higher PCB concentrations than feeder fish.

Effect of membrane filtration on the fate of polychlorinated biphenyls in wastewater treatment.

The Spokane River is impacted by levels of polychlorinated biphenyls (PCBs) that have triggered fish consumption advisories and exceed water quality standards. Select wastewater treatment plants (WWTPs) on the river have been upgraded from secondary (biological) treatment to tertiary treatment in the form of membrane filtration to address phosphorus contamination. Because membrane filtration is effective at removing particles, it is likely to reduce PCB concentrations in the effluent as well. In this work, PCBs measured in the influents and effluent of several WWTPs discharging to the river were examined. Implementation of membrane filtration reduced PCB concentrations in the effluent (and therefore PCB loads to the river) by 33% at a facility that produces recycled and virgin paper and by ∼55% at municipal WWTPs, compared to secondary (activated sludge) treatment. Largest reductions in concentrations in effluent and loads were achieved for higher molecular weight (MW) PCB congeners (i.e. those with six or more chlorines), homologs, and formulations. The more modest reductions in effluent concentrations achieved at the paper WWTP may be due to the mix of PCBs in the wastewater there: it contained primarily the low MW Aroclor 1242 (presumably from carbonless copy paper) and PCB 11 (3,3'-dichlorobiphenyl) possibly from pigments. PCBs that appear to be associated with silicone products such as caulk, tubing, and o-rings are relatively more abundant in the effluent of some plants compared to the influent, suggesting that these congeners arise from contamination during sampling or from within the plant itself. At some WWTPs, this contamination accounts for nearly a third of PCBs measured in the effluent.

Source apportionment of perfluoroalkyl substances in Great Lakes fish.

Due to the complex sources and fate of perfluoroalkyl substance (PFAS), their source apportionment in the environment remains a challenge. A data set of 11 straight-chain PFAS in 139 samples of fish in the Great Lakes was analyzed using positive matrix factorization (PMF) to investigate their primary sources, whose spatial variations were examined against the surrounding environmental factors. PMF analysis produced five fingerprints. Factor 1 (72% of Σ11PFAS, dominated by PFOS) probably represented emissions from primary sources (such as consumer products) and secondary sources (precursors), and increased in average abundance from west to east across the Great Lakes. Factor 2 (13% of Σ11PFAS) and factor 3 (7% of Σ11PFAS), highly loaded with long-chain PFAS and PFNA, respectively, were thought to represent PVDF manufacture or processing in metal plating. They showed higher contributions in sparsely populated Lakes Superior and Huron. Factor 4 (5% of Σ11PFAS, highly loaded with PFOS and PFHxS) presented hot spots near current and former air force bases, suggesting it was related to aqueous film-forming foams (AFFFs). Factor 5 (4% of Σ11PFAS) contained primarily PFOS and PFOSA, which may imply metabolism of precursors (PFOSA) to PFOS in vivo. Unexpectedly, the spatial trends of the five sources all showed abnormally low values near the more urbanized Chicago and Milwaukee in Lake Michigan, which may be due to their unique wastewater and stormwater infrastructure or may arise from atmospheric transport of precursors. Our study indicated that PMF was an effective tool to identify sources of PFAS in fish despite absorption, distribution, metabolism, and excretion (ADME) processes which might alter fingerprints in fish relative to their surrounding environment.

Sources of polychlorinated biphenyls to Upper Hudson River sediment post-dredging.

The Upper Hudson River (UHR) has been contaminated with polychlorinated biphenyls (PCBs) since the 1940s due to the manufacture of capacitors at two plants near Hudson Falls and Fort Edward, NY by General Electric (GE). Dredging of portions of the UHR was conducted from 2009 to 2015 as a partial remedy for this contamination. In 2017, the New York State Department of Environmental Conservation undertook a comprehensive post-dredging survey of sediment contamination in the UHR. Thousands of samples were collected, and 130 of these were analyzed for PCBs using EPA method 1668A. This data set was analyzed using Positive Matrix Factorization. Six factors were observed. One factor resembled the dominant Aroclors used by GE with little alteration. Three factors represented different pathways and/or extents of microbial dechlorination. One factor resembled a mixture of microbial dechlorination products and a higher molecular weight Aroclor used by GE. The congener patterns of the dechlorination factors suggest that removal of chlorines at the ortho position does occur in the UHR sediment, in agreement with several laboratory studies showing that such ortho dechlorination is possible. This ortho dechlorination could theoretically lead to complete dechlorination of PCBs to biphenyl in UHR sediment. Only one factor was not attributable to GE. It represents inputs of PCBs from tributaries and urban areas and explains 1.7% of the PCB mass in the sediments. The small contribution from the non-GE PCB source suggests that recontamination of the sediment after dredging was minor.

