1
|
Sjøholm KK, Dechesne A, Lyon D, Saunders DMV, Birch H, Mayer P. Linking biodegradation kinetics, microbial composition and test temperature - Testing 40 petroleum hydrocarbons using inocula collected in winter and summer. Environ Sci Process Impacts 2022; 24:152-160. [PMID: 34985480 DOI: 10.1039/d1em00319d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Many factors affect the biodegradation kinetics of chemicals in test systems and the environment. Empirical knowledge is needed on how much test temperature, inoculum, test substances and co-substrates influence the biodegradation kinetics and microbial composition in the test. Water was sampled from the Gudenaa river in winter (2.7 °C) and summer (17 °C) (microbial inoculum) and combined with an aqueous stock solution of >40 petroleum hydrocarbons prepared by passive dosing. This resulted in low-concentration test systems that were incubated for 30 days at 2.7, 12 and 20 °C. Primary biodegradation kinetics, based on substrate depletion relative to abiotic controls, were determined with automated Solid Phase Microextraction coupled to GC/MS. Biodegradation kinetics were remarkably similar for summer and winter inocula when tested at the same temperature, except when cooling summer inoculum to 2.7 °C which delayed degradation relative to winter inoculum. Amplicon sequencing was applied to determine shifts in the microbial composition between season and during incubations: (1) the microbial composition of summer and winter inocula were remarkably similar, (2) the incubation and the incubation temperature had both a clear impact on the microbial composition and (3) the effect of adding >40 petroleum hydrocarbons at low test concentrations was limited but resulted in some proliferation of the known petroleum hydrocarbon degraders Nevskia and Sulfuritalea. Overall, biodegradation kinetics and its temperature dependency were very similar for winter and summer inoculum, whereas the microbial composition was more affected by incubation and test temperature compared to the addition of test chemicals at low concentrations.
Collapse
Affiliation(s)
- Karina Knudsmark Sjøholm
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Arnaud Dechesne
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | | | - David M V Saunders
- Concawe, B-1160 Brussels, Belgium
- Shell Health, Shell International B.V., 2596 HR The Hague, The Netherlands
| | - Heidi Birch
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| |
Collapse
|
2
|
Knudsmark Sjøholm K, Birch H, Hammershøj R, Saunders DMV, Dechesne A, Loibner AP, Mayer P. Determining the Temperature Dependency of Biodegradation Kinetics for 34 Hydrocarbons while Avoiding Chemical and Microbial Confounding Factors. Environ Sci Technol 2021; 55:11091-11101. [PMID: 34355887 DOI: 10.1021/acs.est.1c02773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Biodegradation kinetics data are keystone for evaluating the environmental persistence and risk of chemicals. Biodegradation kinetics depend highly on the prevailing temperature, which influences microbial community structures, metabolic rates, and chemical availability. There is a lack of high-quality comparative biodegradation kinetics data that are determined at different test temperatures but with the same microbial inoculum and chemical availability. The present study was designed to determine the effect of test temperature on the biodegradation kinetics of hydrocarbons while avoiding confounding factors. We used inocula from a Northern river (2.7 °C) and a Central European river (12.5 °C). Aqueous stock solutions containing 45 individual hydrocarbons were generated by passive dosing and added to river water containing the native microorganisms. Compound-specific biodegradation kinetics were then determined at 2.7, 12, and 20 °C based on substrate depletion. Main findings comprise the following: (1) Degradation half-times (DegT50) of 34 test chemicals were determined at different test temperatures and were largely consistent with the Arrhenius equation (activation energy, 65.4 kJ/mol). (2) Differences in biodegradation kinetics between tested isomers were rather limited. (3) The recent lowering of standard test temperature from 20 to 12 °C results typically in a doubling of DegT50 values and can lead to a stricter persistency assessment.
