Benzene Occupational Health Risk Assessment Methods And Applied Research

In last few decades, benzene served as the commonly-used agent in the process industry. High concentration exposure to benzene triggered many health problems ranging from dizziness and headaches to anemia and leukemia, which caused widespread concern in the society. Nowadays, occupational diseases in China were increasingly serious; the incidence rates were surging too. However, in China, researches in industry hygiene now mainly focused on the diagnosis and treatment. Studies on quantitative approaches for health risk assessment were few. Based on the pioneer's work, this paper proposed a quantitative method of health risk assessment for benzene occupational exposure, which served for the theoretical basis for occupational health risk assessment in China.Health risk assessment evaluates the potential adverse health effects and their probability of human exposed to hazardous materials. At present, health risk assessment can be divided into four steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization.First, data of the agent of interest, including its physicochemical properties, pathways and routes of exposure, toxicodynamic properties, toxicological effects, long-term animal carcinogenicity studies and human epidemiologic studies, need to be collected. And then, the data should be analyzed and evaluated to decide whether there is an association between exposure to the agent and occurrence of cancer.The method for dose-response assessment here included two steps. First, if benzene-exposed workers inhaled these chemicals, the processes of absorption, distribution and metabolism of benzene in his/her bodies will be quantified by PBPK model. Second, the internal dose obtained from the PBPK model will be used in the dose-response model, the cancer risk can be calculated.Then, a brief analysis of exposure assessment was presented, and the methods in exposure assessment included environmental monitoring, biological monitoring and mathematical models were described in detail. Finally, this paper evaluated health risk of workers exposed to benzene in a paint factory using the proposed method. Using two zone model and Mente Carlo simulation, the benzene concentrations in the workshop were estimated by Crystall Ball software, and simulation values were contrast to the actual measured values. According to benzene concentrations, cancer risk of exposed workers was calculated.