Serum dioxin levels in former chlorophenol workers

Abstract

Using gas chromatography/mass spectrometry, we measured lipid-adjusted serum levels for all 2,3,7,8-substituted dioxins and furans, and four coplanar polychlorinated biphenyls in 62 workers with chlorophenol exposure and 36 workers without chlorophenol exposures working at the same plant during the same time. We oversampled among workers diagnosed with chloracne. Mean dioxin background levels from 36 nonchlorophenol workers were estimated as 6.0 parts-per-trillion (ppt) for 2,3,7,8 tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and 67.5 ppt for 1,2,3,4,6,7,8 heptachlorodibenzo-pdioxin (Hepta-CDD). We found different dioxin and furan profiles for trichlorophenol and pentachlorophenol (PCP) workers. Among trichlorophenol workers with chloracne, we found 2,3,7,8-TCDD (mean ¼ 30.5 ppt) above background levels and among PCP workers with chloracne, we found high levels of Hepta-CDD (mean ¼ 312.5 ppt) and other higher chlorinated dioxins and furans. Cumulative exposure estimates for dioxins for both 2,3,7,8-TCDD and the higher chlorinated dioxins created in the early 1980s for our epidemiology studies were highly correlated with serum dioxin levels when age and body mass index were taken into account. While workers previously diagnosed with chloracne had high serum dioxin levels, some workers without diagnosed chloracne also had high levels. Among tradesworkers with plant-wide responsibilities, we observed serum dioxins and PCB levels higher than background indicating workplace exposures. We estimate that the mean level of 2,3,7,8-TCDD present in the serum of workers on the date workplace exposure terminated was 267 ppt (ranging from 8 to 1184 ppt) assuming a 9-year half-life, 582 ppt (ranging from 10 to 2,641 ppt) assuming a 7-year halflife, and 1928 ppt (ranging from 22 to 17,847) when a toxicokinetic model is used. We conclude that our findings are consistent with other studies reporting high serum dioxin levels among chlorophenol workers after occupational exposures.

Estimating perchlorate exposure from food and tap water based on US biomonitoring and occurrence data

“…Median serum TCDD levels measured in chemical production workers 15 years after workplace exposure ended were 68 pg/g of lipid (Calvert et al, 1996;Calvert et al, 1999). TCDD levels in the U.S. general population were also lower than workers with past trichlorophenol exposure (Collins et al, 2006) and lower than Vietnam veterans 20 years after duty-related exposure to Agent Orange (median serum TCDD concentration was 12.2 pg/g of lipid) (Henriksen et al, 1997).…”

“…In Minnesota and South Carolina farmers who used chlorpyrifos, urinary TCPy levels averaged about sixfold higher than those in the NHANES 1999-2000 subsample (Mandel et al, 2005;CDC, 2005). Urinary levels of TCPy have been found to be hundredsfold higher for chlorpyrifos manufacturing workers (Burns et al, 2006) and episodically many times higher for pesticide applicators than median levels from NHANES 1999(CDC, 2005.…”

Hierarchical cluster analysis of polychlorinated dioxins and furans in Michigan, USA, soils: Evaluation of industrial and background congener profiles

“…The Dow Chemical Company began operations in Midland, Michigan in 1897 and continues to the present. Chemical processes at Dow that may have resulted in the historic discharge of PCDDs and PCDFs to the environment include: electrolysis processes in the 1910s [2]; chlorophenol production, which started in the late 1930s and continued until 1980 [3]; and the incineration and open burning of waste materials dating back to the 1930s [2]. To investigate the impact of contamination on human exposures, the study included participants from four populations in Midland, Saginaw, and part of Bay Counties (MI), and from a comparison population in Jackson and Calhoun Counties (MI) and comprised measurements of dioxin-like compounds in soil, household dust, and serum, as well as the administration of a questionnaire.…”

Chloracne: Still Cause for Concern

“…chemical industry workers exposed to pesticides), since the 1960s when these compounds began to be replaced by synthetic resins, the incidence of chloracne has dropped dramatically, except for cases of accidental exposure as in the ICMESA plant explosion in Seveso (Italy) in 1976 [2,3,4,5]. Recently, however, cases of chloracne have been variously reported in chemical industry workers exposed to chlorophenols [6,7] and in agricultural workers exposed to pesticides [8]. Dioxin is the common name for dibenzo- p -dioxins and dibenzofurans (polychlorinated dibenzodioxins, PCDD, and polychlorinated dibenzofurans, PCDF, respectively), contaminants nearly ubiquitous in the environment (found in animal adipose tissue and in forest soil) and highly resistant to chemical and biological degradation.…”