Abstract
This study investigates the impact of micro-environmental factors on worker breathing zone exposure levels in petrochemical facilities. A laboratory simulation study evaluated near-field exposure to methane for a typical maintenance task. Individual and combinations of micro-environmental factors significantly affected methane exposure. Airflow direction and speed were significant determinants of exposure concentration reduction. A side airflow direction at medium to high speed produced the lowest gas concentration in the breathing zone. Worker body orientation relative to the methane emission point was also a critical factor affecting gas concentration in the worker's breathing zone. The study provides insights into how variations in airflow and small changes in position impact near-field exposures for petrochemical tasks, guiding industrial hygiene professionals' training on qualitative exposure estimation and providing input for near-field exposure modeling to guide quantitative exposure and risk assessment.
Acknowledgments
Special thanks to NIOSH (Drs. John Snawder and Yousef Elmashae), who participated in the data collection process and provided the gas detection direct reading instruments. The authors would like to thank Dr. Rao Marepalli for contributing to the data analysis process.
Disclosure statement
No potential conflict of interest was reported by the author(s).