HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Oporto, C. Articles by Smolders, E. Search for Related Content PubMed PubMed Citation Articles by Oporto, C. Articles by Smolders, E. Agricola Articles by Oporto, C. Articles by Smolders, E. Related Collections Soil Salinity Heavy Metals Soil Chemistry

TECHNICAL REPORTS

Heavy Metals in the Environment

Elevated Cadmium Concentrations in Potato Tubers Due to Irrigation with River Water Contaminated by Mining in Potosí, Bolivia

^a Centro de Aguas y Saneamiento Ambiental, U.M.S.S, Calle Sucre final (Campus), P.O. Box 5783, Cochabamba, Bolivia
^b Lab. for Applied Physical Chemistry and Environmental Technology, K.U.Leuven, W. de Croylaan 46, 3001 Heverlee, Belgium
^c Lab. for Soil and Water Management, K.U.Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium

^* Corresponding author (carlaoporto{at}gmail.com)

Received for publication September 26, 2006. Risk of cadmium (Cd) in the human food chain in Cd-contaminated areas is often limited by phytotoxicity from zinc (Zn) that is associated with the Cd contamination. A semiarid area, 60 km downstream of a tin mine in Bolivia, was surveyed where irrigation with Cd-contaminated river water (65–240 µg Cd L^–1) has increased median soil Cd to 20 mg kg^–1 while median soil Zn was only about 260 mg kg^–1. Cadmium concentrations in potato tubers increased from background values (0.05 mg kg^–1 dry wt.) in soils irrigated with spring water to a median value of 1.2 mg kg^–1 dry wt. in the affected area. Median concentration of Cd in soil solutions was 27 µg L^–1 and exceeded the corresponding value of Zn almost twofold. Soil-extractable chloride ranged from 40 to 1600 mg Cl^– kg^–1 and was positively correlated with soil total Cd. Increasing soil solution Cl^– decreased the solid-liquid distribution coefficient of Cd in soil. Soil total Cd explained 64% of the variation of tuber Cd concentration while only 3% of the variation was explained by soil extractable Cl^– (n = 49). The estimated dietary Cd intake from potato consumption by the local population is about 100 µg d^–1 which exceeds the WHO recommended total daily intake. It is concluded that the food chain risk of Cd in the irrigation water of the semiarid area is aggravated by the association with Cl^– and, potentially, by the relatively large Cd/Zn ratio.

Abbreviations: CEC, cation exchange capacity • dry wt., dry weight • EC, electrical conductivity • fresh wt., fresh weight • TDI, tolerable daily intake