Abstract
Wastewater reclamation is an effective countermeasure to water shortage. However, there is a concern that wastewater reclamation causes health risks of infection by pathogens and cancer by disinfection by-products such as trihalomethanes (THMs). To discuss these risks, the Disability-Adjusted Life Years (DALY) has been employed and integrated with the unit of lost lifetime. Health risks such as infection and cancer in Fukushima city with population of 0.3 millions were evaluated using the DALY in the wastewater reclamation as a drinking water source. The damage [%·day] from the shortage of water was quantified using the product of the percentage deficiency to water supply demand [%] and the period of deficiency [days]. In the current situation of water utilization without reclamation, the DALY for total population was about 11 years. Reclamation of secondary effluent without disinfection brought no increase of DALY when the damage between 0 and 300 %·day was reduced. On the other hand, the DALY drastically increased when the reduction of the damage was over 300 %·days. If the secondary effluent was disinfected with chlorine, the maximum damage of 1200 %·day could be reduced by its reclamation without any increase of DALY.
