Temporal trends of perfluoroalkyl substances in an Australian wastewater treatment plant: A ten-year retrospective investigation.

Per- and poly-fluoroalkyl substances (PFAS) are a problematic group of chemicals used in various industrial and household products. They have been extensively detected in wastewater as a result of day-to-day product usage. Due to concerns about their safety, voluntary and regulatory action to limit the manufacture and use of some individual PFAS has occurred since the year 2000. The impact that this intervention has had on the use and potential exposure of Australians has not been measured. Wastewater serves as a powerful tool to assess the chemical use or consumption patterns of a population over time. We accessed a ten-year wastewater archiving program to conduct a temporal analysis of PFAS trends in an urban Australian population between the years 2010 and 2020. Results showed a decline in the concentrations for most PFAS, and a change in the PFAS profile from perfluorosulfonic acids and long-chain perfluorocarboxylic acids, to the short-chain perfluorocarboxylic acids and PFOS-replacement degradation products such as 5:3 FTCA. Intermittent pulses of PFAS that were significantly higher than 'background' levels (i.e., representing the PFAS input from primarily households) were observed, suggesting continuing industrial PFAS input within the wastewater catchment. This study highlights the long-term consequences of the diffuse use of persistent chemicals in products, and their ability to continue to enter the wastewater stream for decades.

Privileged frameworks from snake venom.

Venom as a form of chemical prey capture is a key innovation that has underpinned the explosive radiation of the advanced snakes (Caenophidia). Small venom proteins are often rich in disulfide bonds thus facilitating stable molecular scaffolds that present key functional residues on the protein surface. New toxin types are initially developed through the venom gland over-expression of normal body proteins, their subsequent gene duplication and diversification that leads to neofunctionalisation as random mutations modify their structure and function. This process has led to preferentially selected (privileged) cysteine-rich scaffolds that enable the snake to build arrays of toxins many of which may lead to therapeutic products and research tools. This review focuses on cysteine-rich small proteins and peptides found in snake venoms spanning natriuretic peptides to phospholipase enzymes, while highlighting their three-dimensional structures and biological functions as well as their potential as therapeutic agents or research tools.