COMPARING DETERMINISTIC AND PROBABILISTIC METHODS IN RISK ASSESSMENT OF INFECTIVE ENTEROVIRUSES FOR CONSUMPTION OF LETTUCE IRRIGATED WITH WASTEWATER EFFLUENT

Background and Aim:Deterministic risk assessment estimates a single point of risk while probabilistic risk assessment evaluates a range of risk with use of probability distribution functions. Application of risk assessment when wastewater effluent is used in agricultural activities is important because of the potential transmission of infective enteroviruses to crop consumers. The aim of this study was to compare the deterministic and probabilistic risk methods in risk assessment of enteroviruses infections for consumption of wastewater effluent-irrigated lettuce.Methods:In this study, 15 wastewater effluent samples were taken from a municipal wastewater treatment plant. The concentration of enteroviruses was measured with cell culture method. Risk assessment was studied with deterministic and probabilistic methods and results were compared with the WHO guideline of 10-3 infection risk per person per year (pppy).Results:Enteroviruses were detected in 40% of samples. Deterministic risk assessment was estimated enteroviruses infection risk with a mean of 0.1424 pppy, although the probabilistic risk assessment was determined the mean enteroviruses infection risk of 0.0448 pppy. In the probabilistic method, based on the sensitivity analysis, Lettuce consumption and enteroviruses concentration in the effluent were important parameters in the increasing risk.Conclusion:Results of this study showed that the estimated risk with deterministic method was higher than the probabilistic method. However, the estimated risk with two methods was more than of the WHO guideline therefore, control approaches should be used for the reduction of enterviruses infection risk for wastewater usage in agricultural activities.

کلیدواژه ها:

Deterministic risk assessment ، Probabilistic risk assessment ، Infection enterovirus ، Effluent wastewater ، Irrigation