2000 Fiscal Year Final Research Report Summary
Monitoring of cadmium pollution by carrot
| Project/Area Number |
11670362
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Public health/Health science
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| Research Institution | Gunma University |
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Principal Investigator |
SUZUKI Shosuke Gunma University, Department of Public Health, Professor, 医学部, 教授 (40010011)
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| Co-Investigator(Kenkyū-buntansha) |
KOYAMA Hiroshi Gunma University, Faculty of Health Sci.Professor, 医学部, 教授 (30143192)
KAWADA Tomoyuki Gunma University, Department of Public Health, Assoc Professor, 医学部, 助教授 (00224791)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Metals / Risk assessment / carrot |
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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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