Heavy Metals Identification and Detection in Incinerated Bottom Ash from Biomedical Solid Waste in Selected Healthcare Facilities in Douala, Cameroon

Nkwenti Peter *

Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.

Etame Loe Gisele Marie

Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.

Justin Djopnang

Laboratory of Fisheries and Aquatic Resources, Institute of Fisheries and Aquatic Sciences at Yabassi, University of Douala, P.O. Box 7236, Douala, Cameroon.

Nnanga Nga

Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.

*Author to whom correspondence should be addressed.


Aims: To identify and detect heavy metals in incinerated bottom ash of Biomedical Solid Waste in selected healthcare facilities in Douala, Cameroon.

Study Design: Cross-sectional fieldwork and laboratory based study design approach that involved quantitative and qualitative data collection methods

Place and Duration of Study: This study was carried out in the Douala, Littoral region of Cameroon from the month of January 2023 to June 2023.

Methodology: 5 grams of filtered incinerated bottom ash from BSW were collected from incinerators of the selected healthcare facilities using labeled plastic polyethylene containers and transported to the laboratory for analysis. Samples were air dried and introduced on polypropylene film to the EDX 7000 spectrometer for sensitive analysis.

Results: Both the quantitative and qualitative concentration percentage of the heavy metals detected from Na to Uranium in each HCF was determined by the EDX 7000 spectrometer device. Zinc had a significant concentration percentage in BDH (7.491±0.009333%), LH (4.255±0.009%), GH (7.506±0.013%), AHD (6,903±0.012%) and Iron had a significant concentration percentage in GOHD (3.669±0.013%).

Conclusion:  It is concluded that improper disposal of incinerated BA from incinerators may pollute the environment and water bodies through leaching into ground water or being carried into water bodies through runoffs, being inhaled in dust from the dump area, and bioaccumulating in plants and animals that stray to the dump site, potentially having a negative impact on the environment and health risks like cancer and respiratory illnesses. Some of the heavy elements found in bottom ash that had been burned during this investigation were above the USEPA-permitted limits.   Assuring proper BA disposal through hygienic landfills may help reduce the amount of heavy metals and other toxic elements in the environment, hence safeguarding human health. To prevent additional environmental damage and human exposure to these elements, waste management practices must be improved through BA recycling. Additionally, it is advised that waste managers in the healthcare industry receive training in safe incinerator bottom ash handling and disposal techniques. Regulatory organizations should also oversee and implement policies for bottom ash management in neighborhood healthcare facilities. In Cameroon, a developing nation that must concentrate on environmental challenges that also benefit human health, this study is fundamentally significant. Sustainable prevention of waste and heavy metals in various HCFs will result from source segregation, knowledge of the problem, and safeguards taken at every stage of the waste cycle.

Keywords: Heavy metal, biomedical solid waste, bottom ash, healthcare facilities, Douala, Cameroon

How to Cite

Peter , N., Marie , E. L. G., Djopnang , J., & Nga , N. (2023). Heavy Metals Identification and Detection in Incinerated Bottom Ash from Biomedical Solid Waste in Selected Healthcare Facilities in Douala, Cameroon. Chemical Science International Journal, 32(5), 33–46. https://doi.org/10.9734/CSJI/2023/v32i5858


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Sarker MAB, Harun-Or-Rashid M, Hirosawa T, Hai MSBA, Siddique MRF, et al. Evaluation of knowledge, practices, and possible barriers among healthcare providers regarding medical waste management in Dhaka, Bangladesh. Medical science monitor: International medical journal of experimental and clinical research. 2014;20:2590.

Jiangwo et al, Biomedical waste management practices and associated factors among health care workers in the era of the Covid-19 pandemic at metropolitan city private hospitals, Amhara region, Ethiopia; 2020.

Doi: 10.1371/journal. pone.0266037

College Gm, & Hospital-32 C (2014) manual for biomedical waste management. Nigerian Jornal of Medical Sciences. pmid:25593667.

Harhay MO, Halpern SD, Harhay JS, Olliaro PL () Health care waste management: a neglected and growing public health problem worldwide. Tropical Medicine & International Health. 2009; 14:1414–1417. pmid:19735368

Buc ̆ataru C; S ̆avescu D; Repanovici A; Blaga L; Coman E; Cocuz ME. The Implications and Effects of Medical Waste on Development of Sustainable Society—A Brief Review of the Literature. Sustainability 2021;13:3300.

Available:https://doi.org/10.3390/ su13063300

Olaniy FC, Ogola JS, Tshitangano TG. A review of medical waste management in South Africa. Open Environmental Science. 2018;10:34–45.

