¹Department of Research, Strategy and Development, Maritime Academy of Nigeria, Oron, Nigeria.

²University of Calabar, Calabar, Nigeria.

*Corresponding Authors’ Contact Details: E-mail Address ✉: mfonslago@yahoo.com; Mobile Phone no ☎: +234(0)8023719490

Accepted August 29, 2022

We used the Mann-Kendall and the Sen’s slope estimates for trend detection of particulate matter (PMPM_2.5 and PMPM₁₀) in Nigeria. Our main objective was to detect trends in PM pollution in the most populated black country in Africa. Also, to monitor the PM concentration then compare it with the World Health Organization (WHO) standards. This was to enable the effective characterization of PM pollution in Nigeria, understanding the trends and finding appropriate ways to mitigate its effects. The monitoring of the PM data was carried out by the European Centre for Medium-Range Weather Forecast (ECMWF), Copernicus Atmospheric Monitoring Service (CAMS) in collaboration with EUMESAT through remote sensing. The application of the Mann-Kendall non-parametric test method and the Sen’s slope estimation to the PM data led to the detection of PM trends in Nigeria during the period 2019 and 2020. The result of our study showed that the mean concentration of PM_2.5 for the year 2019 was 78.5µg/m³, that of PM₁₀ was 162µg/m³. This concentration overshot the WHO threshold. There was an increase in PM_2.5 trend in 2019, negative trend in the dry season, positive in the wet season. There was also an increasing trend in the PM₁₀ concentration in 2019, negative trend in the dry season and increasing trend during the wet season. PM_2.5 recorded negative trend in 2020 while PM₁₀ recorded negative trend in 2020. Mean PM_2.5/PM₁₀ ratio for the year 2019 was 0.65±0.21. The ratio for the dry season of 2019 was 0.614±0.242. That of the rainy season was 0.721±0.190. For the year 2020, it was 0.255±0.08.

Key words: Nigeria; Concentration; PM; sensing; Mann-Kendall.

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