INFLUENCE OF NUTRIENT LEVEL ON METHYLMERCURY CONTENT IN WATER SPINACH
2010 (English)In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 29, no 8, 1735-1739 p.Article in journal (Refereed) Published
Widely consumed vegetables are often cultivated in sewage waters with high nutrient levels. They can contain high levels of methylmercury (MeHg), because they can form MeHg from inorganic Hg in their young shoots. We determined whether the MeHg uptake and the MeHg formation in the shoots of water spinach (Ipomoea aquatica) were affected by the presence of a high nutrient level in the growth medium. Water spinach shoots were rooted and pretreated in growth medium containing 7% (low) or 70% (high) Hoagland nutrient solution; thereafter, the plants were treated with either 0.02 mu M MeHg or 0.2 mu M HgCl2 for 3 d. Half the plants were then analyzed for total Hg and MeHg. The remaining plants were transferred to mercury-free medium with low or high nutrient levels and posttreated for 3 clays before analysis of total Hg and MeHg in order to measure MeHg formation in the absence of external Hg. The results indicate that nutrient level did not influence MeHg uptake, but that a high nutrient level reduced the distribution of MeHg to the shoots 2.7-fold versus low nutrient level. After treatment with HgCl2, MeHg was found in roots and new shoots but not in old shoots. The MeHg:total-Hg ratio was higher in new shoots than in roots, being 13 times higher at high versus low nutrient levels. Thus, MeHg formation was the same in new shoots independent of inorganic Hg concentration, since the total Hg level decreased at a high nutrient level.
Place, publisher, year, edition, pages
2010. Vol. 29, no 8, 1735-1739 p.
Aquatic macrophyte, Heavy metal, Ipomoea aquatica, Methylmercury formation, Methylmercury uptake
IdentifiersURN: urn:nbn:se:su:diva-49193DOI: 10.1002/etc.231ISI: 000280481200011OAI: oai:DiVA.org:su-49193DiVA: diva2:377140
authorCount :22010-12-132010-12-132010-12-13Bibliographically approved