Collapse
Affiliation(s)
- Karina Knudsmark Sjøholm
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Heidi Birch
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Rikke Hammershøj
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - David M V Saunders
- Shell Health, Shell International B.V., 2596 HR The Hague, The Netherlands
| | - Arnaud Dechesne
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Andreas P Loibner
- Institute of Environmental Biotechnology, BOKU - University of Natural Resources and Life Sciences, Vienna, A-3430 Tulln, Austria
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| |
Collapse
|
3
|
Maloney EM, Naile J, Saunders DMV. Quantifying the effect of weathering on acute oil toxicity using the PETROTOX model. Mar Pollut Bull 2021; 162:111849. [PMID: 33248672 DOI: 10.1016/j.marpolbul.2020.111849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/18/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Following accidental release into marine environments, crude oil progressively weathers, influencing composition, fate, and toxicity. However, published studies draw conflicting conclusions on the effects of oil weathering on ecotoxicity. Using the PETROTOX model, this study characterized the effect of weathering on acute oil toxicity for four aquatic species. Results indicated that predicted acute toxicity decreased with increased oil weathering, due to reductions in overall concentrations and bioavailability of hydrocarbon constituents.
Collapse
Affiliation(s)
- E M Maloney
- Shell Health, Shell Oil Company, Houston, TX, USA
| | - J Naile
- Shell Health, Shell Oil Company, Houston, TX, USA.
| | - D M V Saunders
- Shell Health, Shell International, The Hague, Zuid-Holland, the Netherlands
| |
Collapse
|
4
|
Brown DM, Lyon D, Saunders DMV, Hughes CB, Wheeler JR, Shen H, Whale G. Biodegradability assessment of complex, hydrophobic substances: Insights from gas-to-liquid (GTL) fuel and solvent testing. Sci Total Environ 2020; 727:138528. [PMID: 32334217 DOI: 10.1016/j.scitotenv.2020.138528] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/31/2020] [Accepted: 04/05/2020] [Indexed: 04/15/2023]
Abstract
The assessment of substances of Unknown or Variable composition, Complex reaction products or Biological materials (UVCBs) presents significant challenges when determining biodegradation potential and environmental persistence for regulatory purposes. An example of UVCBs is the gas-to-liquid (GTL) products, which are synthetic hydrocarbons produced from natural gas using a catalytic process known as the Fischer-Tropsch process. These synthetic hydrocarbons are fractionated into a wide array of products equivalent in function to their petroleum-derived analogues. Here we summarise the results of an extensive testing program to assess the biodegradability of several GTL products. This program highlights the challenges associated with UVCBs and provides a case study for the assessment of such substances that are also poorly soluble and volatile. When tested with the appropriate methods, all the GTL products assessed in this study were found to be readily biodegradable indicating they are not likely to be persistent in the environment.
Collapse
Affiliation(s)
| | | | | | | | - James R Wheeler
- Shell Health, Shell International B.V., The Hague, the Netherlands
| | - Hua Shen
- Shell Health Americas, Houston, USA
| | - Graham Whale
- Whale Environmental Consultancy Limited, Chester, UK
| |
Collapse
|
5
|
Peng H, Sun J, Saunders DMV, Codling G, Wiseman S, Jones PD, Giesy JP. Hydroxylated 2-Ethylhexyl tetrabromobenzoate isomers in house dust and their agonistic potencies with several nuclear receptors. Environ Pollut 2017; 227:578-586. [PMID: 28505588 DOI: 10.1016/j.envpol.2017.04.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/28/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
In the current study, by combining ultra-high resolution (UHR) MS1 spectra, MS2 spectra, and derivatization, three hydroxylated isomers of 2-ethylhexyl tetrabromobenzoate (OH-TBB) were identified in Firemaster® 550 and BZ-54 technical products. Also, a new LC-UHRMS method, using atmospheric pressure chemical ionization (APCI), was developed for simultaneous analysis of OH-TBB, TBB, hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) and TBPH in 23 samples of dust collected from houses in Saskatoon, SK, Canada. OH-TBBs were detected in 91% of samples, with a geometric mean concentration of 0.21 ng/g, which was slightly less than those of OH-TBPH (0.35 ng/g). TBB was detected in 100% of samples of dust with a geometric mean concentration of 992 ng/g. Significant (p < 0.001) log-linear relationships between concentrations of OH-TBBs, TBB, or OH-TBPHs and TBPH in dust support the hypothesis of a common source of these compounds. OH-TBBs were found to be strong agonists of peroxisome proliferator-activated receptor gamma (PPARγ) and weaker agonists of the estrogen receptor (ER), but no agonistic potencies was observed with the androgen receptor (AR). Occurrence of OH-TBBs in technical products and house dust, together with their relatively strong PPARγ potencies, indicated their potential risk to health of humans.