Isolating different natural and anthropogenic PAHs in the sediments from the northern Bering-Chukchi margin: Implications for transport processes in a warming Arctic.

Polycyclic aromatic hydrocarbons (PAHs) have become the dominating burden in the Arctic ecosystems, but their transport pathways and relative importance of different sources in the Arctic remained unclear, and this would be further complicated by climate change. Here we interpreted 27 PAHs in 34 surface sediments from the northern Bering-Chukchi margin. We integrated source apportionment methods (including diagnostic ratios, principal component analysis, hierarchical analysis, and positive matrix factorization (PMF) model) together with geochemistry parameters, which reveal a gradually clear picture of the spatial patterns of different sources. The total PAH concentrations (50.4 to 896.0 ng/g dw) exhibited a "hilly" shape with the increase of latitude, showing the highest level of PAHs in the northeast Chukchi Sea. The total BaP toxic equivalent quotient (TEQ) for carcinogenic compounds was from 1.06 to 33.3 ng TEQ/g. Most PAHs showed positive correlations with silt content, total organic carbon, stable carbon isotopes and black carbon (p < 0.01 or 0.05). Generally, source apportionment methods revealed an increasing petrogenic source of PAHs with latitudes. The PMF model further differentiated two petrogenic (36.7%), two pyrogenic (softwood and fossil fuel combustion, 35.5%) and one in-situ biogenic source (Perylene, 27.8%). An extremely high petrogenic signal was captured in the Canada Basin margin, possibly originating from the Mackenzie River via ice drifting with Beaufort Gyre, while another petrogenic source may come from coal deposit erosion by deglaciation. Softwood combustion (characterized by Retene) exhibited exclusively higher contribution in the northeast Chukchi Sea and might result from the increasing wildfire in Alaska due to climate change, whereas fossil fuel combustion exhibited similar contributions across different latitudes. Our results revealed natural PAHs as important "inside sources" in the Arctic, which are highly sensitive to global warming and deserves more attention.

Perfluoroalkyl substances in sediments from the Bering Sea to the western Arctic: Source and pathway analysis.

Although perfluoroalkyl substances (PFASs) are ubiquitous in the Arctic, their dominant pathways to the Arctic remain unclear. Most modeling studies support major oceanic transport for PFASs in the Arctic seawater, but this conclusion contradicts the rapid response of PFASs to global emissions in some biota species. Sediments, which act as important PFAS sinks for seawater and potential PFAS source to the benthic food web, are important for interpreting the fate of PFASs in the Arctic. Here we investigate the occurrence of 9 PFASs in one core (1945-2014) and 29 surface sediments from the Bering Sea to the western Arctic. Total PFAS concentrations (0.06-1.73 ng/g dw) in surface sediments were dominated by perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorobutyl sulfonate (PFBS), with higher levels in the Bering Sea slope and the northeast Chukchi Sea. Historical trends in PFASs varied among individuals, with PFOS declining in the early 2000s while PFNA showing an increasing up-core trend. Analysis of positive matrix factorization model identified that the major PFAS sources in the sediment core were dominated by the atmospheric oxidation of consumer use of PFOS precursor-based products (45.0%), while the oceanic transport of fluoropolymer manufacture of polyvinylidene fluoride (mainly PFNA) exhibited an increasing trend over time, becoming dominant in surface sediments (42.8%). Besides, local input of possible aqueous fire-fighting foams (mainly PFOS and PFBS) also acted as an important source currently (30.1%) and historically (34.9%). Our study revealed that the pathways of PFASs in Arctic sediments varied greatly for individuals and the conclusion of PFOS originating from mainly atmospheric oxidation was different from seawater modeling results. This, together with the high possibility of sediments as direct source to Arctic food web (supported by similar PFAS compositions and temporal variations), help provide additional evidence regarding PFAS pathways to the Arctic.

