Determination of OH-PCBs and OH.PBDEs in biological matrices : Method development, identification and quantification

In the present study, an analytical method for determination of hydroxylated polychlorinated biphenyls (OH-PCBs) and polybrominated diphenyl ethers (OH-PBDEs) and a selection of PCBs, PBDEs and pesticides in biological matrices has been developed. The method is a modified version of the method used for determination of PCBs, pesticides and brominated flame retardants at the Laboratory of Environmental Toxicology (MT-lab) at the Norwegian School of Veterinary Science (NVH). Blood samples from sheep and seals and liver samples from chicken, cattle and seals were used for the method development. After acidifying with 1 M H2SO4, extraction with cyclohexane and acetone was performed twice. The combined organic phases were evaporated and the lipid content determined gravimetrically. The residue was redissolved in cyclohexane and concentrated H2SO4 was added to remove lipids. Extraction with 1 M KOH in 50% ethanol was performed twice to separate the neutral and phenolic analytes. The organic phase containing neutral compounds such as PCBs and PBDEs, was analysed by GCECD (PCBs and pesticides) and GC-ECNI-MS (PBDEs). The alkaline phase containing the phenolic analytes was acidified and re-extracted with cyclohexane. Derivatization was performed with acetic anhydride:pyridine (1:1) to yield the acetylated analytes, which were subsequently determined using GC-ECNI-MS. The method was validated for OH-PCBs and one OH-PBDE by spiking sheep blood (~5 g) at five different levels in the range 0.025 - 0.5 ng/g blood, and cattle liver (~4 g) at two different levels; 0.063 - 0.625 ng/g liver. The accuracy given as recovery relative to the internal standard 4 -OH-[13C12]CB159 was in the range 28-128% for blood, with the lowest result being assigned to 4-OH-CB187, which generally gave low recoveries. The other OH-PCBs were within the range 71-128%, and the variation coefficients were in the range 0.9-53%. The recoveries of OH-PCBs and 6-OH-BDE47 from liver samples were in the range 47-123%, with variation coefficients in the range 0.3-6.5%. Estimated instrumental limits of detection for OH-PCBs and the OH-PBDE were in the range 0.01-0.2 ng/ml (0.02-0.4 pg injected). The method limits of detection were in the range 0.001-0.036 ng/g blood and 0.001-0.031 ng/g liver, respectively. The method linearity was in the range 0.9962-0.9992 for the validated concentration range. Validation results for PBDEs, PCBs, DDT and its metabolites, HCB and Mirex are also included in the thesis. All of these gave validation results within the requirements in the accredited quality system at the MT-lab. The validated method has been used to investigate levels of OH-PCBs, 6-OH-BDE47 and PBDEs in plasma samples of female polar bears (n = 10) from Svalbard sampled in 1996/1997, and liver samples of male harbour seals (n = 5) from the Norwegian Coast sampled in 2002. Levels of the two most abundant congeners, 4-OH-CB187 and 4-OHCB146, in polar bear plasma were in the ranges 56.7-178 ng/g (recovery-corrected) and 28.1- 106 ng/g, respectively. The most abundant PBDE congener was BDE-47 which was present in the range 0.101-0.357 ng/g polar bear plasma. Levels of the OH-PCBs were considerably lower in the harbour seal liver samples. 4-OH-CB187 ranged from 0.088-0.159 ng/g liver, while the BDE-47 was present in the range 1.34-5.36 ng/g

Performance of Three-Dimensional Rainbow Trout (Oncorhynchus mykiss) Hepatocyte Spheroids for Evaluating Biotransformation of Pyrene

