Quantum Chemical Investigation of Polychlorinated Dibenzodioxins, Dibenzofurans and Biphenyls: Relative Stability and Planarity Analysis

All the possible polychlorinated aromatic compounds in the classes of dibenzodioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were studied by the quantum chemical methods of HF/6-311++G(d,p), B3LYP/6-311++G(d,p), and MP2/cc-pVTZ. The calculated stabilities and structures of these compounds were compared with the available data on their abundance and toxicity. Prediction models for trends in energy and planarity among these congeners were proposed. The results discussed here can help contribute to the understanding of the role of dioxin-like compounds (DLCs) in the environment.

Quantum Chemical Investigation of Polychlorinated Dibenzodioxins, Dibenzofurans and Biphenyls

All possible polychlorinated aromatic compounds in the classes of dibenzodioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) were studied by quantum chemical methods of HF/6-311++G(d,p), B3LYP/6-311++G(d,p) and MP2/cc-pVTZ. Calculated stabilities and structures of these compounds were compared with available data on their abundance and toxicity. Prediction models for trends in energy and planarity among congeners were proposed. Results discussed here can help contribute to the understanding of the role of dioxin-like compounds (DLCs) in the environment.

Assessment of Air Pollution with Polychlorinated Dibenzodioxins (PCDDs) and Polychlorinated Dibenzofuranes (PCDFs) in Lithuania

Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/F) are highly bioavailable in humans, either through direct inhalation or indirectly by trophic transfer from contaminated food or water. The main sources of pollution with PCDD/F include industrial and non-industrial combustion sources, like domestic contaminated wood burning, house fires, burning of leaves from trees, etc. When looking for alternative energy sources and reduced energy costs, solid waste incineration plants are intended to be built in the vicinity of urbanized areas, and thus, the need emerges for examination and prediction of to what extent the solid waste incineration plants might affect the surrounding ecosystem, air pollution, and human health. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) (or simply PCDD/F congeners) belong to the group of semi-volatile organic compounds with environmental stability and long-range transfer in the ambient air. Dioxin isomers are highly toxic and may have carcinogenic and mutagenic effects in humans. PCDD/F is detected in air, water, sediment, plants and animals. PCDD/F is generally distributed in the particulate phase in ambient air. For solid waste incineration plant emissions, the distribution of PCDD/F particles into particles with a diameter of <10 μm is more than 81% of the total particulate matter, and more than 54% of the PCDD/F is distributed into particles with a diameter of <2.5 μm. The aim of this study is to investigate the sources of PCDD/F, emissions and potential hazards, i.e., a toxic equivalent in Lithuania. The measurements were performed in two largest cities of Lithuania Vilnius and Kaunas, where the level of PCDD/F discovered was from 0.015 to 0.52 pg/m3 and from 0.02 to 0.05 pg/m3, respectively. The sites for the monitoring were selected based on their proximity to the locations of the planned cogeneration power plants in these cities.

KONSENTRASI POLYCHLORINATED BIPHENYLS (PCBS) DAN POLYCHLORINATED DIBENZO-P-DIOXINS/POLYCHLORINATED DIBENZOFURANS (PCDDS/FS) DALAM AIR DARI DAERAH PERKOTAAN JABODETABEK

Determination of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) in water samples from Jabodetabek urban area was conducted. In the results, a unique pattern were found interestingly in Ciliwung river, Pluit, Jakarta, where decachlorinated biphenyl (PCB IUPAC #209), and dichlorinated biphenyl (PCB IUPAC #11) were detected at relatively high concentrations as 406.77 ng/L and 6.38 ng/L, respectively. This congener pattern is different with commercial PCB mixtures, such as arochlor, kanechlor, or chlophen. Octachlorinated dibenzo-p-furan (OCDF) was also detected at a significant concentration in this water as 3.10 ng/L. Decachlorinated biphenyl (PCB IUPAC #209) and OCDF were associated with industrial by-products. Meanwhile, dichlorinated biphenyl (PCB IUPAC #11) was associated with colour pigment which widely used in consumer goods, such as paint and printed ink. Thus, PCBs and PCDD/Fs contamination might have arisen from industrial by-products where various industries located near sampling point. Keywords: polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins /polychlorinated dibenzo-p-furans (PCDDs/Fs), waters, Jabodetabek, industrial by-products.