Work Place Environment and Personal Exposure of PM and PAHs to Workers in Natural Rubber Sheet Factories Contaminated by Wood Burning Smoke

摘要

Work place environment in factories producing Ribbed Rubber Smoke Sheet (RSS), inside of which are heavily contaminated by wood burning smoke, has been evaluated focusing on concentrations of particulate matter and particle bond PAHs as well as their exposure to workers during January, 2006 - February, 2008 in Hat Yai, Thailand. Seasonal changes in the particulates and PAHs concentrations were related to the production amount of RSS and weather conditions. Based on the measurement in four different factories, which have different types of ventilation facilities, influences of ventilation were also discussed. The concentration of total suspended particulates (TSP) in workplace increased linearly with RSS production although it showed a slight dependency on the wind direction to a factory building probably because of the configuration of open sides of the building. TSP concentration in the work place and at the worker's breathing zone ranged 0.02 to 0.28 and 0.14 to 0.56 mg/m~3, respectively. Those are still less than the working environmental standard but rather high PAHs concentrations (94.6 ~131 ng/m~3 in workplace and 153 ng/m~3 at breathing zone) were observed. Ventilation by roof turbines as well as a ridge vent roof may not be efficient enough to remove smoke particles. The workers in the RSS factory were found to have a risk of exposure to rather high concentration of PAHs, which may be both from wood burning and a diesel engine operated inside.