Establishment of international water quality standard and health effects scenarios in wastewater irrigation system

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H05339
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental risk control and evaluation
• Research Institution: Kisarazu National College of Technology
• Principal Investigator: Okubo Tsutomu 木更津工業高等専門学校, 環境都市工学科, 准教授 (60581519)
• Research Collaborator: Uemura Shigeki ; Yasui Nobuhito ; Iguchi Akinori ; Tawfik Ahmed ; Tyagi Vinay Kumar
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 下水処理水の灌漑利用 / 水系感染リスク / 社会工学的評価

Outline of Final Research Achievements

The use of untreated sewage in agriculture is gaining attention as a result of rapid urbanization and increased global water scarcity. However, the incidence of waterborne infections among farmers in such areas is increasing due to the exposure of contaminated sewage. The aim of this study was to estimate the risk and health impact related to waterborne infections in farmers using agricultural drainage wastewater (ADW) for irrigation in the West Nile Delta. A total of nine viruses were detected by quantitative PCR and quantitative real-time PCR in ADW samples. The results of quantitative microbial risk assessment and disability-adjusted life year evaluation indicated that ADW of the Dishody drain is not acceptable for irrigation reuse. A water recirculation system including appropriate sewage treatment technology must be quickly installed to reduce microbial risks for farmers in the West Nile Delta.

Free Research Field

衛生工学

Academic Significance and Societal Importance of the Research Achievements

世界人口の増加により一人当りが使用可能な淡水資源量が減少する中、下水の灌漑利用が今後も世界的に増えていくと予想される。しかしながら下水には病原性微生物やウイルスなど、人の健康に直結する危険因子が含まれており、安全を担保した上での利用が求められる。本研究では、下水灌漑を行っている諸外国において汚染の実態調査を行い、現地で栽培されている農作物から農業従事者が農作業中に汚水を誤飲する量と頻度を設定し、人に対する健康影響を評価した。また、健康リスクを低減するにはそれら危険因子を減らす必要があり、現地に適用可能な下水処理方式を、消費電力とウイルス除去性能の両方を加味した上で比較評価し提言した。