Recent developments in polyfluoroalkyl compounds research: a focus on human/environmental health impact, suggested substitutes and removal strategies

Abstract

Between the late 1940s and early 1950s, humans manufactured polyfluoroalkyl compounds (PFCs) using electrochemical fluorination and telomerisation technologies, whereby hydrogen atoms are substituted by fluorine atoms, thus conferring unnatural and unique physicochemical properties to these compounds. Presently, there are wide ranges of PFCs, and owing to their bioaccumulative properties, they have been detected in various environmental matrices and in human sera. It has thus been suggested that they are hazardous. Hence, this review aims at highlighting the recent development in PFC research, with a particular focus on perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), the most studied and predominantly found PFCs in various environmental matrices, although recent reports have included perfluorobutane sulfonate (PFBS), which was previously regarded as innocuously harmless, when compared to its counterparts, PFOA and PFOS. As such, proper investigations are thus required for a better understanding of short-chain PFC substitutes, which have been suggested as suitable replacements to long-chained PFCs, although these substitutes have also been suggested to pose various health risks comparable to those associated with long-chain PFCs. Similarly, several novel technologies, such as PFC reduction using zero-valent iron, including removal at point of use, adsorption and coagulation, have been proposed. However, regardless of how efficient removers some of these techniques have proven to be, short-chain PFCs remain a challenge to overcome for scientists, in this regard.

Propensity of Tagetes erecta L., a Medicinal Plant Commonly Used in Diabetes Management, to Accumulate Perfluoroalkyl Substances

“…As both PFOA and PFOS are classified as long-chained PFASs, while PFBS is identified as a short-chain compound [42], it was previously suggested that PFOA and PFOS prevalence in the Western Cape rivers might be attributed to a highly active agricultural sector [29]. These two PFASs have been the most studied and have predominantly been found in various environmental matrices, both worldwide and in South Africa [14]. Recent reports have now indicated that PFBS, previously thought to be harmless, fits the category of POPs [14].…”

“…These two PFASs have been the most studied and have predominantly been found in various environmental matrices, both worldwide and in South Africa [14]. Recent reports have now indicated that PFBS, previously thought to be harmless, fits the category of POPs [14]. In addition, recent reports have now indicated that PFBS, previously known as a harmless PFAS, fits the category of POPs [14,43,44,45], and it has been found to be the most dominant PFAS in this study—a pattern previously reported by Heydebreck et al [46] and Pan et al [47].…”

“…This assertion is based largely on evidence indicating that plants are capable of taking up and accumulating nutrients and a variety of other chemicals to which they are, either directly or indirectly, exposed. Thus, compelling evidence has demonstrated that plants accumulate and metabolize environmental contaminants, ultimately suggesting that plants are reservoirs for chemical substances [14,15]. Some scientists have reported the prevalence of toxic substances and/or heavy metals in plants [16,17,18,19,20,21,22,23,24].…”

Greaseproof paper products: A review emphasizing ecofriendly approaches

“…The term "perfluoro" is used when all the hydrogens on an alkyl chain have been replaced by fluorine atoms. The health effects of fluorinated materials are a concern, especially in cases where the paper products come into contact with food (Birnbaum and Grandjean 2015;Blum et al 2015;Mudumbi et al 2017). Fluorinated compounds attributable to greaseproof treatments of paper products have been found in sludge from municipal wastewater treatment (Lee et al 2010).…”

“…On the positive side, this situation makes it possible for humans to enjoy such products as non-stick frying pans, sealing tape for plumbing connections, and greaseproof containers, especially for fast foods. But on the negative side, perfluorinated compounds products are very persistent in the environment (Mudumbi et al 2017). Those compounds also have been associated with increased risks of cancers, developmental toxicity, immunotoxicity, and metabolic disruption (Schaider et al 2017;Tokronov et al 2019).…”