Collapse
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Garry Codling
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; School of Environment and Sustainability, 117 Science Place, Saskatoon, SK, S7N 5C8, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada; Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; Department of Biology and Chemistry, City University of Hong Kong, Kowloon, People's Republic of China; School of Biological Sciences, University of Hong Kong, People's Republic of China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China
| |
Collapse
|
6
|
Peng H, Saunders DMV, Sun J, Jones PD, Wong CKC, Liu H, Giesy JP. Correction to Mutagenic Azo Dyes, Rather than Flame Retardants, are the Predominant Brominated Compounds in House Dust. Environ Sci Technol 2017; 51:3593. [PMID: 28281751 DOI: 10.1021/acs.est.7b00919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
|
7
|
Peng H, Saunders DMV, Jones PD, Giesy JP. Response to Comment on "Mutagenic Azo Dyes, Rather than Flame Retardants, are the Predominant Brominated Compounds in House Dust". Environ Sci Technol 2017; 51:3591-3592. [PMID: 28282130 DOI: 10.1021/acs.est.7b00675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK Canada
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, SK Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK Canada
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, People's Republic of China
- Zoology Department, Center for Integrative Toxicology, Michigan State University , 1129 Farm Lane Road, East Lansing, Michigan United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region, Peoples republic of China
| |
Collapse
|
8
|
Peng H, Saunders DMV, Sun J, Jones PD, Wong CKC, Liu H, Giesy JP. Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust. Environ Sci Technol 2016; 50:12669-12677. [PMID: 27934287 DOI: 10.1021/acs.est.6b03954] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Characterization of toxicological profiles by use of traditional targeted strategies might underestimate the risk of environmental mixtures. Unbiased identification of prioritized compounds provides a promising strategy for meeting regulatory needs. In this study, untargeted screening of brominated compounds in house dust was conducted using a data-independent precursor isolation and characteristic fragment (DIPIC-Frag) approach, which used data-independent acquisition (DIA) and a chemometric strategy to detect peaks and align precursor ions. A total of 1008 brominated compound peaks were identified in 23 house dust samples. Precursor ions and formulas were identified for 738 (73%) of the brominated compounds. A correlation matrix was used to cluster brominated compounds; three large groups were found for the 140 high-abundance brominated compounds, and only 24 (17%) of these compounds were previously known flame retardants. The predominant class of unknown brominated compounds was predicted to consist of nitrogen-containing compounds. Following further validation by authentic standards, these compounds (56%) were determined to be novel brominated azo dyes. The mutagenicity of one major component was investigated, and mutagenicity was observed at environmentally relevant concentrations. Results of this study demonstrated the existence of numerous unknown brominated compounds in house dust, with mutagenic azo dyes unexpectedly being identified as the predominant compounds.
Collapse
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, SK S7N 5C8, Canada
| | - Chris K C Wong
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University , Hong Kong, China
| | - Hongling Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, People's Republic of China
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, People's Republic of China
- Center for Integrative Toxicology, Zoology Department, Michigan State University , 1129 Farm Lane Road, East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region, People's Republic of China
- Department of Veterinary Biomedical Sciences, University of Saskatchewan , Saskatoon, Saskatchewan, Canada S7N 5B3
| |
Collapse
|
9
|
Peng H, Chen C, Cantin J, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, Li A, Rockne KJ, Sturchio NC, Cai M, Giesy JP. Untargeted Screening and Distribution of Organo-Iodine Compounds in Sediments from Lake Michigan and the Arctic Ocean. Environ Sci Technol 2016; 50:10097-105. [PMID: 27611727 DOI: 10.1021/acs.est.6b03221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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.