Available:https://doi.org/ 10.2174/1876325101810010034

Debrah JK, Vidal DG, Dinis MAP. Envi- ronmental waste sustainability: organic valorisation and socioeconomic benefits towards sustainable development in Ghana. In: Leal Filho W., Vidal DG, Dinis MAP. DRC (eds.) Sustainable Policies and Practices in Energy, Envi- ronment and Health Research. World Sustainability Series. Springer, Cham. 2022b;425–437. Available:https://doi.org/10.1007/978-3-030-86304-3_24

Oli AN, Ekejindu CC, Adje DU, Ezeobi I, Ejiofor OS, Ibeh CC, Ubajaka CF. Healthcare waste management in selected government and private hospitals in Southeast Nigeria. Asian Pacific Journal of Tropical Biomed‑ icine. 2016;6:84–89. Available:https://doi.org/10.1016/j.apjtb.2015.09.019

World Health Organization (WHO). health-care waste; (2018.

Available:https://www.who.int/news-room/fact- sheets/detail/health-care-waste. Retrieved 10 October 2022

Debere MK, Gelaya KA, Alamdo AG. Assess- ment of the health care waste generation rates and its man- agement system in hospitals of Addis Ababa. BMC Public Health. 2013;12(13):28.


Nkwenti P, Etamé Loé G, Joel N, Nga N, Bih Larrisse N. Determination of Nickel in Selected Surface Waters of the Bonaberi Industrial Zone, Douala IV Council, Littoral Cameroon. 10.9734/mrji/2023/v33i21365 Microbiology Research Journal International; 2023

Oduro-Kwarteng S, Addai R, Essandoh HMK. Healthcare waste characteristics and management in Kumasi, Ghana. Scientific African. 20211;2:e00784.

Available:https://doi. org/10.1016/j.sciaf.2021.e00784

Debrah JK, Carlotto IN, Vidal DG, Dinis MAP. Managing medical waste in Ghana-the reality. International Journal of Environmental Studies. 2021a;1–17.


Debrah JK, Teye GK, Dinis MAP. Barriers and challenges to waste management hindering the circu- lar economy in sub-Saharan Africa. Urban Science. 2022a; 6:57.


Debrah JK, Vidal DG, Dinis MAP. Environmental waste sustainability: organic valorisation and socioeconomic benefits towards sustainable development in Ghana. In: Leal Filho W., Vidal DG, Dinis MAP. DRC (eds.) Sustainable Policies and Practices in Energy, Envi- ronment and Health Research. World Sustainability Series. Springer, Cham. 2022b;425–437. Available:https://doi.org/10.1007/978-3-030-86304-3_24

Debrah JK, Vidal DG, Dinis MAP. (). Sustain- able pharmaceutical waste management: pharmacist and patients perception in Ghanaian hospitals. In: In Hand- book of Sustainability Science in the Future., Walter Lea (eds.) Cham, Switzerland: Springer Cham pp 2022c; 425–437. Available:https://doi.org/10.1007/978-3-030-68074-9_131-1

Debrah JK, Vidal DG, Dinis MAP. Vulner- abilities of waste scavengers to COVID-19 impacts: out- comes of an exploratory study in Ghana. In W. Leal Filho (Ed.), Handbook of Human and Planetary Health . Springer, Cham.2022d;187–201. Available:https://doi.org/10.1007/978-3-031-09879-6_12

Debrah JK, Vidal DG, Dinis MAP. Recovering from COVID-19 environment and social impacts in sub-Saharan Africa: the role of social engagement. In W. L. Filho, A. M. Azul, F. Doni, & A. L. Salvia (Eds.), Handbook of Sustainability Science in the Future: Policies, Technologies, and Education by 2050;1–16. Springer Cham; 2022e.


Debrah JK, Wahaj Z, Sadaf L, Dinis MAP. Assessment of biomedical waste in Ghana. InternationalJournal of Environmental Studies; 2022f Available:https://doi.org/10.1080/ 00207233.2022.2135891

Leal Filho W, Dinis MAP, Ruiz-de-Maya S, Doni F, Eustachio JH, Swart J, Paço A. The econom- ics of the UN Sustainable development goals: Does sus- tainability make financial sense? Discover Sustainability. 2022a;3:20.


