Perfluoroalkyl substances in Breast milk, infant formula and baby food from Valencian Community (Spain)

Priority list of potential endocrine-disrupting chemicals in food chemical contaminants: a docking study and in vitro/epidemiological evidence integration

Diet is an important exposure route of endocrine-disrupting chemicals (EDCs), but many unfiltered potential EDCs remain in food. The in silico prediction of EDCs is a popular method for preliminary screening. Potential EDCs in food were screened using Endocrine Disruptome, an open-source platform for inverse docking, to predict the binding probabilities of 587 food chemical contaminants with 18 human nuclear hormone receptor (NHR) conformations. In total, 25 contaminants were bound to multiple NHRs such as oestrogen receptor α/β and androgen receptor. These 25 compounds mainly include pesticides and per- and polyfluoroalkyl substances (PFASs). The prediction results were validated with the in vitro data. The structural features and the crucial amino acid residues of the four NHRs were also validated based on previous literature. The findings indicate that the screening has good prediction efficiency. In addition, the epidemic evidence about endocrine interference of PFASs in food on children was further validated through this screening. This study provides preliminary screening results for EDCs in food and a priority list for in vitro and in vivo research.

Emerging and Legacy Perfluoroalkyl Substances in Breastfed Chinese Infants: Renal Clearance, Body Burden, and Implications

BACKGROUND

Human breast milk is a primary route of exposure to perfluoroalkyl substances (PFAS) in infants. To understand the associated risks, the occurrence of PFAS in human milk and the toxicokinetics of PFAS in infants need to be addressed.

OBJECTIVES

We determined levels of emerging and legacy PFAS in human milk and urine samples from Chinese breastfed infants, estimated renal clearance, and predicted infant serum PFAS levels.

METHODS

In total, human milk samples were collected from 1,151 lactating mothers in 21 cities in China. In addition, 80 paired infant cord blood and urine samples were obtained from two cities. Nine emerging PFAS and 13 legacy PFAS were analyzed in the samples using ultra high-performance liquid chromatography tandem mass spectrometry. Renal clearance rates (CLrenals) of PFAS were estimated in the paired samples. PFAS serum concentrations in infants (<1 year of age) were predicted using a first-order pharmacokinetic model.

RESULTS

All nine emerging PFAS were detected in human milk, with the detection rates of 6:2 Cl-PFESA, PFMOAA, and PFO5DoDA all exceeding 70%. The level of 6:2 Cl-PFESA in human milk (median concentration=13.6 ng/L) ranked third after PFOA (336 ng/L) and PFOS (49.7 ng/L). The estimated daily intake (EDI) values of PFOA and PFOS exceeded the reference dose (RfD) of 20 ng/kg BW per day recommended by the U.S. Environmental Protection Agency in 78% and 17% of breastfed infant samples, respectively. 6:2 Cl-PFESA had the lowest infant CLrenal (0.009mL/kg BW per day), corresponding to the longest estimated half-life of 49 y. The average half-lives of PFMOAA, PFO2HxA, and PFO3OA were 0.221, 0.075, and 0.304 y, respectively. The CLrenals of PFOA, PFNA, and PFDA were slower in infants than in adults.

CONCLUSIONS

Our results demonstrate the widespread occurrence of emerging PFAS in human milk in China. The relatively high EDIs and half-lives of emerging PFAS suggest potential health risks of postnatal exposure in newborns. https://doi.org/10.1289/EHP11403.

Perfluoroalkyl substances in the surface water and fishes in Chaohu Lake, China

The concentration and composition of 13 perfluoroalkyl substances (PFASs) in surface water and fishes in Chaohu Lake, China, were systematically studied in October 2019. Results showed that the PFASs composition has changed greatly. The concentration levels of perfluorooctane sulfonate (PFOS) in the surface water of Chaohu Lake have decreased significantly compared with past years. Perfluorobutanoic acid (PFBA) has become the dominant component, and it was mainly come from industrial wastewater. The highest concentration of perfluorooctanoic acid (PFOA) was measured in the lake inlet of the Baishitian River (southwest part), which mainly received domestic sewage. Different types of wastewater lead to varying compositions of PFASs in the lake water. PFOA and PFBS were homologous in some areas of Chaohu Lake, which reflected the unbalanced promotion of prohibition and substitution of long-chain PFASs around Chaohu Lake. On the basis of the risk quotient and tolerable daily intake assessment, drinking water and eating fish from Chaohu Lake do not lead to apparent PFAS risk, but PFOS in fish has evident bioaccumulation and biomagnification effects. PFOS-based human daily intake of Channa argus accounts for 22.4% of the tolerable daily intake. Thus, the risk caused by PFOS needs close attention. This study is useful for enhancing people's understanding of the environmental behavior and the risk of PFASs in Chaohu Lake.