The aquatic bioconcentration of a chemical is typically determined using conventional fish tests. To foster the approach of alternatives to animal testing, a combination of computational models and in vitro substrate depletion bioassays (e.g., primary hepatocytes) can be used. One recently developed in vitro assay is the three‐dimensional (3D) hepatic spheroid model from rainbow trout (Oncorhynchus mykiss). The aim of the present study was to evaluate the metabolic competence of the 3D spheroids from rainbow trout when exposed to pyrene, using 2 different sampling procedures (SP1 and SP2). The results were compared with previously published intrinsic clearance (CL) results from S9 fractions and primary hepatocyte assays. Extraction of pyrene using SP1 suggested that the spheroids had depleted 33% of the pyrene within 4 h of exposure, reducing to 91% after 30 h. However, when applying SP2 a substantial amount (36%) of the pyrene was bound to the exposure vial within 2 h, decreasing after 6 h of exposure. Formation of hydroxypyrene‐glucuronide (OH‐PYR‐Glu) was obtained throughout the study, displaying the metabolic competence of the 3D spheroids. The 2 sampling procedures yielded different CLin vitro, where pyrene depletion using SP2 was very similar to published studies using primary hepatocytes. The 3D spheroids demonstrated reproducibile, log‐linear biotransformation of pyrene and displayed formation of OH‐PYR‐Glu, indicating their metabolic competence for 30 h or more.publishedVersio

Review of recent literature on tri-substituted phosphate esters (2015-2016)

Research in the field of risk assessment of replacement chemicals for brominated flame retardants is rapidly expanding with more than 70 peer reviewed publication in the international literature published in 2015-2016 alone. These publications show a variety of data includi11g taxicity, environmental levels and persistence or bioaccumulation assessments. Despite this there still is a lack of information for several of the 19 OPFRs included in tlus literature review. For eleven of the compou11ds 110 EDC taxicity data was available but for five 110 recent acute/ chro1uc taxicity data was found

Review of recent literature on tri-substituted phosphate esters (2015-2016)

Project Manager Katharina Bjarnar Løken.Research in the field of risk assessment of replacement chemicals for brominated flame retardants is rapidly expanding with more than 70 peer reviewed publication in the international literature published in 2015-2016 alone. These publications show a variety of data includi11g taxicity, environmental levels and persistence or bioaccumulation assessments. Despite this there still is a lack of information for several of the 19 OPFRs included in tlus literature review. For eleven of the compou11ds 110 EDC taxicity data was available but for five 110 recent acute/ chro1uc taxicity data was found.publishedVersio

Performance of Three-Dimensional Rainbow Trout (Oncorhynchus mykiss) Hepatocyte Spheroids for Evaluating Biotransformation of Pyrene

The aquatic bioconcentration of a chemical is typically determined using conventional fish tests. To foster the approach of alternatives to animal testing, a combination of computational models and in vitro substrate depletion bioassays (e.g., primary hepatocytes) can be used. One recently developed in vitro assay is the three‐dimensional (3D) hepatic spheroid model from rainbow trout (Oncorhynchus mykiss). The aim of the present study was to evaluate the metabolic competence of the 3D spheroids from rainbow trout when exposed to pyrene, using 2 different sampling procedures (SP1 and SP2). The results were compared with previously published intrinsic clearance (CL) results from S9 fractions and primary hepatocyte assays. Extraction of pyrene using SP1 suggested that the spheroids had depleted 33% of the pyrene within 4 h of exposure, reducing to 91% after 30 h. However, when applying SP2 a substantial amount (36%) of the pyrene was bound to the exposure vial within 2 h, decreasing after 6 h of exposure. Formation of hydroxypyrene‐glucuronide (OH‐PYR‐Glu) was obtained throughout the study, displaying the metabolic competence of the 3D spheroids. The 2 sampling procedures yielded different CLin vitro, where pyrene depletion using SP2 was very similar to published studies using primary hepatocytes. The 3D spheroids demonstrated reproducibile, log‐linear biotransformation of pyrene and displayed formation of OH‐PYR‐Glu, indicating their metabolic competence for 30 h or more

First report of chlorinated and brominated hydrocarbon pollutants in marine bird eggs from an oceanic Indian Ocean island

