Microplastics have been detected as widespread in an aquatic environment at the microscale, also known as plastic debris. They have continuously increased due to the increase in population, production of synthetic plastics and poor waste management. They are ubiquitous and slowly degrade in soil and water. They are emerging contaminants that have received attention from research communities and public audiences over the last few years. They have high stability and can absorb several other pollutants like heavy metals, pesticides, etc. After entering the environment, they can accumulate and persist for a long time. They can create a serious threat to freshwater ecosystems and human health. These particles can cause physical damage to freshwater organisms. Raman spectroscopy, Fourier-transform infrared spectroscopy, visual identification, density separation, microscopic method, chemical method, thermos-analytical method and hyperspectral imaging method are the commonly known approaches for identification and quantification of microplastics. The noticed concentration of microplastics depends on the analysis method, sampling location and technique. The authors reviewed the sources, health impact, transport and treatment of microplastics in freshwater environments in detail. This study will provide the baseline data for the researchers to do more research on microplastic pollution in the future.

Climate change is one of the widely acknowledged challenges faced by international communities in the 21^st century. It poses challenges to fundamental elements of our understanding of appropriate goals for socioeconomic policies, such as the connection of prosperity, growth, equity and sustainable development. Human activities-induced climatic changes have been widely perceived as threatening criteria for the long-term resilience of societies and communities throughout the world. The United Nations Intergovernmental Panel on Climate Change (UNIPCC) reported that greenhouse gas (GHG) emissions due to human activities, such as the burning of fossil fuels for energy generation, is changing the climate of Earth. Despite contributing less towards the causes, poor citizens of developing countries bear a lot of its impacts. In particular, women and girls face a major impact and finally, they migrate due to the social gender division and scarcity of food. Studies on gender and climate change-induced migration are scarce. This study provides an overview of the induced impact of climate change on the livelihood, health and migration of women and girls. The aim of this study would significantly advance our understanding of the current inter-linkages between migration, displacement patterns and climate change impacts.

Nanoscience is a rapidly growing science stream that has been one of the cost-effective and energy-efficient approaches with wide applications. Water pollution is a major issue that is increasing continuously due to anthropogenic activities and several organic and inorganic contaminants. To overcome this issue, nanoparticles (NPs) have been successfully used to treat water. These NPs possess many beneficial applications in many fields like agriculture, cosmetics, photoconductors, environmental biotechnology, glass and alloy production, solar cells, nanomedicine and drug deliveries, biosensors, food industries, etc. The properties comprising high surface area, greater chemical reactivity, and mechanical properties play a vital role in imparting such beneficiary properties. As a result, there has been an increasing demand for the synthesis of NPs. However, excess usage of NPs further creates toxic by-products. Therefore, scientists and researchers are now focussing on the biogenic synthesis of NPs. The biological routes of NP synthesis have been crucial because they are eco-friendly and environmentally safe. This chapter highlights the usage of different approaches and biogenic sources for the production of NPs. It also discusses the recent advancement in the use of biogenic NPs with respect to applications for wastewater treatment.