How Does Contamination of Rice Soils with Cd and Zn Cause High Incidence of Human Cd Disease in Subsistence Rice Farmers

Abstract

Rice (Oryza sativa L.) grown on Zn mine waste contaminated soils has caused unequivocal Cd effects on kidney and occasional bone disease (itai-itai) in subsistence rice farmers, but high intake of Cd from other foods has not caused similar effects. Research has clarified two important topics about how Cd from mine waste contaminated rice soils has caused Cd disease: (1) bioaccumulation of soil Cd into rice grain without corresponding increase in Zn, and (2)

Risk assessment of Cd polluted paddy soils in the industrial and township areas in Hunan, Southern China

“…Field investigation in heavy metal contamination area in Palmerton, PA indicated that ratios of Zn to Cd (lower than 100 to 1) increase the Cd content in plants (Chaney, 2015). However, our research found more than 90% of the paddy soil samples had Zn: Cd higher than 100: 1, and the highest is 338:1.…”

“…It was reported most of the Cd is recovered from the Zn during ore processing (Chaney, 2015). Field investigation in heavy metal contamination area in Palmerton, PA indicated that ratios of Zn to Cd (lower than 100 to 1) increase the Cd content in plants (Chaney, 2015).…”

Regional accumulation characteristics of cadmium in vegetables: Influencing factors, transfer model and indication of soil threshold content

“…The evaluation of the Cd level in leafy vegetables, bio-solid modified soils, and in animal tissues, indicated any regulation on the Cd concentrations in crops should also consider the levels of Zn (Turner, 1973;Chaney et al, 1978). Cadmium and Zn are closely related from pollution sources and are accumulated in crops (McBride, 2002;Chaney, 2015 (SEPAC, 1990). Only 2.3% of the analyzed samples possessed a Zn:Cd ratio <100:1, suggesting that Zn had no control over the accumulation of Cd in vegetables.…”

“…Cadmium (Cd) can cause adverse health effects and is a subject of concern in food production and consumption since the element is easily incorporated in crops such as rice and vegetables (Turner, 1973;McBride, 2002;Adams et al, 2004;Chaney, 2015). The consumption of vegetables is a probable cause of Cd exposure in several world areas including China (Hough et al, 2004;Xu et al, 2013;Norton et al, 2015).…”

Lead in Urban Soils: A Real or Perceived Concern for Urban Agriculture?

“…Although certain contaminants (e.g., Cd) have a high potential to be absorbed by plants (Chaney, 2015), plant absorption of Pb is relatively low, often showing no significant relationship to enriched soil Pb (Table 2). Despite this, concerns about the perceived human health risk of gardening on urban soils due to possible or real crop contamination continue to hinder the revitalization of underutilized urban lots by deterring potential gardeners.…”