EPIDEMIOLOGY AND HEALTH DATA INSIGHTS
Original Article
Sep 23, 2026 4 3

Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria

Uju Maryanne Onuorah 1 * ,
Abigail Oghenefejiro Ogheneovo 2,
Etiedu Christopher Ekara 2,
Chinemerem Henry Ugo 1,
Michael Chijioke Chiwenite 2,
Ihuoma Utom Chukwuemeka 2
1 Department of Nutrition and Dietetics, University of Nigeria, Nsukka, Nigeria2 Department of Nutrition and Dietetics, Alex Ekwueme Federal University Teaching Hospital, Abakaliki, Ebonyi, Nigeria* Corresponding Author
Epidemiology and Health Data Insights, 2(5), 2026, ehdi055, https://doi.org/10.63946/ehdi/19345
Publication date: Sep 23, 2026
Full Text (PDF)

ABSTRACT

Background: Commercially prepared foods may serve as sources of microbial and chemical contamination that threaten public health, particularly in environments with inadequate hygiene and environmental exposure.
Objective: This study assessed and compared the heavy metal contamination and microbial loads of cooked foods sold in motor parks and restaurants in Abakaliki, Ebonyi State, Nigeria.
Materials and Methods: Two commonly consumed ready-to-eat foods, rice with stew and African salad (Abacha), were obtained from three vendors each in Akubaraoha Central Park (open environment) and selected restaurants (enclosed environment) in Abakaliki. Heavy metals (zinc, copper, and lead) were analysed using Atomic Absorption Spectrophotometry after acid digestion, while microbial load was determined using the pour plate technique on Plate Count Agar. Data were analysed using one-way Analysis of Variance and Duncan’s Multiple Range Test at p < 0.05 with SPSS version 22.0.
Results: Lead was not detected in any of the food samples analysed. Zinc and copper were present in all samples, with the highest zinc (5.19 mg/100 g) and copper (1.75 mg/100 g) concentrations recorded in Abacha obtained from restaurants. Significant differences in heavy metal concentrations were observed among the food samples (p < 0.05). The highest microbial load (3.1 × 10⁵ cfu/g) was recorded in rice with stew obtained from restaurants, while the lowest (1.2 × 10⁵ cfu/g) was observed in Abacha from restaurants. Microbial loads differed significantly among the samples (p < 0.05).
Conclusion: The analysed food samples were free from detectable lead contamination. Although zinc concentrations were within acceptable limits, the copper concentrations observed suggest the need for continued monitoring of commercially prepared foods. The microbial counts obtained were within acceptable ranges but may indicate suboptimal hygiene and food handling practices. Improved food safety practices and regular monitoring of ready-to-eat foods are recommended to reduce potential public health risks.

KEYWORDS

Food Contamination Heavy Metals Microbial Load Ready-to-Eat Foods Street Food

CITATION (Vancouver)

Onuorah UM, Ogheneovo AO, Ekara EC, Ugo CH, Chiwenite MC, Chukwuemeka IU. Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria. Epidemiology and Health Data Insights. 2026;2(5):ehdi055. https://doi.org/10.63946/ehdi/19345
APA
Onuorah, U. M., Ogheneovo, A. O., Ekara, E. C., Ugo, C. H., Chiwenite, M. C., & Chukwuemeka, I. U. (2026). Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria. Epidemiology and Health Data Insights, 2(5), ehdi055. https://doi.org/10.63946/ehdi/19345
Harvard
Onuorah, U. M., Ogheneovo, A. O., Ekara, E. C., Ugo, C. H., Chiwenite, M. C., and Chukwuemeka, I. U. (2026). Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria. Epidemiology and Health Data Insights, 2(5), ehdi055. https://doi.org/10.63946/ehdi/19345
AMA
Onuorah UM, Ogheneovo AO, Ekara EC, Ugo CH, Chiwenite MC, Chukwuemeka IU. Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria. Epidemiology and Health Data Insights. 2026;2(5), ehdi055. https://doi.org/10.63946/ehdi/19345
Chicago
Onuorah, Uju Maryanne, Abigail Oghenefejiro Ogheneovo, Etiedu Christopher Ekara, Chinemerem Henry Ugo, Michael Chijioke Chiwenite, and Ihuoma Utom Chukwuemeka. "Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria". Epidemiology and Health Data Insights 2026 2 no. 5 (2026): ehdi055. https://doi.org/10.63946/ehdi/19345
MLA
Onuorah, Uju Maryanne et al. "Heavy Metal Contamination and Microbial Quality of Ready-to-Eat Foods Sold in Motor Parks and Restaurants in Abakaliki, Nigeria". Epidemiology and Health Data Insights, vol. 2, no. 5, 2026, ehdi055. https://doi.org/10.63946/ehdi/19345

