A study on the transfer of chromium from meadows to grazing livestock: an assessment of health risk

The present investigation was performed in different district of Punjab to determine the chromium level in soil, forages, and blood plasma of the small ruminants (goat and sheep). The results showed that the mean concentrations of chromium in the soil of Sargodha, Mianwali, and Bhakkar districts were ranged from 1.8 to 2.3, 3.01 to 4.99, and 2.04 to 2.87 mg/kg, respectively. The chromium level was higher in Mianwali compared with Sargodha and Bhakkar. The mean concentrations of chromium in forages which were used for feeding purposes were found between 0.672 and 1.631, 1.493 and 2.612, and 0.7804 and 1.047 mg/kg for Sargodha, Mianwali, and Bhakkar, respectively. The mean concentrations of chromium in blood plasma of goat which consumed the contaminated forages were between 0.666 and 1.269 mg/L in Sargodha, 0.657 and 0.752 mg/L in Mianwali, and 1.39 and 2.37 mg/L in Bhakkar. In blood plasma of sheep, the residual levels of chromium in the districts Sargodha, Mianwali, and Bhakkar were ranged from 0.673 to 1.384, 0.83 to 1.086, and 1.496 to 3.611 mg/L, respectively. In the present research, there was a higher concentration of chromium in blood plasma of sheep from Bhakkar and the lowest was in Sargodha. The chromium level in blood samples was found to be higher than the tolerable level of 1.0 mg/L in all districts. In light of these results, it was concluded that chromium levels in the soil and forages of all sites were present within the safe limit while in blood samples of sheep and goats were found to be above the acceptable limit. Sheep and goats also consume water from river, streams, and ponds and other contaminated water sources. So it might be the reason of higher level of chromium in their blood plasma. Hence, the proper monitoring of study sites will be necessary to prevent the excessive accumulation of chromium in ruminants in the near future.