Source Apportionment of Polychlorinated Biphenyls in Atmospheric Deposition in the Seattle, WA, USA Area Measured with Method 1668.

Atmospheric deposition can be an important pathway for the delivery of toxic polychlorinated biphenyls (PCBs) to ecosystems, especially in remote areas. Determining the sources of atmospheric PCBs can be difficult, because PCBs may travel long distances to reach the monitoring location, allowing for a variety of weathering processes that may alter PCB fingerprints. Previous efforts to determine the sources of atmospheric PCBs have been hampered by the electron capture detection methods used to measure PCBs. In this work, EPA method 1668, which is capable of measuring all 209 congeners, was used to measure PCBs in bulk atmospheric deposition at seven locations in the Green-Duwamish River watershed in and near Seattle, WA. Analysis of this data set via Positive Matrix Factorization allowed the identification of six factors that represent PCB sources. Four factors, representing approximately 88% of all PCB mass, are strikingly similar to unweathered Aroclors, suggesting minimal weathering during transport and/or local PCB sources at some sites. A fifth factor contained virtually all of the PCB 11 mass and represents PCBs from pigments. It explained approximately 39% of the Toxic Equivalency Quotient in the atmospheric deposition samples. The remaining factor contained non-Aroclor PCBs and may be related to silicone.

Alterations in fingerprints of polychlorinated biphenyls in benthic biota at the Portland Harbor Superfund Site (Oregon, USA) suggest metabolism.

In order to understand the sources and fate of polychlorinated biphenyls (PCBs) in several species of benthic biota, including clams (Corbicula fluminea), oligochaetes (Lumbriculus variegatus), and mussels (Margaritifera falcata and Anodonta nuttalliana) at the Portland Harbor Superfund Site (PHSS), their congener fingerprints were examined. First, diagnostic ratios of congeners known to be metabolizable vs. recalcitrant in the cytochrome P450 (CYP) pathway were significantly lower in biota than in its co-located sediment, indicating metabolism may have occurred. Next, the congener patterns were analyzed using Positive Matrix Factorization (PMF). The dominant fingerprint (by mass) in benthic biota is related to Aroclor 1260 but displays differences in the fingerprint that are consistent with weathering via absorption, distribution, metabolism, and excretion (ADME). This fingerprint is similar to one isolated from PCBs in fish from Washington State, indicative of common metabolic pathways and consistent with CYP metabolism. When metabolism is taken into account, the spatial distribution of the PMF-isolated PCB fingerprints in biota matches well with those from co-located sediment samples, suggesting that the same mix of sources at one location partitions into biota and sediment. In accordance to their higher hydrophobicity, higher molecular weight (MW) PCB formulations were proportionately more abundant in biota than in sediment, although low MW PCBs (e.g., PCBs 4 and 11) do bioaccumulate in benthic organisms and should not be ignored in risk assessment efforts. Finally, fingerprinting suggests potential reasons why lab-based and field-based biota-sediment accumulation factors (BSAFs) differ substantially for bivalves.

Positive Matrix Factorization analysis shows dechlorination of polychlorinated biphenyls during domestic wastewater collection and treatment.

