Dioxin, dioxin everywhere

General Formulation of Characteristic Travel Distance for Semivolatile Organic Chemicals in a Multimedia Environment

“…The characteristic length for TCDD was calculated using the four-compartment Lagrangian system described above and was found to be approximately 600 km. This value is on the same order of magnitude as, or greater than, the distance between urban centers and provides insight on the fairly uniform TCDD concentrations found in the northern hemisphere (5).…”

“…Semivolatile organic pollutants originate from a broad range of human activities, including combustion for energy production and transportation, industrial processes, and agricultural uses of pesticides. Recent studies have reported surprising levels of regional atmospheric dispersion, deposi tion to and uptake by vegetation of PAH and PCDD/F compounds ( − ). A methodology to determine the characteristic spatial scale for airborne chemical pollutants is needed to evaluate and classify the potential human health and ecological impacts of a chemical released into the environment and to determine whether the pollutant can have a local, regional, or global scale impact.…”

Application of gas chromatography high-resolution mass spectrometry to the determination of trace monobromopolychlorodibenzo-p-dioxins in environmental samples

“…Analyses of held samples such as fly ash from a municipal waste incinerator are usually much more complicated because hundreds to thou sands of organic compounds coexist with BPCDDs. The criteria for identifying BPCDDs in such samples are (1) two exact masses of a congener at > 10,000 mass resolution must be detected at the same retention time; (2) the observed isotope ratio of the two ions monitored must not deviate > ± 15% from theoretical isotope ratio; (3) the chromatographic peaks must show an elution within the defined w indo ws for the congeners; (4) the relat ive retention times to the internal standards mu st be within ± 10% as measured in calibr ation runs; (5) the signal-to-noise-ratio of the peak must be > 2.5.…”

“…Quantification of BPCDDs and preliminary identification of some specific BPCDD isomers in fly ash samples are also reported. (] Am Soc Mass Spectrom 1992, 3, 248-259) T he analy sis of environmental and biological samples for polychlorinated dibenzo-p-dioxins (PCDDs) has received considerable public and scientific attention during the past several decades [1][2][3] because these compounds are highly toxic [4,5]. Recent fmdings of polybrominated dibenzo-p-dioxins (PBDOs) in some samples [6][7][8][9][10][11][12] have also raised concern about their environmental impact.…”

Persistent organic pollutants in Lithuania: Assessment of air and soil contamination

“…Among different organic matters, POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, polychlorinated dibenzop-dioxins, and dibenzofurans) are the most interesting from the point of view of their behaviour in the environment. Different classes of POPs are emitted from various sources: PAHs are mainly emitted in combustion processes from industrial or domestic sites and traffic [2], PCBs are spread via chemicals used in semiconductor industry and by waste disposal [3,4], dibenzop-dioxins and dibenzofurans via operation of landfills and incinerations [5,6], and pesticides are spread via dispersion to the soil [7,8]. Furthermore, secondary sources of POPs include the spreading of sludge on the ground surface and remobilization of previously deposited compounds from soil and water bodies.…”