Toxicological, Chemical, Social, and Economic Challenges Associated with PFAS and Replacement Aqueous Film-Forming Foams (AFFF)

Abstract

Poly- and perfluorinated alkyl substances (PFAS) are a group of chemicals that are widely used, prevalent in the environment, associated with several toxic effects, and often have long half-lives. Their persistence and relevant toxicity are the primary causes of environmental and human health concerns, and they are referred to as "forever chemicals" because of their persistence. Environmental accumulation caused by slow natural biodegradation and subsequent long environmental half-lives leads to bioaccumulation and makes PFAS more likely to be chronically toxic with potential transgenerational effects. Ultimately, it is this persistence that causes the greatest concern because PFAS-contaminated sites need costly remediation techniques, or else the contaminated areas will not be available for proper economic development because of social and economic suppression. Non-PFAS, alternative Aqueous Film Forming Foams (AFFF) that are considered environmentally friendly, are being heavily considered or currently used for fire suppression instead of PFAS-based products. The bioaccumulation and toxicity of alternative AFFF are just starting to be studied. The purpose of this review is to discuss the basic environmental and human health effects of PFAS and alternative AFFF that propel regulatory changes, increase clean-up costs, reduce economic development, and drive the development of novel alternatives.

Keywords: PFAS; PFOS; bioaccumulation; biodegradation; chronic toxicity; economic; forever chemical; half-life; regulation.

Figure 1

PFAS exposure has negative consequences on the environment and human health, and in turn negative social and economic impacts related to it’s toxicity and persistence. As toxicologists, we often consider only the bioaccumulation or toxic responses; however, the novel properties of PFAS have led to reduced economic investment, repressed property values, expensive remediation and clean-up costs, and ultimately a search for alternatives. Adverse environmental and human health effects caused by PFAS are often the result of biomagnification and bioaccumulation (blue). PFAS’s persistence and toxic effects leads to the need for regulations and novel remediation strategies (green). In addition, there are social and economic stresses caused by PFAS bioaccumulation and toxicity such as increased clean up costs, reduced property value, reduced investment, and increased healthcare costs. This figure was created using Biorender.

Figure 2

The structure of many PFAS shows high similarity to fatty acids, with the replacement of hydrogens with fluorines. An eight-carbon mid-chain fatty acid is compared to PFOS and PFOA.

Figure 3

PFOS, PFOA, and other PFAS have multiple effects on several different organ systems. Most of these adverse effects are complicated or worsened by the bioaccumulation of some PFAS. This allows for disruption of lipid metabolism and other metabolic pathways, subsequent perturbations in reactive oxygen species and inflammation, and development, including neurodevelopment, and immune surveillance.

Figure 4

PFAS contamination has negative consequences on property values and healthcare costs. These problems are especially acute in poor or minoritized areas where factories, landfills, testing grounds, and waste facilities are more likely to be found. This figure was created with Biorender.