Nonylphenol in the environment: a critical review

Nonylphenol (NP), an anaerobic breakdown product of a widely used nonionic surfactant nonylphenol ethoxylate (NPEO), is currently of environmental concern because of its toxicity, estrogenic properties and widespread contamination. Nonylphenol has been detected in surface and ground water, sediments, aquatic organisms, wastewater effluent, air, and human food. Although concentrations of NP are typically low, the potential risk to human populations and ecosystems at these concentrations is still unclear and is a topic of considerable debate. A better understanding of the fate and transport of NP and its parent compound, NPEO, is needed for determining the associated risk to the environment and human health posed by these compounds. This paper presents a critical review of the literature and issues related to NP in the environment, including the associated gaps, conflicts and research needs in this area. The similarities and differences between NP and historical contaminants of interest such as PCBs and current contaminants such as pharmaceuticals are noted, as is the need for analyzing the life cycle of chemicals in the environment prior to widespread use. Finally, issues of risk and how these guide policy as related to NP are discussed. Key words: nonylphenol ethoxylate, estrogenic compounds, wastewater, nonionic surfactant