27 International Journal of Sustainable Infrastructure for Cities and Societies Research Article: IJSICS Volume: 08 Rehabilitating Mining Waste Sites in West Balkans to Source Metals for Plastics and Wood-Plastic Composites While Mitigating Environmental Pollution- A Case Study for the West Balkan Region Gazaldeep Kaur 1 , Dr. Vikramjit S. Rathee 2 , Jeewanjot Singh 3 & Dr. Nirmaljit K. Rathee 4 This work is licensed under a Creative Commons International License. Abstract The incorporation of metal additives in plastics and wood-plastic composites (WPCs) can result in leaching and consequent environmental pollution [1,2]. Concomitantly, abandoned mining waste sites containing valuable metals in the West Balkans are causing severe contamination of land and water due to improper containment [3]. This study proposes the rehabilitation of said mining waste sites to extract metals through bioleaching to provide feedstock for the plastics and WPC industry, thereby mitigating fresh mining requirements and pollution. Metals including Fe, Mn, Cr, Zn, Cu, Al, and Pb are critical in plastics and WPCs as fillers, pigments, slipping agents, stabilizers, and flame retardants [1,4], however their improper disposal leads to ecological damage [2,5]. Acidophilic iron and sulfur oxidizing bacteria, such as Acidithiobacillus ferrooxidans, can effectively extract these metals from mining residues via bioleaching without high energy inputs [7–9]. Compared to conventional methods, bioleaching requires less energy, minimal chemicals, and lower capital costs. The recovered metals can then be utilized by the plastics and WPC industry. This systems approach can transform mining wastes into resources [3,6], conferring environmental and socio-economic benefits. However, stakeholder cooperation is requisite to address technological and policy challenges surrounding bioleaching implementation in the West Balkans. Authors: 1 Senior Lecturer Chemistry, Government Senior Secondary School (Amritsar), Punjab, India. 2 Chief Scientific Officer, Nine Star Initiative, Delaware, USA. 3 Head Pharmacist, Guru Teg Rasila Charitable hospital, Punjab, India. 4 Professor & Director, Delaware State University, Delaware, USA. Introduction Plastics and wood-plastic composites (WPCs) are extensively used materials owing to their durability, strength and lightweight properties [10]. However, they contain metal additives as pigments, slipping agents, stabilizers and flame retardants, which enhance their functional properties [1,11]. For instance, zinc oxide provides UV shielding in