ABSTRACT
One hundred and thirty samples, fifty of market raw milk and twenty each of Domiati cheese, cooking butter, yoghurt and milk powder including infant foods collected from different markets in Cairo and Giza, were examined and analysed for quantitative and quantitative determination of organochlorine pesticide residues. The results obtained [p.p.b] revealed the following data: nearly all milk samples were contaminated with most of the investigated pesticides. DDT complex was present in a mean value of 36.005 +/- 3.315 p.p.b and total hexachlorhexane with, a mean value of 0.420 +/- 0.119 p.p.b. Results indicated that all samples of analysed cheese were found to be contaminated with one or more of the concerned pesticides. HCH and its isomers also were present with a mean value of 25.697 +/- 4.5 p.p.b. The results of residues levels in cooking butter showed that, HCH and its isomers and DDT and its isomers were detected in all examined samples with mean value of 120.892 +/- 17.710 and 87.159 +/- 12.005 p.p.b. respectively. Data indicated that HCH and its isomers were detected in all samples of yoghurt. DDT and its analogues were detected in 19 samples, with a mean value of 26.447 +/- 4.921 p.p.b. Aldrin and dieldrin could not be detected in any of the examined yoghurt samples. HCH and its isomers were detected in all milk powder samples with a mean value of 20.276 +/- 2.565 p.p.b. DDT complex was detected in 18 samples, with a mean value ot 5.030 +/- 0.951. Endrin was detected in 3 samples, with a mean value of 0.184 +/- 0.038. It is worthly mentioned that dieldrin and aldrin could not be detected in any of the examined milk powder samples. Results obtained showed some loss in the pesticides added to the raw milk due to the effect of heat. The average recovery of p,p -DDT, p,p - DDE and p,p DDD was 83.87, 86.08 and 83.09 p.p.b. respectively. Their mean of degradation percent as a result of pasteurization was 26.15%, 23.15% and 30.05% respectively, while it was 76.97%, 72.60%, and 72.25% due to boiling. The average increase of P,P - DDD due to pasteurization and boiling was 30.05% and 72.25% respectively. The growth and numbers of the examined bacteria was inhibited by lindane and endrin especially at high concentration. We conclude that most of market dairy products exposed for sale in Cairo and Giza proved to be contaminated with different types of pesticide residues, therefore, application of modem quality assurance methods in all analytical work, related to pesticide residues is essential to improve the quality of our dairy products, in addition to enforced legislative control measures. In conclusion, it seems necessary that concerned authorities should impose regulations and take active part in methods of importation, distribution, usage and application of pesticides, to protect our environment and health from the danger of such chemical pollutants