Variability in dust exposure in a cement factory in Tanzania

Area of Science:

• Occupational Health
• Environmental Science
• Epidemiology

Background:

• Chronic respiratory health effects are a concern in industrial settings.
• Cement factory workers are potentially exposed to high levels of dust.
• Understanding dust exposure levels is crucial for implementing effective health and safety measures.

Purpose of the Study:

• To assess total dust exposure levels in a Tanzanian cement factory.
• To evaluate the probability of overexposure relative to the occupational exposure limit (OEL) for different occupational groups.
• To analyze the effectiveness of occupational grouping for epidemiological studies.

Main Methods:

• Collected 120 personal 'total' dust samples from 80 workers across eight occupational groups.
• Utilized a 37 mm Millipore sampler for dust collection.
• Employed mixed-effect models to estimate variances and probabilities of overexposure.

Main Results:

• Geometric means of total dust exposure were highest in cranes (38.64 mg m(-3)), packing (21.30 mg m(-3)), and crushers (13.48 mg m(-3)).
• Probabilities of overexposure to total cement dust (OEL=10 mg m(-3)) were 96% for crane operators, 88% for packing workers, and 73% for crusher workers.
• The occupational grouping scheme demonstrated high contrast between groups (0.78) and minimal slope attenuation (1.0%).

Conclusions:

• Crane, packing, and crusher occupational groups exhibit significantly higher total dust exposure levels.
• These groups also show the highest probabilities of exceeding the occupational exposure limit, indicating a substantial risk of overexposure.
• The defined occupational groups are effective for epidemiological studies due to distinct exposure contrasts.