Prof. Dr. Le Hong Khiem uses moss as a biological indicator to study air pollution
Prof. Dr. Le Hong Khiem at the Joint Institute of Nuclear Research (Dubna, Russian Federation)
He and his colleagues at Institute of Physics are considered the first group to conduct research on air pollution using moss biomarkers in Vietnam. The author's team has conducted air pollution monitoring in many provinces and cities across the country such as Hanoi, Hai Phong, Lam Dong, Bac Ninh and, Hung Yen and gave many results on the level of heavy metal pollution, the source of pollutant emissions opening up a new direction of air pollution monitoring in Vietnam.
Prof. Acad. Le Hong Khiem was born in 1958 and is currently a member of the Scientific Council of the Dubna Nuclear Research Union. He is the former Director of the Institute of Physics, former Plenipotentiary Representative of the Government of Vietnam at the Institute of the Union of Nuclear Research, Russian Federation. He graduated from Hanoi University in 1980, received his Ph.D. in 1991 at the Dubna Joint Institute of Nuclear Research (Soviet Union) and was promoted to Professor in 2015. He is the author of many works published in prestigious international journals, has been in charge of many topics/tasks at all levels, guiding many doctoral students and graduate students. His main research area is Nuclear Physics, the application of nuclear engineering in materials and environmental studies.
Professor Khiem shared: Air pollution is an invisible, silent killer that cannot be observed with the naked eye like other types of pollution. In order to accurately detect diseases for the air, it is necessary to have good diagnostic tools and methods, and monitoring needs to be carried out regularly and continuously is an urgent requirement to determine the "health" of the air.
Currently, to measure the level of air pollution, Vietnam has built automatic monitoring stations. However, the number of installation stations is still modest due to the large cost investment and the need for a team of highly qualified staff to maintain and recalibrate the analytical equipment. In addition, the service life of the equipment is not long because the stations are placed outdoors under extreme weather. In addition, these stations are only equipped with equipment to monitor toxic gases such as SOx, NOx, Cox, etc. PM10, PM2.5 fine dust content, it is difficult to solve the problem of pollution of chemical elements in the air and it is even more difficult to detect the sources of pollution emissions accurately. Another way to determine the level of air pollution is to use an intake pump in combination with filters but it is not possible to monitor over a large area at the same time. Moreover, the results of the analysis only reflect the level of immediate pollution over a certain period of time. In addition, portable air pollution meters are commonly used by environmental regulators. However, due to the very low detection sensitivity of this machine, it should only be used in case of environmental problems.
Prof. Khiem is always concerned about finding new monitoring methods with low cost, easy to apply and at the same time can be deployed in many areas. After years of research, he has found the answer is to use the moss directive.
Moss - a biological indicator for the study of air pollution
Since the 1970s in Europe, the method of using low-level plants such as lichens, moss, algae as a biological indicator to study air pollution has been applied. This method is inexpensive, easy to implement, and can be deployed in multiple regions at the same time. However, so far, this method has not been implemented in Vietnam.
Moss is a low-order plant with a false root system, almost no epidermis, no outer membrane, very high porosity, large air contact surface, its growth is mainly due to the suction of nutrients from the air. Physically, it acts like a filter to absorb toxins in the air. In addition, moss grows naturally in many places and is easy to live, so the collection, preservation and analysis of samples is very convenient.
Prof. Dr. Le Hong Khiem shared: In European countries such as France today, they also build moss walls to clean the air in the city. A Google search for "moss biominitoring technique for air pollution" will yield 230,000 results in just 0.63 seconds. Proving in the world that the use of moss as a biological indicator for the study of air pollution is of interest.
Developing new research directions
After learning about the doctoral project of Dr. Nguyen Viet Hung (Hanoi University of Public Health) conducted in France applied the moss method to monitor air pollution in Hanoi, Thai Nguyen in 2011, Prof. Khiem met and discussed with Dr. Hung. Dr. Hung shared that the moss species in Vietnam chosen by French experts called Barbula indica is appropriate, from here, Prof. Khiem and his colleagues began to search for and use this moss to monitor and study air pollution.
By 2017, the team had implemented the method of using moss directives to measure the level of heavy metal pollution in Hanoi and Hai Phong with more than 1,000 moss samples collected in these 2 cities. From the samples obtained, the team built an air pollution map from 2017-2019, which is the result of the national science and technology project "Research on heavy metal pollution in the air through the Barbula indica moss directive" (code ND T.25.RU/17).
In 2022 - 2023, the research team continues to carry out the project "Research on air pollution using moss bioindicators" (code VAST07.05/22-23). With the goal of using moss biological indicators and nuclear engineering to study air pollution in several different areas in Vietnam such as Hai Phong and Lam Dong.
Sampling locations in Hai Phong and Lam Dong
Distribution of pollution factors in Hai Phong city
In the study, the team analyzed and presented a table of content of 29 chemical elements in moss samples collected at 40 different locations in Lam Dong province and a table of content of 40 chemical elements in live moss samples taken at 39 locations in Hai Phong city. When applying the moss biological indicator method and nuclear engineering to analyze the content of chemical substances that cause air pollution in moss in the study area, the team showed the level of pollution and detected the sources of pollutant emissions into the air. In which, six 6 polluting factors in the area of Hai Phong city are built using GIS software.
Processing moss samples in the laboratory
Prof. Khiem said: There are 2 methods of monitoring air pollution with moss that are very suitable to be applied in Vietnam. One is to use live moss collected in the area to be studied, which is applied to areas with this type of moss (passive method). The second is to take samples of live moss in non-polluted areas and put them in net bags made of plastic material to hang in areas to be surveyed (active method).
To develop this research direction, it is necessary to have a lot of equipment and, laboratories... specialized for analyzing the chemical composition and toxins in moss samples. However, in Vietnam, there are currently no analytical instruments that reach the necessary sensitivity. The analysis in this study was carried out on the IBR-2 nuclear reactor of the Dubna Nuclear Research Union and the Da Lat nuclear reactor. Vietnam is an official member of this international scientific organization, so we can use modern equipment here for research like Poland, Hungary and Czechoslovakia are is doing very effectively. In fact, Vietnam does not have qualified research groups to independently and effectively exploit such modern equipment, so it is necessary to send officials to participate in research groups of other countries to practice and learn. As a member of the Scientific Council of the Dubna Nuclear Research Union and enthusiastic about developing the research direction of air pollution using moss bioindicators in Vietnam, Prof. Dr. Le Hong Khiem devotes a lot of energy to research, grasping new technologies and making efforts to connect with international experts to promote the development of Vietnamese research groups in Dubna. From the results achieved, he hopes to continue to research and implement new methods in many provinces and cities and move towards the application of the biological indicator of Barbula indica moss into a popular air pollution monitoring method in Vietnam, effectively supporting the policy making of pollution management and public health protection in Vietnam future.
Translated by Phuong Ha
Link to Vietnamese version
