Impact of Human Activities on the Carbon Monoxide Levels in Port Harcourt Metropolis: A Rare Experience with Covid-19 Lockdown

This study was conducted to monitor the impact of human activities on the air quality of Port Harcourt Metropolis, during and after the Covid-19 Lockdown period where human activities were brought to an all-time low. Ten selected locations, evenly distributed around Port Harcourt Metropolis were studied while Rivers State University served as the Control Site. The meteorological parameters studied alongside carbon monoxide were atmospheric temperature, relative humidity, wind speed, and wind direction. Standard methods were applied in capturing data in-situ, using hand-held devices. Data were collected for six months capturing rainy and dry season months and the lockdown periods. Air Quality Indices were also calculated for CO. The results obtained reveal that meteorological data gathered were characteristic of the study area. The values of carbon monoxide were higher in the Sampling Sites with a mean range of (0.632 – 3.291) ppm in the rainy season and (0.422 – 9.037) ppm in the dry season) than in the Control Site with a mean of (0.133 ppm in the rainy season and 0.493 ppm in the dry season). The level of CO was higher in the dry season as compared to the rainy season. There was strong positive correlation with respect to carbon monoxide amongst sampling locations with similar human activities. The correlation of the sampling locations with the Control Site were mostly weak. A reduction of the concentrations of carbon monoxide was recorded during the Covid-19 Lockdown periods. The AQI values indicate that the air quality was categorized as good with respect to carbon monoxide in the lockdown periods and was between moderate to unhealthy in the non-lockdown periods. It is clearly evident that air quality is a function of the level of human activities, especially those that result in the emission of noxious air pollutants. It is recommended that the air quality be put under regular monitoring in order to regulate the human activities that can impact on the air quality.