Roe deer antlers as monitoring units for assessing temporal changes in environmental pollution by fluoride and lead in a German forest area over a 67-year period.

Fluoride and lead concentrations were analyzed in antlers of adult roe bucks (Capreolus capreolus) collected between 1932 and 1998 in a forest area of 800 ha, that directly borders on the eastern suburbs of Cologne (Germany). Values ranged between 158 and 3,713 mg/kg dry weight for fluoride and from 0.4 to 12.0 mg/kg dry weight for lead, and varied significantly between periods (1932-49, 1950-59, 1960-69, 1970-79, 1980-89, 1990-98). Antler bone levels of both contaminants decreased markedly during the 1980s and 1990s. As a consequence, mean fluoride and lead concentrations in antlers collected in the 1990s were significantly lower than those from all preceding periods. These findings indicate a pronounced decline in fluoride and lead pollution of the study area, which is attributed to reduced emissions from stationary sources and, in the case of lead, to the introduction of unleaded gasoline and the subsequent phasing out of leaded gasoline in Germany. Because antlers are replaced annually, grow during a seasonally fixed period of some months, and are regularly collected and kept by hunters, they are useful monitoring units for recording past and present environmental pollution by "bone-seeking" pollutants in a cost-effective way. Due to its relative abundance and its rather narrow home range, the roe deer is well suited as a monitoring species for assessing changes in ambient contaminant levels on a local scale.