Monitoring of cadmium in the chain from soil via crops and feed to pig blood and kidney.

The relationships between cadmium (Cd) levels in soil, feed crops, feed concentrate, pig feed mixture, water, pig blood, and kidney from 49 farms were investigated and the possibility to use pig kidney as a bioindicator of available Cd in the agricultural environment was evaluated. There were correlations between Cd levels in soil and wheat, between wheat and barley, and between feed and kidney. The accumulation ratio between Cd levels in feed and kidney was on average 3. Animals from the same farm, raised in the same environment, given the same feed, and slaughtered at the same age had Cd levels in kidney and blood that could differ several times. This great variation, together with a considerable Cd contribution from nonlocally produced feed ingredients (concentrates), limits the possibilities to use Cd in pig kidney as an indicator of the available Cd in the local environment.