Work related health

O1.1 VARIABILITY IN RESPIRABLE DUST EXPOSURE IN A MANUALLY OPERATED COAL MINE IN TANZANIA

S. H. D. Mamuya^1,2, M. Bråtveit¹, J. Mwaiselage¹, B. E. Moen¹.Section for Occupational Medicine, University of Bergen, Norway

Introduction: Respirable dust was measured among workers in a manually operated coal mine in Tanzania. This study aims at assessing appropriate grouping schemes for an exposure response study on respiratory health effects.

Methods: Full shift personal respirable dust samples (n = 204) were collected from 141 randomly chosen workers among about 600 workers at underground and surface work sites. Variance components were estimated by random effect models.

Results: The arithmetic mean exposure level for respirable dust varied from 0.07 mg/m³ for office workers up to 25.16 mg/m³ for pneumatic drillers. Three grouping schemes were evaluated; work site (eight groups), job title (11 groups), and main type of material handled (five groups). The grouping strategy based on work site resulted in the highest percentage of explained variance between workers (83.7%), followed by the job title (77.6%) and material handled (71.4%). High contrasts in exposure between the groups were found for all grouping schemes (ε >0.94). The attenuation of the theoretical exposure-response relation was lower when grouping by material handled (1.5%) than when grouping by work site (5.9%) or job title (5.2%).

Conclusion: According to the minimal theoretical attenuation, the material grouping scheme might be appropriate for studying the association between respirable dust exposure and respiratory effects. Since historical job changes for individual workers were not recorded during the data collection process, cumulative dust exposure cannot be calculated by job title grouping.

O1.2 THE USE OF HEALTHCARE SERVICES FOLLOWING A WORKPLACE INJURY: A STUDY OF WORKERS AND THEIR FAMILIES IN BRITISH COLUMBIA

J. Brown^1,2, H. Shannon^1,2, P. McDonough², C. Mustard².¹Program in Occupational Health and Environmental Medicine, McMaster University, Canada; ²Department of Public Health Science, University of Toronto, Canada

Introduction: The pressure of coping with …