Arsenic and Selenium Concentrations in Central Coast California Soils and Wine.

Arsenic (As) and selenium (Se) are both naturally occurring soil constituents that, when absorbed by crops in high quantities, can render the fruits of the harvest toxic to people. This study was conducted to determine the concentration of As and Se in the soil and wine of a California Central Coast vineyard and compare these levels to the maximum allowable levels of these elements dictated by several regulatory agencies. The effect of sampling location and wine grape varietal were investigated. Four composite soil samples were collected from 2 planting blocks planted to Pinot Noir and 2 planting blocks planted to Chardonnay grapes.  Wine samples were collected from the same locations from which the soils were collected from the 2014 vintage.  Soil samples were digested according USEPA Method 3050B and both soil and wine samples were analyzed via inductively coupled plasma-optical emission spectrophotometry (ICP-OES). Due to matrix interferences during ICP-OES analysis, the method of standard addition was used to extrapolate the actual concentrations of As and Se in both the soil and wine samples. Since As and Se are typically found in trace amounts in soils worldwide, we expect the concentrations of these elements to be below regulatory maximum contamination levels in both the soil and wine found in the California Central Coast vineyard. Investigations of As and Se concentrations in soils and food and drink products produced on soils are important for elucidating how these known human toxins may potentially accumulate in the food chain.