Comparison of RBCA, CLEA and CalTOX for Health Risk Assessment of a Benzo [a] pyrene Contaminated Site
RBCA、CLEA及CalTOX模型在苯并[a]芘污染场地健康风险评估中的应用比较

To investigate the differences in health risk assessment of contaminated sites using different models, RBCA, CLEA and CalTOX models were applied to conduct health risk assessment of an industrial site with surface soil contaminated by benzoa]pyrene (Ba]P). The differences in the assessment results and the causes of the differences among RBCA, CLEA and CalTOX models were discussed. The main exposure parameters in each model were ranked by sensitivity analysis. The soil cleanup levels were also developed based on risk probability distribution. Results showed that the total carcinogenic risk of Ba]P obtained by RBCA, CLEA and CalTOX was 2.40×10-4, 6.32×10-4 and 7.04×10-6, respectively. Oral ingestion and dermal contact were the dominant exposure pathways, contributing most to the total risk. Degradation assumption in CalTOX model was an important reason for obtaining different results from those of RBCA and CLEA models. The parameter selection and methodological difference also contributed to the differences in the assessment results obtained by the three models. Besides, the sensitivity of exposure parameters ranked differently in the three models. Based on risk probability distribution, the soil cleanup levels obtained by RBCA, CLEA and CalTOX were 0.18, 0.08, 0.13 (CalTOX without degradation assumption) and 10.74 (CalTOX with degradation assumption) mg·kg-1, which were 1.5-2.6 times of the values derived directly by the three models. The method based on risk probability distribution can reduce the influence of parameter uncertainty on the risk assessment, providing reference for developing soil cleanup levels of industrial contaminated sites.