Collapse
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Chunli Chen
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- Key Laboratory of Poyang Lake Environment and Resource Utilization of MOE, School of Resources, Environmental and Chemical Engineering, Nanchang University , Nanchang 330047, People's Republic of China
| | - Jenna Cantin
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Song Tang
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Garry Codling
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, Saskatchewan S7N 5C8, Canada
| | - An Li
- School of Public Health, University of Illinois at Chicago , Chicago, Illinois 60612, United States
| | - Karl J Rockne
- Department of Civil and Materials Engineering, University of Illinois at Chicago , 842 West Taylor Street, Chicago, Illinois 60607, United States
| | - Neil C Sturchio
- Department of Geological Sciences, University of Delaware , 255 Academy Street, Newark, Delaware 19716, United States
| | - Minghong Cai
- SOA Key Laboratory for Polar Science, Polar Research Institute of China , Shanghai 200136, China
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- Zoology Department, Center for Integrative Toxicology, Michigan State University , 1129 Farm Lane Road, East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region, Peoples Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210093, People's Republic of China
| |
Collapse
|
10
|
Sun J, Tang S, Peng H, Saunders DMV, Doering JA, Hecker M, Jones PD, Giesy JP, Wiseman S. 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). Environ Sci Technol 2016; 50:7781-90. [PMID: 27322799 DOI: 10.1021/acs.est.6b01249] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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 × 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.
Collapse
Affiliation(s)
- Jianxian Sun
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Song Tang
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Hui Peng
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Jon A Doering
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- Department of Veterinary Biomedical Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B4, Canada
- Zoology Department, Center for Integrative Toxicology, Michigan State University , East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region 999077, People's Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210093, People's Republic of China
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| |
Collapse
|
11
|
Ma Z, Tang S, Su G, Miao Y, Liu H, Xie Y, Giesy JP, Saunders DMV, Hecker M, Yu H. Effects of tris (2-butoxyethyl) phosphate (TBOEP) on endocrine axes during development of early life stages of zebrafish (Danio rerio). Chemosphere 2016; 144:1920-1927. [PMID: 26547027 DOI: 10.1016/j.chemosphere.2015.10.049] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 10/11/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
Due to phasing out of additive flame retardants such as polybrominated diphenyl ethers (PBDEs), Tris (2-butoxyethyl) phosphate (TBOEP) is widely used as a substitute. TBOEP is ubiquitous in the environment and has been measured at concentrations of micrograms per liter (μg L(-1)) in surface waters and wastewater. Information on potential adverse effects on development of aquatic organisms caused by exposure to environmentally relevant concentrations of TBOEP is limited, especially for effects that may be caused through impairment of endocrine-modulated homeostasis. Therefore, this study was conducted to determine effects of TBOEP on ontogeny and transcription profiles of genes along the hypothalamus-pituitary-thyroidal (HPT), hypothalamus-pituitary-adrenal (HPA), and hypothalamus-pituitary-gonadal (HPG) axes in embryos/larvae of zebrafish (Danio rerio). Exposure to TBOEP (2-5,000 μg L(-1)) from 3 h post-fertilization (hpf) to 120 hpf induced developmental malformations in zebrafish with a LC50 of 288.54 μg L(-1) at both 96 hpf and 120 hpf. The predicted no observed effect concentration (PNOEC) was 2.40 μg L(-1). Exposure to 2, 20, or 200 μg TBOEP L(-1) altered expression of genes involved in three major molecular pathways in a concentration-dependent manner after 120 hpf. TBOEP caused lesser expression of some genes involved in synthesis of hormones, such as (pomc and fshβ) as well as upregulating expression of some genes coding for receptors (thr, tshr, gr, mr, er and ar) in zebrafish larvae. These changes at the molecular level could result in alterations of endocrine function, which could result in edema or deformity and ultimately death.
Collapse
Affiliation(s)
- Zhiyuan Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Song Tang
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
| | - Guanyong Su
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yueqiu Miao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Hongling Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
| | - Yuwei Xie
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - John P Giesy
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada; School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
| | - Markus Hecker
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
| | - Hongxia Yu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| |
Collapse
|
12
|
Peng H, Chen C, Cantin J, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, Li A, Rockne KJ, Sturchio NC, Giesy JP. Untargeted Screening and Distribution of Organo-Bromine Compounds in Sediments of Lake Michigan. Environ Sci Technol 2016; 50:321-330. [PMID: 26618527 DOI: 10.1021/acs.est.5b04709] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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.
