| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
373 carrot samples were collected from 232 cities, towns and villages in 46 prefectures other than Okinawa. According to geographical features and vegetation, the 46 prefectures were divided into 9 provinces : Hokkaido, Tohoku, Kanto, Hokuriku, Tokai, Kinki, Shikoku, Chugoku and Kyushu.
Cadmium (Cd) in the solutions was measured by a flameless atomic absorption spectrophotometer (AAS) (Hitachi Z9000) at a wavelength of 228.8 nm. The reliability of Cd assessment was 7.4%, in terms of the coefficient of variation of 10 repeated analyses of the same sample lot. A recovery test was conducted by adding 0.04μg of Cd to each ten carrot sample (0.1 gram). The recovery rate was 103% on average.
As the frequency distribution of Cd content in the 373 carrot samples was skewed to the left, a logarithmic transformation was made. Geometric mean (GM) and the geometric standard deviation (GSD) of Cd were 24.4 ng/g wet weight and 2.2, respectively. The range was 2.1 to 179.1 ng/g wet weight.
GMs and GSDs of the Cd contents of carrot samples from 9 provinces in Japan are calculated. Multiple comparison by the Ryan's method was conducted. Cd was highest (36.7 ng/g) in carrots from Chugoku, followed Tohoku (36.1 ng/g). Cd was lowest (15.8 ng/g) in carrots from Kinki. Cd contents of carrots from Chugoku and Tohoku were significantly higher than those of carrots from Hkuriku and Kinki (p<.05).
Cd contents of carrots by soil type are also calculated. The highest Cd level was in the soil type Fluvisol (171.9 ng/g), and the lowest (50.1 ng/g) was in Cambisol.
The correlation coefficient of Cd in rice and Cd in carrot using 20 samples was 0.492 (p<.05).
The authors conclude that carrots are an ideal indicator food for monitoring of Cd pollution in other countries of the worlds as opposed to rice.
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