Human Health Risk Assessment due to Solvent Exposure from Pharmaceutical Industrial Effluent: Deterministic and Probabilistic Approaches

Treated effluents from a pharmaceutical industry were analysed using purge and trap coupled with gas chromatography-mass spectrophotometry to determine the presence of organic solvents. Solvents such as dichloromethane, chloroform, toluene, tetrahydrofuran and chlorobenzene were detected. A health risk assessment study using both the deterministic method and a probabilistic approach by Monte Carlo simulations were then carried out on children, adults and pregnant women considering oral ingestion, dermal contact and fish intake as the exposure routes. Among the various categories of receptors considered, the results obtained by both methods revealed that children are more sensitive followed by pregnant women, since their total hazard index (HI total risk ) exceeded the safe exposure limit for non-carcinogens. It is also evidenced that oral and dermal contact are the crucial routes of exposure among children, adults and pregnant women. The fish intake had the minimal impact on all receptors, which might be due to the lesser affinity of these solvents to sorb onto fish tissues. Cancer risk because of dichloromethane and chloroform exposure was found to be negligible (2.8×10 -8 for children, 1.3×10 -7 for adults, 3.9×10 -7 for pregnant women) since the computed risk was well below the acceptable range (10 -4 - 10 -6 ). The total non-carcinogenic risk calculated from the probabilistic approach exceeded the deterministic approach by 1.9 times, 1.02 times, 1.8 times for children, adults and pregnant women, respectively. This might be due to incorporating lower values among the possible range for the parameters involved during deterministic risk assessment.