Project's information

Project's title Studying the status and changing of environmental pollution and proposal solutions to control and reduce the impacts on coastal ecosystems of the Mong Cai coastal area
Project’s code VAST06.04/20-21
Research hosting institution Institute of Marine Environment and Resources
Project leader’s name Dr. Dang Hoai Nhon
Project duration 01/01/2020 - 31/12/2021
Project’s budget 600 million VND
Classify Fair
Goal and objectives of the project

- Assessment of the status pollution of sediment, water in the Mong Cai coastal area and the changing pollutants by human impacts during the past century.
- Proposal solutions to control, reduce the pollution impacts to sediment, water and coastal ecosystems in the Mong Cai coastal area.

Main results

Theoretical results: The project has evaluated the characteristics of water and sediments on the Mong Cai coast. Water quality through parameters of pH, DO, TSS and salinity and heavy metals in the water were lower than Vietnam Standard QCVN 10-TM:2015/BTNMT. The Mong Cai coast distributes mainly coarse sediments (sand), the fine sediments (silt) are distributed less common. The mineral compositions were range from hight to low contents: quartz > illite > kaolinite > feldspar > chlorite > gothite > gibbsite. Most of the heavy metals in surface sediments were lower than the Vietnamese Standard QCVN 43:2017/BTNMT and the ISQGs in both the surface and cores sediment. In general, present heavy metal concentrations are lower than in the past, only average concentrations As was higher than the ISQG (7.2mg/kg) in 2 sediment cores. The OCPs content is quite high, higher than Vietnamese Standard QCVN 43:2017/BTNMT with BHCs (lindan), DDTs (p,o' DDD; p,p' DDT; p,p' DDE; p,o' DDE) and the highest was dieldrin, the risk quotient (RQ) of these OCPs were quite high, the highest up to 171.3 of dieldrin. The PAHs contents were low, but they were increasing over time from 2008 in the C1 sediment core and from 1944 in the C2 sediment core.

Applied results: The project used radioactive isotopes to determine sediment chronology, persistent organic pollutants (PAHs, OCPs), and heavy metals in sediments. Project results have determined the status and their changing over time of pollutants, reflecting the anthropogenic impacts on the sedimentary environment in the Mong Cai area.

Novelty and actuality and scientific meaningfulness of the results

Project results contributed information about sediment characteristics, sedimentation rate, distribution of heavy metals, OCPs, and PAHs on the border between Vietnam and China. The existence of high concentrations of OCPs in the past and a reduction in the current period shows that humans used a lot of pesticides on the mainland and it was brought to the coastal areas. OCPs in sediment decrease over time because both Vietnam and China have been parties to the Stockholm Convention since 2001 and which has been in effect since 2004 in both countries.

Products of the project

- Scientific papers in referred journals (list):
•    Bui Thi Thanh Loan, Nguyen Mai Luu, Nguyen Huy Hoang, Le Van Nam, Pham Tien Dung, Nguyen Dac Ve, Le Nhu Sieu, Dang Hoai Nhon, Tran Duc Thanh, 2022. Some sedimentary environment characteristics in the Mong Cai area, Quang Ninh Province, Viet Nam. VNU Journal of Science: Earth and Environmental Sciences. Vol.38 (1),57-70.
•    Nhon, D.H., Thao, N.V., Lan, T.Đ., Ha, N.M., Nghi, D.T., Ha, T.M., Hao, D.M., Chien, N.V., Thanh, T.D., 2021. Enrichment and distribution of metals in surface sediments of the Thanh Hoa coastal area, Viet Nam. Regional Studies in Marine Science 41, 101574. https://doi.org/10.1016/j.rsma.2020.101574.
•    Dang Hoai Nhon, Duong Thanh Nghi, Tran Duc Thanh, 2020. Intertidal zone in the north of Viet Nam: Feature and potenntial development. Publishing for Science and Technology, Ha Noi, 260pp.
•    Dang, N., Duong Thanh, N., Nguyen Manh, H., Nguyen Thi Mai, L., Do Thi Thu, H., Hoang Thi, C., Le Van Nam, N., Vu Manh, H., Bui Van, V., Bui Thi Thanh, L., Nguyen Dac, V., Chien, N.V., Tran Duc, T., 2022. Distribution and ecological risks of heavy metal(loid)s in surface sediments of the Hai Phong coastal area, North Vietnam. Chemistry and Ecology 38(1): 27-47. DOI:10.1080/02757540.2021.2017901. SCI-E, accepted and online.
- Scientific reports (list):
•    Report on characteristic physicochemistry of coastal water (T0C, DO, S‰, pH, TSS and heavy metals (Cu, Pb, Zn, As, Cd, Co, Ni)).
•    Report on characteristic distribution of grain sizes, mineral compositions, heavy metals (Cu, Pb, Zn, As Cd, Co, Ni), total organic carbon, nitrogen and phosphorus in sediment.
•    Report results of sedimentation rate and changes in the sedimentary environment over the past century according to sediment cores.
•    The report assesses changes in the century of persistent organic pollutants (PCBs, PAHs, pesticides) in sediments by radioactivities isotopes.
•    The report assesses the impacts of pollution caused by human activities on coastal ecosystems and proposes solutions to control and reduce it.

Research area

The result can be transferred to the Department of Natural Resources and Environment of Mong Cai City or the Department of Science and Technology, Department of Natural Resources and Environment of Quang Ninh province as a scientific basis for environmental management in the border area.

Recommendations

In order to clarify the source of OCPs from Vietnam or cross-border sources, it is necessary to further carry out the analysis of the OCPs on agricultural lands, and river systems around the Mong Cai city.

Images of project
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