Comparison of the contributions of polychlorinated dibenzo-p-dioxins and dibenzofurans and other unintentionally produced persistent organic pollutants to the total toxic equivalents in air of steel plant areas

Abstract

h i g h l i g h t sLevel of dioxin and dioxin-like compounds in air of steel plant areas was studied. Relative contribution of dioxins and dioxin-like compounds was compared. Profiles of dioxins and dioxin-like compounds in the ambient air were stated. a r t i c l e i n f o , and 0.02-0.12 pg TEQ N m À3 , respectively. The PCNs were the most abundant compounds (by mass concentration), contributing about 87% of the total mass concentrations of the analytes that were found in the air of the steel plant areas. The PCDFs contributed about 47% of the total TEQs, following by the PBDFs (28%) and the PCDDs (18%). The dioxin-like compounds together contributed up to 40% of the total TEQs, so their contributions to the toxic effects that could be caused by exposure to the air of the steel plant areas were significant. The congener profiles in the air were similar to the congener profiles that were found in stack gas emissions, indicating that the steelmaking plants were possible sources of the PCDDs, PCDFs, and dioxin-like compounds that were found in the air of the steel plant areas.

Particle Size Distributions of PCDD/Fs and PBDD/Fs in Ambient Air in a Suburban Area in Beijing, China

“…As shown in Fig. 6(b), the PBDFs, especially the higher brominated PBDFs, were the dominant PBDD/F congeners in the particles in every size range Li et al, 2015a). The fraction of the higher brominated PBDFs in the particulate phase decreased as the particle size increased, but that was not the case for the PBDDs.…”

“…The results showed that the PCDD/Fs were adsorbed onto the particles. In this study and in a previous study (Li et al, 2015a), the PBDFs were the main contributors to the PBDD/Fs. The PBDF distributions in the particles of different sizes were therefore also studied (Table 3).…”

“…The extract was then cleaned using a multilayer silica gel column, a basic alumina column, and then an activated carbon column. The clean-up procedure has been described in detail previously (Li et al, 2015a). The extract was then concentrated under a gentle stream of nitrogen, and transferred into 10 µL of nonane in a mini-vial.…”

“…Toxic equivalency factors (TEFs) have not yet been determined for the PBDD/Fs, so the World Health Organization toxic equivalency factors for the PCDD/Fs were used for the corresponding PBDD/F congeners (Duan et al, 2011;Zhang et al, 2012;van den Berg et al, 2013;Li et al, 2015a). The concentrations and TEQs of the PXDD/Fs found for the ambient air samples are summarized in Tables S1 and S2.…”

Variations and factors that influence the formation of polychlorinated naphthalenes in cement kilns co-processing solid waste

“…The unintentional production of PCNs during thermal processes has already been the main source of PCNs in ambient air. Previous studies have reported larger amounts of PCNs than PCDD/Fs were emitted during various thermal processes [9,10]. Therefore, studies of PCN emissions during different thermal processes are of significance necessary.…”