Due to these advantages, nanoparticles with physical and chemical properties such as antimicrobial activity, catalytic capacity, and optoelectronics are demanded in various sectors. It is also used in personal care products in the cosmetics industry due to its sunscreen and UV rays reflecting and absorbing properties. It is also preferred in wastewater treatment plants, photocatalysis, disinfection, and membrane processes. The increasing number of nanoparticles, which is referred to as a new technological development, usage area, and the amount has revealed the necessity of investigating the effects on human health and the environment. It is necessary to treat high-level pollutant wastes that may occur due to the production processes of industry and industrial organizations. Wastewater treatment systems designed for industrial wastewater treatment vary according to many criteria such as sector, production method, wastewater amount, and pollution values. It has become a necessity to investigate new methods that are thought to have less impact on human health and the environment in wastewater treatment processes. For wastewater treatment plants, the most appropriate method in terms of environmental sustainability can be evaluated as the use of nanoparticles. However, it is imperative to investigate the effects of nanoparticles because of their application in wastewater treatment processes. In this study, information about the toxic effects of nanoparticles on humans and the environment because of the use of nanoparticles in industrial wastewater treatment systems has been given by reviewing the literature.