Low-level cadmium exposure in Toyama City and its surroundings in Toyama prefecture, Japan, with references to possible contribution of shellfish intake to increase urinary cadmium levels.
ABSTRACT This study was initiated to examine if exposure to cadmium (Cd) was high also outside of the previously identified Itai-itai disease endemic region in the Jinzu River basin in Toyama prefecture in Japan.
Morning spot urine samples were collected in June-August 2004 from 651 adult women (including 535 never-smokers) in various regions in Toyama prefecture, and subjected to urinalyses for cadmium (Cd), alpha1-microglobulin (alpha1-MG), beta2-microglobulin (beta2-MG), N-acetyl-beta-D-glucosaminidase (NAG), specific gravity (SG or sg) and creatinine (CR or cr). Three months later, the second urine samples were collected from those with elevated Cd in urine (e.g., > or =4 microg/g cr), together with answers to questionnaires on shellfish consumption.
The geometric mean (GM) Cd, alpha1-MG, beta2-MG and NAG (after correction for CR) for the total participants were 2.0 microg/g cr, 2.4 mg/g cr, 104 microg/g cr and 2.8 units/g cr, respectively; further analysis with never-smoking cases only did not induce significant changes in these parameters. Analyses of the second urine samples from the high Cd subjects showed that there was substantial decrease (to about a half) in Cd in the 3-month period, and that the decrease was accompanied by reduction in alpha1-MG and NAG (beta2-MG did not show elevation even in the first samples). The urinalysis results in combination with the results of the questionnaire survey suggest that the high urinary Cd was temporary and might be induced by intake of shellfish that is edible whole.
The overall findings appear to suggest that Cd exposure in Toyama populations (outside of the Itai-itai disease endemic region) was at the levels commonly observed on the coast of the Sea of Japan, and that the Cd level in urine might be modified by the intake of some types of seafood. Further studies are necessary to elucidate the relation of urinary Cd with seafood intake.
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ABSTRACT: To estimate rates of cadmium (Cd) uptake from the digestive tract and changes in Cd in biological specimens after intake of Cd mainly in rice. Twenty-five young non-smoking Japanese female volunteers (20-23 in age) were recruited and a 20-d experimental study was conducted. With polished rice containing 0.004 ppm and 0.340 ppm of Cd, Meal L and Meal H were prepared. Approximately 12% of total Cd in Meal L and 92% of total Cd in Meal H originated in rice. The volunteers ate Meal L for 11 d to achieve a stable intake-output balance of Cd. Fifteen of the 25 volunteers ate Meal H on the 12(th) day (Group D1), and the remaining 10 ate Meal H on the 12(th), 13(th) and 14(th) day (Group D3). All 25 subjects then resumed the consumption of Meal L to the end of the study (20(th) day). All meals, feces and urine were collected during the study, and Cd intake from the daily meals (Cd-I), Cd in feces (Cd-F) and Cd in urine (Cd-U) were determined. For measurement of Cd in blood (Cd-B), venous blood was collected from all volunteers on the day before the study and again on the 12(th) and 20(th) day; venous blood was also collected from 4-8 volunteers at additional time points. Mean Cd-I was 4.51 microg/d (range: 1.85-6.93) or 48.48 microg/d (range: 27.98-56.27) when they ate Meal L or Meal H. Cd-F and Cd-B exhibited faster responses to the change in Cd-I than did Cd-U. The Cd(uptake) rate, defined as (1-Cd-F(excess) /Cd-I(excess)) (Fig. 1), was 47.2% (range: -9.4-83.3%) in Group D1 and 36.6% (range: -9.2-73.5%) in Group D3, and the Cd(balance) rate, defined as (1-Cd-F(output) /Cd-I(intake)), was 23.9% (range: -4.0-37.7%) in Group D1 and 23.7% (range: -8.2-56.9%) in Group D3. Cd-F and Cd-B are better biological monitoring parameters for assessing change in Cd-I than Cd-U. The Cd(uptake) and Cd(balance) rates appeared to be higher than those in previous papers when ingested Cd mainly originated in rice.Journal of Occupational Health 02/2003; 45(1):43-52. · 1.63 Impact Factor
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ABSTRACT: To examine whether lead (Pb) in urine and cadmium (Cd) in blood, especially the former, can be used as markers of environmental exposure of general populations to these metals. Between 1991 and 1998, spot urine and peripheral blood samples, together with 24 h duplicates of food intake were collected from 607 non-smoking adult women in 30 survey sites (SS) in seven administrative regions all over Japan. Urine, blood and food duplicate samples were analyzed by inductively-coupled plasma spectrometry, for Cd and Pb in urine (Cd-U and Pb-U), in blood (Cd-B and Pb-B) and in food duplicates (Cd-F and Pb-F). Correlation between the measurements was examined by regression analysis. The Cd-B correlated closely with Cd-U, and both Cd-B and Cd-U with Cd-F, on an individual basis (n = 607), on an SS basis (n = 30) and on a regional basis (n = 7). The Pb-U however did not correlate with Pb-B on a regional basis although they correlated with each other when analyzed on an individual as well as SS basis. Moreover, the correlation coefficients between Pb-U and Pb-B were much smaller than those between Cd-U and Cd-B. Neither Pb-U nor Pb-B showed significant correlation with Pb-F on any levels of statistical analysis. Both Cd-B and Cd-U can be employed as biomarkers of environmental Cd exposure. The reliability of Pb-U for use in place of Pb-B appeared to be small.International Archives of Occupational and Environmental Health 05/2000; 73(3):163-70. · 2.10 Impact Factor
- Journal of Occupational Health - J OCCUP HEALTH. 01/2002; 44(4):240-247.