Occupational exposure to arsenic is considered a potential confounder for environmental arsenic exposure. A large fraction of the population works has been working as coal miners of an arsenic-rich coal. But the uptake of arsenic from coals remains yet to be determined.

Occupational exposure to arsenic was estimated with a British job-exposure matrix (JEM):

Pannett B, Coggon D, Acheson ED. A job-exposure matrix for use in population based studies in England and Wales. Br J Ind Med 1985; 42:777-83

Modifications were performed with respect to

(1) the local occupational exposure conditions (arsenic rich coal and coal ash)

(2) arsenic exposure according to CAREX International Information System on Occupational Exposure to Carcinogens, www.occuphealth.fi/list/data/CAREX

see also: Pesch B et al. Int J Epidemiol 2000;29:1014-24

and discuss pros and cons of job-exposure matrices.