Sulfur, chromium, and selenium accumulated in Chinese cabbage under direct covers

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2004.08.011 Byline: Diego A. Moreno (a), Gemma Villora (a), Maria T. Soriano (b), Nicolas Castilla (b), Luis Romero (a) Abstract: Currently, pollution of our agricultural soils and waters is increasing and is often associated with many human health ailments. Soils contaminated with low levels of heavy metals and other trace elements are frequently used for growing vegetable crops and in such a situation, these toxic contaminants often accumulate in the edible portions of these agricultural plants and thereby enter the human food chain. In 3 consecutive years of field experiments (1994-1996), two different crop-covering treatments -- T (50[mu]m perforated polyethylene), and T.sub.2 (17gm.sup.-2 non-woven polypropylene) -- were used to modify the environmental conditions for the growth of Chinese cabbage 'Nagaoka 50' [Brassica rapa L. (Pekinensis group)]. Open-air plots (T.sub.0) were used as controls. Analytical determinations of chromium (Cr), selenium (Se), two forms of sulfur (total-S and sulfate-S), and amino acids (Isoleucine, leucine, lysine, methionine, serine, threonine, and valine) were performed utilizing plant shoots for analysis. The T.sub.1 and T.sub.2 treated plants contained concentrations of lysine, methionine, serine, and threonine higher than in T.sub.0. Under T.sub.1, the extent of Cr and Se removal in the field was more favorable. Direct covers could be used in contaminated agricultural zones for a variety of plant species, not just for use with those plants previously reported to be efficient at bio-accumulating toxic elements because the thermal effect created by the covers favors phytoextraction processes. However, it is clear that the accumulation of these toxic substances in the plants (Cr) would deem the plant material unsuitable for human consumption and use as animal fodder. Author Affiliation: (a) Departamento de Fisiologia Vegetal, Facultad de Ciencias, Universidad de Granada, Fuentenueva S/N, E-18071, Granada, Spain (b) Departamento Horticultura, C.I.F.A. Camino de Purchil S/N-Apdo. 2027, 18004 Granada, Spain Article History: Received 20 September 2003; Revised 23 July 2004; Accepted 26 August 2004