Cumulative Risk Assessment of Organophosphorus Pesticides in the Diet

식품을 통한 유기인계농약류의 동시노출위해성평가

Risk assessment traditionally are conducted on individual chemicals; however, humans are exposed to multiple chemicals in daily life. The organophosphorus (OP) pesticides are considered in a single risk assessment because they act by a common mechanism of toxicity, and there is likely to be expose to multiple OP pesticides simultaneously or sequentially. The OP pesticides act by inhibiting the enzyme acetylcholinesterasc (AChE) and have available extensive database. AChE is widely distributed throughout the body, most importantly in the nervous system. Inhibition of AChE results in accumulation of acetylcholine in the nervous system that results in clinical signs of cholinergic toxicity, including increased salivation and lacrimation, nausea and vomiting, muscle fasciculation, lethargy and fatigue, among others. To conduct an exposure assessment for pesticides in the diet, we need to know the food consumption patterns of the populations, and the pesticide residue levels in the foods that are consumed. This study was conducted to identify cumulative dietary risk due to multiple OP pesticides that can be exposed through various foods. Total 22 food samples including cereals, vegetables and fruits were collected randomly two times from food markets in several sites (4 cities). The subjected foods were selected by regarding of highly consumed foods to general Korean people. The 12 OP pesticides including Acephate, Azinphos-methyl, Chlorpyrifos, and Diazinon were monitored. For the exposure assessment, general adult group of 60 kg body weight was regarded as target population and food consumption data suggested by Lee et al. (2000) were used as consumed value of individual food. Analyses of samples for OP pesticides have been carried out according to the multiclass multiresidue analysis method and acephate and methamidophos analysis method of Korea Food Code. In general the levels of OP pesticides found in the food samples were very low or not detected.

유기인계 농약은 주로 수확률을 증가시킬 목적으로 과일, 채소, 곡류를 포함한 농산물에 사용하는 살충제로, 최근의 위해성평가기술은 독성기전이 동일한 물직들에 대해서 기준이 되는 물질의 특성을 1로하여 상대독성계수를 고려하므로 동시노출평가(cumulative risk assessment)를 수행하고 있다. 본 연구에서는 식품섭취를 통한 유기인계 농약의 동시다중노출에 기인된 위해정도를 판단하기 위하여 유기인계 농약과 다소비노출가능식품 등을 대상으로 cumulative risk assessment 를 실시코자 하였다. 펑가에 고려된 농약은 우리나라에서 사용빈도가 높은 농약(Acephate, Azinphos-methyl, Chlorpyrifos, Diazinon, Dimethoate, Ethion, Malathion, Methamidophos, Methidathion, Parathion-methyl, Phosmet, Pirimiphos-methyl) 12종이었고, 평가대상식품은 국내에서 유통되는 다소비식품을 위주로 곡류 4종(쌀, 보리, 밀, 옥수수), 과일류 5종(사과, 감, 밀감, 바나나, 배), 및 채소류 13종(배추, 양배추, 상추, 시금치, 오이, 토마토, 호박, 양파, 고추, 마늘, 무, 파, 당근)을 포함하여 총 22종의 식품을 대상으로 하였으며, 시료의 대표성을 부여하기 위하여 샘플링은 전국 4개 대도시(서울, 부산, 광주, 대전)를 대상으로 총2회 실시하였다. 12종의 유기인계 농약의 동시다중 노출에 대한 위해성평가를 위하여 노출평가시 TEF(독성등가치, Toxic Equivalency Factor) 방법을 적용하였고, FAO/WHO 의 만성인체노출평가방법을 기초로 우리나라 일반 성인을 대상으로 다수의 식품섭취를 통한 다수의 농약에 대한, 동시인체노출평가를 실시하였다. 노출의 안전수준을 결정하기 위해 필요한 독성값은 chlorpyrifos를 기준으로 하여 U.S.EPA 에서 제시한 AChE저해작용을 endpoint로 하는 RfD 값을 활용하였으며, 다수의 유기인계 농약으로부터 동시노출 되었을 때 나타날 수 있는 비발암독성에 대한 위해도를 결정하기 위하여 위험지수(Hazard Index, HI) 방법을 사용하였다.