Analyzing the role of soil and rice cadmium pollution on human renal dysfunction by correlation and path analysis

The aim of this study was to investigate the role of soil and rice pollution on human renal dysfunction. The participants were 97 inhabitants (46 men and 51 women) who are aged 50 to 60 years old and have been living in Xiaogan (Hubei, China) from birth. We collected samples of soil, rice, and urinary correspondingly. Urinary N-acetyl-β-D-glucosaminidase (NAG) and β-2-microglobulin (β₂MG) were used as indicators of renal dysfunction, and urinary cadmium (U-Cd) was used as indicator of total internal cadmium exposure. We made a hypothesis that soil cadmium concentration (S-Cd) and rice cadmium concentration (R-Cd) could be used as indicators of environmental cadmium exposure. Correlation and path analysis were used to estimate the relationships among the levels of rice cadmium (R-Cd), soil cadmium (S-Cd), urinary cadmium (U-Cd), and renal damage indicators (NAG and β₂MG). Our results showed that there was positive significant relationship between S-Cd (R-Cd, U-Cd), and U-NAG (U-β₂MG). The standard multiple regression describing the relationship between S-Cd (R-Cd, U-Cd) and U-NAG was Y₁ = 1.26X₁-6.53X₂ + 9.32, where Y is U-NAG, X₁ is U-Cd, X₂ is S-Cd. The equation of U-β₂MG was Y = 49.32X₁ + 3085.99X₂ + 143.42, where Y is U-β₂MG, X₁ is U-Cd, X₂ is R-Cd. It is obvious that the effect of S-Cd and R-Cd on NAG or U-β₂MG cannot be ignored. Through our study, we can find that the effects of S-Cd on renal health even as significant as R-Cd. To protect people from the damage of cadmium pollution, it is vital to monitor the situation of soil and rice cadmium pollution.