Serum Levels of Perfluoroalkyl Substances (PFAS) in Adolescents and Young Adults Exposed to Contaminated Drinking Water in the Veneto Region, Italy: A Cross-Sectional Study Based on a Health Surveillance Program.

BACKGROUND: In spring 2013, groundwater of a vast area of the Veneto Region (northeastern Italy) was found to be contaminated by perfluoroalkyl substances (PFAS) from a PFAS manufacturing plant active since the late 1960s. Residents were exposed to high concentrations of PFAS, particularly perfluorooctanoic acid (PFOA), through drinking water until autumn 2013. A publicly funded health surveillance program is under way to aid in the prevention, early diagnosis, and treatment of chronic disorders possibly associated with PFAS exposure. OBJECTIVES: The objectives of this paper are: a) to describe the organization of the health surveillance program, b) to report serum PFAS concentrations in adolescents and young adults, and c) to identify predictors of serum PFAS concentrations in the studied population. METHODS: The health surveillance program offered to residents of municipalities supplied by contaminated waterworks includes a structured interview, routine blood and urine tests, and measurement of 12 PFAS in serum by high-performance liquid chromatography-tandem mass spectrometry. We studied 18,345 participants born between 1978 and 2002, 14-39 years of age at recruitment. Multivariable linear regression was used to identify sociodemographic, lifestyle, dietary, and reproductive predictors of serum PFAS concentrations. RESULTS: The PFAS with the highest serum concentrations were PFOA [median 44.4 ng/mL, interquartile range (IQR) 19.3-84.9], perfluorohexanesulfonic acid (PFHxS) (median 3.9 ng/mL, IQR 1.9-7.4), and perfluorooctanesulfonic acid (PFOS) (median 3.9 ng/mL, IQR 2.6-5.8). The major predictors of serum levels were gender, municipality, duration of residence in the affected area, and number of deliveries. Overall, the regression models explained 37%, 23%, and 43% of the variance of PFOA, PFOS, and PFHxS, respectively. CONCLUSIONS: Serum PFOA concentrations were high relative to concentrations in populations with background residential exposures only. Interindividual variation of serum PFAS levels was partially explained by the considered predictors. https://doi.org/10.1289/EHP5337.

On the Ability of Perfluorohexane Sulfonate (PFHxS) Bioaccumulation by Two Pseudomonas sp. Strains Isolated from PFAS-Contaminated Environmental Matrices.

PFASs (perfluoroalkyl and polyfluoroalkyl substances) are highly fluorinated, aliphatic, synthetic compounds with high thermal and chemical stability as well as unique amphiphilic properties which make them ingredients in a range of industrial processes. PFASs have attracted consideration due to their persistence, toxicity and bioaccumulation tendency in the environment. Recently, attention has begun to be addressed to shorter-chain PFASs, such as perfluorohexane sulfonate [PFHxS], apparently less toxic to and more easily eliminated from lab animals. However, short-chain PFASs represent end-products from the transformation of fluorotelomers whose biotic breakdown reactions have not been identified to date. This means that such emergent pollutants will tend to accumulate and persist in ecosystems. Since we are just learning about the interaction between short-chain PFASs and microorganisms, this study reports on the response to PFHxS of two Pseudomonas sp. strains isolated from environmental matrices contaminated by PFASs. The PFHxS bioaccumulation potential of these strains was unveiled by exploiting different physiological conditions as either axenic or mixed cultures under alkanothrofic settings. Moreover, electron microscopy revealed nonorthodox features of the bacterial cells, as a consequence of the stress caused by both organic solvents and PFHxS in the culturing substrate.

Stability analysis of the antibiotic cocktail used by Treviso Tissue Bank Foundation for tissues decontamination.

Although careful donor selection reduces tissue contamination, close microbiological control of harvested allografts remains a key task of tissue banks. To guarantee the safety of human tissues for allograft transplantation, a decontamination regimen must be adopted which, as recommended by European guidelines, is active against the majority of microorganisms isolated in tissues. Antibiotic decontamination methods differ from one tissue bank to another in terms of antimicrobial agents, temperature and length of exposure. After identifying the most effective antibiotics against the bacterial strains most commonly isolated in allografts, Treviso Tissue Bank Foundation demonstrated the efficacy of an antibiotic cocktail for tissue decontamination containing Gentamicin, Vancomycin and Meropenem. The aim of this study was to analyse the degradation kinetics of the three antibiotics according to preparation method and use. The results show that only Meropenem is unstable at + 4 °C, while Gentamicin and Vancomycin are valid for over 10 days. We thus established to add Meropenem before the start of the tissue decontamination phase.

Expeditious synthesis of water-soluble, monolayer-protected gold nanoparticles of controlled size and monolayer composition.

A protocol is reported for the preparation of water-soluble, thiol-protected Au nanoparticles (Au-MPC) where dioctylamine is used as a stabilizing agent when the gold cluster is formed using the two-phase Brust and Schiffrin procedure. The amount of amine controls the size of the nanoparticles in the 1.9-8.9 nm diameter range. The final stabilization of the gold clusters by addition of functionalized thiols is performed under very mild conditions compatible with most biomolecules. The procedure is suitable for a wide variety of functional groups present in the thiol and allows one to use thiol mixtures with a precise control of their composition in the monolayer. As a proof of principle, examples of nanoparticles protected with thiols comprising functional groups ranging from polyethers, saccharides, polyamines and ammonium ions are reported.

Cooperative nanosystems.

Multivalent systems are well known for their enhanced ability to bind multivalent counterparts. This contribution addresses the question whether they can also behave as cooperative catalysts. Analyzing examples from our own laboratory we show that self-assembled systems obtained by covering gold nanoclusters with thiol-terminated amino acids and peptides behave indeed as cooperative catalysts. By comparing their activity profiles with those of discrete, multivalent systems we show what are minimal conditions to elicit cooperativity in multivalent systems. Reactions taken into considerations for our analysis are the hydrolyses of carboxylate- and phosphate esters.

Multivalent catalysts for the cleavage of nucleic acids and their models.

Multivalent systems, i.e. systems presenting a discrete collection of several functional groups, are well recognized for their ability to increase binding constants. Less explored is their use as catalysts. We present a number of multivalent nanostructures based on self-assembled gold nanoparticles and dendrimers, which are particularly efficient in the cleavage of nucleic acids and their models.