Chromosome stability test in both cattle and river buffaloes exposed to dioxin.

Polychlorodibenzodioxins (PCDDs) and related substances including polychlorodibenzofurans (PCDF) and the dioxin-like polychlorobiphenyls (DL-PCBs) are powerful mutagens that can enter the food chain as the result of a number of industrial processes, waste incineration or illegal waste burning. Cytogenetic tests could be useful to reveal the presence of such mutagens in the food chain by simply monitoring food producing species. In previous studies we studied sheep exposed to dioxins and found a pronounced chromosome fragility in exposed herds, compared to unexposed one (control) by using both SCE and chromosome abnormality (AC) test. In this study we applied the SCE-test in both cattle and river buffaloes reared in dioxin-contaminated areas, although the WHO-TEQ levels of bulk milk were much lower than those earlier detected in sheep milk. Peripheral blood cultures were performed in samples from 15 dairy cows showing average milk values over (18.56 pg/g of fat as WHO-TEQ) than those permitted (6.0 pg/g of dioxins+furans+PCBs as WHO-TEQ) and the results were compared with samples from 16 dairy cows (1.75 pg/g of fat as WHO-TEQ) used as control. Significantly (P < 0.01) higher mean number of SCE/cell (7.10 ± 2.8) were found in dioxin exposed cows compared to those measured in the controls (SCE/cell=5.24 ± 2.51). The same test was applied on 26 river buffaloes showing average values of WHO-TEQ over (21.79 pg/g of fat as WHO-TEQ) than those achieved in the milk mass of 26 river buffaloes (1.30 pg/g of fat as WHO-TEQ) used as control. Opposite to cattle, no significant differences were found between mean number of SCE/cell in exposed vs. non exposed river buffaloes (8.73 ± 3.32 vs. 8.79 ± 3.40).