The edible red seaweed Gelidium pusillum is common in Bangladesh, offering a potentially nutritious and healthy source of selenium-rich food for the local population. However, seaweeds can bioaccumulate a range of heavy metals and we assess heavy metal (Fe, Mn, Ni, Cu, As, Zn, Se, and Hg) concentrations in these two seaweed species. Metals were measured in G. pusillum in the order (mg/kg): Fe (797±67) > Mn (69±4) > Ni (12±5) > Zn (9±4) > Cu (9 ± 4) > Se (0.1 ± 0.1) > Hg (0.1 ± 0.01). These levels of metals in the seaweeds pose no risk to human health as part of a normal diet and beneficial levels of selenium.

1. Heavy Metal
Contamination in Gelidium
Pusillum: A Human Health
Risk Assessment
ID: ICERIE_77
CORRESPONDING AUTHOR:
SAAD AL-DIN SIFAT
DEPT. OF FOOD ENGINEERING AND TEA
TECHNOLOGY, SUST

2. Heavy metal contamination in Gelidium pusillum: A
human health risk assessment
Md. Solaiman Hossain1,
Saad Al-din Sifat2 *,
Eurida Liyana1,
Sharmin Akter3, and
Muhammad Zobayer Bin Mukhlish4
1Dept. of Oceanography, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh, Email: solaiman-ocg@sust.edu;
eurida.milestogo@gmail.com
2Dept. of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh, Email:
saadaldinsifat@gmail.com
3Dept. of Petroleum and Mining Engineering, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh, Email:sharmin-
pme@sust.edu
4Dept. of Chemical Engineering and Polymer Sciences, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh, Email:
zobayer-cep@sust.edu

3. Presentation Outline
1 • Introduction
2 • Research Goal
3 • Materials and Methods
4 • Results and Discussion
5 • Conclusion

4. Presentation Outline
Introduction
Research Goal
Materials and Methods
Results and Discussion
Conclusion

5. Introduction
Edible red seaweed Gelidium pusillum, common in Bangladesh, is a
potential nutritious and healthy source of protein, polysaccharides, lipids,
and fiber. (Shannon and Abu-Ghannam 2019, Islam et al. 2020).

6. Introduction(Contd.)
Seaweeds as Foods
Green Seaweed Salad
Red Ogo Seaweed Salad
Seaweed Uses
Cosmetics and much more…

7. Introduction(Contd.)
However, seaweeds can bioaccumulate a range of heavy metals (Fe,
Mn, Ni, Cu, As, Zn, Se, and Hg as per our assessment)
Why
Heavy Metals
In Seaweed?
Fe
Se
Mn
As
Ni

8. Introduction(Contd.)
Sea
Pollution

9. Presentation Outline
Introduction
Research Goal
Materials and Methods
Results and Discussion
Conclusion

10. Research Goal
The goals were (1) to assess the concentrations of heavy metals (Fe, Mn
, Ni, Cu, As, Zn, Se, and Hg ), (2) to evaluate the health risk posed by
Gelidium using targeted hazard quotient and hazard index, and, (3) to
assess health risk in terms of Mercury- Selenium Indices.

11. Presentation Outline
Introduction
Research Goal
Materials and Methods
Results and Discussion
Conclusion

12. Materials and methods
Mn Ni
Hg Se
Study Area
Red Seaweed (Gelidium pusillum)
ICP-OES
Heavy
Metals
(Rubio et al. 2017)

13. • Health risk assessment was determined using following
formulas:
Materials and Methods (Contd.)
• The selenium health benefit value (HBVSe or Se-HBV) was
measured using the formula:
𝑆𝑒 − 𝐻𝐵𝑉 = [(μ𝑚𝑜𝑙 𝑆𝑒/𝐾𝑔) × (𝑆𝑒/𝐻𝑔)] − [(μ𝑚𝑜𝑙 𝐻𝑔/𝐾𝑔) × (𝐻𝑔/𝑆𝑒)]………………. .4
(Olmedo et al. 2013)
(USEPA 2020, Mohammadi et al. 2019)

14. Presentation Outline
Introduction
Research Goal
Materials and Methods
Results and Discussion
Conclusion

15. Results and Discussions
1) Concentration of heavy metals present in the seaweed sample in
(mg/kg):

16. Results and Discussions (Contd.)
2) Health risk assessment using Targeted Hazard Quotient
(THQ):

17. Results and Discussions (Contd.)
3) Health risk assessment using Mercury- Selenium Indices:

18. 0
10
20
30
40
50
60
70
80
Fe Mn Ni Zn Cu Se Hg (total) Hg
(methyl)
PTDI Amount (mg/day): Female PTDI Amount (mg/day): Male
10g/adult*/day of G. pusillum
4) Comparison to recommended Provisional Tolerable Daily Intake (PTDI)
Results and Discussions (Contd.)

19. Presentation Outline
Introduction
Research Goal
Materials and Methods
Results and Discussion
Conclusion

20. Conclusions
Gelidium pusillum
Safe-for-human consumption
on the levels of seven heavy
metals
No risk for humans consumption based
on hazard indices (THQ and HI)
Se-HBV Analysis: no potential for risks
involved with Hg toxicity

21. Acknowledgements
The authors wish to thank Shahjalal University of Science and Technology’s SUST
Research Centre, Sylhet, Bangladesh for funding this research and grant number as
PS/2019/1/25.
Grant has been received by Md. Solaiman Hossain, Assistant Professor, Department
of Oceanography, Shahjalal University of Science and Technology.
The authors also would like to thank the authority of Atomic Energy Centre, Dhaka
for giving laboratory facilities (AAS for mercury and EDXRF for selenium)
particularly for mercury and selenium concentration testing in seaweed.

22. References
Rubio, C., Napoleone, G., Luis-González, G., Gutiérrez, A.J., González-Weller, D. Hardisson, A. and Revert, C.
(2017) Metals in edible seaweed. Chemosphere 173,572-579.
USEPA (2020) Human Health Risk Assessment. Agency, E.P. (ed), Washington, DC. USA. Mohammadi, A.A.,
Zarei, A., Majidi, S., Ghaderpoury, A., Hashempour, Y., Saghi, M.H., Alinejad, A., Yousefi, M.,
Hosseingholizadeh, N. and Ghaderpoori, M. (2019) Carcinogenic and non-carcinogenic health risk
assessment of heavy metals in drinking water of Khorramabad, Iran. MethodsX 6, 1642-1651.
Olmedo, P., Hernández, A., Pla, A., Femia, P., Navas-Acien, A. and Gil, F. (2013). Determination of essential
elements (copper, manganese, selenium and zinc) in fish and shellfish samples. Risk and nutritional
assessment and mercury–selenium balance. Food and chemical toxicology 62, 299-307.
Islam, M.M. (2020) Potential uses and prospects of seaweed culture in coastal areas of Bangladesh.

24. Now…