Spatial Distributions of Anthropogenic Induced Gaseous - Particulate Pollutants and Non-Enzymatic Abiotic Stress Responses of Citrius sinesis Leaves

Aims: To determine the spatial distribution pattern of anthropogenic induced gaseous and particulate pollutants in air samples around major roads within Uyo Metropolis, Southern Nigeria. Also, to assess the response in terms of changes in concentrations of some non-enzymatic biochemical markers of Citrius sinesis leaves (orange) collected from these locations.

Study Design: Air samples from six major heavy traffic roads and a control site within Uyo Metropolis was collected. Citrius sinesis leaves were also collected from each major roads and Control to determine possible variations in concentrations of biochemical markers contents.

Place and Duration of Study: Department of Chemistry, University of Uyo, Uyo, between September 2019 and January 2020.

Methodology: Absorption train techniques involving the adsorption of pollutant gases from air samples in a particular location into appropriate reagent solutions was adopted for this study. Estimation of the concentrations of SO2, NO2 and CO was done by calorimetric techniques. Concentrations of total phenolic, proline, malonialdehyde (MDA), cellulose, chlorophyll and ascorbic acid contents in Citrius sinesis leaves were determined using UV/Visible spectrophotometer.

Results: Air samples collected from major roads with heavy traffic and extraneous local automobile emissions recorded higher levels of all the gaseous and particulates pollutants analyzed than Control. Leaves of C. sinesis exposed to higher concentrations of these pollutants showed a higher accumulation of all the biochemical markers studied except chlorophyll, which was higher in leaves from the control site.

Conclusion: Anthropogenic activities directly increases the spatial distribution pattern and concentrations of gaseous and particulate pollutants (PM10 and PM2.5). Also, C. sinesis leaves from major roads within Uyo Metropolis showed different responses in terms of accumulation of these biochemical markers.