Important progress has been made in the study of cadmium biological effectiveness in rice at the South China Botanical Garden of the Chinese Academy of Sciences

Original title: Important progress has been made in the study of cadmium biological effectiveness in rice at the South China Botanical Garden of the Chinese Academy of Sciences
With the development of economy and the acceleration of urbanization, human activities have led to the pollution of large areas of farmland, especially rice fields, by harmful heavy metals. Cadmium (Cd) is a common toxic element in soil pollution, the results of the first national soil pollution census show that heavy metal CD pollution increased, the national land CD point exceeding the standard rate of 7.0%. A national survey showed that nearly 65 per cent of all rice produced near the mine exceeded the national food standard for rice cadmium (0.2 mg/kg). After being ingested into the human body by heavy metals,
rice
will undergo the digestive process in the stomach and intestines, and then accumulate with the blood circulation into different tissue organs of the human body, causing changes in the tissue form and metabolism of the organs, thus producing toxic effects on the human body. The health risks of residents caused by the accumulation of heavy metals in the body caused by rice intake have aroused widespread concern.
in order to accurately assess human exposure to heavy metals in contaminated food, it is necessary to measure the
of
metals. Bioavailability is used to indicate the proportion of the total amount of heavy metals ingested through the mouth that can pass through the gastrointestinal tract and eventually into circulation in the human system, usually using live experimental methods (in vivo). Biosyscence is an indication of the biological effectiveness of the largest mesopatheconial pathway of pollutants, so many research work on the biological effectiveness of pollutants takes bio-giving as the starting point and object of research, usually using the research method in vitro, which has the advantage of overcoming the high cost, long cycle and moral and ethical defects of the
life
model. However, bio-giving is not the same as biological effectiveness, and it is not clear whether in-body simulation experiments can effectively predict biological effectiveness and regulatory factors.
The Soil Ecology and Ecological Engineering Research Group of the South China Botanical Garden studied the biosothyability and biological effectiveness of cadmium in rice by establishing four different in-body simulations and animal (mouse) models with six different
cadmium pollution
concentrations. The study found that the biological effectiveness of cadmium in rice was 15-56%, 18-56% and 3.71-54% respectively (with kidney, liver and fascep as organs), and negative correlation with the total cadmium concentration in contaminated rice (r2 -0.74-0.94). There were differences in biosothicity of rice CD as measured by different in-body simulated digestion methods, and the biosothyability of CD stomach and intestines obtained from 4 in-body digestion methods was 57-83%, 55-94% and 4 respectively. 2-98% and 34-94% (gastric stage) and 34-49%, 21-43%, 28-55% and 14-56% (intestinal stage). When assessing the relationship between in vitro and in vivo data, the correlation between the four in vitro methods and the mouse model based on liver or kidney was weak, with a correlation coefficient of r2 to 0.0006-0.52. The results of in-body digestion models vary greatly from method to method, indicating that there are some limitations in predicting the biological effectiveness of CD in contaminated rice. The results of this study are of great significance to demonstrate the feasibility of in vitro digestion methods to predict the biological effectiveness of experiments in the body.
research has been published in science of The Total Environment, an authoritative SCI journal in the field of the environment. The research was funded by the National Natural Science Foundation of China and projects such as the Guangdong Natural Science Foundation and Guangzhou Science and Technology Research. Link to paper: