Trace elements in wild berries from reclaimed lands: Biomonitors of contamination by atmospheric dust

Wild berries (bearberry, blueberry, cranberry, dogwood, gooseberry, pin cherry, raspberry and rose hips) collected from lands reclaimed after open-pit bitumen mining, were analyzed for a wide range of trace elements (TEs) using ICP-QMS. The range in Al concentrations (8-247 mg/kg) indicates that the dust contents of the berries are highly variable; this is seen also with other conservative, lithophile elements. Comparing TE concentrations with those of Al reveals two main types of geochemical behaviours: TEs which vary almost exclusively with dust inputs, and TEs which are largely independent of them. Micronutrients such as Cu, Zn, Ni and Mo are unaffected by dust; these elements are dominated by plant uptake from the substrate. Potentially toxic light metals are either dominated by dust inputs (Li) or independent of them (Be). The same is true of potentially toxic heavy metals: Pb is strongly correlated with Al (r = 0.901, n = 31) whereas Tl is not (r = 0.329, n = 19). In respect to elements enriched in bitumen (V, Ni and Mo), V in the berries is proportional to Al (r = 0.969, n = 31) whereas Ni and Mo are not (r = 0.040 and 0.027, respectively; n = 31); their concentrations in the berries are dictated by root uptake. Comparing the Pb/Y and V/Y ratios to the corresponding values for the Upper Continental Crust shows that neither element is enriched in the berries. Data for berries from remote locations and commercial growers help to place the results obtained from reclaimed lands into perspective. For example, the greatest concentrations of Mn, Cd, Ni and Mo, were found in berries from rural and remote locations.