title: Assessing occupational exposure to chemicals in an international epidemiological study of brain tumours.
abstract: The INTEROCC project is a multi-centre case-control study investigating the risk of developing brain cancer due to occupational chemical and electromagnetic field exposures. To estimate chemical exposures, the Finnish Job Exposure Matrix (FINJEM) was modified to improve its performance in the INTEROCC study and to address some of its limitations, resulting in the development of the INTEROCC JEM. An international team of occupational hygienists developed a crosswalk between the Finnish occupational codes used in FINJEM and the International Standard Classification of Occupations 1968 (ISCO68). For ISCO68 codes linked to multiple Finnish codes, weighted means of the exposure estimates were calculated. Similarly, multiple ISCO68 codes linked to a single Finnish code with evidence of heterogeneous exposure were refined. One of the key time periods in FINJEM (1960-1984) was split into two periods (1960-1974 and 1975-1984). Benzene exposure estimates in early periods were modified upwards. The internal consistency of hydrocarbon exposures and exposures to engine exhaust fumes was improved. Finally, exposure to polycyclic aromatic hydrocarbon and benzo(a)pyrene was modified to include the contribution from second-hand smoke. The crosswalk ensured that the FINJEM exposure estimates could be applied to the INTEROCC study subjects. The modifications generally resulted in an increased prevalence of exposure to chemical agents. This increased prevalence of exposure was not restricted to the lowest categories of cumulative exposure, but was seen across all levels for some agents. Although this work has produced a JEM with important improvements compared to FINJEM, further improvements are possible with the expansion of agents and additional external data.
authors: Centre for Human Exposure Science, Institute of Occupational Medicine (IOM), Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK.
authors: Martie
authors: M
authors: van Tongeren
authors: Laurel
authors: L
authors: Kincl
authors: Lesley
authors: L
authors: Richardson
authors: Geza
authors: G
authors: Benke
authors: Jordi
authors: J
authors: Figuerola
authors: Timo
authors: T
authors: Kauppinen
authors: Ramzan
authors: R
authors: Lakhani
authors: Jérôme
authors: J
authors: Lavoué
authors: Dave
authors: D
authors: McLean
authors: Nils
authors: N
authors: Plato
authors: Elisabeth
authors: E
authors: Cardis
mesh_terms: D001554:Benzene / Q000009:adverse effects / Q000032:analysis; D001564:Benzo(a)pyrene / Q000009:adverse effects / Q000032:analysis; D001932:Brain Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D016022:Case-Control Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D016021:Epidemiologic Studies; D006801:Humans; D009784:Occupational Diseases / Q000139:chemically induced* / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis / Q000706:statistics & numerical data*; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects / Q000032:analysis
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D001564:Benzo(a)pyrene; D001554:Benzene
keywords: cancer epidemiology; case–control; job-exposure matrix