Attaining sustainable development in Nigeria: the role of solid waste, urbanization and pollution in reducing under-five mortality.

The United Nations, through its subsidiary agency United Nations Children's Fund (UNICEF), has put in such resources to curb infant mortality in pursuit of the Sustainable development goals (SDG). Nevertheless, the issue of under-five mortality is still persistent in so many developing countries, especially in sub-Saharan Africa. Therefore, this study investigated the long-term and short-term impacts of solid waste, urbanization, and pollution on under-five mortality, employing the Autoregressive distributed lag (ARDL) and the dynamic Autoregressive distributed lag (DARDL) models for the empirical investigations and robustness checks, respectively. The study found that there is significant cointegration between the interest variables. While key findings from the DARDL results revealed that pollution, urbanization, and solid waste have long-term significant positive impacts on under-five mortality in Nigeria, the short-run outcome shows that urbanization and solid waste had a significant positive impact on under-five mortality, while pollution was statistically insignificant. Moreover, lead exposure showed a significant long-term positive and short-term negative impact on under-five mortality in Nigeria. Furthermore, the DARDL simulations show higher long-run shocks and variations as compared to the short run. Thus, CO₂ emissions, urbanization, and solid waste encourage under-five deaths in Nigeria. The study recommends, among other things, the enactment of environmental laws that will curb CO₂ emissions in the country while also strengthening the existing ones, discourage indiscriminate solid waste disposal, and encourage investment in clean technologies and modern healthcare facilities in urban areas of Nigeria.