Collapse
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Chunli Chen
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- Key Laboratory of Poyang Lake Environment and Resource Utilization of MOE; School of Resources, Environmental and Chemical Engineering, Nanchang University , Nanchang 330047, China
| | - Jenna Cantin
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Song Tang
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Garry Codling
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - An Li
- School of Public Health, University of Illinois , Chicago, Illinois 60612, United States
| | - Karl J Rockne
- Department of Civil and Materials Engineering, University of Illinois , 842 West Taylor Street, Chicago, Illinois 60607, United States
| | - Neil C Sturchio
- Department of Geological Sciences, University of Delaware , 255 Academy Street, Newark, Delaware 19716 United States
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
- Zoology Department, Center for Integrative Toxicology, Michigan State University , 1129 Farm Lane Road, East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region, People's Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210093, People's Republic of China
- Biology Department, Hong Kong Baptist University , Hong Kong, SAR China
| |
Collapse
|
13
|
Alharbi HA, Saunders DMV, Al-Mousa A, Alcorn J, Pereira AS, Martin JW, Giesy JP, Wiseman SB. Inhibition of ABC transport proteins by oil sands process affected water. Aquat Toxicol 2016; 170:81-88. [PMID: 26650706 DOI: 10.1016/j.aquatox.2015.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/13/2015] [Accepted: 11/14/2015] [Indexed: 06/05/2023]
Abstract
The ATP-binding cassette (ABC) superfamily of transporter proteins is important for detoxification of xenobiotics. For example, ABC transporters from the multidrug-resistance protein (MRP) subfamily are important for excretion of polycyclic aromatic hydrocarbons (PAHs) and their metabolites. Effects of chemicals in the water soluble organic fraction of relatively fresh oil sands process affected water (OSPW) from Base Mine Lake (BML-OSPW) and aged OSPW from Pond 9 (P9-OSPW) on the activity of MRP transporters were investigated in vivo by use of Japanese medaka at the fry stage of development. Activities of MRPs were monitored by use of the lipophilic dye calcein, which is transported from cells by ABC proteins, including MRPs. To begin to identify chemicals that might inhibit activity of MRPs, BML-OSPW and P9-OSPW were fractionated into acidic, basic, and neutral fractions by use of mixed-mode sorbents. Chemical compositions of fractions were determined by use of ultrahigh resolution orbitrap mass spectrometry in ESI(+) and ESI(-) mode. Greater amounts of calcein were retained in fry exposed to BML-OSPW at concentration equivalents greater than 1× (i.e., full strength). The neutral and basic fractions of BML-OSPW, but not the acidic fraction, caused greater retention of calcein. Exposure to P9-OSPW did not affect the amount of calcein in fry. Neutral and basic fractions of BML-OSPW contained relatively greater amounts of several oxygen-, sulfur, and nitrogen-containing chemical species that might inhibit MRPs, such as O(+), SO(+), and NO(+) chemical species, although secondary fractionation will be required to conclusively identify the most potent inhibitors. Naphthenic acids (O2(-)), which were dominant in the acidic fraction, did not appear to be the cause of the inhibition. This is the first study to demonstrate that chemicals in the water soluble organic fraction of OSPW inhibit activity of this important class of proteins. However, aging of OSPW attenuates this effect and inhibition of the activity of MRPs by OSPW from Base Mine Lake does not occur at environmentally relevantconcentrations.
Collapse
Affiliation(s)
- Hattan A Alharbi
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Ahmed Al-Mousa
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jane Alcorn
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Alberto S Pereira
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, Edmonton, AB, Canada
| | - Jonathan W Martin
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, Edmonton, AB, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada; Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; School of Biological Sciences, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong Special Administrative Region, People's Republic of China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.
| | - Steve B Wiseman
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada.
