ACCUMULATION AND LOSS OF ARSENIC AND BORON, ALONE AND IN COMBINATION,IN MALLARD DUCKS

Arsenic and boron are common in the environment, and wildlife can be e xposed to toxic concentrations through both natural and human-influenc ed processes. We exposed adult male mallard ducks to dietary concentra tions of 300 ppm arsenic as sodium arsenate, 1,600 ppm boron as boric acid, or both and estimated the tissue accumulation and loss rates whe n the ducks were returned to uncontaminated food. Both elements were a ccumulated rapidly; equilibrium levels were reached for arsenic in 10 to 30 d and for boron in 2 to 15 d. Accumulation of each element was s lowed by the presence of the other in the diet. Boron was eliminated b y mallards very rapidly, with few detectable residues greater than or equal to 1 d after removal of boron from the diet; arsenic was also ra pidly lost with half-lives of 1 to 3 d (half-lives were not constant t hroughout the loss period). Arsenic loss rate was not affected by the presence of boron. Arsenic accumulated to the highest level in liver t issue, with blood and brain levels lower; concentrations in the liver and blood were proportional but affected by the presence of boron. Bor on concentrations were highest in the blood, followed by the brain and liver; concentrations in the blood and liver were proportional.