الفهرس 
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Abstract
A total of 240 random samples were collected as 150 samples from plant I (30 raw milk, 30 pasteurized milk, 30 cream, 30 butter and 30 yoghurt), 30 yoghurt samples from plant II and 60 samples from dairy shops (30 raw milk and 30 yoghurt) were collected from different sources and localities in Beni-Suef Governorate in the period between August 2012 to July 2013 to determine the level of lead, cadmium and copper in milk and milk products by using UNICAM 969 Atomic Absorption Spectrophotometer.
6.1. Heavy metal residues in milk and some dairy products:-
6.1.1. Raw milk:-
6.1.1.1. Dairy farm raw milk:-
Lead concentration in raw milk ranged from 0.0138 to 0.0976 ppm with a mean of 0.064±0.003 ppm. Statistical analysis showed that 29 (96.7%) out of 30 raw milk samples contained lead above the permissible limit.
Cadmium concentration in raw milk ranged from 0.0168 to 0.7833 ppm with a mean of 0.123±0.024 ppm. Statistical analysis revealed that 25 (83.3%) out of 30 raw milk samples contained cadmium above the permissible limit.
Copper concentration in raw milk ranged from 0.0382 to 0.333 ppm with a mean of 0.179±0.056 ppm. Statistical analysis showed that 17 (56.7%) out of 30 raw milk samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0128, 0.0246 and 0.0358 mg per adult person from consumption of 200 ml milk per day and these representing 5.12, 35.14 and 0.358% of provisional ADI, respectively.
6.1.1.2. Dairy shops raw milk:-
Lead concentration in raw milk ranged from 0.029 to 0.968 ppm with a mean of 0.499±0.052 ppm. Statistical analysis revealed that 30 (100%) out of 30 raw milk samples contained lead above the permissible limit.
Cadmium concentration in raw milk ranged from 0.048 to 0.691 ppm with a mean of 0.335±0.035 ppm. Statistical analysis showed that 29 (96.7%) out of 30 raw milk samples contained cadmium above the permissible limit.
Copper concentration in raw milk ranged from 0.0139 to 0.573 ppm with a mean of 0.123±0.0187 ppm. Statistical analysis indicated that 1 (3.3%) out of 30 raw milk samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0998, 0.0670 and 0.0246 mg per adult person from consumption of 200 ml milk per day and these representing 39.92, 95.7 and 0.25 % of provisional ADI, respectively.
6.1.2. Pasteurized milk:-
Lead concentration in ranged from 0.0078 to 0.9685 ppm with a mean of 0.4±0.057 ppm. Statistical analysis showed that 25 (83.3%) out of 30 pasteurized milk samples contained lead above the permissible limit.
Cadmium concentration in ranged from 0.0046 to 0.4842 ppm with a mean of 0.201±0.027 ppm. Statistical analysis revealed that 20 (66.7%) out of 30 pasteurized milk samples contained cadmium above the permissible limit.
Copper concentration in ranged from 0.0161 to 0.7425 ppm with a mean of 0.215±0.027 ppm. Statistical analysis revealed that 6 (20%) out of 30 pasteurized milk samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0800, 0.0402 and 0.0430 mg per adult person from consumption of 200 ml milk per day and these representing 32, 57.4 and 0.43 % of provisional ADI, respectively.
6.1.3. Cream:-
Lead concentration ranged from 0.0494 to 0.5567 ppm with a mean of 0.28±0.020 ppm. Statistical analysis revealed that 30 (100%) out of 30 cream samples contained lead above the permissible limit.
Cadmium concentration ranged from 0.057 to 0.996 ppm with a mean of 0.665±0.042 ppm. Statistical analysis revealed that 30(100%) out of 30 cream samples contained cadmium above the permissible limit.
Copper concentration ranged from 0.0031 to 0.5103 ppm with a mean of 0.226±0.023 ppm. Statistical analysis revealed that 27 (90%) out of 30 cream samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.028, 0.0665 and 0.0226 mg per adult person from consumption of 100 g cream per day and these representing 11.2, 95 and 0.23 % of provisional ADI, respectively.
6.1.4. Butter:-
Lead concentration ranged from 0.0229 to 0.7743 ppm with a mean of 0.5±0.036 ppm. Statistical analysis revealed that 30 (100%) out of 30 butter samples contained lead above the permissible limit.