Polychlorinated biphenyls (PCBs) are persistent, toxic and bioaccumulative pollutants. One of the few pathways via which they break down is microbial dechlorination, which has been shown to occur in sewers. Questions remain about where within sewers this process takes place and which conditions encourage dechlorination. These issues were examined using a large data set on PCBs in influent and effluents from a main and bypass outfall from a wastewater treatment facility in the Mid-Atlantic region of the USA. A data set containing 64 chromatographic peaks representing 103 PCB congeners measured in 74 whole water samples was analyzed by Positive Matrix Factorization (PMF). PMF resolved four factors, three of which represented Aroclors 1242, 1254, and 1260. The remaining factor represented an advanced dechlorination regime of PCBs characterized by high proportions of PCBs 4 and 19 and comprised about 35% of the PCBs in the treated effluent, among the highest levels of dechlorination observed in previous studies. Concentrations of dechlorination products were not correlated with total suspended solids, indicating they were mostly dissolved and explaining the poor removal via sedimentation during the treatment process. The factors representing Aroclors were positively correlated with total influent flow, but the dechlorination signal was not, suggesting that the dechlorination signal arises from different locations and/or processes than the Aroclors. Even though treatment and dechlorination reduced the dioxin-like toxicity of the PCB mixture, this effect might be offset by the incomplete removal of dechlorination products.

Sewer Sediment Bacterial Communities Suggest Potential to Transform Persistent Organic Pollutants.

Sediments of combined sewers are seeded with microbes from a variety of sources, and experience varying biogeochemical conditions. A variety of redox processes have been demonstrated to occur within sewer systems, as well as transformation of several recalcitrant xenobiotic contaminants. Illumina sequencing of the 16S ribosomal RNA gene from sediments of three combined sewer systems in the northeastern United States resulted in 10 000 to 47 000 operational taxonomic units per sample. Whereas orders Clostridiales and Bacteroidales, considered human fecal indicators, were dominant in one city's sediments; other cities had communities suggestive of diverse redox processes, including reductive dechlorination of chlorinated organic compounds. Collection systems previously associated with polychlorinated biphenyl (PCB) biotransformation, and those with elevated in situ PCB concentrations, had high abundances of Dehalococcoidetes. The results suggest that wastewater collection systems have intrinsic passive treatment capacity, reducing contaminant loads on water resource recovery facilities and, ultimately, on receiving waters.

Using positive matrix factorization to investigate microbial dehalogenation of chlorinated benzenes in groundwater at a historically contaminated site.

Chlorinated benzenes are common groundwater contaminants in the United States, so demonstrating whether they undergo degradation in the subsurface is important in determining the best remedy for this contamination. The purpose of this work was to use a new data mining approach to investigate chlorinated benzene degradation pathways in the subsurface. Positive Matrix Factorization (PMF) was used to analyze long-term measurements of chlorinated benzene concentrations in groundwater at a contaminated site in New Jersey. A dataset containing 597 groundwater samples and 5 chlorinated benzenes and benzene collected from 144 wells over 20 years was investigated using PMF2 software. Despite the heterogeneity of this dataset, PMF analysis revealed patterns indicative of microbial dechlorination in the groundwater and provided insight about where dechlorination is occurring, to what extent, and under which geochemical conditions. PMF resolved a factor indicative of a source of 1,2,4-trichlorobenzene and 1,2-dichlorobenzene and two factors representing stages of dechlorination, one more advanced than the other. The PMF results indicated that virtually all of the 1,2-dichlorobenzene at the site arises from its use onsite, not from the dechlorination of trichlorobenzenes. Factors were further interpreted using ancillary data such as geochemical indicators and field parameters also measured in the samples. Analysis suggested that the partial and advanced dechlorination signals occur under different subsurface physical conditions. The results provided field validation of the current understanding of anaerobic dechlorination of chlorinated benzenes in the subsurface developed from laboratory studies. PMF is thereby shown to be a useful tool for investigating chlorinated benzene dechlorination.

Forensic Analysis of Polychlorinated Dibenzo-p-Dioxin and Furan Fingerprints to Elucidate Dechlorination Pathways.

Polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) are persistent organic pollutants whose main removal process in the environment is due to biodegradation, and particularly anaerobic reductive dechlorination. Since PCDD/F congeners that are substituted in the lateral 2, 3, 7, and 8 positions are the most toxic, removal of these chlorines is advantageous, but previous studies have only demonstrated their removal under laboratory conditions. We evaluated a concentration data set of PCDD/F congeners with four or more chlorines along with all 209 polychlorinated biphenyl (PCB) congeners in surface water, treated and untreated wastewater, landfill leachate, and biosolids (NY CARP data set) to determine whether peri and peri/lateral dechlorination of PCDD/Fs occurs in these environments. Positive Matrix Factorization (PMF) applied to the data set revealed a factor indicative of the microbial dechlorination of PCBs, and this factor also contained a variety of non-2,3,7,8 substituted PCDD/F congeners. These results suggest that dechlorination of PCDD/Fs at the lateral positions is facile if not preferred in these environments. The relative lack of tetra- and penta-chlorinated PCDD/Fs suggested that dechlorination proceeds to PCDD/F congeners with less than four chlorines. The PMF results were confirmed by examining three samples that contained >90% PCB dechlorination products from the Fresh Kills Landfill and the Hudson River. Even without factor analysis, these samples demonstrated almost identical PCDD/F congener patterns. This study suggests that PCDD/Fs are reductively dechlorinated to nontoxic non-2,3,7,8 PCDD/F congeners in sewers and landfills as well as in the sediment of the Upper Hudson River.

Source Apportionment of Atmospheric Polychlorinated Biphenyls in New Jersey 1997-2011.

Concentrations of polychlorinated biphenyls (PCBs) in the Delaware River currently exceed the Water Quality Criteria of 16 pg/L for the sum of PCBs due in part to atmospheric deposition. The purpose of this work was to use a source apportionment tool called Positive Matrix Factorization (PMF) to identify the sources of PCBs to the atmosphere in this area and determine whether their concentrations are declining over time. The data set was compiled by the Delaware Atmospheric Deposition Network (DADN) from samples taken in Camden, NJ from 1999 to 2011 and New Brunswick, NJ from 1997 to 2011. The PMF analysis revealed four resolved factors at each site. The factors that dominate the PCB burden in the atmosphere at both Camden and New Brunswick resemble Aroclor 1242. These factors declined in concentration during some portions of the monitoring period, but this decline slowed or stopped during 2003-2011. None of the factors displayed consistent declines in concentration throughout the monitoring periods, and some factors actually increased in concentration during some periods. This suggests natural attenuation alone will not control atmospheric PCB concentrations, and additional efforts are needed to control PCB atmospheric emissions as well as the numerous other sources of PCBs to the estuary.

Historical sources of polychlorinated biphenyls to the sediment of the New York/New Jersey Harbor.

Using dated sediment cores, polychlorinated biphenyl (PCB) congener concentrations in the New York/New Jersey Harbor and Lower Hudson River were investigated using Positive Matrix Factorization. Of the seven factors resolved, six represent Aroclors in various stages of weathering. Factor 1 resembles Aroclor 1242 and is consistent with the Upper Hudson River PCB signal associated with the General Electric capacitor plants near Hudson Falls, NY. This factor is the dominant source of PCBs in the upper layers of the sediment core collected in the Lower Hudson River. Factor 2 (Aroclor 1248) was the dominant PCB component in the core depths corresponding with around 1970, but it has decreased more rapidly since its peak (estimated half-life of about 5 years) than factor 1 (half-life of about 14 years), suggesting that PCBs from the Upper Hudson have delayed the recovery of the Harbor from PCB contamination. The seventh factor, comprised of PCBs 206, 208, and 209, was greatest in concentration in the deepest core slices and is thought be associated with inadvertent production of PCBs during the manufacture of titanium dioxide and/or with foundry waxes containing PCBs. PCB 11, which is thought to be associated with the use of color organic pigments, was examined separately and was detected in sediment throughout the Harbor. Its maximum concentrations generally occurred at the same depth as the maximum total PCB concentrations, suggesting that PCB 11 concentrations decreased after the mid-1970s.

Microbial dechlorination of polychlorinated biphenyls, dibenzo-p-dioxins, and -furans at the Portland Harbor Superfund site, Oregon, USA.

