The relationship between vineyard soil lead concentration and the concentration of lead in grape berries

Abstract

The concentration of lead in Australian grape berries was compared with that of the soil surrounding the vines during three seasons. These data were collected in three surveys, the first comprising 13 vineyards of six grape varieties, the second, 12 vineyards planted with cv. Shiraz, and the third, two vineyards each planted with the same 10 varieties. There were significant differences between the concentration of total-lead and EDTA-extractable lead in both the 0–10 cm and 10–30 cm soil layers. On average, the uppermost layer had a greater concentration of lead (whether total or EDTA-extractable), but this difference failed to reach significance. Washed and unwashed berries differed significantly in the concentration of lead in their pulp, but not in their juice. None of the soil and associated berry measurements were significantly correlated. Pulp with skins, but without seeds, contained c. 14 times more lead than juice in washed berries and 22 times more lead in unwashed berries. There was significant variation in the concentration of lead in both soil and berries between and within locations, but not between varieties in the same vineyard. It is concluded that the contribution of lead from the soil or from the aerial vineyard environment to that of grape berries and especially to that of grape juice is low. Thus grapes are a minor contributor to the concentration of lead in Australian wines, which is low by international standards, according to published data, and lower than the Australian permissible concentration of lead in drinking water.