We report for the first time levels of persistent organic pollutants in marine bird eggs from an oceanic island in the Indian Ocean, the world's third largest ocean. Ten eggs each of the Common Noddy, also known as the Brown Noddy (Anous stolidus), and Sooty Tern (Sterna fuscata) were collected from Ile Cocos off the coast of the island of Rodrigues, located 560 km east of the island of Mauritius. ΣPCBs had the highest levels (2.2 and 2.6 ng/g wm, wet mass; 20 and 19 ng/g lm, lipid mass) for common Noddy and Sooty Tern, respectively (and following), then ΣDDT (1.9 and 3.1 ng/g wm; 17 and 23 ng/g lm), and mirex (0.96 and 0.69 ng/g wm; 8.7 and 5.0 ng/g lm). ΣChlordanes (0.094 and 0.15 ng/g wm; 0.48 and 0.73 ng/g lm) and Σtoxaphenes (0.26 and 0.61 ng/g wm; 2.4 and 5.9 ng/g lm) are rare data for these compounds from this ocean. Brominated flame retardants were low (0.08 and 0.07 ng/g wm; 0.7 and 0.7 ng/g lm). Multivariate analyses indicated different contamination patterns in the prey items as Sooty Terns had significantly higher levels of mean Σchlordanes and Σtoxaphenes, as well as CB105, -108 and -157. p,p′-DDE had an association with thinner eggshells in the Sooty Tern. Although the contaminant levels were in all respects low, industrialisation, development on the periphery, commercial exploitation of the marine environment, and pollutants transferred over long distances by marine debris is likely to add to chemical pressure in this region. Monitoring changes in background levels of pollutants in remote regions will indicate such trends, and marine bird eggs from Rodrigues would be an excellent site.http://dx.doi.org/10.1016/j.envres.2012.05.00

Line ferries and cargo ships for the monitoring of marine contaminants of emerging concern: Application along a Europe-Arctic transect

Contaminants of emerging concern (CEC) are a focus in marine protection. Several CECs are released with wastewater effluents to coastal environments and their offshore occurrence has been recently documented. Routine monitoring is key for implementing marine protection acts, however infrastructural, financial, and technical limitations hinder this task along broad spatial transects. Here we show the efficacy of a new infrastructure enabling unmanned sampling of surface water from ships of opportunity in providing reliable and cost-effective routine monitoring of CECs along a Europe-Arctic transect. The distribution and long-range transport of several pharmaceuticals and personal care products, artificial food additives, and stimulants were assessed. Validation of operations through strict procedural and analytical quality criteria is presented. A framework to estimate a compound-specific spatial range (SR) index of marine long-range transport based on monitoring results and information on source spatial distribution, is introduced. Estimated SR values ranged 50–350 km depending on compound, yielding a ranking of long-range transport potential which reflected expectations based on degradation half-lives. SR values were used to calculate prior maps of detection probability that can be used to plan future routine monitoring in the region

Effect-Directed Analysis To Explore the Polar Bear Exposome: Identification of Thyroid Hormone Disrupting Compounds in Plasma

Compounds with transthyretin (TTR)-binding potency in the blood plasma of polar bear cubs were identified with effect-directed analysis (EDA). This approach contributes to the understanding of the thyroid disrupting exposome of polar bears. The selection of these samples for in-depth EDA was based on the difference between the observed TTR-binding potency on the one hand and the calculated potency (based on known concentrations of TTR-binding compounds and their relative potencies) on the other. A library-based identification was applied to the liquid chromatography–time-of-flight–mass spectrometry (LC-ToF-MS) data by screening for matches between compound lists and the LC-ToF-MS data regarding accurate mass and isotope pattern. Then, isotope cluster analysis (ICA) was applied to the LC-ToF-MS data allowing specific screening for halogen isotope patterns. The presence of linear and branched nonylphenol (NP) was observed for the first time in polar bears. Furthermore, the presence of one di- and two monohydroxylated octachlorinated biphenyls (octaCBs) was revealed in the extracts. Linear and branched NP, 4′-OH-CB201 and 4,4′-OH-CB202 could be successfully confirmed with respect to their retention time in the analytical system. In addition, branched NP, mono- and dihydroxylated-octaCBs showed TTR-binding potencies and could explain another 32 ± 2% of the total measured activities in the extracts

Parental leave policies and socio-economic gaps in child development: Evidence from a substantial benefit reform using administrative data

This paper examines the effects of substantial changes in paid parental leave on child development and socio-economic development gaps. The authors exploit a German reform from 2007 that both expanded paid leave in the first year and removed paid leave in the second year following childbirth. Higher-income households benefited relatively more from the reform than low-income households. They use administrative data from mandatory school entrance examinations containing detailed child development assessments at age six within a difference-in-differences approach. Their precise and robust estimates reveal no effects of the changes in parental leave benefits on child development across various socio-economic groups, and consequently no effects on socio-economic development gaps