The Portland Harbor (Oregon, USA) has been declared a "Superfund" site because it is impacted by a variety of contaminants, including polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs). Using data collected in the remedial investigation, concentrations of PCBs and PCDD/Fs in sediment and water were examined using positive matrix factorization to look for evidence that PCBs and PCDD/Fs are dechlorinated by anaerobic bacteria. This process has long been known to occur in sediments. Recently, it has been recognized that PCB and PCDD/F dechlorination may also occur in other anaerobic environments, such as in landfills, sewers, and groundwater. The results indicate that a factor related to the dechlorination of PCBs and PCDD/Fs was present in the water but not in the sediment. Spatial patterns in dechlorination products suggest that they come primarily from groundwater. Dechlorination products comprise 22% of the PCBs in the water. The Portland Harbor therefore represents the third major US watershed in which PCBs appear to undergo dechlorination in an environment other than sediment, suggesting that the microbial dechlorination of PCBs and PCDD/Fs is more common than previously assumed. In addition, the Portland Harbor is impacted by PCBs generated inadvertently during the production of pigments, such as PCB 11, which alone exceeded the 64 pg/L federal water quality standard for the sum of PCBs in two of 120 whole water samples.

Indoor air quality in green buildings: A case-study in a residential high-rise building in the northeastern United States.

Improved indoor air quality (IAQ) is one of the critical components of green building design. Green building tax credit (e.g., New York State Green Building Tax Credit (GBTC)) and certification programs (e.g., Leadership in Energy & Environmental Design (LEED)) require indoor air quality measures and compliance with allowable maximum concentrations of common indoor air pollutants. It is not yet entirely clear whether compliance with these programs results in improved IAQ and ultimately human health. As a case in point, annual indoor air quality measurements were conducted in a residential green high-rise building for five consecutive years by an industrial hygiene contractor to comply with the building's GBTC requirements. The implementation of green design measures resulted in better IAQ compared to data in references of conventional homes for some parameters, but could not be confirmed for others. Relative humidity and carbon dioxide were satisfactory according to existing standards. Formaldehyde levels during four out of five years were below the most recent proposed exposure limits found in the literature. To some degree, particulate matter (PM) levels were lower than that in studies from conventional residential buildings. Concentrations of Volatile Organic Compounds (VOCs) with known permissible exposure limits were below levels known to cause chronic health effects, but their concentrations were inconclusive regarding cancer health effects due to relatively high detection limits. Although measured indoor air parameters met all IAQ maximum allowable concentrations in GBTC and applicable LEED requirements at the time of sampling, we argue that these measurements were not sufficient to assess IAQ comprehensively because more sensitive sampling/analytical methods for PM and VOCs are needed; in addition, there is a need for a formal process to ensure rigor and adequacy of sampling and analysis methods. Also, we suggest that a comprehensive IAQ assessment should include mixed mode thermal comfort models, semi-volatile organic compounds, assessment of new chemicals, and permissible exposure levels of many known indoor VOCs and bioaerosols. Plus, the relationship between energy consumption and IAQ, and tenant education on health effects of indoor pollutants and their sources may need more attention in IAQ investigations in green buildings.

Polychlorinated biphenyl congener patterns in fish near the Hanford Site (Washington State, USA).

It is well-known that absorption, distribution, metabolism, and excretion (ADME) processes in fish can alter polychlorinated biphenyl (PCB) congener patterns in fish, but these patterns have never been investigated using an advanced source-apportionment tool. In this work, PCB congener patterns in freshwater fish were examined with positive matrix factorization (PMF). PCB congeners were quantified via EPA Method 1668 in fillet and carcass of six species in four study areas in the Columbia River near the Hanford Site. Six factors were resolved with PMF2 software. Depletion and enhancement of PCB congeners in factors, relative to Aroclor 1254, suggested biotransformation (via cytochrome P450) and bioaccumulation in fish, respectively. Notable differences were observed among species and across study locations. For example, sturgeon and whitefish exhibited congener patterns consistent with Aroclor weathering, suggesting potential PCB metabolism in these species. In terms of location, average concentration of total PCBs for all species combined was significantly higher (P < 0.05) at Hanford 100 and 300 areas, relative to upriver and downriver study sites. Furthermore, a distinct PCB signature in sturgeon and whitefish, collected at Hanford study areas, suggests that Hanford is a unique PCB source.