PFAS risk propagation terminology in spatial and temporal scales: Risk intensification, risk attenuation, and risk amplification.

Poly- and per fluorinated alkyl substances (PFAS) are man-made chemicals that are used in many industrial applications to improve performance and durability of products. The CF bond is one of the strongest bonds in organic chemistry which makes PFAS highly persistent in the environment. Therefore, PFAS levels have increased in different environmental compartments (air, water, soil) at global scale over time since the early 1950s. Terminology used for describing potential risks and those used in risk communication can be confusing as different disciplines use risk concepts and vocabulary that are different from those used for exposure and/or health risk assessment for hazardous materials. For example, terms such as emergent risk, emerging risk, risk intensification, risk awareness, risk perception, risk attenuation, risk amplification, and risk absorption are often misused or misinterpreted, especially in describing and communicating risks associated with PFAS in the environment or PFAS exposure. In addition, appropriate risk terms associated with psychological, social, institutional, and cultural elements are often misused. Here, appropriate risk terminology for describing and quantifying risks and health risks in reference to PFAS exposure and PFAS related risk propagation in spatial and temporal scales are explained with examples.