A Case Study about Joining Databases for the Assessment of Exposures to Noise and Ototoxic Substances in Occupational Settings.

Evaluating risks associated with multiple occupational exposures is no easy task, especially when chemical and physical nuisances are combined. In most countries, public institutions have created databases, which gather extensive information on occupational exposures or work-related diseases. Unfortunately, these tools rarely integrate medical and exposure information, and, above all, do not take into account the possible adverse effects of co-exposures. Therefore, an attempt to exploit and join different existing databases for the assessment of the health effects of multiple exposures is described herein. This case study examines three French databases describing exposures to noise and/or ototoxic chemicals (i.e., toxic to the ear) and the incidence rate of occupational deafness in different sectors. The goals were (1) to highlight occupational sectors where the workers are the most (co)exposed and (2) to determine whether this approach could confirm the experimental data showing that this co-exposure increases the risk of developing hearing loss. The results present data per occupational sector exposing workers to noise only, ototoxic chemicals only, noise and ototoxic chemicals, and neither of these two nuisances. The ten sectors in which the proportion of exposed workers is the highest are listed. This analysis shows that the rate of hearing loss in these sectors is high but does not show an increased incidence of hearing loss in co-exposed sectors.