Effects of Variations in Cadmium and Lead Levels in River Sediments on Local Foods and Body Burden of Local Residents in Non-Polluted Areas in Japan

Abstract

This study was initiated to examine if variations in the concentrations of cadmium (Cd) and lead (Pb) in water environment may affect metal levels in local foods and body burden of local residents in non-polluted areas in Japan. Two nationwide databases have been made available on concentrations of Cd in locally harvested brown rice and of Cd and Pb in sediments in local river beds. These data were combined with published data on metal concentrations in polished rice, food duplicates, and blood and urine from the residents. Cd in river sediments correlated significantly with those in brown rice, food duplicates, blood, and urine. Cd in food duplicates correlated with Cd in rice. In contrast, Pb concentrations in the river sediments either did not correlate or correlated only weakly with Pb in biological materials or food duplicates. Possible implication of the different behavior between Cd and Pb regarding the intensity of correlation was discussed with reference to the different routes of exposure to the elements. In conclusions, the Cd body burden on local residents in Japan is significantly influenced by Cd levels in water in the general environment, whereas water-borne Pb did not show clear correlation with the Pb body burden.

Maternal Cadmium Exposure during Pregnancy and Size at Birth: A Prospective Cohort Study

“…Rice samples collected from 63 families in the study area contained on average 69 μg Cd/kg dry weight (10th and 90th percentiles, 11–98 μg Cd/kg) (Kippler et al 2010b), which would correspond to a daily intake of 25–35 μg Cd, assuming a daily consumption of 400–500 g rice grains for an adult person (Khan et al 2009). This daily Cd intake is similar to that in other Asian countries where rice is the main staple food and also to that in most individuals consuming vegetarian diets (European Food Safety Authority 2009; Ikeda et al 2010). It is essential to investigate other potential sources of Cd, particularly vegetables and wheat, as well as agricultural fertilizers that may be a major contributor to Cd in agricultural soil.…”

Low Cadmium Levels in Urine of Residents in two Prefectures where Cadmium Levels in Locally Harvested Brown Rice are Higher than in other Prefectures in Japan

“…Correspondingly, no significant elevation in the prevalence of β 2 -MG-uria was detected in the seven prefectures ( [6] and the present survey). Thus, Cd exposure (in terms of Cd-U) from the environment [22] was elevated in some of the five prefectures (other than prefectures 1 and 7), but the elevation appeared to be lower than the level to induce tubular dysfunction [6,23].…”

Lack of correlation between cadmium level in local brown rice and renal failure mortality among the residents: a nation-wide analysis in Japan

“…The residents in these prefectures therefore would not import rice from other prefectures but depend on locally harvested rice, so that the Cd-induced elevation in SMR or AARIMR should be detectable if it were the case. From nation-wide viewpoints, significant correlations (P \ 0.01-0.05) were observed among Cd in rice, daily dietary Cd intake, and Cd in blood and urine of the residents (Ikeda et al 2009). …”