Background: In Map Ta Phut, Rayong Province, Thailand, the concentrations of benzene (BZ) and 1,3-butadiene (BD) in ambient air exceeds the standards set by the US Environmental Protection Agency (EPA). Therefore, health surveillance of exposure pathways and target organs in exposed individuals is important.
Methods: This cross-sectional study aimed to provide insights into blood biochemistry and serum malondialdehyde from BZ and 1,3-BD exposure among outdoor workers working in the Map Ta Phut industrial estate, Thailand. The study sample consisted of 200 people from four occupations: local fishers, street vendors, bus drivers, and traffic police.
Results: The local fishers group had higher levels of 1,2-DNB compared with the other groups (P < 0.05). Regarding health effects, the bus drivers group had higher white blood cell counts than the other groups (P < 0.05), particularly showing elevated neutrophil-to-lymphocyte ratio (NLR), monocyteto- lymphocyte ratio (MLR), basophil-to-lymphocyte ratio (BLR), and eosinophil-to-lymphocyte ratio (ELR) (P < 0.05). Malondialdehyde (MDA) levels were higher in the traffic police group than in the other groups (P < 0.05). The workers in the red zone (where 1,3-butadiene (BD) in the air exceeded the standard) had different blood cell parameters compared with workers in other color zones (P < 0.05).
Conclusion: Workers in the red zone area had lower red blood cell counts than those in other areas. Therefore, red blood cell count parameters should be used as indicators of health surveillance. Workers should also wear masks during outdoor work and monitor their health in response to air quality reports.