Contamination Levels of POPs in Various Food Items from the Southernmost of Thailand: Primary Health Risk Assessment Through Dietary Intake
The objectives of this study were to determine concentrations of OCPs and PCBs in food products and marine food and to assess the potential health risk involved consuming contaminated food through dietary intake. The food samples collected were various brands of processed fish ball, baby food, instant cereal, canned seafood, frying oil and fresh marine food as well as fishes and shellfishes. They were purchased from local main markets in Yala and Pattani cities and the vicinity districts. These markets received food product items from all over Thailand and abroad. Biological samples were purchased from the major domestic markets. Analytical method was modified and validated to suit local conditions in laboratory experiment. The recovery results of several concentration levels of standards were within the acceptable range of 70-130 % as recommended by US-EPA. Solid samples were soxhlet extracted with the solvent mixture of hexane and dichloromethane (in 1:1 ratio). Cooking oil samples were liquid-liquid extracted with acetonitrile using separatory funnel. The extracted solvents were concentrated by rotary evaporator and cleaned up by hot florisil column. The final sample was analyzed by GC-ECD. The linearity of ECD detector responses were in good condition within the calibration ranges. The results showed that the commonly found OCPs in the analysed food samples were p, p'-DDD, p, p'-DDE, endrin aldehyde, endosulfan 1, endosulfan sulfate and some PCB congeners at wide range concentration levels. Health risk assessment methodology and all estimated values involved in this work were based on US-EPA’s IRIS databases. The concentrations of OCPs detected in food samples were then converted into average daily exposure per person (ug/kg body weight per day). The ratios of calculated daily intake values against reference dose (RfD) were used for the evaluation of possible health risk effects associated with contaminated food ingestion.