CASE I:CUMULATIVE RISK ASSESSMENT FOR PESTICIDE REGULATION Debut of multi-chemical assessment of pesticide exposure through food,water,and residential uses Highly refined dose-response and exposure assessment Nationally representative dietary assessment What do we know about risk characterization for such complex assessments？ Debut of multi-chemical assessment of pesticide exposure through food, water, and residential uses  Highly refined dose-response and exposure assessment  Nationally representative dietary assessment  What do we know about risk characterization for such complex assessments?