| |
Collapse
|
14
|
Peng H, Chen C, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, Li A, Rockne KJ, Giesy JP. Untargeted Identification of Organo-Bromine Compounds in Lake Sediments by Ultrahigh-Resolution Mass Spectrometry with the Data-Independent Precursor Isolation and Characteristic Fragment Method. Anal Chem 2015; 87:10237-46. [DOI: 10.1021/acs.analchem.5b01435] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Hui Peng
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - Chunli Chen
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - David M. V. Saunders
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - Jianxian Sun
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - Song Tang
- School of Environment and Sustainability, 117 Science Place, Saskatoon, Saskatchewan Canada, S7N 5C8
| | - Garry Codling
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - Markus Hecker
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
- School of Environment and Sustainability, 117 Science Place, Saskatoon, Saskatchewan Canada, S7N 5C8
| | - Steve Wiseman
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
| | - Paul D. Jones
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
- School of Environment and Sustainability, 117 Science Place, Saskatoon, Saskatchewan Canada, S7N 5C8
| | - An Li
- School
of Public Health, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Karl J. Rockne
- Department of Civil and Materials Engineering (MC 246), University of Illinois at Chicago, 842 West Taylor Street, Chicago, Illinois 60607-7023, United States
| | - John P. Giesy
- Toxicology
Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan Canada, S7N 5B3
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan Canada S7N 5B3
- Zoology Department,
Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824United States
- School of Biological Sciences, University of Hong Kong, Hong Kong Special Administrative Region, Peoples Republic of China
- State Key Laboratory of Pollution Control
and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People’s Republic of China
| |
Collapse
|
15
|
Peng H, Saunders DMV, Sun J, Codling G, Wiseman S, Jones PD, Giesy JP. Detection, identification, and quantification of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate isomers in house dust. Environ Sci Technol 2015; 49:2999-3006. [PMID: 25621784 DOI: 10.1021/es505743d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ultra-High Resolution LC/mass spectrometry (LC-UHRMS; Thermo Fisher Q-Exactive) was used to identify two novel isomers of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) which were unexpectedly observed in a commercial standard of TBPH. By combining ultra-high resolution (UHR) mass spectra (MS(1)), mass errors to theoretical [TBPH-Br+O](-) were 2.1 and 1.0 ppm for the two isomers, UHR-MS(2) spectra and NMR analysis; the structures of the two compounds were identified as hydroxylated TBPH with a hydroxyl group on the aromatic ring. Relatively great proportions of the two isomers of OH-TBPH were detected in two technical products, Firemaster 550 (FM-550; 0.1% and 6.2%, respectively) and Firemaster BZ 54 (BZ-54; 0.1% and 7.9%), compared to a commercial standard (0.4% and 0.9%). To simultaneously analyze OH-TBPH isomers and TBPH in samples of dust, a method based on LC-UHRMS was developed to quantify the two compounds, using negative and positive ion modes, respectively. The instrumental limit of detection for TBPH was 0.01 μg/L, which was 200-300 times better than traditional methods (2.5 μg/L) based on gas chromatography-mass spectrometry. The analytical method combined with a Florisil cleanup was successfully applied to analyze TBPH and OH-TBPH in 23 indoor dust samples from Saskatoon, Saskatchewan, Canada. Two OH-TBPH isomers, OH-TBPH1 and OH-TBPH2, were detected in 52% and 91% of dust samples, respectively. Concentrations of OH-TBPH2 (0.35 ± 1.0 ng/g) were 10-fold greater than those of OH-TBPH1 (0.04 ± 0.88 ng/g) in dust, which was similar to profiles in FM-550 and BZ-54. TBPH was also detected in 100% of dust samples with a mean concentration of 733 ± 0.87 ng/g. A significant (p < 0.001) log-linear relationship was observed between TBPH and OH-TBPH isomers, further supporting the hypothesis of a common source of emission. Relatively small proportions of OH-TBPH isomers were detected in dust (0.01% ± 0.67 OH-TBPH1 and 0.1% ± 0.60 OH-TBPH2), which were significantly less than those in technical products (p < 0.001). This result indicated different environmental behaviors of OH-TBPH and TBPH. Detection of isomers of OH-TBPH is important, since compounds with phenolic groups have often shown relatively greater toxicities than nonhydroxylated analogues. Further study is warranted to clarify the environmental behaviors and potential toxicities of OH-TBPH isomers.
