الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
A total of 153 food samples grouped in 9 commodities (18 orange; 18 wheat; 18 vegetable oil; 18 tomato; 18 sesame; 18 potato; 18 rice and 9 dry bean) were collected from 9 different governorates in Egypt during 2015- 2016 and analyzed for polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs), using High Resolution Gas chromatography - High Resolution Mass Spectrometer (HRGC-HRMS). For PCDD/Fs, the most dominant congener in analysed samples was 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin (OCDD), while (PCBs 118) congener was the more frequent dl-PCBs. The mean Toxic Equivalency (TEQ) concentration of ΣPCDD/Fs & dl-PCBs was descending arranged as following 0.9569, 0.1710, 0.1692, 0.1169, 0.0986, 0.0944, 0.0846, 0.0716 and 0.0440 pgWHO-TEQ2005/g w.w. in vegetable oil, orange, wheat, potatoes, onion, sesame, tomatoes, rice and dry bean, respectively. In all analysed foodstuffs samples all detected concentrations levels of dioxins and dioxin-like PCBs were lower than the maximum permissible limits of Egyptian Standardization and European Community.
The average estimated daily intake of the sum of PCDD/Fs and dl-PCBs of plant origin represented in this study of nine commodities from the Egyptian customers by 60 kg body weight was 1.7147pg WHO-TEQ/kg body weight/day lower than the WHO acceptable daily intake (4pgWHO-TEQ/ kg b.w/day), but it represents 42.87% from the risk intake percentage of these contaminants. The main contributors to total intake for adults were wheat (about 53%), vegetable oil (about 14%) and tomato (about 10%).Of all analysed foodstuffs samples, wheat showed the highest risk dietary intake exposure to PCDD/Fs and dl-PCBs by 22.59%. When the calculation of daily intake of wheat is based on the average TEQ concentration of ΣPCDD/Fs + dl-PCBs, the average daily intake is 0.9038 pg WHO-TEQ/ kg b.w/day, which is very close to the lowest limit (1 pg WHO-TEQ/ kg b.w/day) set by the WHO. On the other hand, when the calculation of daily intake of wheat is based on the maximum TEQ concentration, the daily intake due to these contaminants will be 2.189 pg WHO-TEQ/ kg b.w/day, which is higher than the lowest limit (1 pg WHO-TEQ/ kg b.w/day) set by the WHO.
Keywords: PCDD/Fs; DL-PCBs; HRGC/MS; Dietary intake; Food and Egypt.