Nesta Bortey-Sam

  • Assistant Professor
  • Faculty in Environmental and Occupational Health

My research focuses on understanding many aspects of environmental toxicology, including the fate, bioaccumulation, phase I & II metabolism, excretion, and effects of toxic substances such as metals/metalloids, PCBs, and pesticides, and assessing the effects of air pollution. Other research areas include isotope ratios and epidemiological studies investigating the association between exposure to Pb, As, Cd, Al, and PAHs, and occurrences of lipid peroxidation, DNA damage, chronic kidney disease, myalgia, and respiratory outcomes, while also studying the association between smoking/vaping and birth defects/fetal growth restriction.


2007 | Kwame Nkrumah University of Science & Technology, Ghana | BS Chemistry
2012 | Kwame Nkrumah University of Science & Technology, Ghana | MS Environmental Chemistry
2016 | Hokkaido University, Sapporo, Japan | PhD Toxicology

  • Chemical/Environmental Toxicology
  • Chem Toxicol in the Age of Green Chemistry
  • Environmental Health & Disease
  • Chemistry
  • Risk Assessment
  • Epigenetics & Epigenomics of Env. Hlth.
  • Environmental Exposures
  • Foundations in Public Health
  • Intro to Env Health Sciences
Selected Publications

Nimako, C., Ikenaka, Y., Akoto, O., Bortey-Sam, N., Ichise, T., Nakayama, S. M., ... & Ishizuka, M. (2021). Human exposures to neonicotinoids in Kumasi, Ghana. Environmental Toxicology and Chemistry, 40(8), 2306-2318.

Guck D, Kim D, Logue B,Bortey-Sam N, Tubbs N, Craft D, & Haouzi P. Very High Sputum Cyanide Concentrations during Acute Pulmonary Exacerbations in Cystic Fibrosis Patients (2021). Research Square DOI:

Bortey-Sam N, Jackson R, Gyamfi A.O, Bhadra S, Freeman C, Mahon B.S, Brenner M, Rockwood R.G, Logue A.B. Diagnosis of cyanide poisoning using an automated, field-portable sensor for rapid analysis of blood cyanide concentrations. Analytica Chemica Acta 1098: 125-132 (2020)

Gyamfi O.A,Bortey-Sam N, Mahon S.B, Brenner M, Rockwood G.A, Logue BA. Metabolism of cyanide by glutathione to produce the novel cyanide metabolite, 2-aminothiazoline-4-oxoaminoethanoic acid. Chemical Research in Toxicology (2019).DOI:10.1021/acs.chemrestox.8b00384

Nakayama S.M.M, Nakata H, Ikenaka Y, Yabe J, Oroszlany B, Yohannes Y.B,Bortey-Sam N, Muzandu K, Choongo K, Kuritani T, Nakagawa M, Ishizuka M. Effects of 1 year exposure to Cd- and Pb-contaminated soil on metal accumulation and alteration of global DNA methylation in rats Environmental Pollution 252: 1267-1276 (2019)

Bortey-Sam N, Ikenaka Y, Akoto O, Nakayama S.M.M, Asante A.K, Baidoo E, Obirikorang C, Mizukawa H, Ishizuka M. Association between human exposure to heavy metals/metalloid and occurrences of respiratory diseases, lipid peroxidation and DNA damage in Kumasi, Ghana. Environmental Pollution 235: 163-170 (2018).

Thompson L.A, Ikenaka Y, Yohannes Y.B, Ichise T, Ito G,Bortey-Sam N, Van Vuren J.J, Wepener V, Smit N, Darwish W.S, Nakayama S.M.M, Mizukawa H, Ishizuka M. Human Health Risk from Consumption of Marine Fish Contaminated with DDT and its Metabolites in Maputo Bay, Mozambique. Bulletin of Environmental Contamination and Toxicology 100(5): 672-676 (2018).

Ogbomida E.T, Nakayama S.M.M,Bortey-Sam N, Oroszlany B, Tongo I, Enuneku A.A, Ozekeke O, Ainerua O.M, Fasipe I.P, Ezemonye L.I, Mizukawa H, Ikenaka Y, Ishizuka M. Accumulation patterns and risk assessment of metals and metalloid in muscle and offal of free-range chickens, cattle and goat in Benin City. Ecotoxicology and Environmental Safety 151: 98-108 (2018).

Bortey-Sam N, Ikenaka Y, Akoto O, Nakayama SMM, Asante KA, Baidoo E, Obirikorang C, Saengtienchai A, Nimako C, Ishizuka M. Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) Kumasi, Ghana. Environmental Pollution 228: 311-320 (2017).

Saengtienchai A, Ikenaka Y,Bortey-Sam N, Jermnark U, Mizukawa H, Kawai YK, Nakayama SMM, Ishizuka M. The African hedgehog (Atelerix albiventris): low phase I and phase II metabolism activities. Comparative Biochemistry and Physiology-Part C Toxicology and Pharmacology 190: 38-47 (2016).

Yabe J, Nakayama SMM, Ikenaka Y, Yohannes YB,Bortey-Sam N, Oroszlany B, Muzandu K, Choongo K, Kabalo AN, Ntapisha J, Mweene A, Umemura T, Ishizuka M. Lead poisoning in children from townships in the vicinity of a lead-zinc mine in Kabwe, Zambia. Chemosphere 119: 941-947 (2015).

Bortey-Sam N, Ikenaka Y, Nakayama M.M.S, Akoto O, Yared YB, Baidoo E, Mizukawa H, Ishizuka M..Occurrence, distribution, sources and toxic potential of Polycyclic Aromatic Hydrocarbons (PAHs) in surface soils from the Kumasi metropolis, Ghana. Science of the Total Environment 496: 471-478 (2014).