Leal Filho W, Salvia AL, Vasconcelos CRP, Anholon R, Rampasso IS., Eustachio J. HPP, Liakh O, Dinis MAP, Olpoc RC, Bandanaa J, Aina YA, Lukina RL, Sharifi A. Barriers to institutional social sustainability. Sustainability Science; 2022b;1–16. Available:https:// Doi.org/10.1007/s11625-022-01204-0

Leal Filho W, Wall T, Barbir J, Alverio G. N, Dinis MAP, Ramirez J. Relevance of international partner- ships in the implementation of the UN Sustainable Devel- opment Goals. Nature Communications. 2022c;13:613.

Available:https://doi. org/10.1038/s41467-022-28230-x

Joseph DL, Newman DA. Emotional intelligence: An integrative meta-analysis and cascading model. Journal of Applied Psychology. 2010;95(1):54–78. Available:https://doi.org/10.1037/a0017286

Michelozza P, Fusco D, Forastiere F, Ancona C, Dell’Orco V, Perucci CA. Small area study of mortality among people living near multiple sources of air pollution. Occupational and Environmental Medicine, 55. 1998;611–615.


Dockery DW, Pope CA, III. Acute respiratory effects of particulate air pollution. Annual Review of Pub‑ lic Health, 15, 1994;107–132. Available:https://doi.org/10.1146/annurev. pu.050194.000543

Rapiti E, Daniela P, Francesco F, Danilo F, Carlo A. Pe. Socioeconomic status and survival of persons with AIDS before and after the Introduction of Highly Active Antiretroviral Therapy. Epidemiology no. 2000:11(5):496–501. Available:http://www.jstor.org/stable/3703989.

Elliott P, Shaddick G, Kleinschmidt I, Jolley D, Walls P, Beresford J, et al. Cancer incidence near municipal solid waste incinerators in Great Britain. British journal of cancer, 1996/03/01- 702

DOI: 10.1038/bjc.1996.122

Landrigan P, Gary FS, John RK, Raymond L. Ruhe, Arthur S. Common-Source community and industrial exposure to trichloroethylene, archives of environmental health. An International Journal. 1987;42:6:327-332.

DOI: 10.1080/00039896.1987.9934354

Kurttio P, Juha P, Georg A, Mikko P, Jouni JK, Jaakkola, Olli P. Heinonen increased mercury exposure in inhabitants living in the vicinity of a hazardous waste incinerator: A 10-year follow-up, archives of environmental health. An International Journal. 1998;53:2:129-137.

DOI: 10.1080/00039896.1998.10545974

Wrbitzky R, Goen T, Letzel S, Frank F, Angerer J. Internal esposure of waste incineration workers to organic and inorganic substances. International Achieves of Occupational and Environmental Health, 1995;68:13–21.


Angerer J, Heinzow B, Reimann DO, Knor, W, Lehnert G. Internal exposure to organic substances in a municipal waste incinerator. International Archives of Occu‑ pational and Environmental Health ‑ Springer.1992;64:265–273.


Dzekashu LG, Akoachere JF, Mbacham WF. Medical waste management and disposal practices of health facilities in Kumbo East and Kumbo West health districts. International Journal of Medicine and Medical Sciences. 2017;9(1):1-11.

Mochungong PI, Gulls G, Sodemann M, Hospital workers awareness of health and environmental impacts of poor clinical waste disposal in the NorthWest region of Cameroon, Int J Occup Environmen Health. 2010;16(1):53-59.

Douala Cameroon. Available:https://www.britannica.com

Abor PA. Bouwer A. Medical waste management practices in a Southern African hospital. International Journal of Health Care Quality Assurance, 2008;21, 356–364. Available:https://doi.org/10.1108/09526860810880153

Dharmaraj S, Ashokkumar V, Pandiyan R, Halimatul MHS, Chew KW, Chen, et al. Pyrolysis: an effective technique for degradation of COVID-19 medical wastes. Chemosphere. 2021;275:130092.

Available:https://doi.org/10.1016/j chemosphere.2021.130092

Xu L, Dong K, Zhang Y, Li H. Comparison and analysis of several medical waste treatment technologies. IOP Conference Series: Earth and Environmental Science. 2020;615(1):012031. Available:https://doi.org/10.1088/1755-1315/615/1/012031

Zhao HL, Wang L, Liu F, Liu HQ, Zhang N, Zhu YW. Energy, environment and economy assessment of medical waste disposal technologies in China. Science of the Total Environment. 2021;796:148964.


