Flame Retardants and Legacy Chemicals in Great Lakes’ Water

The Great Lakes have been the focus of extensive environmental research, but recent data on the aquatic concentrations of emerging compounds, such as flame retardants, are scarce. Water samples from 18 stations on the five Great Lakes were collected in 2011 and 2012 using XAD-2 resin adsorption and analyzed for PCBs, organochlorine pesticides, PAHs, polybrominated diphenyl ethers (PBDEs), and emerging flame retardants, including organophosphate flame retardants (OPEs). Total PCB concentrations ranged from 117 ± 18 pg/L in Lake Superior to 623 ± 113 pg/L in Lake Ontario. Among the organochlorine pesticides, the most abundant was dieldrin, with the highest average concentration of 99 ± 26 pg/L in Lake Erie, followed by <i>p</i>,<i>p′</i>-DDD with an average concentration of 37 ± 8 pg/L in Lake Ontario. Total PAH concentrations were higher in Lakes Erie and Ontario than in Lakes Michigan, Huron, and Superior. Total PBDE concentrations were highest in Lake Ontario (227 ± 75 pg/L), and the most abundant congeners were BDE-47, BDE-99, and BDE-209. Total OPE concentrations ranged between 7.3 ± 4.5 ng/L in Lake Huron to 96 ± 43 ng/L in Lake Erie

Enantiospecific Perfluorooctane Sulfonate (PFOS) Analysis Reveals Evidence for the Source Contribution of PFOS-Precursors to the Lake Ontario Foodweb

Exposure to perfluorooctane sulfonate (PFOS) may arise directly, from emission and exposure to PFOS itself, or indirectly via the environmental release and degradation of PFOS-precursors. Human serum enantiomer fractions (EFs) of 1<i>m</i>-PFOS have been shown to be nonracemic, suggesting that PFOS-precursors are a significant source of PFOS in humans, but little is known about the importance of PFOS-precursors in ecosystems. In the current work, concentrations of PFOS, perfluorooctane sulfonamide (PFOSA), PFOS isomer profiles, and EFs of 1<i>m</i>-PFOS were determined in Lake Ontario water, sediment, fishes and invertebrates. Concentrations of PFOS and PFOSA were highest in slimy sculpin and <i>Diporeia</i>, and concentrations of the two compounds were often correlated. 1<i>m</i>-PFOS was racemic in sediment, water, sculpin and rainbow smelt, but nonracemic in the top predator, lake trout, and all invertebrate species. Furthermore, EFs were correlated with the relative concentrations of PFOS and PFOSA in invertebrates. Overall, these empirical observations with a new analytical tool confirm previous suggestions that PFOS-precursors contribute to PFOS in the food web, likely via sediment. Implications are that future PFOS exposures in this ecosystem will be influenced by an in situ source, and that the apparent environmental behavior of PFOS (e.g., bioaccumulation potential) can be confounded by precursors

Non-target assessment of the maternal transfer of non-polar toxic organic compounds in European eels by GCxGC-TOF and GC-FTICR-MS

Chemical pollution is hypothesized as one of the factors driving the strong decline of the critically endangered European eel population. Specifically the impact of contaminants on the quality of spawning eels and subsequent embryo survival and development has been discussed as crucial investigation point. However, so far only very limited information on potential negative effects of contaminants on the reproduction of eels is available.  Through the combination of non-targeted ultra-high resolution mass spectrometry and multidimensional gas chromatography, combined with more conventional targeted analytical approaches, compounds of particular relevance and their maternal transfer in artificially matured European eels from the German river Ems have been identified.  Substituted diphenylamines were, unexpectedly, found to be the primary organic contaminants in the eel samples, with concentrations exceeding 10 µg g-1 ww. Furthermore, it could be shown that these contaminants, as well as known contaminants in eel such as polychlorinated biphenyls (PCBs), organochlorine pesticides and polyaromatic hydrocarbons (PAHs), are not merely stored in lipid rich tissue of eels, but maternally transferred into gonads and eggs.  The results of this study provide unpreceded information on both the fate and behavior of substituted diphenylamines in the environment as well as their relevance as contaminants in European eels.</p

Identification and Occurrence of Analogues of Dechlorane 604 in Lake Ontario Sediment and their Accumulation in Fish

The dechlorane family of flame retardants, which includes Mirex (also known as Dechlorane), Dechlorane Plus (DP), and Dechloranes (Dec) 602, 603, and 604, were manufactured at a facility along the Niagara River, upstream of Lake Ontario. Some of these compounds remain in use. In a previous study, we found Mirex and Dec602 to have greater bioaccumulation potentials than Dec604 and DP based on calculated biota-sediment accumulation factors (BSAFs). In this study, analogues of Dec604, containing fewer bromines and mixed substitutions of bromine and chlorine, were identified in Lake Ontario sediment and fish using high and ultrahigh resolution mass spectrometric techniques. The tribromo-Dec604 (Br₃Dec604) analogue, known as Dechlorane 604 Component B (Dec604 CB), was present in lake trout and whitefish at concentrations of 10–60 ng/g lipid weight, approximately 50–200 times greater than concentrations measured for Dec604. In addition, BrDec604 and Br₂Dec604 analogues, and mixed Br₂Cl₂Dec604, Br₃ClDec604, Br₂ClDec604, and BrCl₂Dec604 analogues were also present. We have shown that solutions of Dec604 and Dec604 CB exposed to UV-light undergo photodebromination and give rise to the analogues found in sediment and fish. Dec604 CB and other lesser halogenated analogues of Dec604 show greater bioaccumulation potentials than Dec604, Dec602 and DP, based on BSAFs, which highlight the need to consider likely impurities and degradation products in the assessment of persistent, bioaccumulative, and toxic compounds

Evidence for High Concentrations and Maternal Transfer of Substituted Diphenylamines in European Eels Analyzed by Two-Dimensional Gas Chromatography–Time-of-Flight Mass Spectrometry and Gas Chromatography–Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Chemical pollution is hypothesized to be one of the factors driving the strong decline of the critically endangered European eel population. Specifically, the impact of contaminants on the quality of spawning eels and subsequent embryo survival and development has been discussed as crucial investigation point. However, so far, only very limited information on potential negative effects of contaminants on the reproduction of eels is available. Through the combination of nontargeted ultrahigh-resolution mass spectrometry and multidimensional gas chromatography, combined with more-conventional targeted analytical approaches and multimedia mass-balance modeling, compounds of particular relevance, and their maternal transfer in artificially matured European eels from the German river Ems have been identified. Substituted diphenylamines were, unexpectedly, found to be the primary organic contaminants in the eel samples, with concentrations in the μg g^–1 wet weight range. Furthermore, it could be shown that these contaminants, as well as polychlorinated biphenyls (PCBs), organochlorine pesticides, and polyaromatic hydrocarbons (PAHs), are not merely stored in lipid rich tissue of eels but maternally transferred into gonads and eggs. The results of this study provide unique information on both the fate and behavior of substituted diphenylamines in the environment as well as their relevance as contaminants in European eels