The Seasonal Variation of the Concentrations of Ozone, Sulfur Dioxide, and Nitrogen Oxides in Two Nigerian Cities

Abstract

A combination of multivariate statistical methods including factor analysis, principal component analysis, principal component regression, and multiple linear regression (MLR) were employed to evaluate the influence of seasons on the concentrations of ozone, sulfur (IV) oxide, and oxides of nitrogen in ambient air of Nigerian cities of Lagos and Ilorin. The former city is located in the coastal area, and it is highly congested with a high intensity of marine, vehicular, and industrial activities, and the latter city is a medium size town, located in the central guinea savannah zone of Nigeria. Samples were collected using a high-volume sampler from near the ground at various sites of diverse human and industrial activities, during wet and dry seasons from 2003 to 2006. The PCA reveals three distinct groupings during the day for all data, which is a reflection of different factors contributing to the atmospheric chemistry of these cities. The predicted ozone concentration values by MLR agree fairly well with the measured data. The dependence of ozone on meteorological parameters including relative humidity, air temperature, and sun exposure and the precursor pollutants depends on weather and the anthropogenic activities. The results for the two cities indicate that reduction in the level of NO 2 is accompanied by an increase in the level of ozone, suggesting the interconversion between the two via photochemical activity.

Evaluation of seasonal variation of water quality using multivariate statistical analysis and irrigation parameter indices in Ajakanga area, Ibadan, Nigeria

“…Several published research studies have employed the use of multivariate statistical analysis in the interpretation of groundwater quality data obtained from various sources (Sundaray 2010;Singh et al, 2008;Uddamari et al 2014;Oketola et al 2013;Molla et al 2015;Arslan 2013;Zhang et al 2014;Majolagbe et al 2016;Markic et al 2015;Razmkhah et al 2010). Scientists have also employed the use of principal component analysis (PCA) to study soil physicochemical properties and its geochemical constituents, identification of heavy metals pollutants in soil, analysis of heavy metals presence in dust and evaluation of influence of seasons on air pollution (Adhikari et al 2003;Ma et al 2016;Satyanarayanan et al 2016;Gergen and Harmanescu 2012;Iwara et al 2014;Lu et al 2010;Burt et al 2014;Benhaddya and Hadjel 2014;Abdul Raheem et al 2008). However, the study of irrigation suitability of groundwater samples within dumpsite and their interpretation using multivariate statistical analysis has not been efficient.…”

nvironmental Monitoring of NOX, Total Oxidants and the Implications for Photochemistry of Air Pollution over Ilorin Shed, Nigeria

“…Figures 1 to 3 indicate that O3 has an inverse-correlation with traffic density during daytime and reduces towards zero values during the hours when the sun is switched off. These are clearly indicative of the strong influence of solar radiation in the photochemical processes leading to O3 formation (Abdul Raheem et al, 2008). Since O3 is not emitted by urban sources, but through photochemical transformation, the observed profile has expected should be strongly correlated with the trends in surface penetration of solar radiation.…”

“…Traffic counts were undertaken at hourly intervals. The minimum and maximum temperatures were between 23 0 C and 34.3 0 C (Abdul Raheem et al, 2008), throughout the sampling time.…”

Prediction of hourly ozone concentrations with multiple regression and multilayer perceptron models

“…The application of statistical methods to analyze pollutants temporal variations has been largely considered. Raheem et al [7] used a combination of multivariate statistical tools, to evaluate seasonal influences on O 3 concentrations in two Nigerian cities, and O 3 links with meteorological parameters and anthropogenic activities.…”