Nanotechnology is growing rapidly and its applications are enormous. A number of nano-based products are available currently on the market. Increased use of nanoproducts has become hazardous for both environmental and human life. Nanoparticles (NPs) have been increasingly released into environments through various means. Different NPs have different mechanisms of toxicity in various organisms. In the environment, water bodies in particular get severely deteriorated with discharged nanomaterials. This has severely impacted the flora & fauna. Various measures are needed for the selective removal of toxic nanomaterials from the environment. The present chapter provides concentric knowledge of toxic effects of NPs and nanoproducts. This chapter elaborates on NP exposure to humans via potential routes and also interaction of NPs to natural ecosystem,s plants as well as humans.