Collapse
Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan, Canada , S7N 5B3
| | | | | | | | | | | | | |
Collapse
|
16
|
Saunders DMV, Podaima M, Wiseman S, Giesy JP. Effects of the brominated flame retardant TBCO on fecundity and profiles of transcripts of the HPGL-axis in Japanese medaka. Aquat Toxicol 2015; 160:180-187. [PMID: 25646719 DOI: 10.1016/j.aquatox.2015.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 06/04/2023]
Abstract
The novel brominated flame retardant, 1,2,5,6-tetrabromocyclooctane (TBCO) is an additive flame retardant which is marketed under the trade name Saytex BCL-48. TBCO has recently been investigated as a potential alternative to the major use brominated flame retardant, hexabromocyclododecane (HBCD), which could have major implications for significant increases in amounts of TBCO used. Yet there is a lack of information regarding potential toxicities of TBCO. Recently, results of in vitro experiments have demonstrated the potential of TBCO to modulate endocrine function through interaction with estrogen and androgen receptors and via alterations to the synthesis of 17-β-estradiol and testosterone. Further research is required to determine potential endocrine disrupting effects of TBCO in vivo. In this experiment a 21-day fecundity assay with Japanese medaka (Oryzias latipes) was conducted to examine endocrine disrupting effects of TBCO in vivo. Medaka were fed a diet containing either 607 or 58μg TBCO/g food, wet mass (wm). Fecundity, measured as cumulative deposition of eggs and fertilization of eggs, as well as abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were measured as indicators of holistic endocrine disruption and to determine mechanisms of effects, respectively. Cumulative fecundity was 18% lesser by medaka exposed to 58μg TBCO/g, wm food. However, fecundity of medaka exposed to 607μg TBCO/g, wm food was not significantly different from that of controls. Organ-specific and dose-dependent alterations to abundances of transcripts were observed in male and female medaka. A pattern of down-regulation of expression of genes involved in steroidogenesis, metabolism of cholesterol, and regulatory feedback mechanisms was observed in gonads from male and female medaka which had been exposed to the greater concentration of TBCO. However, these effects on expression of genes were not manifested in effects on fertilization of eggs or fecundity. In livers from male and female medaka exposed to the lesser concentration of TBCO greater expression of genes that respond to exposure to estrogens, including vitellogenin II, choriogenin H, and ERα, were observed. The results reported here confirm the endocrine disrupting potential of TBCO and elucidate potential mechanisms of effects which include specific patterns of alterations to abundances of transcripts of genes in the gonad and liver of medaka.
Collapse
Affiliation(s)
- David M V Saunders
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada.
| | - Michelle Podaima
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada; Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong, China; School of Biological Sciences, University of Hong Kong, Hong Kong, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China
| |
Collapse
|
17
|
Liu H, Tang S, Zheng X, Zhu Y, Ma Z, Liu C, Hecker M, Saunders DMV, Giesy JP, Zhang X, Yu H. Bioaccumulation, biotransformation, and toxicity of BDE-47, 6-OH-BDE-47, and 6-MeO-BDE-47 in early life-stages of zebrafish (Danio rerio). Environ Sci Technol 2015; 49:1823-33. [PMID: 25565004 DOI: 10.1021/es503833q] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), 6-hydroxy-tetrabromodiphenyl ether (6-OH-BDE-47), and 6-methoxy-tetrabromodiphenyl ether (6-MeO-BDE-47) are the most detected congeners of polybrominated diphenyl ethers (PBDEs), OH-BDEs, and MeO-BDEs, respectively, in aquatic organisms. Although it has been demonstrated that BDE-47 can interfere with certain endocrine functions that are mediated through several nuclear hormone receptors (NRs), most of these findings were from mammalian cell lines exposed in vitro. In the present study, embryos and larvae of zebrafish were exposed to BDE-47, 6-OH-BDE-47, and 6-MeO-BDE-47 to compare their accumulation, biotransformation, and bioconcentration factors (BCF) from 4 to 120 hpf. In addition, effects on expression of genes associated with eight different pathways regulated by NRs were investigated at 120 hpf. 6-MeO-BDE-47 was most bioaccumulated and 6-OH-BDE-47, which was the most potent BDE, was least bioaccumulated. Moreover, the amount of 6-MeO-BDE-47, but not BDE-47, transformed to 6-OH-BDE-47 increased in a time-dependent manner, approximately 0.01%, 0.04%, and 0.08% at 48, 96, and 120 hpf, respectively. Expression of genes regulated by the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and mineralocorticoid receptor (MR) was affected in larvae exposed to 6-OH-BDE-47, whereas genes regulated by AhR, ER, and the glucocorticoid receptor (GR) were altered in larvae exposed to BDE-47. The greatest effect on expression of genes was observed in larvae exposed to 6-MeO-BDE-47. Specifically, 6-MeO-BDE-47 affected the expression of genes regulated by AhR, ER, AR, GR, and thyroid hormone receptor alpha (TRα). These pathways were mostly down-regulated at 2.5 μM. Taken together, these results demonstrate the importance of usage of an internal dose to assess the toxic effects of PBDEs. BDE-47 and its analogs elicited distinct effects on expression of genes of different hormone receptor-mediated pathways, which have expanded the knowledge of different mechanisms of endocrine disrupting effects in aquatic vertebrates. Because some of these homologues are natural products, assessments of risks of anthropogenic PBDE need to be made against the background of concentrations from naturally occurring products. Even though PBDEs are being phased out as flame retardants, the natural products remain.
