Entry of Heavy Metals into Food Chains: a 20-year Comparison Study in Northern Moravia (Czech Republic)

Abstract

The aim of the study presented here was to assess cadmium, lead and mercury contamination of wild-living animals and cattle in Northern Moravia (Czech Republic). Samples were collected in 2005–2007 at the same locations as in 1986–1989, in the same season of the year, and they were analyzed using the same methods (AAS ). In 2005–2007, a significant decrease (P < 0.01) in cadmium concentrations in plant fodders was found, while changes in lead and mercury concentrations were less marked, and they depended on the type of commodity. In the 2005–2007 period, a marked decrease (P < 0.01) in cadmium concentrations in the muscle and kidneys of the cattle, fallow deer, roe deer and pheasants (muscle 0.002–0.009 mg kg-1, kidneys 0.11–0.69 mg kg-1) was found. In the same period, mercury concentrations in the muscle, liver and kidneys were significantly lower (P < 0.01) in cattle, roe deer and hare tissues (muscle: 0.6–3.5 μg kg-1, liver 3.3–41.0 μg kg-1, kidney 16.3–43.2 μg kg-1). Lower lead concentrations in the 2005–2007 period were only found in cows (0.04 mg kg-1, 0.1 mg kg-1 and 0.6 mg kg-1 in muscle, liver and kidney samples, respectively). No significant differences in lead concentrations were found in the tissues of other animals. The study demonstrated a reduction in the amounts of heavy metals entering food chains in the study area in recent years.