Atmospheric deposition of trace elements around point sources and human health risk assessment. II. Uptake of arsenic and chromium by vegetables grown near a wood preservation factory.

Kale, lettuce, carrots and potatoes were grown in 20 experimental plots surrounding a wood preservation factory, to investigate the amount and pathways for plant uptake of arsenic and chromium. Arsenate used in the wood preservation process is converted to the more toxic arsenite by incineration of waste wood and is emitted into the atmosphere. Elevated concentrations of inorganic arsenic and chromium were found both in the test plants and in the soil around the factory. Multivariate statistical analysis of the results indicated that the dominating pathway of arsenic and chromium from the factory to the leafy vegetables grown nearby was by direct atmospheric deposition, while arsenic in the root crops originated from both the soil and the atmosphere. Consumption of vegetables grown near the source would result in an increased intake of inorganic arsenic, but the intake via the total diet was estimated to be below the provisional tolerable daily intake for inorganic arsenic established by FAO/WHO.