Collapse
MESH Headings
- Animals
- Anisoles/pharmacokinetics
- Anisoles/toxicity
- Biotransformation
- Embryo, Nonmammalian/drug effects
- Embryo, Nonmammalian/metabolism
- Endocrine Disruptors/pharmacokinetics
- Endocrine Disruptors/toxicity
- Flame Retardants/pharmacokinetics
- Flame Retardants/toxicity
- Gene Expression Regulation, Developmental/drug effects
- Halogenated Diphenyl Ethers/pharmacokinetics
- Halogenated Diphenyl Ethers/toxicity
- Larva/drug effects
- Larva/genetics
- Larva/metabolism
- Polybrominated Biphenyls/pharmacokinetics
- Polybrominated Biphenyls/toxicity
- Receptors, Androgen/genetics
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Estrogen/genetics
- Receptors, Glucocorticoid/genetics
- Receptors, Mineralocorticoid/genetics
- Receptors, Thyroid Hormone/genetics
- Water Pollutants, Chemical/pharmacokinetics
- Water Pollutants, Chemical/toxicity
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
Collapse
Affiliation(s)
- Hongling Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, Jiangsu 210023, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Saunders DMV, Podaima M, Codling G, Giesy JP, Wiseman S. A mixture of the novel brominated flame retardants TBPH and TBB affects fecundity and transcript profiles of the HPGL-axis in Japanese medaka. Aquat Toxicol 2015; 158:14-21. [PMID: 25461741 DOI: 10.1016/j.aquatox.2014.10.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 10/21/2014] [Accepted: 10/23/2014] [Indexed: 06/04/2023]
Abstract
The novel brominated flame retardants (NBFRs), bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) and 2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB) are components of the flame retardant mixture Firemaster 550 and both TBPH and TBB have recently been listed as high production volume chemicals by the US EPA. These NBFRs have been detected in several environmental matrices but very little is known about their toxic effects or potencies. Results of in vitro assays demonstrated potentials of these NBFRs to modulate endocrine function through interactions with estrogen (ER) and androgen receptors (AR) and via alterations to synthesis of 17-β-estradiol (E2) and testosterone (T), but in vivo effects of these chemicals on organisms are not known. Therefore a 21-day short term fish fecundity assay with Japanese medaka (Oryzias latipes) was conducted to investigate if these NBFRs affect endocrine function in vivo. Medaka were fed a diet containing either 1422 TBPH:1474 TBB or 138:144 μg/g food, wet weight (w/w). Cumulative production of eggs was used as a measure of fecundity and abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were quantified to determine mechanisms of observed effects. Cumulative fecundity was impaired by 32% in medaka exposed to the greatest dose of the mixture of TBPH/TBB. A pattern of global down-regulation of gene transcription at all levels of the HPGL axis was observed, but effects were sex-specific. In female medaka the abundance of transcripts of ERβ was lesser in livers, while abundances of transcripts of VTG II and CHG H were greater. In male medaka, abundances of transcripts of ERα, ERβ, and ARα were lesser in gonads and abundances of transcripts of ERβ and ARα were lesser in brain. Abundances of transcripts of genes encoding proteins for synthesis of cholesterol (HMGR), transport of cholesterol (HDLR), and sex hormone steroidogenesis (CYP 17 and 3β-HSD) were significantly lesser in male medaka, which might have implications for concentrations of sex hormones. The results of this study demonstrate that exposure to components of the flame retardant mixture Firemaster(®) 550 has the potential to impair the reproductive axis of fishes.
Collapse
Affiliation(s)
- David M V Saunders
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada S7N 5B3.
| | - Michelle Podaima
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada S7N 5B3
| | - Garry Codling
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada S7N 5B3
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada S7N 5B3; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3; Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; School of Biological Sciences, University of Hong Kong, Hong Kong Special Administrative Region; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada S7N 5B3
| |
Collapse
|