Exposure to mixtures and congeners of polychlorinated biphenyls

1994 ◽  
Vol 40 (7) ◽  
pp. 1409-1415 ◽  
Author(s):  
S Skerfving ◽  
B G Svensson ◽  
L Asplund ◽  
L Hagmar
Keyword(s):  
Polychlorinated Biphenyls ◽  
Biological Samples ◽  
Total Pcbs ◽  
Limited Information ◽  
Biomarkers Of Exposure ◽  
Equivalency Factors ◽  
Specific Analysis ◽  
Toxic Equivalency Factors ◽  
Toxic Equivalents ◽  
The Relationship

Abstract There are 209 congeners of polychlorinated biphenyls (PCBs), the metabolism and toxicity of which vary by congeners. Use of PCBs is now restricted, but environmental contamination and human exposure persist. Analysis for "total PCBs" in biological samples gives limited information; congener-specific analysis is far more informative, but more complicated. Concentrations of congeners in serum/plasma, adipose tissue, or milk are useful biomarkers of exposure. Lipids may contain similar concentrations and congener patterns, but these vary between exposures and are different from those of the corresponding exposure mixtures; hence, analysis of lipids cannot be used to identify the original exposure. Some non- and mono-ortho congeners may attain a coplanar conformation, which renders them capable of a dioxin-like action. Toxic equivalency factors (TEFs) have been used to sum that risk as toxic equivalents (TEQs), which are considerably different from congener concentrations. No reliable data have been developed on the relationship between concentrations of "total PCBs" or congeners in biological samples and effects of PCBs on human health, mainly because of the various analytical procedures involved and confounding exposures.

scholarly journals Development of a laboratory analytical method beneficial to the policies of the Canada-wide standards for dioxins and furans

2021 ◽  
Author(s):  
Eric Paul Buan
Keyword(s):  
Correction Factor ◽  
Operating Cost ◽  
Cost Savings ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Equivalency Factors ◽  
Soils And Sediments ◽  
Toxic Equivalency Factors ◽  
Toxic Equivalents ◽  
Health Organization

An enzyme-linked immunosorbent assay (ELISA) was tested for its ability to screen for PCDD/F in soils and sediments at 50, 1000 and 10,000 picograms toxic equivalents per gram of soil pgTEQ g-₁ (n=48, r²=0.994, slope=0.94). These results relied on two concepts developed in this thesis. The first, a congener correction factor, corrects ELISA results for differences in how ELISA and GC-HRMS calculate the dioxin content of a sample. The congener correction factor increased the correlation between ELISA and GC-HRMS TEQ values calculated using World Health Organization (WHO) toxic equivalency factors (TEF) from 83% to 94%. The correlation between ELISA and GC-HRMS TEQ values calculated using North Atlantic Treaty Organization (NATO) TEF remained strong when the correction factor was applied, falling from 102% to 94%. The second concept, a sample algorithm allows ELIAS to efficiently measure unknown PCDD/F concentrations between 30 and 10,5000 pgTEQ g-¹. The algorithm successfully placed 24 of 28 samples into their correct concentration ranges in a maximum of two ELISA each. A cost analysis of using the algorithm predicted that ELISA can screen samples three times faster than GC-HRMS while at a 60% reduction in operating cost. The success of ELISA in conjunction with its time and cost savings indicate that it can replace GC-HRMS in situations where the high precision of GC-HRMS is not required.

scholarly journals Dietary Exposure to Polychlorinated Biphenyls and Dioxins and Its Relationship to Telomere Length in Subjects Older Than 55 Years from the SUN Project

Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 353
Author(s):  
Lucia Alonso-Pedrero ◽  
Carolina Donat-Vargas ◽  
Maira Bes-Rastrollo ◽  
Ana Ojeda-Rodríguez ◽  
Guillermo Zalba ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Telomere Length ◽  
Quantitative Polymerase Chain Reaction ◽  
Dietary Exposure ◽  
Cross Sectional Study ◽  
Total Pcbs ◽  
Linear Regression Models ◽  
Cross Sectional ◽  
Toxic Equivalents ◽  
Sun Project

Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the “Seguimiento Universidad de Navarra” (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = −0.30 × 10−7; 95% CI, −0.55 × 10−7 to −0.06 × 10−7), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = −6.17 × 10−7; 95% CI, −11.30 × 10−7 to −1.03 × 10−7), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = −5.02 × 10−7; 95% CI, −9.44 × 10−7 to −0.61 × 10−7), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = −13.90 × 10−7; 95% CI, −37.70 × 10−7 to 9.79 × 10−7). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.

scholarly journals Development of a laboratory analytical method beneficial to the policies of the Canada-wide standards for dioxins and furans

