Forensic Analysis of Polychlorinated Dibenzo-p-Dioxin and Furan Fingerprints to Elucidate Dechlorination Pathways

Abstract

Polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) are persistent organic pollutants whose main removal process in the environment is due to biodegradation, and particularly anaerobic reductive dechlorination. Since PCDD/F congeners that are substituted in the lateral 2, 3, 7, and 8 positions are the most toxic, removal of these chlorines is advantageous, but previous studies have only demonstrated their removal under laboratory conditions. We evaluated a concentration data set of PCDD/F congeners with four or more chlorines along with all 209 polychlorinated biphenyl (PCB) congeners in surface water, treated and untreated wastewater, landfill leachate, and biosolids (NY CARP data set) to determine whether peri and peri/lateral dechlorination of PCDD/Fs occurs in these environments. Positive Matrix Factorization (PMF) applied to the data set revealed a factor indicative of the microbial dechlorination of PCBs, and this factor also contained a variety of non-2,3,7,8 substituted PCDD/F congeners. These results suggest that dechlorination of PCDD/Fs at the lateral positions is facile if not preferred in these environments. The relative lack of tetra- and penta-chlorinated PCDD/Fs suggested that dechlorination proceeds to PCDD/F congeners with less than four chlorines. The PMF results were confirmed by examining three samples that contained >90% PCB dechlorination products from the Fresh Kills Landfill and the Hudson River. Even without factor analysis, these samples demonstrated almost identical PCDD/F congener patterns. This study suggests that PCDD/Fs are reductively dechlorinated to nontoxic non-2,3,7,8 PCDD/F congeners in sewers and landfills as well as in the sediment of the Upper Hudson River.

Concentrations of organic contaminants in industrial and municipal bioresources recycled in agriculture in the UK

“…OCDD and HpCDD were the most dominant dioxin congeners in the bioresources , particularly for the biosolids and CLO, which is a typical pattern observed for sewage sludge and compost (Zennegg et al, 2013;Beníšek et al, 2015;Rodenburg et al, 2017) as well as soil and sediments. However, the most dominant OCDD/Fs and HpCDD/Fs have the lowest overall toxicities, compared to the other dioxin and furan congeners (Van den Berg et al, 2005).…”

What can we learn from 28 years of monitoring of fish tissue polychlorinated biphenyls in Michigan's rivers?

“…First, the reference dose is based on an Aroclor 1254 concentration rather than total PCB concentrations (MDCH, 2012). Since weathering processes modify congener profiles (Rodenburg et al, 2017), Aroclor methods are rendered inaccurate (Robertson et al, 2018). Second, this threshold concentration protects against immunological effects rather than the known carcinogenic effects (Lauby-Secretan et al, 2013).…”

Disentangling Source Profiles and Time Trends of Halogenated Flame Retardants in the Great Lakes

“…Thirty-five PBDE congeners (7,10,15,17,28,30,47,49,66,85,99,100,119,126,(138)(139)(140)153, 154 [coelutes with 2,2′,4,4′,5,5′-hexabromobiphenyl, PBB-153], 156, 169, 180, 183, 184, 191, 196, 197, 201, and 203−209) and eight alternative flame retardants, namely, hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), TBE and DBDPE, EHTBB, BEHTBP, and syn-and anti-Dechlorane Plus isomers were measured in a total of 2140 samples. Detailed information on the sample preparation and instrumental analyses is given elsewhere.…”

“…PMF analysis reveals the fingerprints of the suspected sources (i.e., F matrix) and the contribution of each source to each sample (i.e., G matrix). PMF was originally developed to investigate sources of atmospheric aerosols , and has proven to be a useful source apportionment tool for POPs in the environment. − Total air samples (vapor plus particles) collected between 2005 and 2019 from Chicago, Cleveland, Point Petre, Sleeping Bear Dunes, and Sturgeon Point, as well as from 2005 to 2016 from Eagle Harbor, were analyzed using PMF2. Thirteen PBDE congeners in 1774 samples were submitted for PMF analysis.…”