REFERENCES

  1. Sadiku MN, Ashaolu TJ, Musa SM. Food contamination: a primer. Int J Adv Sci Res Eng. 2020;6(3):1-7. https://doi.org/10.31695/IJASRE.2020.33736
  2. Onakpa MM, Njan AA, Kalu OC. A review of heavy metal contamination of food crops in Nigeria. Ann Glob Health. 2018;84(3):488-496. https://doi.org/10.29024/aogh.2314
  3. Weldeslassie T, Naz H, Singh B, Oves M. Chemical contaminants for soil, air and aquatic ecosystem. In: Oves M, editor. Contaminants in Agriculture and Environment: Health Risks and Remediation. Cham: Springer; 2018. p. 1-22. https://doi.org/10.1007/978-3-319-64501-8_1
  4. Usman S, Afolabi OO, Modupe LH. Evaluation of microbial load in fast food establishments in Kaduna metropolis. J Community Med Public Health Care. 2019;6:042. https://doi.org/10.24966/CMPH-1978/100042
  5. Kwiri R, Winini C, Tongonya J, Gwala W, Mpofu E, Mujuru F, Makarichi L, Muredzi P, Gwala ST. Microbiological safety of cooked vended foods in an urban informal market: a case study of Mbare Msika, Harare, Zimbabwe.
  6. Kirk MD, Pires SM, Black RE, Caipo M, Crump JA, Devleesschauwer B, Döpfer D, Fazil A, Fischer-Walker CL, Hald T, Hall AJ. World Health Organization estimates of the global and regional disease burden of 22 foodborne bacterial, protozoal, and viral diseases, 2010: a data synthesis. PLoS Med. 2015;12(12):e1001921. https://doi.org/10.1371/journal.pmed.1001921
  7. Kirk MD, Angulo FJ, Havelaar AH, Black RE. Diarrhoeal disease in children due to contaminated food. Bull World Health Organ. 2017;95(3):233-234. https://doi.org/10.2471/BLT.16.173229
  8. Salamandane A, Malfeito-Ferreira M, Brito L. The socioeconomic factors of street food vending in developing countries and its implications for public health: a systematic review. Foods. 2023;12(20):3774. https://doi.org/10.3390/foods12203774
  9. Mengistu DA, Tolera ST. Prevalence of microorganisms of public health significance in ready-to-eat foods sold in developing countries: systematic review and meta-analysis. Int J Food Sci. 2020;2020:8867250. https://doi.org/10.1155/2020/8867250
  10. Łepecka A, Zielińska D, Szymański P, Buras I, Kołożyn-Krajewska D. Assessment of the microbiological quality of ready-to-eat salads: are there any reasons for concern about public health? Int J Environ Res Public Health. 2022;19(3):1582. https://doi.org/10.3390/ijerph19031582
  11. Izah SC, Etebu EN, Odubo TC, Aigberua AO, Iniamagha I. A meta-analysis of microbial contaminants in selected ready-to-eat foods in Bayelsa State, Nigeria: public health implications and risk-reduction strategies. Hyg Environ Health Adv. 2022;4:100017. https://doi.org/10.1016/j.heha.2022.100017
  12. Oluwapelumi OB, Oluwasegun SA, Funmilayo AJ, Yomi AR. Evaluation of bacterial contamination of ready-to-eat foods sold in Ado-Ekiti, Ekiti State, Nigeria. Am J Biomed Sci. 2020;12(3):164-172. https://doi.org/10.5099/aj200300164
  13. Kodiya MA, Modu MA, Ishaq K, Yusuf Z, Wakili AZ, Dayyabu N, Jibrin MA, Babangida MU. Environmental pollution in Nigeria: unlocking integrated strategies for environmental sustainability. Afr J Environ Sci Renew Energy. 2025;18(1):30-50. https://doi.org/10.62154/ajesre.2025.018.010588
  14. Liu YR, Van der Heijden MG, Riedo J, Sanz-Lazaro C, Eldridge DJ, Bastida F, Moreno-Jiménez E, Zhou XQ, Hu HW, He JZ, Moreno JL. Soil contamination in nearby natural areas mirrors that in urban greenspaces worldwide. Nat Commun. 2023;14(1):1706. https://doi.org/10.1038/s41467-023-37428-6
  15. Sethi S, Gupta P. Soil contamination: a menace to life. In: Soil Contamination—Threats and Sustainable Solutions. London: IntechOpen; 2020. https://doi.org/10.5772/intechopen.94280