2021 ◽  
Author(s):  
Eric Paul Buan
Keyword(s):  
Correction Factor ◽  
Operating Cost ◽  
Cost Savings ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Equivalency Factors ◽  
Soils And Sediments ◽  
Toxic Equivalency Factors ◽  
Toxic Equivalents ◽  
Health Organization

An enzyme-linked immunosorbent assay (ELISA) was tested for its ability to screen for PCDD/F in soils and sediments at 50, 1000 and 10,000 picograms toxic equivalents per gram of soil pgTEQ g-₁ (n=48, r²=0.994, slope=0.94). These results relied on two concepts developed in this thesis. The first, a congener correction factor, corrects ELISA results for differences in how ELISA and GC-HRMS calculate the dioxin content of a sample. The congener correction factor increased the correlation between ELISA and GC-HRMS TEQ values calculated using World Health Organization (WHO) toxic equivalency factors (TEF) from 83% to 94%. The correlation between ELISA and GC-HRMS TEQ values calculated using North Atlantic Treaty Organization (NATO) TEF remained strong when the correction factor was applied, falling from 102% to 94%. The second concept, a sample algorithm allows ELIAS to efficiently measure unknown PCDD/F concentrations between 30 and 10,5000 pgTEQ g-¹. The algorithm successfully placed 24 of 28 samples into their correct concentration ranges in a maximum of two ELISA each. A cost analysis of using the algorithm predicted that ELISA can screen samples three times faster than GC-HRMS while at a 60% reduction in operating cost. The success of ELISA in conjunction with its time and cost savings indicate that it can replace GC-HRMS in situations where the high precision of GC-HRMS is not required.

scholarly journals Polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in New Zealand cetaceans

1999 ◽  
pp. 157-167 ◽  
Author(s):  
Paul D. Jones ◽  
Donald J. Hannah ◽  
Simon J. Buckland ◽  
Tania Van Maanen ◽  
Scott V. Lea Ihem ◽  
...  
Keyword(s):  
New Zealand ◽  
Polychlorinated Biphenyls ◽  
Trophic Levels ◽  
Limited Information ◽  
Halogenated Aromatic Hydrocarbons ◽  
Baleen Whales ◽  
Right Whale ◽  
Beaked Whales ◽  
Dusky Dolphins ◽  
Toxic Equivalents

Limited information is available on the concentrations of halogenated aromatic hydrocarbons (HAHs) in cetaceans from the Southern Hemisphere. This paper presents data on blubber concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in Hector's dolphins, dusky dolphins, southern right whale dolphins, blue whales, minke whales, Gray's beaked whales, Cuvier's beaked whales and pygmy right whales stranded in New Zealand. Both HAH concentrations and toxic equivalents (TEQs) are found to be higher in Hector's dolphins, a species with an inshore distribution, than in other odontocetes, which are more oceanic. Baleen whales, which are oceanic and feed at lower trophic levels, present the lowest levels of pollutants, with PCDD and PCDF concentrations usually below detection limits. The PCB profiles of the various species suggest that they are exposed to different PCB sources. Overall, HAH levels detected are lower than those reported for comparable species in the Northern Hemisphere. The relative abundance of low chlorinated PCB congeners in New Zealand cetaceans, as compared to those from northern waters, suggests that the origin of these compounds is mostly atmospheric deposition.

Identification of the biomechanical factors associated with the perception of distension in the human esophagus

2002 ◽  
Vol 282 (4) ◽  
pp. G683-G689 ◽  
Author(s):  
J. D. Barlow ◽  
H. Gregersen ◽  
D. G. Thompson
Keyword(s):  
Cross Sectional Area ◽  
Sectional Area ◽  
Limited Information ◽  
Butyl Bromide ◽  
Cross Sectional ◽  
Impedance Planimetry ◽  
Sensory Responses ◽  
Human Esophagus ◽  
Biomechanical Factors ◽  
The Relationship

Current techniques used to investigate the mechanisms responsible for the sensory responses to distension of the human esophagus provide limited information because the degree of circumferential stretch required to determine tension can only be inferred. We used impedance planimetry to measure the cross-sectional area during esophageal distension to ascertain the degree of stretch and tension that initiated motor and sensory responses. Hyoscine- N-butyl bromide (HBB), a cholinergic muscarinic receptor blocker, was also used to alter esophageal tension during distension. Motor activity was initiated at a lower degree of stretch and tension than that which initiated sensory awareness; both increased directly with increasing distension. HBB reduced both esophageal motility and tension during distension without altering the relationship between sensation intensity and cross-sectional area. Esophageal stretch, rather than tension, thus appears to be the major factor influencing sensory responses to esophageal distension.

Sign in / Sign up

Export Citation Format

Share Document