Mortality patterns among industrial workers exposed to chloroprene and other substances: I. General mortality patterns

Marsh, GM; Youk, AO; Buchanich, JM; Cunningham, M; Esmen, NA; Hall, TA; Phillips, ML

HERO ID

625187

Reference Type

Journal Article

Year

2007

Language

English

PMID

16999943

HERO ID 625187
In Press No
Year 2007
Title Mortality patterns among industrial workers exposed to chloroprene and other substances: I. General mortality patterns
Authors Marsh, GM; Youk, AO; Buchanich, JM; Cunningham, M; Esmen, NA; Hall, TA; Phillips, ML
Journal Chemico-Biological Interactions
Volume 166
Issue 1-3
Page Numbers 285-300
Abstract We conducted an historical cohort study to investigate the mortality experience of industrial workers potentially exposed to chloroprene (CD) and other substances, including vinyl chloride (VC), with emphasis on cancer mortality, including respiratory system (RSC) and liver. In 1999, the International Agency for Research on Cancer (IARC) classified CD as a possible carcinogen (Group 2B); VC was classified in 1987 as a known human carcinogen (Group 1). Subjects were 12,430 workers ever employed at one of two U.S. industrial sites (Louisville, KY (n = 5507) and Pontchartrain, LA (n = 1357)) or two European sites (Maydown, Northern Ireland (n = 4849) and Grenoble, France (n = 717)), with earliest CD production dates ranging from 1942 (L) to 1969 (P). Two sites (L and M) synthesized CD with the acetylene process that produced VC exposures. We determined vital status through 2000 for 95% of subjects and cause of death for 95% of the deaths. Historical exposures for individual workers were estimated quantitatively for CD and VC. Workers ever exposed to CD ranged from 92.3% (M) to 100% (G); to VC from 5.5% (M) to 22.7% (L). We computed standardized mortality ratios (SMRs) (using national and regional standard populations) in relation to selected demographic, work history and exposure factors. We used worker pay type (white or blue collar) as a rough surrogate for lifetime smoking history. For the combined cohort, SMRs (95% CIs) for all causes combined, all cancers combined, RSC and liver cancer were, respectively, 0.72 (0.69–0.74), 0.73 (0.68–0.78), 0.75 (0.67–0.84) and 0.72 (0.43–1.13). Site-specific (L, M, P and G, respectively) SMRs were: for all cancers combined: 0.75 (0.69–0.80), 0.68 (0.56–0.80), 0.68 (0.47–0.95) and 0.59 (0.36–0.91); for RSC: 0.75 (0.66–0.85), 0.79 (0.58–1.05), 0.62 (0.32–1.09) and 0.85 (0.41–1.56); for liver cancer: 0.90 (0.53–1.44) (17 deaths), 0.24 (0.01–1.34) (1 death), 0.0 (0–2.39) (no deaths) and 0.56 (0.01–3.12) (1 death). Among all workers ever exposed to CD, SMRs were: for all cancers combined: 0.71 (0.66–0.76); for RSC: 0.75 (0.67–0.84); for liver cancer: 0.71 (0.42–1.14). We also observed no increased mortality risks among cohort subgroups defined by race, gender, worker pay type, worker service type (short/long term), time period, year of hire, age at hire, duration of employment, the time since first employment, and CD or VC exposure status (never/ever exposed). In summary, our study has many strengths and is the most definitive study of the human carcinogenic potential of exposure to CD conducted to date. We conclude that persons exposed to chloroprene or vinyl chloride at the levels encountered in the four study sites did not have elevated risks of mortality from any of the causes of death examined, including all cancers combined and lung and liver cancer, the cancer sites of a priori interest. This conclusion is corroborated by our detailed analyses of mortality in relation to qualitative and quantitative exposures to CD and VC at each of the four study sites, reported in our companion paper (Marsh et al., submitted for publication).
Doi 10.1016/j.cbi.2006.08.011
Pmid 16999943
Wosid WOS:000246096600033
Url https://www.scopus.com/inward/record.uri?eid=2-s2.0-33947168166&doi=10.1016%2fj.cbi.2006.08.011&partnerID=40&md5=76603fa9429c08c019de0bf539216c51
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword Chloroprene; Vinyl chloride; Cohort study; Liver cancer; Lung cancer; Mortality
Is Qa No