الفهرس 
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Abstract
Milk and dairy products has a very special position in the diet of infants, children and elderly for whom it is considered as a perfect natural food. Being a fat rich food it is an important source of organochlorine compounds accumulation. As such consumers of dairy products are exposed to these residues. This fact has caused concern since dairy products are an important exposure route for persistent pollutants in general.
Although the organochlorine pesticide use has been restricted or banned in many countries, several studies have documented their presence in dairy products and their presence both in human blood and body tissues.There is, therefore, the need for constant monitoring of levels of these residues in foodstuffs and the environment in order to avert any environmental and health disaster.
In this study we determined residue of certain groups of organochlorine compounds in milk and cheese samples from different districts in Alexandria city and calculate the children exposure to organochlorine pesticide and PCBs by make a questionnaireof dairy product consumption frequency by school children in Alexandria city.
We found that the sequence of detected OCPs and PCBs, depending on their concentration level in milk samples from Alexandria Governorate was lindane, p,p’-DDE >Ʃ PCBs> HCB, p,p’-DDD.
In general, contaminant concentrations in milk samples were higher in Wassat, Al-Gomrok and Al-Montaza district than the other sites. Organochlorine pesticide and PCBs concentrations were generally closer in different seasons.
The highest concentration of ƩOCPs in the milk samples was 5.71 ng/kg on fat basis found in Wassat district in winterwhereas, the lowest concentration of ƩOCPs in the milk samples was 2.63ng/kg on fat basis found in Al-Amriya district in autumn. p,p’ DDE is the compound that appeared at highest concentrations 3.2 ng/kg in Wassat district in autumn.
The highest concentration of ƩPCBs in the milk samples was 2.4 ng/kg on fat basis found in Al-Gomrok district in winter while, the lowest concentration of ƩPCBs was 1.1 ng/kg on fat basis found in Al-Amriya district in summer.
The highest concentration of Ʃ OCPs in the cheese samples was 0.124 ng/kg on fat basis found in Al-Amriya district in spring (table 9) whereas, the lowest concentration of Ʃ OCPs in the cheese samples were 0.06 ng/kg on fat basis found in Al-Montaza district in summer
The highest concentration of Ʃ PCBs in the cheese samples was 1.4 ng/kg on fat basis found in Al-Montaza district in autumn and the lowest concentration of Ʃ PCBs were 0.2 ng/kg on fat basis found in Sharak district in summer
In general, levels of organochlorine pesticide concentrations in cheese samples were much lower than levels of Ʃ PCBs concentrations.In all cheese samples levels of organochlorine pesticide concentrations showed unexpected decrease than its levels in milk samples.
Level of children exposure age (3-7) to organochlorine pesticide from milk in Wassat district was higher than other districts while the highest level of children exposure age (3-7) to organochlorine pesticide and ƩPCBs from milk found in winter.
Levels of children exposure age (3-7) to ƩPCBs from milk were less than half of levels of children exposure age (3-7) to organochlorine pesticide from milk.
Levels of children exposure age (8-12) to organochlorine pesticide and PCBs from milk were about half children exposure age (3-7) to organochlorine pesticide and ƩPCBs from milk and cheese.
VI. CONCLUSION AND RECOMMENDATIONS
The present study showed the contamination of milk and cheese with OCPs and PCBs. The levels of OCs residues in milk and cheese were much lower than their maximum residue levels which mayreflect such kind of safety on human health.
The residues of such persistent compound may exist for a long time in the environment and so, they would require much more time to be completely phased out from the ecosystem.
These compounds may represent a real threat for human because milk and dairy products has a very special position in the diet of infants, children and elderly for whom it is considered as a perfect natural food. Being a fat rich food it is an important source of organochlorine compounds accumulation this need concern since dairy products are an important exposure route for persistent pollutants in general.
Since the obtained results are alarming, as many of these compounds are reported to be carcinogenic, mutagenic and teratogenic, it become essential to check the organochlorine pesticide and PCBs pollution problem by educating through the mass media,carry out further monitoring studies in order to improve food safety and adopting integrated pest management (IPM) by utilizing alternate methods like mechanical, cultural, biological and use of botanical pesticide for the control of pests and disease vectors.