  16. Darlington P, Eruteya OC, Akomah-Abadaike ON. Occurrence of virulence genes of Staphylococcus aureus and Escherichia coli in vended foods in selected motor parks in Obio/Akpor, Rivers State. FUDMA J Sci. 2024;8(2):5-14. https://doi.org/10.33003/fjs-2024-0802-2326
  17. Akharaiyi FC, Thomas AA, Efe IL. Bacterial composition of roasted plantains and maize sold in Ado-Ekiti main motor park and their antibiotics sensitivity.
  18. Okoli CE, Njoga EO, Enem SI, Godwin EE, Nwanta JA, Chah KF. Prevalence, toxigenic potential and antimicrobial susceptibility profile of Staphylococcus isolated from ready-to-eat meats. Vet World. 2018;11(9):1214-1219. https://doi.org/10.14202/vetworld.2018.1214-1219
  19. Jomova K, Alomar SY, Nepovimova E, Kuca K, Valko M. Heavy metals: toxicity and human health effects. Arch Toxicol. 2025;99(1):153-209. https://doi.org/10.1007/s00204-024-03903-2
  20. Balali-Mood M, Naseri K, Tahergorabi Z, Khazdair MR, Sadeghi M. Toxic mechanisms of five heavy metals: mercury, lead, chromium, cadmium, and arsenic. Front Pharmacol. 2021;12:643972. https://doi.org/10.3389/fphar.2021.643972
  21. Rehman K, Fatima F, Waheed I, Akash MSH. Prevalence of exposure of heavy metals and their impact on health consequences. J Cell Biochem. 2018;119(1):157-184. https://doi.org/10.1002/jcb.26234
  22. Engwa GA, Ferdinand PU, Nwalo FN, Unachukwu MN. Heavy metal toxicity in humans. In: Poisoning in the Modern World: New Tricks for an Old Dog? London: IntechOpen; 2019.
  23. Codex Alimentarius Commission. General standard for contaminants and toxins in food and feed (CXS 193-1995). Rome: Food and Agriculture Organization of the United Nations and World Health Organization; 1995. Available from: Codex General Standard for Contaminants and Toxins in Food and Feed
  24. Udu-Ibiam OE, Nwankwo CE. Dangers of bacterial contamination: an overview of the antibiogram of bacterial species from ready-to-eat Abacha (African salad) sold in Abakaliki metropolis, Ebonyi State, Nigeria. World J Adv Res Rev. 2025;25(2):100-108. https://doi.org/10.30574/wjarr.2025.25.2.0512
  25. Djedjibegovic J, Marjanovic A, Tahirovic D, Caklovica K, Turalic A, Lugusic A, Omeragic E, Sober M, Caklovica F. Heavy metals in commercial fish and seafood products and risk assessment in adult population in Bosnia and Herzegovina. Sci Rep. 2020;10(1):13238. https://doi.org/10.1038/s41598-020-70205-9
  26. Possas A, Perez-Rodriguez F. New insights into cross-contamination of fresh produce. Curr Opin Food Sci. 2023;49:100954. https://doi.org/10.1016/j.cofs.2022.100954
  27. Anukwuorji CA, Okigbo RN, Chikwendu AE, Anuagasi CL, Anukwu JU. Heavy metals contamination of some food materials from markets in South Eastern Nigeria. Eur J Nutr Food Saf. 2020;12(2):94-101. https://doi.org/10.9734/ejnfs/2020/v12i230197
  28. Nkwunonwo UC, Odika PO, Onyia NI. A review of the health implications of heavy metals in food chain in Nigeria. Sci World J. 2020;2020:6594109. https://doi.org/10.1155/2020/6594109
  29. Anakwue RC, Nnakenyi ID, Maduforo AN, Young EE, Okoli CI, Ndiokwelu CI, Ezenduka CC. Heavy metal content of rice meals sold in a Nigerian market population with a high prevalence of hypertension. Ann Afr Med. 2021;20(1):37-41. https://doi.org/10.4103/aam.aam_12_20
  30. Sun Z, Shao Y, Yan K, Yao T, Liu L, Sun F, Wu J, Huang Y. The link between trace metal elements and glucose metabolism: evidence from zinc, copper, iron, and manganese-mediated metabolic regulation. Metabolites. 2023;13(10):1048. https://doi.org/10.3390/metabo13101048
  31. Hashemi M, Salehi T, Aminzare M, Raeisi M, Afshari A. Contamination of toxic heavy metals in various foods in Iran: a review. J Pharm Sci Res. 2017;9(10):1692-1697.

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