Cadmium concentration ranged from 0.0324 to 1.3263 ppm with a mean of 0.481±0.074 ppm. Statistical analysis revealed that 29(96.7%) out of 30 butter samples contained cadmium above the permissible limit.
Copper concentration ranged from 0.0059 to 1.5101 ppm with a mean of 1.219±0.078 ppm. Statistical analysis revealed that 28 (93.3%) out of 30 butter samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0040, 0.0038 and 0.0098 mg per adult person from consumption of 8 g butter per day and these representing 1.6, 5.49 and 0. 1% of provisional ADI, respectively.
6.1.5. Yoghurt:-
6.1.5.1. Yoghurt of plant I:-
Lead concentration ranged from 0.0019 to 0.7973 ppm with a mean of 0.231±0.049 ppm. Statistical analysis revealed that 28(93.3%) out of 30 samples contained lead above the permissible limit.
Cadmium concentration in yoghurt ranged from 0.0028 to 0.5035 ppm with a mean of 0.163±0.033 ppm. Statistical analysis revealed that 21(70%) out of 30 samples contained cadmium above the permissible limit.
Copper concentration in yoghurt ranged from 0.0121 to 0.5317 ppm with a mean of 0.260±0.022 ppm. Statistical analysis revealed that 12 (40%) out of 30 samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0231, 0.0163 and 0.026 mg per adult person from consumption of 100 g yoghurt per day and these representing 9.24, 23.29 and 0.26% of provisional ADI, respectively.
6.1.5.2. Yoghurt of plant II:-
Lead concentration ranged from 0.1908 to 0.9618 ppm with a mean of 0.475±0.032 ppm. Statistical analysis revealed that 30(100%) out of 30 samples contained lead above the permissible limit.
Cadmium concentration in raw milk ranged from 0.024 to 0.7983 ppm with a mean of 0.307±0.037 ppm. Statistical analysis revealed that 27(90%) out of 30 samples contained cadmium above the permissible limit.
Copper concentration in raw milk ranged from 0.022 to 1.095 ppm with a mean of 0.364±0.039 ppm. Statistical analysis revealed that 16 (53.3%) out of 30 samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0475, 0.0307 and 0.0364 mg per adult person from consumption of 100 g yoghurt per day and these representing 19, 43.86 and 0.364 % of provisional ADI, respectively.
6.1.5.3. Dairy shops yoghurt:-
Lead concentration ranged from 0.1026 to 1.0837 ppm with a mean of 0.569±0.049 ppm. Statistical analysis revealed that 30(100%) out of 30 samples contained lead above the permissible limit.
Cadmium concentration in raw milk ranged from 0.0341 to 0.702 ppm with a mean of 0.340±0.039 ppm. Statistical analysis revealed that 28(93.3%) out of 30 samples contained cadmium above the permissible limit.
Copper concentration in raw milk ranged from 0.0181to 0.7906 ppm with a mean of 0.180±0.032 ppm. Statistical analysis revealed that 5 (16.7%) out of 30 samples contained copper above the permissible limit.
The calculated daily intake of Pb, Cd and Cu were 0.0569, 0.0340 and 0.0180 mg per adult person from consumption of 100 g yoghurt per day and these representing 22.76, 48.57 and 0.18 % of provisional ADI, respectively.
6.2. Effect of milk manufacture on distribution of heavy metals in some dairy products:-
The concentration of lead in pasteurized milk was 0.4 ppm, while in the manufactured cream, butter and yoghurt were 0.28, 0.5 and 0.231 ppm, respectively. Moreover, the retention levels of lead in cream, butter and yoghurt were 70, 125 and 57.75%, respectively of the total lead content in pasteurized milk.
On the other hand, cadmium concentration in pasteurized milk was 0.201 ppm, but in cream, butter and yoghurt were 0.665, 0.481 and 0.163 ppm, which represent retention levels of 330, 239 and 81.9%, respectively of the total cadmium content in pasteurized milk.
According to copper concentration in pasteurized milk, it was 0.215 ppm but in cream, butter and yoghurt were 0.226, 1.219 and 0.260 ppm, respectively. These amounts represented by 105, 566.9 and 120.9% of the total copper content in pasteurized milk.