Health risk due to exposure to airborne pesticides is highly concerned in suburbs of local cities where residential and agricultural areas are mixing. A number of local cities currently promote urban centralization and agricultural production for local consumption. This promotion probably affect distributions of farmland as origin of pesticides and population, resulting in considerable change in exposure of residents to airborne pesticides in the future. We estimated the exposure to airborne pesticides for residents in Utsunomiya city, Japan as a typical local city in the year of 2050 by predicting land use and population distribution.
 The result revealed that chloropicrin (CP), a soil fumigant, poses the highest health risk to residents among 12 pesticides selected on the basis of usage in this city and its toxicity. CP is used usually in summer but nobody in Utsunomiya is exposed at concentration higher than the reference value (2.2 × 10^-3 mg/m³) at the present even in that season. On the other hand, farmland expansion promoted with urban centralization was estimated to increase the exposure to CP in the future and to expose 0.02% of population to CP in excess of the reference value during summer night due to lighter wind than in daytime. Such a significant level of exposure to other airborne pesticides was not found as of 2050. For comparison, we also estimated the future exposure in Aomori city, another typical local city and demonstrated that as much as 3.0% of population will be exposed to airborne CP over the reference value in this city where residential area is closer to agricultural area than Utsunomiya city.

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 Because solid residue and digestate liquid should be treated or disposed when food wastes are anaerobically digestated, combined system in which these waste are treated in incineration facility considered better strategy. In this study, two scenarios of combined system with dry type anaerobic digestion and incineration were evaluated for net recovery of electricity; power generation by gas turbine and biogas use in a super heater for generated steam in an incinerator. For both scenarios, two cases of input waste in anaerobic digestion were supposed: food waste only and food waste plus mixed paper. Sensitivity analysis of main parameters of the system was performed to find a way to improve performance. Energy recovery of combined system is higher than that incineration system in which food waste is burned, however, it is only caused by the increased power generation efficiency in incineration. For this reason, separation of paper waste increase biogas generation, but total recovery of energy is reduced.

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