Seasonal and Multivariate Characteristics of Atmospheric Gases, Particulate Matter and Heavy Metals in Lagos-Suburban

Aim: Insufficient data on atmospheric pollution research exists in Lagos-suburban areas, and in some cases, studies are yet to be carried out. The aim is to study criteria pollutants seasonal characteristics, suspended particulate matter, and particulate heavy metal concentrations interactions in the Lagos suburban by multivariate techniques

Methodology: Assessment of 3 criteria pollutants, suspended particulate matter (SPM), and 6 particulate heavy metal concentrations, at 10 different suburban locations in Lagos was performed and interpreted by multivariate analysis to determine their sources, distribution, and pollution status. AQI values indicated a non-hazardous environment that is moderately unhealthy and sensitive to vulnerable populations.

Results: Values of CO among the 10 sites ranged from 468-1350 µg/m3 during the wet season, and 447-1864 µg/m3 during dry seasons and both exceeded World Health Organization (WHO), and Nigerian Federal Ministry of Environment (FMEnv) regulations. NO2 concentration exceeded the FMEnv standard and suggest the likelihood of health challenges to the unsuspecting population. Cl- anion accounts for 85% of the total anion concentrations, and others had low standard deviations < 5%. A correlation of (Na+ and SO42-), (Ca2+ and NO3-), (K+ and SO42-) showed active atmospheric water chemistry in the study locations. Determined levels of Cd and Ni particulate did not exceed WHO guidelines, while only Alagbado and Surulere were the major Pb hotspots. Pearson correlation showed the heavy metals differ from each other during each season, but Zn/Zn and Fe/Fe showed a strong link between the metal concentrations and the seasons. Peripheral component analysis indicated that Cd and Cu particulate matter accounts for 75% of the variance, while cluster analysis showed the similarity of relationship in terms of concentration for the wet season.

Conclusion: The findings of the present study provided invaluable data on atmospheric pollution and the development of improved protocols for pollution guidelines in suburban Lagos.