Study On Regulations That Harmful Elements Are Absorebed In Soil--Plant (Vegetables) System In The Subub Of Zhengzhou City

The characters and regulations that the harmful elements are absorbed in the twenty_three kinds of vegetables in the suburb of zhengzhou city was studied. The results showed that: all the vegetables had been polluted in the suburb of zhengzhou city. Mercury is the most pollutant in all elements. The characters that the heavy metals were absorbed in different kinds of vegetables was not the same. The capacity of vegetables of absorbing and enriching cadmium(Cd) ,chromium(Cr) and arsenic(As) was: leaf eaten vegetables > flower and grain eaten vegetables >root eaten vegetables. The capacity of vegetables of enriching lead(Pb) and copper(Cu) was: flower and grain eaten vegetables >leaf eaten vegetables >root eaten vegetables . While the capacity of vegetables of enricching mercury(Hg) was: leaf eaten vegetables > root eaten vegetables > flower and grain eaten vegetables . vegetables displayed a lower capacity of enriching As ,Hg and Pb in soil . The contents in vegetableswas fewer than that of in soli . The highest enrichment coefficient respectly was : 47.1328, 26.23 , 34.33. But vegetables displayed a high capacity of enriching Cr, Cd and Cu. The enrichment coefficient were all over 100. The contents of Cu in vegetables was 10 times-100 times than that of in soil. Using single pollution exponent and synthesis exponent, the vegetables in the suburb of zhengzhou city were assessed. The results showed that : Hg was the biggest pollutant. And the exceeding percentage-which exceeds the food health standard was 100%. While the exceeding percentage of Cu and Cd were 86% and 82%. The exceeding percentage of Pb , Cr and As were lower, beeing 56%, 61% and 39%, respectly. All the vegetables .synthesis pollution exponent is over 2.4. None is green vegetable. Which showed that the vegetables in the suburb of zhengzhou city were all polluted, and Hg pollution is the most serious.