Health risk assessment of pesticides and polychlorinated biphenyls contaminations in dairy products from selected farms in Greater Accra Region - Ghana

The residual concentrations of synthetic chemicals such as organochlorines pesticides (OCPs), pyrethroids and polychlorinated biphenyls (PCBs) in dairy products (milk, yoghurt, cheese) from selected farms in Greater Accra were analyzed using Gas Chromatography (GC). A total of 50 samples of dairy products (9 cheese, 25 cow milk and 16 yogourt) were analyzed for OCPs, prethroids and PCBs. Of the numerious pesticides evaluated, detectable levels of OCPs (β-HCH, endrin, heptachlor, endosulfan, p'p-DDT and methoxchlor); synthetic prethroids (permathrin, allethrin, cypermethrin and deltamethrin) and PCBs (18, 28, 52, 101, 153, 138, and 180) were found in all the dairy product samples analysed. Milk samples were found to be the most contaminated with respect to the OCPs and the levels ranged between 0.0001µg/ml and 0.0407µg/ml. ß-HCH was the highest OCP with concentration of 0.0407µg/ml while cyfluthrin was the highest synthetic prethroids recorded in yoghurt sample (0.0318µg/ml). The highest PCB 18 (2,2,5-Trichlorobiphenyl) recorded (0.2668µg/ml) in yoghurt samples. (Data obtained from the field survey regarding safe use of pesticides, toxicity awareness and symptoms among farmers indicated that a very high proportion of animal farmers were at a high risk of pesticide poisoning from occupational exposure. More than 70% of farm workers did not practise safety precaution during pesticide mixing and application leading to considerable prevalence of pesticide related illness including nausea, vomiting, blurred vision, abdominal cramps, dizziness, diarrhoea and headaches in this agricultural community. The presence of pesticide residues in dairy products was of further concern because milk is the main protein diet for infants. The estimated dose for γ-chlordane(8.5x105 µ/ml), endrin(0.0114 µg/ml) p'p'-DDT(8.5x105µg/ml), DDE(8.5x105 µg/ml),heptachlor(2.5x105 µg/ml), dieldrin(6.8x105 µg/ml) do not pose a direct hazard to human health, although present in milk samples since the values were lower than toxic threshold as well as reference doses of (γ-chlordane:0.0005µg/ml, endrin:0.20µg/ml, p'p'-DDT:0.50µg/ml, DDE:0.50µg/ml, Heptachlor:0.0001 µg/ml and Dieldrine:0.005µg/ml and may indicate minimum risk to human. However, β-HCH(0.0375μg/ml), endosulfan(0.0142μg/ml), methoxychlor(0.0746μg/ml) and PCBs(0.0498μg/ml) levels exceeded the reference doses of (β-HCH:0.003μg/ml, endosulfan:0.006μg/ml), methoxychlor:0.005μg/ml and PCBs:0.002μg/ml) in children between the ages of 0 - 1year, 1 - 11 years and adults indicating a great potential for systematic toxicity in all age groups especially children who are considered to be the most vunerable population sub-group. The result implicitly reveald that improper pesticide usage in the study area has led to contamination of dairy products and exposed the farmers and consumers to the potential health hazards of pesticides. (au)