Are temporal trends of some persistent organochlorine and organobromine compounds in Swedish breast milk slowing down?

We investigated body burdens of persistent organic pollutants (POPs) in Swedish first-time mothers by measurements in breast milk, and followed up the temporal trends between 1996 and 2017. POPs were analysed in individual samples (n = 539) from participants from Uppsala county, Sweden. This made it possible to adjust temporal trends for age of the mother, pre-pregnancy BMI, weight gain during pregnancy, weight loss after delivery, and education, the main determinants for POP body burdens, apart from sampling year. We also compared observed body burdens with the body burdens determined to be safe from a health perspective in the risk assessment of dioxin-like polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), published by the European Food Safety Authority (EFSA). Declining temporal trends in breast milk of on average -4 to 14% per year were observed 1996-2017 for PCBs, PCDD/Fs, chlorinated pesticides, and brominated flame retardants, except for the polybrominated diphenyl ethers (PBDEs) BDE-153 and BDE-209. The toxic equivalents (TEQs) for PCDD declined faster than PCDF TEQs, -6.6% compared to -3.5% per year. For CB-169, CB-180, PCDDs, PCDFs, Total TEQ, and hexachlorobenzene (HCB), a change point year (CP) was observed around 2008-2009 and after that, the decline in levels has slowed down. If breast milk levels follows the exponential declining trend of total TEQ estimated for the entire period (-5.7% per year), 97.5% of first time mothers from the Uppsala area will have body burdens below the estimated safe level in year 2022. If instead it follows the estimated % decline after the CP in 2008 (-1.6% per year), it will take until 2045 before 97.5% is below the estimated safe level. It is important to proceed with the monitoring of POPs in breast milk from Swedish mothers in order to further observe if the levels are stabilizing or continue to decline.

Chlorinated paraffins in indoor air and dust: concentrations, congener patterns, and human exposure.

Chlorinated paraffins (CPs) are large production volume chemicals used in a wide variety of commercial applications. They are ubiquitous in the environment and humans. Human exposure via the indoor environment has, however, been barely investigated. In the present study 44 indoor air and six dust samples from apartments in Stockholm, Sweden, were analyzed for CPs, and indoor air concentrations are reported for the first time. The sumCP concentration (short chain CPs (SCCPs) and medium chain CPs (MCCPs)) in air ranged from <5-210 ng m(-3) as quantified by gas chromatography coupled to electron ionization tandem mass spectrometry (GC/EI-MS/MS). Congener group patterns were studied using GC with electron capture negative ionization MS (GC/ECNI-MS). The air samples were dominated by the more volatile SCCPs compared to MCCPs. SumCPs were quantified by GC/EI-MS/MS in the dust samples at low µg g(-1) levels, with a chromatographic pattern suggesting the prevalence of longer chain CPs compared to air. The median exposure to sumCPs via the indoor environment was estimated to be ~1 µg day(-1) for both adults and toddlers. Adult exposure was dominated by inhalation, while dust ingestion was suggested to be more important for toddlers. Comparing these results to literature data on dietary intake indicates that human exposure to CPs from the indoor environment is not negligible.

Identification of the flame retardant decabromodiphenyl ethane in the environment.

The brominated flame retardant decabromodiphenyl ethane, DeBDethane, is marketed as an alternative to decabromodiphenyl ether, BDE209. There are currently no data available about the presence of DeBDethane in the environment. In this study, DeBDethane was positively identified by high-resolution mass spectrometry and quantified by low-resolution mass spectrometry with electron capture negative ionization in sewage sludge, sediment, and indoor air. It was found in 25 of the 50 Swedish sewage treatment plants investigated, with estimated levels up to about 100 ng/g dry weight. The concentration of DeBDethane in sediment from Western Scheldt in The Netherlands was 24 ng/g dry weight, and in an air sample from a Swedish electronics dismantling facility it was 0.6 ng/m3. DeBDethane was also found together with nonabromodiphenyl ethanes in water piping insulation. All samples contained BDE209 in higher concentrations as compared to DeBDethane (DeBDethane/BDE209 ratios ranging from 0.02 to 0.7), probably reflecting the higher and longer usage of BDE209. There is an ongoing risk assessment within the European Union regarding BDE209. Since DeBDethane has similar applications, it is important to investigate its environmental behavior before using it to replace BDE209.

Photolytic clean-up of biological samples for gas chromatographic analysis of chlorinated paraffins.

A method based on gas chromatography electron capture detection (GC-ECD) for the analysis of chlorinated paraffins (CPs) in biological samples has been investigated. The method includes photolytic destruction of halogenated aromatic compounds, such as PCBs, to eliminate some of the interferences in the analysis of CPs in environmental samples. Gel permeation chromatography was used to isolate CPs from the interfering components of Toxaphene and chlordane after the photolysis. GC-ECD gave a detection limit of 20 ng CPs/g fresh muscle tissue. The recovery of CPs from a spiked moose liver sample was estimated to 94%.