title: Organophosphorus pesticide residues in milled rice (Oryza sativa) on the Chinese market and dietary risk assessment.
abstract: The present study investigates the occurrence of acetylcholinesterase (AChE)-inhibiting organophosphorus (OP) pesticide residues in milled rice samples obtained form local markets in China during the period 2004-2006 and estimates their cumulative exposure. Concentrations of OP pesticides were determined by gas chromatography with flame photometric detection (GC-FPD). The results showed that 9.3% of the samples contained detectable residues of at least one of the seven target OP pesticides (chlorpyrifos, dichlorvos, omethoate, methamidophos, parathion-methyl, parathion and triazophos) mainly used for agriculture in China, with concentrations ranging 0.011-1.756 mg kg(-1). Rice consumption data was obtained from an individual food consumption survey. Relative potency factors (RPFs) for each pesticide were calculated with methamidophos as the index compound (IC), using 1- or 2-year chronic non-observed adverse effect levels (NOAEL) for AChE inhibition, mostly in rat brain, obtained from international evaluations of pesticides. Exposure to AChE-inhibiting pesticides for the population above 7 years old at P99.9 represented 52-94.5% of the acceptable daily intake (ADI) expressed as methamidophos. Estimated exposure for children aged 2-4 and 4-7 years at P99.9 were 119 and 104.3% of the ADI level, respectively. This study suggests that a yearly monitoring program for OP pesticide residues and strict implementation of the national safety standard for milled rice is necessary.
authors.affiliation: Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Mingxue
authors.initials: M
authors.lastname: Chen
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Chen
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Qian
mesh_terms: D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D002681:China; D004032:Diet; D004285:Dogs; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008297:Male; D008452:Maximum Allowable Concentration; D008875:Middle Aged; D009010:Monte Carlo Method; D009943:Organophosphorus Compounds / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D051381:Rats; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D009943:Organophosphorus Compounds; D010573:Pesticide Residues