Zimmermann K. Microwave technologies: An emerging tool for inactivation of biohazardous material in developing countries. Recycling, 2018;3(3):34. Available:https://doi.org/10.3390/recycling3030034

Leal FW, Vidal DG, Chen C, Petrova M, Dinis MAP, Yang P, Rogers S, Álvarez-Castañón L. del C, Djekic I, Sharifi A, Samara N. An assessment of requirements in investments, new technolo- gies, and infrastructures to achieve the SDGs. Environmental Sciences Europe. 2022d;1–17.

Available:https://doi.org/10.1186/ s12302-022-00629-9

Dinis MAP, Neto B, Begum H, Vidal DG. Editorial: Waste challenges in the context of broad sustain- ability challenges. Frontiers in Environmental Scienc. 2022; 10:964366.


Dwivedi P, Mishra PK, Mondal MK, Srivastava N. Non-biodegradable polymeric waste pyrolysis for energy recovery. Heliyon. 2019;5:e02198. Available:https://doi.org/10


Premkumar MP, Thiruvengadaravi KV, Senthil KP, Nandagopal J, Sivanesan S. Eco-friendly treatment strategies for wastewater containing dyes and heavy metals. Environmental Contaminants: Measurement, Modelling and Control. Springer Singapore, Singapore. 2018;317–360. Available:https://doi.org/10.1007/978-981-10-7332-8_14

Wei W, Shi X, Wu L, Ni BJ. Insights into coconut shell incineration bottom ash mediated microbial hydrogen production from waste activated sludge. Journal of Cleaner Production. 2021 ;322:129157.


Adama M, Esena R., Fosu-Mensah B, Yirenya-Tawiah D. Heavy metal contamination of soils around a hospital waste incinerator bottom ash dumps site. Journal of Environmental and Public Health. 2016:8926453.


Batterman S. Findings on assessment of small-scale incinerators for health-care waste. Water, Sanitation and Health Protection of the Human Environment. Geneva, Switzerland: World Health Organization; 2004. [Google Scholar]

Abor PA, Bouwer A. Medical waste management practices in a Southern African hospital. International Journal of Health Care Quality Assurance. 2008; 21(4):356–364.

DOI: 10.1108/09526860810880153. [PubMed] [CrossRef] [Google Scholar]

WHO. Air Quality Guidelines for Europe 2000. chapter 5.11. Copenhagen, Denmark: WHO Regional Office for Europe. Polychlorinated dibenzodioxins and dibenzofurans. (European Series no. 91). [Google Scholar]; 2011.

Beyersmann D. Effects of carcinogenic metals on gene expression. Toxicology Letters. 2002;127(1–3):63–68.

DOI: 10.1016/s0378-4274(01)00484-2. [PubMed] [CrossRef] [Google Scholar]

Md Anamul H, Rahman J, Tanvir M. Zn and Ni of bottom ash as a potential diffuse pollutant and their application as ‘Fine Aggregate’ Journal of Civil Engineering Research. 2012;2(6):64–72.

DOI:10.5923/j.jce.20120206.03. [CrossRef] [Google Scholar]

Zhao L, Zhang F.-S, Chen M, Liu Z, Wu DBJ. Typical pollutants in bottom ashes from a typical medical waste incinerator. Journal of Hazardous Materials. 2010; 173(1–3):181–185.

DOI: 10.1016/j.jhazmat.2009.08.066. [PMC free article] [PubMed] [CrossRef] [Google Scholar]

Mohajer R, Salehi MH, Mohammadi J, Emami MH, Azarm T. The status of lead and cadmium in soils of high prevalenct gastrointestinal cancer region of Isfahan. Journal of Research in Medical Sciences. 2013;18(3):210–214. [PMC free article] [PubMed] [Google Scholar]

Gidarakos E, Petrantonaki M, Anastasiadou K, Schramm KW. Characterization and hazard evaluation of bottom ash produced from incinerated hospital waste. Journal of Hazardous Materials. 2009;172(2-3):935–942.

Doi:10.1016/j.jhazmat.2009.07.080. [PubMed] [CrossRef] [Google Scholar]

Ministry of Local Government and Rural Development. Draft Guideline for Management of Health Care and Vertinary Waste in Ghana. Accra, Ghana: Government of Ghana; 2002. [Google Scholar]

Müller G. Index of geoaccumulation in the sediments of the Rhine River. GeoJournal. 1969;2(3):108–118. [Google Scholar]

Atiemo SM, Ofosu FG., Kuranchie-Mansah H, Osei Tutu A, Palm Linda NDM., Blankson AS. Contamination assessment of heavy metals in road dust from selected roads in Accra, Ghana. Research Journal of Environment and Earth Sciences. 2011;3(5):473–480. [Google Scholar]