@article {85, title = {Spatial and temporal trends in poly- and per-fluorinated compounds in the Laurentian Great Lakes Erie, Ontario and St. Clair.}, journal = {Environ Pollut}, volume = {237}, year = {2018}, month = {2018 Jun}, pages = {396-405}, abstract = {

The temporal and spatial trends in sediment of 22 poly- and perfluorinated (PFAS) compounds were investigated in the southern Great Lakes Erie and Ontario as well as Lake St. Clair. Surface concentrations measured by Ponar grab samples indicated a trend for greater concentrations near to urban sites. Mean concentrations ∑PFAS were 15.6, 18.2 and 19 ng g dm for Lakes St. Clair, Erie and Ontario, respectively. Perfluoro-n-butanoic acid (PFBA) and Perfluoro-n-hexanoic acid (PFHxA) were frequently determined in surface sediment and upper core samples indicating a shift in use patterns. Where PFBA was identified it was at relatively great concentrations typically \>10 ng g dm. However as PFBA and PFHxA are less likely to bind to sediment they may be indicative of pore water concentrations Sedimentation rates between Lake Erie and Lake Ontario differ greatly with greater rates observed in Lake Erie. In Lake Ontario, in general concentrations of PFAS observed in core samples closely follow the increase in use along with an observable change due to regulation implementation in the 1970s for water protection. However some of the more water soluble PFAS were observed in deeper core layers than the time of production could account for, indicating potential diffusion within the sediment. Given the greater sedimentation rates in Lake Erie, it was hoped to observe in greater resolution changes since the mid-1990s. However, though some decrease was observed at some locations the results are not clear. Many cores in Lake Erie had clearly observable gas voids, indicative of gas ebullition activity due to biogenic production, there were also observable mussel beds that could indicate mixing by bioturbation of core layers.

}, keywords = {Environmental Monitoring, Fluorocarbons, Great Lakes Region, Lakes, Ontario, Water Pollutants, Chemical, Water Pollution, Chemical}, issn = {1873-6424}, doi = {10.1016/j.envpol.2018.02.013}, author = {Codling, Garry and Sturchio, Neil C and Rockne, Karl J and Li, An and Peng, H and Tse, Timothy J and Jones, Paul D and Giesy, John P} } @article {93, title = {Identification of Chemicals that Cause Oxidative Stress in Oil Sands Process-Affected Water.}, journal = {Environ Sci Technol}, volume = {51}, year = {2017}, month = {2017 Aug 01}, pages = {8773-8781}, abstract = {

Oil sands process-affected water (OSPW) has been reported to cause oxidative stress in organisms, yet the causative agents remain unknown. In this study, a high-throughput in vitro Nrf2 reporter system was used, to determine chemicals in OSPW that cause oxidative stress. Five fractions, with increasing polarity, of the dissolved organic phase of OSPW were generated by use of solid phase extraction cartridges. The greatest response of Nrf2 was elicited by F2 (2.7 {\textpm} 0.1-fold), consistent with greater hydroperoxidation of lipids in embryos of Japanese medaka (Oryzias latipes) exposed to F2. Classic naphthenic acids were mainly eluted in F1, and should not be causative chemicals. When F2 was fractionated into 60 subfractions by use of HPLC, significant activation of Nrf2 was observed in three grouped fractions: F2.8 (1.30 {\textpm} 0.01-fold), F2.16 (1.34 {\textpm} 0.05-fold), and F2.25 (1.28 {\textpm} 0.15-fold). 54 compounds were predicted to be potential chemicals causing Nrf2 response, predominated by SO and O species. By use of high-resolution MS spectra, these SO and O species were identified as hydroxylated aldehydes. This study demonstrated that polyoxygenated chemicals, rather than classic NAs, were the major chemicals responsible for oxidative stress in the aqueous phase of OSPW.

}, keywords = {Animals, Carboxylic Acids, Oil and Gas Fields, Oryzias, Oxidative Stress, Water, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/acs.est.7b01987}, author = {Sun, Jianxian and Peng, Hui* and Alharbi, Hattan A and Jones, Paul D and Giesy, John P and Wiseman, Steve B} } @article {100, title = {Combined Transcriptomic and Proteomic Approach to Identify Toxicity Pathways in Early Life Stages of Japanese Medaka (Oryzias latipes) Exposed to 1,2,5,6-Tetrabromocyclooctane (TBCO).}, journal = {Environ Sci Technol}, volume = {50}, year = {2016}, month = {2016 07 19}, pages = {7781-90}, abstract = {

Currently, the novel brominated flame retardant 1,2,5,6-tetrabromocyclooctane (TBCO) is considered a potential replacement for hexabromocyclododecane (HBCD). Therefore, use of TBCO could increase in the near future. To assess potential toxicological risks to aquatic organisms, embryos of Japanese medaka (Oryzias latipes) were exposed to 10, 100, or 1000 μg/L TBCO from 2 h postfertilization until 1 day post-hatch. TBCO accumulated in embryos in the order of 0.43-1.3 {\texttimes} 10(4)-fold, and the rate constant of accumulation was 1.7-1.8 per day. The number of days to hatch and the hatching success of embryos exposed to the medium and the greatest concentrations of TBCO were impaired. Responses of the transcriptome (RNA-seq) and proteome were characterized in embryos exposed to 100 μg/L TBCO because this was the least concentration of TBCO that caused an effect on hatching. Consistent with effects on hatching, proteins whose abundances were reduced by exposure to TBCO were enriched in embryo development and hatching pathways. Also, on the basis of the responses of transcriptome and proteome, it was predicted that TBCO might impair vision and contraction of cardiac muscle, respectively, and these effects were confirmed by targeted bioassays. This study provided a comprehensive understanding of effects of TBCO on medaka at early life stages and illustrated the power of "omics" to explain and predict phenotypic responses to chemicals.

