Emissions of PBDD/Fs, PCDD/Fs and PBDEs from a TV Back Cover under Thermal Stress

Paper submitted to the 32th International Symposium on Halogenated Persistent Organic Pollutants, Cairns, Australia, 26-31 Aug. 2012.There is growing concern about the potential for human exposure to brominated flame retardants (BFRs), which are present in commonly used articles such as electronic equipment, household furnishings, building materials, and car interiors. Some BFRs, such as polybrominated diphenyl ethers (PBDEs), are additives that are not chemically bound to the plastic and therefore may be released more readily into the environment.Valencian Community Government (Spain) (research project PROMETEO/2009/043/FEDER)

Emissions of PBDD/Fs, PCDD/Fs and PBDEs from flame-retarded high-impact polystyrene under thermal stress

The emissions of polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and their chlorinated analogues (PCDD/Fs) during the thermal treatment of a high impact polystyrene (HIPS) TV casing were investigated. The halogenated compounds were analyzed in the original material and in the gases emitted during its treatment at temperatures between 50 °C and 250 °C. DecaBDE was the primary PBDE in the TV casing, which also contained high levels of PBDFs (ppm range). At the lower treatment temperatures, non-modified PBDEs evaporated from the samples. Conversely, at 200 °C or above, debromination reactions led to the formation of additional tri- through nonaBDE. The formation of new PBDD/Fs was also detected in the gas phase when the plastic was heated to 200 °C or 250 °C, with higher yields of furans than dioxins. This appreciably increased the toxic equivalent (TEQ) levels of the gas phase relative to those seen in the untreated sample. In all cases, the levels and TEQ contributions from PCDD/Fs were negligible compared to those for brominated analogues.Support for this work was provided by the Generalitat Valenciana (research project Prometeo/2009/043/FEDER) and a mobility grant by the University of Alicante (Spain) that enabled Nuria Ortuño to visit Umeå University

Brominated dioxins in plastics – Emissions during fires

Resumen de la comunicación presentada en PIC2015 – the 14th International Congress on Combustion By-Products and Their Health Effects, Umeå, Sweden, 14-17 June 2015.In this presentation we show examples of levels and patterns of PBDD/Fs and BFRs that may be found in plastics related to electronic equipment. We also show examples of the quantities and types of PBDD/Fs and BFRs that are emitted as the plastics are heated at different temperatures and conditions. Emission data are shown for all from controlled lab-scale experiments, semi-controlled pilot-scale experiments to an uncontrolled accidental fire. For the latter, the levels and patterns found in the environment after the fire are also presented

Combining Leaching and Passive Sampling to Measure the Mobility and Distribution between Porewater, DOC and Colloids of Native Oxy-PAHs, N-PACs and PAHs in Historically Contaminated Soil

Different methods to quantify soil porewater concentrations of contaminants will provide different types of information. Passive sampling measurements give freely dissolved porewater concentrations (Cpw,free), while leaching tests provide information on the mobile concentration (Cpw,leach), including contaminants associated with dissolved organic carbon (DOC) and particles/colloids in the porewater. This study presents a novel combination of these two measurements, to study the sorption and mobility of polycyclic aromatic compounds (PACs) to DOC and particulate organic carbon (POC) in 10 historically contaminated soils. The PACs investigated were polycyclic aromatic hydrocarbons (PAHs), oxygenated-PAHs, and nitrogen containing heterocyclic PACs. Observed Cpw,leach was up to 5 orders of magnitude higher than Cpw,free; implying large biases when Cpw,leach is used to assess bioavailability or soil partitioning. Sorption of PACs to DOC and POC was important for the mobility of compounds with log KOW > 4. Average DOC/water-partitioning coefficients (KDOC) correlated well with KOW (log KDOC = 0.89 × log KOW +1.03 (r2 = 0.89)). This relationship is likely more accurate for historically contaminated soils than previously published data, which suffer from artifacts caused by problems in measuring Cpw,free correctly or not using historically contaminated soils. POC/water-partitioning coefficients (KPOC) were orders of magnitude larger than corresponding KDOC, suggesting sorption to mobile particles/colloids is the dominant mechanism for PAC mobility

Democracy Report 2022: Autocratization Changing Nature?

Varieties of Democracy (V-Dem) produces the largest global dataset on democracy with over 30 million data points for 202 countries from 1789 to 2021. Involving over 3,700 scholars and other country experts, V-Dem measures hundreds of different attributes of democracy. V-Dem enables new ways to study the nature, causes, and consequences of democracy embracing its multiple meanings. The Democracy Report 2022 presents findings based on the newest edition of the V-Dem dataset (version 12). The data is the result of a vast international collaboration. We are immensely grateful to the 3,700 country experts without whose contribution V-Dem would not be possible, and to the Country Coordinators, Regional Managers, Project Managers, and Steering Committee Members for their principal roles.

Polar polycyclic aromatic compounds (polar PACs) occurence and origin : issues and requirements for future investigations

International audiencePolar polycyclic aromatic compounds (polar PACs) are less known than PAHs, and neither monitored nor regulated anywhere, despite their potential harmfulness and greater mobility. They were rarely intentionally produced, and they occur mainly as PAH metabolites. They often occur at the same sites (gasworks, coke plants, wood treatment sites) as PAHs and other PACs but have been mostly overlooked. Other potential sites include wood tar production and oil refineries or storage affected by accidents. PAH remediation treatments, such as thermal desorption or chemical oxidation may have promoted the formation of oxy-PACs while applied, along with the mitigation of regulated PAHs. According to existing regulations, the site contamination level related to the sum of PAH was reduced, but the actual risk may have been increased. In order to identify potential risks, the monitoring of oxy-PACs is required. However, analytical capabilities are not developed, data on oxy-PACs are scarce and research is still needed. Available results from contaminated site databases and from our investigations suggest that polar PACs may constitute between 10 and 20% of total PACs in soil, and their occurrence in shallow groundwater is often overlooked at contaminated sites. Their potential impact on risk analysis is largely unknown and may be underestimated, as their transfer properties are by far less favourable than those of PAHs. Their monitoring would require analysis standards and commercially available analytical services before any regulatory approach is undertaken. This is most important for sustainable remediation of PAH-contaminated sites