| Cadmium is a kind of white soft metal, which is harmful to environment and does not degrade easily. Once it hits the environment, the cadmium is difficult to eliminate. Cadmium can be transferred to humans through the food chain, and it will exert toxic effect on the respiratory system, cardiovascular system and so on. The studies on investigations of cadmium pollution have been carried on in China since1980s, and are developing quickly now. The results found that there were up to11provinces and25regional cities affected by cadmium pollution. Although many literatures have been reported the related content, the reports mainly focused on the occupational exposure to the crowd, and the sample was small, which can’t reflect the practical situation of Cd pollution. It is necessary to carry out a large-scale investigation of cadmium pollution and the harmful effect of exposed populations.The paper based on the survey of central industry area in northeast China, involving698plant and animal samples and1635participants, calculated the Cd concentration in animals and the exposure indicators of Cd in body. The concentration of urine cadmium was used as exposure biomarkers, UNAG and Uβ2-MG as biomarkers of renal dysfunction, and the criterion of health failure zone about environmental cadmium pollution as judgement basis of abnormal index. The paper calculated the corresponding relationship between urinary cadmium and health effect indicators. The paper used Gamma model, Logistic model, Log-Logistic model to calculate BMD and BMDL of urine cadmium. The results follow:1. Cadmium concentration of animal and plant:the cadmium concentration of animals and plants were below the national standard and the GM of urine cadmium, Uβ2-MG and UNAG were close to the national standard.2. The relationship between cadmium exposure indicator and renal dysfunction indicator:according to the Chi-square test and unitary linear recursive analysis, there was significant increase on abnormal rate of UNAG and Uβ2-MG, when the level of UCd was higher than2μg/g Cr, and the abnormal rate grew with the increase of UCd concentration, which had a statistically significant linear relationship. According to simple correlation and multiple stepwise regressions, the regression equation of urine cadmium with UNAG and Uβ2-MG as follows:Y=0.194x1+0.003x2+0.284, R2=0.229, p=0(Y, UCd; x1, UNAG; x2Uβ2-MG). According to path analysis, there was a significant correlation between urine cadmium and renal dysfunction indicators.3. BMD/BMDL of urine cadmium:According to the calculation of BMD/BMDL, the BMDL of women were less than men, and the Uβ2-MG was more sensitive than UNAG. Choosing the model of Gamma as the best model, the UCd of BMD/BMDL of UNAG was6.38/3.41μg/g Cr for males,5.64/3.30μg/g Cr for females, and5.87/3.81μg/g Cr for whole persons. According to the Chi-square test, the p-value was greater than0.1, which showed the match of the model is good and reliable. The UCd of BMD/BMDL of Uβ2-MG was2.88/1.50μg/g Cr for males,1.38/1.14ug/g Cr for females, and1.78/1.20μg/g Cr for whole persons. According to the Chi-square test, the p-value was greater than0.1, which also showed the match of the model is good and reliable. According to the calculation of BMD/BMDL, the BMDL of women were less than men, and the Uβ2-MG was more sensitive than UNAG. In view of the BMDL was lower than the reference level of5μg/g Cr for renal effects suggested by the World Health Organization, the paper suggested that on the base of using more sensitive Uβ2-MG, appropriately lower urinary cadmium biological exposure limits. |
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