Hair as a noninvasive tool for risk assessment: Do the concentrations of cadmium and lead in the hair of wood mice (Apodemus sylvaticus) reflect internal concentrations?

• Metal concentrations in hair as predictors of those in organs and soils are evaluated.
• Individual characteristics (age, gender) and sampling sessions affected predictions.
• Hair can be considered a useful estimator of Pb internal concentrations.
• Cd concentrations in hair only weakly predicted Cd concentrations in organs.
• Further studies should develop hair as a noninvasive tool for risk assessment.

There is an increasing need for developing noninvasive markers of accumulation when studying the transfer of pollutants in wildlife, in response to problems caused by sacrifice of animals (disturbed population dynamics, respect of ethical protocols). Thus, the aim of this work was to determine whether trace metal (TM) concentrations in hair could be used as an accurate noninvasive estimator of internal and environmental concentrations. For that purpose, on a 40 km² site surrounding an ancient smelter, 321 wood mice (Apodemus sylvaticus) were sampled on seven squares (500×500 m) and 4 squares in fall 2010 and spring 2011, respectively. The relationships between the cadmium (Cd) and lead (Pb) concentrations in hair and those in the liver, kidneys, and soils were described. The results indicated that hair concentration was a relatively good predictor of Pb concentrations in organs (p<0.001, 0.46