Evaluation of Selected Ambient Air Concentrations in Major Roundabout and Solid Waste Dump Site in Katsina Metropolis, Katsina State, Nigeria

Abstract

This current study is aimed at investigating the ambient air concentration of major roundabouts and 
waste dump sites within the Katsina metropolis. This was carried out concerning four air pollutants 
which include Nitrogen dioxide (NO₂), sulfur (IV) oxide (SO₂), carbon monoxide (CO), and Ammonia 
(NH₃), with the sole objective of determining their atmospheric concentrations to evaluate their ambient 
air level in Katsina metropolis. Six locations and one control were studied from November 2021 to 
February 2022. Measurements were carried out three times daily (7 – 9 am, 12 – 3 pm, and 4 – 7 pm) by 
using a Gasman air monitor. Descriptive statistics and multivariate analysis were used in analyzing the 
data set generated. Results of the air pollutants showed that the KTSTA roundabout had the highest CO 
(10.61±14.54 ppm), the KT roundabout exhibited the highest pollutant concentration in NH₃ (2.056 ± 
1.71 ppm), and the GRA roundabout was the lowest. Both Kofar Kaura and KTSTA roundabouts have 
the highest pollutants of NO₂  (0.69 ± 0.90 ppm) and (0.69 ± 0.78 ppm). Kofar Kaura, Liyafa 
Roundabout, and Behind ATC dumpsite had the same and highest SO₂ concentrations (0.10± 0.15 
ppm), (0.10± 0.15 ppm), and (0.10 0.014 ppm). CO was found to be highest in concentration in the 
morning period (10.39±11.00 ppm). The findings of this study show that there are lots of commercial 
and vehicular activities in the vicinity from 7 to 9 am, which are responsible for the observed elevated 
ambient air level. However, the ambient air pollutant concentration at the control site was all-time low 
compared to the studied sites. According to the Nigerian Ambient Air Quality Standard, elevated 
ambient air pollutants are responsible for many respiratory-related diseases. Regular and strict 
monitoring of the levels of ambient air pollutants in the studied area is therefore recommended because 
of the adverse health implications of elevated ambient air pollutants on humans.