Assessment of air pollution in Calabar using geo-accumulation index

Ewona, I.O and Akwagiobe, J. U and Ekah, B. J and Udo, S. O (2025) Assessment of air pollution in Calabar using geo-accumulation index. World Journal of Advanced Engineering Technology and Sciences, 14 (3). pp. 339-348. ISSN 2582-8266

This study investigates the levels of airborne toxic substances in Calabar, Nigeria, using the gravitational settling method to collect airborne particles along with rainwater over a nine-month period, from January to September 2023. The collected sediments underwent spectroscopic analysis to determine concentrations of heavy metals and other toxic substances. The salinity and conductivity of the rainwater samples were also measured. The results were averaged across sub-locations and generalized to represent Calabar, with the geoaccumulation index calculated to assess the degree of contamination. Statistical analysis was performed using MS Excel for computation and graphical presentation of results. The findings revealed that most of the elements, including cadmium, chromium, aluminum, cobalt, copper, iron, zinc, potassium, nitrite, nitrate, fluoride, and sodium, showed no contamination (Class 0), while nickel (Ni) exhibited extremely polluted contamination (Class 6). Lead (Pb) showed moderately to heavily polluted contamination (Class 3), and manganese was heavily contaminated (Class 4). The rainwater samples showed extremely polluted salinity and low conductivity, indicating the presence of dissolved salts and minimal ionization, respectively. These results provide insight into the contamination levels of toxic metals in the environment and the impact of anthropogenic activities in Calabar.