Plant uptake and leaching of dimethylnitrosamine

Abstract

THE occurrence of carcinogenic nitrosamines is of considerable interest because they have been found in foods consumed by humans¹ and they can be produced, at least in vitro, from agricultural chemicals^2,3. Furthermore, the widespread occurrence of potential precursors of nitrosamines—secondary or tertiary amines and inorganic nitrogen compounds that are readily converted to nitrite by microorganisms—led to studies demonstrating that the carcinogens can be formed in soil samples and aquatic environments^4,5. A hazardous chemical in soil is not of toxicological significance, however, unless it is volatilised or enters the human food chain by being assimilated by food crops or leached through soil into ground waters ultimately used for drinking. We report here that dimethylnitrosamine (DMNA) can be assimilated by the roots of lettuce and spinach, is translocated to the tops and that it also moves readily through soil.