The rapid urbanization witnessed in developing countries in Asia and Africa has led to a substantial increase in municipal solid waste (MSW) generation. However, the corresponding disposal strategies, along with constraints in land resources and finances, compounded by unorganized public behaviour, have resulted in ineffective policy implementation and monitoring. This lack of systematic and targeted orientation, combined with blind mapping, has led to inefficient development in many areas. This review examines the key challenges of MSW management in developing countries in Asia and Africa from 2013 to 2023, drawing insights from 170 academic papers. Rather than solely focusing on recycling, the study proposes waste sorting at the source, optimization of landfill practices, thermal treatment measures, and strategies to capitalize on the value of waste as more pertinent solutions aligned with local realities. Barriers to optimizing management systems arise from socio-economic factors, infrastructural limitations, and cultural considerations. The review emphasizes the importance of integrating the study area into the circular economy framework, with a focus on enhancing citizen participation in solid waste reduction and promoting recycling initiatives, along with seeking economic assistance from international organizations.

One of the most serious environmental issues is air pollution. Unlike other environmental concerns, this form of pollution is extremely challenging to regulate. The greenery of roadside trees plays a significant role in air purification and pollutant absorption, therefore helping to mitigate environmental pollution. Several plants can absorb and store toxins in their leaves from the atmosphere. Green plants have the potential to work as sinks and filters for air pollutants. Green belt development along national highways is a cost-effective and environmentally sustainable method of reducing air pollution. Sensitive and tolerant plants against air pollution can be identified by evaluating their air pollution tolerance index (APTI) and anticipated performance index (API) values. In this study, the susceptibility level of plant species to air pollution was assessed using APTI and API. The four parameters on which APTI depends are ascorbic acid content, total chlorophyll content, relative water content, and leaf extract pH. For the estimation of API, the plant's biological and socioeconomic factors like tree habit, canopy structure, type, size, texture, and hardness of the plant are also assessed. These parameters were determined and incorporated into a formula that represents the APTI and API of plants. Moreover, multilinear regression modeling was performed using a Statistical Package for the Social Sciences (SPSS, V25) and found that pH and ascorbic acid content in plant leaves have a significant role in the calculation of APTI and tolerance potential of plants. Therefore, APTI was assessed with seventeen plant species that are abundant in the area along the national highway in Kanpur, Uttar Pradesh, from Jan to Mar 2020. The APTI showed that Saraca asoca was the most resistant to air pollution, whereas Vachellia nilotica was the most sensitive. In addition, plants with higher APTI can also be used to reduce air pollution, while plants with lower APTI can be utilized to monitor air pollution. Based on the calculated API score, it is found that Ficus elastica (% score > 90) is the best option for green belt development. Urban local body (ULB) can also adopt Ficus religiosa, Saraca asoca, and Aucuba japonica (having % a grade score of 80-90) for mitigation of air pollution. The study indicates that plantations of tolerant species are useful for biomonitoring and developing green belts on and along national highways.