Cadmium concentrations and their implications in Mallard and Coot from fish pond areas

• Cd concentrations in duck kidneys are comparable to those from the past five years.
• Concentrations differed between the studied areas and species.
• Age influenced concentrations only in Mallards.
• No correlation between internal organ concentrations and blood occurred.
• No relationship between internal concentrations, feather and excrements was noted.

During the studies in 2003, high concentrations of cadmium (Cd) were noted among Mallards and Coots in Poland. Further research, five years later, showed the histopathological alterations in birds from the same area which were probably stimulated by Cd. This paper presents the analysis of Cd in ten different materials collected from these species (n = 180) in years 2006–2009 in two areas, including southern – Zator and western Poland – Milicz. Similarly high concentrations to those from 2003 were noted only in kidneys of Mallards from the Zator area (up to 56.49 μg g−1 d.w.). Other comparable materials accumulated significantly lower concentration of Cd. Generally, lower concentrations occurred in birds from Milicz. Concentrations varied also between species and age groups. They correlated between liver and kidneys, brain and muscle and brain and spleen. Potential in vivo bioindicators (blood, feathers and excrements) did not seem to be useful as biomarkers in both areas.