What heavy metals contaminate soil in China?
Heavy metal has influenced humans’ health in recent years. The government is acquiescent to this kind of behavior because of economic development.
| Governments need to pay more attention to the pollution to the soil because it relates to daily life and public health. On the other hand, the industries and plants need to follow the rules and laws that do not discharge the untreated waste to the environment. For example, the Government needs some specific organization to monitor these pollution first and have qualified organizations to treat these pollution to improve the environment and rice quality. Public also needs to report the industries that do not follow the rules to a relative monitoring organization. Future works could search how to degrade these pollution in a short time with low or no negative effect to the soil. Because people also need to cultivate rice in the same soil for the long term. |
Rice is important in daily life, but the condition of the rice is not pretty good. As a result, means they became polluted by lots of external factors. Heavy metals are a critical part of this, and this article will discuss the relationship between the rice growth and heavy metal.
People in China consume plenty of foods including rice. And the soil related to the production of the foods. But the pollution in the cultivated land became influenced by contaminants such as heavy metal discharged by the plants. But the vehicle emission also is a part of this pollution, ignored by people normally (Zhang Hui, Wu Caiqiu, Gong Jiping, Yuan Xuyin, Wang Qiao, Pei Wenming, Long Tao, Qiu Jie, Zhang Hanpei, 2017)4. Finally, the overuse of the fertilizer also will directly influence the soil and increase the heavy metal content (Xu, Yilan, 2018)10.
In China, 16.1% of the agricultural land polluted by heavy metals and DDT (Delang Claudio, 2017)9. Liao Ning in China is a good place to grow rice because of the geographical and climatic reasons. At the same time, the government introduces some large enterprises to promote economic development followed by the pollution. Heavy metal includes plumbum, copper, mercury and zinc. All of these will influence the growth of rice and be harmful to humans.
Findings
From the maps given above, In Liao Ning, some agricultural areas are close to the industrial areas. Pb and Cd are high concentration in those areas, which means the sources of these pollutants are industries and stays into the soil. Rice is a fragile plant, it is easy to be influenced by the surrounding environments. The cadmium in the soil will finally transfer into the humans’ body when people consume the rice, which will lead to the disease in kidney and lung (Martin&Griswold,2009)7. Furthermore, the height of rice will decrease significantly if polluted by Cd.
The relationship between the pollution content and the height of rice became illustrated. Ck is the control group with the average height 82 cm and the average height of rice polluted by Cd is 76 cm which is the shortest in these treatments. And also, the content of Cd is increasing by 0.02% in 7 years. Copper has the smallest influence on the rice height. It is almost the same with the control group even if the content is high. The average height influenced by Pb is 77 cm and the contents doubled in 14 years and reached 49.
The concentration detected by technology, atomic absorption spectrophotometry (Qixing Zhou, Xin Wang , Renluo Liang & Yanyu Wu, 2003)2.
According to Arthar and Masood, the order for toxic effects of several heavy metals to the plants is Cd>Cu>Ni>Zn>Pb>Cr.
The geographical relationship between the rice and industries are clearly shown. It clearly shows that the areas containing both industries and agricultural fields got the higher level of contamination for specific heavy metals. And the area with the expressway also had the higher level of pollution of some elements like the lead.
Map A and Map B are the degree of the soil pollution in China and I highlight the location of Liao Ning. Map C to Map G are the distribution of the heavy metal pollution in China by different elements including Pb, Cd, Hg, Cr and As. From the maps, the pollution of Pb, Hg, and Cd is serious in Liao Ning. And most of the pollution is close to the south of Liao Ning.
Discussion
The heavy metal does influence the height of the rice, but it depends on different metals. The external factors are the same shown, but the height is different because of different heavy metals. The shortest one is treatment polluted by Pb, which means Pb significantly influences the height among the given elements. It is amazing that the height of rice polluted by Copper is higher than the control group, which is over 82 centimeters.
Even though copper is important for plant growth, it also contains toxicity. But normally the contaminations are not the single heavy metal. The height of rice polluted by double element treatment is lower than single element treatment, meaning to say double element contamination is much more serious than single element contamination. (Qixing Zhou , Xin Wang , Renluo Liang & Yanyu Wu, 2003)2. When the concentration for Cr and Cd in the stem is higher than balance value, the stem will decrease to the half of original length (LuPeng Xie, 2018)8.
Moreover, the experiments became carried out in the pot. It can easily control the external factors and make sure that there were no interaction effects between different treatments. In terms of the weight of polluted rice, there were no significant changes to the weight. For the relative yields, the yields for polluted treatments had significant decreases in Pb treatment. In addition, double elements treatments, which fluctuated from 80% to 70%. But for the Cd, Cu, Zn and As treatments, The relative yield is 85% to 100%, and the control group is 100%. (Qixing Zhou , Xin Wang , Renluo Liang & Yanyu Wu, 2003) 2.
Conclusion
There were lots of factors that influenced the growth of rice in China Liao Ning. Industries with illegal emission and agricultural areas are near each other so that the pollution to the soil is significant especially for heavy metals. The rice here was polluted by those elements. The height of rice was decreasing seriously due to the heavy metals and the shortest one is Cd treatment. The weight did not change so much compared to the control group. Finally, the relative yields for each treatment had a different decrease. Overall, the weight is an unaffected factor to the heavy metals. Yield is more easily affected than height.
