Introduction

Until very recently, the main focus on chemicals in the environment has been on heavy metals, pesticides and other organic chemicals such as PAHs, PCBs and dioxins. In recent years, there has been increasing concern over the so-called ‘emerging contaminants’ such as metabolites, transformation products (formed in the environment and treatment processes), human pharmaceuticals, veterinary medicines, nanomaterials, personal care products and flame retardants. These substances have been shown to be released to the environment, or in the case of nanomaterials, will be released to the environment in increasing amounts in the future. In the few monitoring studies that have looked for them, they have been detected in surface waters, groundwaters and drinking waters (e.g., Kolpin et al.1998a, b; 2002; Ferrer et al. 2000; Juhler et al. 2001; Li et al. 2001; Schnoebelen et al. 2001; Lagana et al. 2002; Zimmerman et al. 2002; Battaglin et al. 2003).

Alongside the monitoring, studies have been performed to explore the effects of a range of emerging contaminants at the biochemical, cellular, whole organism, population and community levels. While much of the data that have been produced on different classes of emerging contaminants indicate that many pose a small risk to ecosystems and human health, there is some evidence that selected emerging contaminants could affect human and environmental health.