Personal exposure to inhalable dust and the specific latex aero-allergen, Hev b6.02, in latex glove manufacturing in Thailand

Abstract

Objectives: Latex product manufacturing is an important industry in south-east Asia but has the potential for considerable occupational exposure of workers to latex allergens. Although exposure to latex allergens can result in adverse health reactions, few studies to characterize this exposure have been conducted to date. This study therefore aimed to characterize current airborne inhalable dust and the specific allergen, Hev b 6.02, exposures in this industry in Thailand.

Methods: Workers were recruited from three factories in the southern part of Thailand. Full-shift inhalable dust personal air sampling was conducted using IOM sampling heads equipped with polytetrafluoroethylene filters at a 2.0 l min(-1) flowrate. After weighing to determine inhalable dust levels, filters were extracted and analysed for Hev b 6.02 using an enzyme immunometric assay.

Results: Two hundred and seventy-five workers agreed to participate, resulting in a total of 292 measurements. Geometric mean (GM) personal exposure to inhalable dust was 0.88 mg m(-3), but individual exposures up to 12.34 mg m(-3) were measured. The pattern of exposure was similar across factories, with highest exposures in the stripping (GM 2.08-4.05 mg m(-3) for the 3 factories) and tumbling departments (1.11-2.17 mg m(-3)). Within-worker (day-to-day) variability contributed 92% to total variability. The Hev b 6.02 exposure pattern was similar with time-weighted average GM exposure levels in the oldest factory ranging from 8.7 mg m(-3) in the laboratory to 30.2mg m(-3) in the stripping department. In contrast to inhalable dust exposure, total exposure variability was primary driven by variability between workers (67%).

Conclusions: Workers in these latex product factories get routinely exposed to measurable Hev b 6.02 levels, which may give rise to increased incidence of allergic symptoms and occupational asthma. Also, in this measurement campaign a 10mg m(-3), but not 15 mg m(-3), occupational exposure limit for inhalable dust was occasionally exceeded. Highest Hev b 6.02 exposures were found in the stripping and tumbling departments, which would be natural targets for interventions aimed at reducing exposure.

Keywords: allergens; allergy; glove manufacturing; hev b 6.02; inhalable dust; latex allergens; latex gloves; latex products; occupational asthma; occupational exposure; occupational hygiene.