Effect of quarrying and stone crushing activities on nutritional composition, heavy metals and oxidative stress indices of Aspilia Africana

Abstract

Background and Objective: Physiological and biochemical changes in plants are indicators used for monitoring cellular activity of plant prior and post exposure to harsh environment. This study investigated the impact of quarrying and stone crushing activities on heavy metals, plant nutritional composition, phytochemicals and oxidative stress indices of Aspilia africana. Materials and Methods: Different parts of A. africana were collected from the quarry site and compared to those growing from non-quarry mining environment. Results: The result shows that A. africana from quarry mining site had significant (p<0.05) increase in phenol, tannin, alkaloid, saponin, flavonoid, Mg2+, Na+, Fe2+, Cu2+ and Zn2+ levels when compared to that of control site. Ascorbic acid, chlorophyll and Air Pollution Tolerance Index (APTI) level significantly (p<0.05) decreased in the quarry site. The photomicrograph of the A. africana leaves from the quarry site demonstrated a squeezed venial arrangement, necrotized surface, closed stomata and compressed vein. Conclusion: The result suggests that quarrying and stone crushing activities may induce oxidative stress on A. africana. Based on its APTI rating, A. african can be used in the monitoring of air pollution. The results revealed that quarrying and stone crushing activities increased health promoting phytochemicals and some minerals of A. africana growing around the quarry environment.