Gbalé G. K. Jean-Christophe^1,, Adon A. Marcellin², Koua A. Antonin¹

Monitoring of radionuclides in aerosols is essential for understanding the factors influencing temporal variations in atmospheric deposition of elements such as ²¹⁰Pb, which is frequently used as a tracer in atmospheric studies. However, long-term monitoring remains limited. Very few studies on air radioactivity are available in Africa and particularly in Côte d'Ivoire. In this study, we measured the radioactivity of ²¹⁰Pb in surface aerosols collected on a weekly basis in the city of Abidjan in south−eastern Côte d'Ivoire from March 2022 to February 2023, using HPGe gamma spectrometry. The mean activity of ²¹⁰Pb was 0.78 ± 0.2 mBq/m³. This activity concentration showed strong seasonal variations, with maximum concentrations recorded during the dry seasons and minimum in the rainy seasons. Statistically significant correlations were observed between ²¹⁰Pb concentration and temperature (r = 0.47; p-value = 0.02), as well as a negative correlation with precipitation (r= -0.48; p-value = 0.02). A statistical test comparing the data obtained in the present work with some bibliographic values of ²¹⁰Pb in aerosols showed that our level of activity concentration is statistically identical to the other previous studies carried out in the world. The active dependence of ²¹⁰Pb with temperature and precipitation was investigated through simple linear regression analysis. Model evaluation and comparison functions were also used. Overall, this study provides an understanding of the behavior, correlations and variability of observed ²¹⁰Pb concentrations influenced by atmospheric conditions in our study area.

²¹⁰Pb, Aerosol, Coastal city, Environmental radioactivity