}, keywords = {Animals, Oryzias, Proteomics, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/acs.est.6b01249}, author = {Sun, Jianxian and Tang, Song and Peng, Hui* and Saunders, David M V and Doering, Jon A and Hecker, Markus and Jones, Paul D and Giesy, John P and Wiseman, Steve} } @article {103, title = {Untargeted Screening and Distribution of Organo-Bromine Compounds in Sediments of Lake Michigan.}, journal = {Environ Sci Technol}, volume = {50}, year = {2016}, month = {2016 Jan 05}, pages = {321-30}, abstract = {

Previously unreported natural and synthetic organo-bromine compounds (NSOBCs) have been found to contribute more than 99\% of total organic bromine (TOB) in environmental matrices. We recently developed a novel untargeted method (data-independent precursor isolation and characteristic fragment, DIPIC-Frag) and identified \~{}2000 NSOBCs in two sediments from Lake Michigan. In this study, this method was used to investigate the distributions of these NSOBCs in 23 surficial samples and 24 segments of a sediment core from Lake Michigan. NSOBCs were detected in all 23 surficial samples and exhibited 10- to 100-fold variations in peak abundance among locations. The pattern of distributions of NSOBCs was correlated with depth of the water column (r(2) = 0.61, p \< 0.001). Hierarchical cluster analysis showed that sediments in close proximity exhibited similar profiles of NSOBCs. Distributions of NSOBCs in 24 segments of a sediment core dated from 1766 to 2008 were investigated, and samples from similar depths exhibited similar profiles of NSOBCs. NSOBCs were grouped into four clusters (soft-cluster analysis) with different temporal trends of abundances. 515 and 768 of the NSOBCs were grouped into cluster 1 and cluster 3 with increasing temporal trends, especially since 1950, indicating that abundances of these compounds might have been affected by human activities.

}, keywords = {Bromine Compounds, Environmental Monitoring, Geologic Sediments, Halogenated Diphenyl Ethers, Hydrocarbons, Brominated, Lakes, Michigan, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/acs.est.5b04709}, author = {Peng, Hui and Chen, Chunli and Cantin, Jenna and Saunders, David M V and Sun, Jianxian and Tang, Song and Codling, Garry and Hecker, Markus and Wiseman, Steve and Jones, Paul D and Li, An and Rockne, Karl J and Sturchio, Neil C and Giesy, John P} } @article {98, title = {Untargeted Screening and Distribution of Organo-Iodine Compounds in Sediments from Lake Michigan and the Arctic Ocean.}, journal = {Environ Sci Technol}, volume = {50}, year = {2016}, month = {2016 09 20}, pages = {10097-105}, abstract = {

The majority of halogenated organic compounds present in the environment remain unidentified. To address this data gap, we recently developed an untargeted method (data-independent precursor isolation and characteristic fragment; DIPIC-Frag) for identification of unknown organo-bromine compounds. In this study, the method was adapted to enable untargeted screening of natural and synthetic organo-iodine compounds (NSOICs) in sediments. A total of 4,238 NSOIC peaks were detected in sediments from Lake Michigan. Precursor ions and formulas were determined for 2,991 (71\%) of the NSOIC peaks. These compounds exhibited variations in abundances (\<10(3) to \~{}10(7)), m/z values (206.9304-996.9474), retention times (1.0-29.7 min), and number of iodine atoms (1-4). Hierarchical cluster analysis showed that sediments in closer proximity exhibited similar profiles of NSOICs. NSOICs were screened in 10 samples of sediment from the Arctic Ocean to compare the profiles of NSOICs between freshwater and marine sediments. A total of 3,168 NSOIC peaks were detected, and profiles of NSOICs in marine sediments were clearly distinct from Lake Michigan. The coexistence of brominated and iodinated analogues indicated that some NSOICs are of natural origin. Different ratios of abundances of iodinated compounds to brominated analogues were observed and proposed as a marker to distinguish sources of NSOICs.

}, keywords = {Geologic Sediments, Iodine Compounds, Lakes, Michigan, Oceans and Seas, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/acs.est.6b03221}, author = {Peng, Hui and Chen, Chunli and Cantin, Jenna and Saunders, David M V and Sun, Jianxian and Tang, Song and Codling, Garry and Hecker, Markus and Wiseman, Steve and Jones, Paul D and Li, An and Rockne, Karl J and Sturchio, Neil C and Cai, Minghong and Giesy, John P} }