- Analysis of heavy metals (Pb, Hg, Cd, As...) in clams (Meretrix Lyrata) and rock oysters (Saccostrea Glomerata).
- Geo-ecological assessment of coastal areas, specifically Quang Ninh and Hai Phong waters through accumulation of heavy metal content in clams (Meretrix Lyrata), rock oysters (Saccostrea Glomerata).

The reseach has studied and analyzed the concentration of heavy metals including arsenic, lead, mercury, and cadmium in the culture water and the body of white clams and rock oysters:
The results showed that white clams and rock oysters exhibited different levels of heavy metal accumulation even though they had similar living conditions.
Heavy metal concentrations followed the order As > Pb > Hg > Cd in clam tissues and As > Cd > Hg > Pb in oyster tissues
Oysters and clams were contaminated with the highest concentrations of As among the four heavy metals studied at the sampling sites. As concentrations in oysters and clams studied varied from 0.72 mg/kg to 7.84 mg/kg wet weight and obtained an average of 2.81 ± 1.07 and 1.6 ± 0, 62 mg/kg wet weight for clams and oysters, respectively.
A higher level of Cd accumulation in oyster species (0.36 ± 0.13 > 0.16 ± 0.06 mg/kg wet weight) was confirmed.
The measured BCF values ​​in clams and oysters are As > Hg > Cd > Pb, respectively. BCF values ​​>1000 for As and Hg concentrations in the case at Van Don sampling station showed significant accumulation, potentially causing chronic effects and food chain accumulation.

The study provides results of survey and assessment of heavy metal concentration in cultured water and tissue of white clam and rock oyster. As the result, the biogeography of the oyster and clam was evaluated through the bioaccumulation index. Geo-ecological assessment through metal accumulation in benthic animals can also provide results related to food quality, monitoring and warning of areas with high risk of heavy metal pollution in farming and catching this group of benthic animals.

- Publications: 
1. Dang, T. T., Vo, T. A., Duong, M. T., Pham, T. M., Van Nguyen, Q., Nguyen, T. Q., Bui, M. Q., Syrbu, N. N., & Van Do, M. (2022). Heavy metals in cultured oysters (Saccostrea glomerata) and clams (Meretrix lyrata) from the northern coastal area of Vietnam. Marine Pollution Bulletin, 184, 114140. IF =7.
2. Van Do, M., Vo, T. A., Duong, M. T., Le, T. T. X, Huynh, D. L, Pham, T. M., Dang, T. T. Investigation of heavy metal pollution on cultured clams and oyster in Van Don – Quang Ninh, north Viet Nam. Expected to be published in “Journal of Analytical Chemistry, Physics and Biology” issue 3 or 4 in 2022.
- Other products: 01 Master

Investigation of futher research on the composition of organic compounds accumulated in bivalves, and the scope of research in other sea areas across the country.
Continue to strengthen research cooperation between the Institute of Environmental Technology, the Vietnam Academy of Science and Technology and V. I. Il`ichev Pacific Oceanological Institute, Russian Academy of Science in the field of heavy metal accumulation in bivalves.