Job-exposure matrix for historical exposures to rubber dust, rubber fumes and n-Nitrosamines in the British rubber industry

Occup Environ Med. 2019 Apr;76(4):259-267. doi: 10.1136/oemed-2018-105182. Epub 2019 Feb 16.

Abstract

Objectives: To develop a quantitative historical job-exposure matrix (JEM) for rubber dust, rubber fumes and n-Nitrosamines in the British rubber industry for 1915-2002 to estimate lifetime cumulative exposure (LCE) for a cohort of workers with 49 years follow-up.

Methods: Data from the EU-EXASRUB database-rubber dust (n=4157), rubber fumes (n=3803) and n-Nitrosamines (n=10 115) collected between 1977 and 2002-were modelled using linear mixed-effects models. Sample year, stationary/personal measurement, industry sector and measurement source were included as fixed explanatory variables and factory as random intercept. Model estimates and extrapolations were used to construct a JEM covering all departments in both sectors of the rubber manufacturing industries for the years 1915-2002. JEM-estimates were linked to all cohort members to calculate LCE. Sensitivity analyses related to assumptions about extrapolation of time trends were also conducted.

Results: Changes in rubber dust exposures ranged from -6.3 %/year (crude materials/mixing) to -1.0 %/year (curing) and -6.5 %/year (crude materials/mixing) to +0.5 %/year (finishing, assembly and miscellaneous) for rubber fumes. Declines in n-Nitrosamines ranged from -17.9 %/year (curing) to -1.3 %/year (crude materials and mixing). Mean LCEs were 61 mg/m3-years (rubber dust), 15.6 mg/ m3-years (rubber fumes), 2483.2 µg/m3-years (n-Nitrosamines sum score), 18.6 µg/m3-years (N-nitrosodimethylamine) and 15.0 µg/m3-years (N-itrosomorpholine).

Conclusions: All exposures declined over time. Greatest declines in rubber dust and fumes were found in crude materials and mixing and for n-Nitrosamines in curing/vulcanising and preprocessing. This JEM and estimated LCEs will allow for evaluation of exposure-specific excess cancer risks in the British rubber industry.

Keywords: JEM; industrial cohort study; job-exposure matrix; nitrosamines; occupational exposures; rubber dust; rubber fumes; rubber industry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Dust / analysis
  • Female
  • Gases / analysis
  • Humans
  • Industry / methods
  • Industry / statistics & numerical data
  • Male
  • Middle Aged
  • Nitrosamines / adverse effects*
  • Nitrosamines / metabolism
  • Occupational Exposure / adverse effects*
  • Occupational Exposure / statistics & numerical data
  • Rubber / adverse effects*
  • Rubber / metabolism
  • United Kingdom

Substances

  • Dust
  • Gases
  • Nitrosamines
  • Rubber