Minimizing health risks during secondary effluent application via subsurface drip irrigation

摘要

Health risks posed on consumers due to the use of agricultural products irrigated with reclaimednwastewater were assessed by numerical simulation. The analysis is based on defining of annExposure Model (EM) which takes into account several parameters: (i) the quality of the appliednwastewater, (ii) the irrigation method, (iii) the elapsed times between irrigation, harvest, andnproduct consumption, and; (iv) the consumers’ habits. The exposure model is used for numericalnsimulation of human consumers’ risks by running the Monte Carlo simulation method. Althoughnsome deviations in the numerical simulation which are probably due to uncertaintyn(impreciseness in quality of input data) and variability due to diversity among populationsnreasonable results were accepted. Accordingly, there is a several orders of magnitude differencenin the risk of infection between the different exposure scenarios with the same water quality. Thenvariability indicates the need for setting risk-based criteria for wastewater reclamation, includingnthe application method and environmental conditions, rather than single water quality guidelines.nExtra data is required to decrease uncertainty in the risk assessment. Future research needs toninclude definite acceptable risk criteria, more accurate dose-response modeling, informationnregarding pathogen survival in treated wastewater, additional data related to the passage ofnpathogens into and in the plants during irrigation, and information referring to the consumingnhabits of the human community.