Occurrence of selected per- and polyfluorinated alkyl substances (PFASs) in food available on the European market - A review on levels and human exposure assessment

Per- and polyfluorinated alkyl substances (PFASs) are considered emerging persistent organic pollutants, which are chemically, thermally, and biologically stable, or degrade to persistent end products. Dietary intake is considered as one of the main human exposure pathways of these chemicals and, having entered the human body, PFASs are not metabolised and accumulate in tissues, while their toxicological properties may cause various health problems. Several studies on the occurrence of PFASs in various food types have been conducted, including the assessment of dietary exposure. The most important sources were fish, meat, eggs, fruits, and vegetables. Fruits and vegetables recently showed relatively high levels of PFASs, and have become a more significant source of PFASs than meat. In 2020, the European Food Safety Authority (EFSA) published an opinion, setting the tolerable weekly intake (TWI) of 4.4 ng kg-1 b.w. for the sum of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulphonic acid (PFHxS), and perfluorooctanesulphonic acid (PFOS). The emphasis in this paper is on the systematization of available information on the distribution of PFASs and their levels in different food, with a special interest in data from the Europe. The current legislation and estimated dietary intakes by the general population are described. While the available information on tolerably daily intakes estimated in a number of European countries often exceeds the newly established EFSA TWI, a critical evaluation of performance characteristics of the reviewed analytical methodologies revealed the insufficient sensitivity of quantification procedures for accurate risk assessment according to the guidelines proposed by EFSA.

Confirmatory Analysis of Per and Polyfluoroalkyl Substances in Milk and Infant Formula Using UHPLC-MS/MS

An ultra-high performance liquid chromatography tandem mass spectrometry method was developed and validated for the sensitive determination and unambiguous confirmation of residues of per and polyfluorinated alkyl substances (PFAS) in breastmilk, retail milk and infant formulas following two sample preparation methods. Sample pre-treatment was carried out by a simplified QuEChERS method without requiring dSPE or any further clean-up. The method was validated in accordance with the requirements of Commission Decision 657/2002/EC with slight modifications. The method displayed good linearity with R² ranging from 0.9843–0.9998 for all target PFAS. The recovery and within-laboratory reproducibility of the method (n = 63) were in the range 60–121% and 5–28%, respectively. The decision limit, detection capability and limit of quantitation ranged from 30–60 ng kg⁻¹ to 40–100 ng kg⁻¹ and 5–50 ng kg⁻¹, respectively. Acceptable matrix effect values in the range −45–29% were obtained with uncertainty of measurement lower than 25% for all target PFAS. The method displays its suitability for the sensitive and high-throughput confirmatory analysis of C₄–C₁₄ PFAS in breastmilk, dairy milk and infant formulas.

Exposure characteristics for congeners, isomers, and enantiomers of perfluoroalkyl substances in mothers and infants

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in the environment, making it inevitable for humans to be exposed to these pollutants. The exposure begins while in utero and continues in infancy, during the potentially most sensitive early stages of life. This review summarizes the current knowledge on pre- and neo-natal exposures based on more than 200 articles published from 2000 to date. All relevant biological matrices used in the cited studies were included, such as maternal blood, umbilical cord blood, breast milk, placenta, amniotic fluid, fetal organs, newborns' dried blood spots, and infant serum. We show that such exposures are geographically global with significant discrepancies among countries and continents, and that while the levels of major legacy PFASs (PFOS and PFOA) have declined since 2000, those of others may have not. We also show that levels of PFOS and PFOA exceed those of some major environmental toxins, such as p,p'-DDE, BDE-47, PCB-153, PBB-153, and OH-PBDEs in maternal blood. Given that the behavior and potential effects have an origin in molecular structure, biomonitoring and research at the levels of isomers and enantiomers are critically important. Through critical analysis of these works, we summarize the major achievements, consensus, and the deficiencies of existing research. To our knowledge, this is the first review on the overall internal exposure status of mothers and infants to PFASs during pregnancy and lactation.

Presence of emerging contaminants in baby food

Food safety becomes imperative when it aims to protect infants. The objective of this study was to investigate the presence of emerging contaminants of which some act as endocrine-disruptors in baby food. Persistent organic pollutants (POPs), perfluoroalkyl substances (PFASs), parabens and antibiotics were analysed in 112 baby food of different categories (meat, fish, vegetables, fruit, cheese). As regard POPs, PFASs and antibiotics, no residues were detected, while one sample showed methyl-paraben (4.14 ng g^-1), whereas another three contained propyl-paraben (median 1.70 ng g^-1). Special attention must be paid on parabens metabolites, as 4-hydroxybenzoic acid, the principal parabens metabolite, was detected in all samples (median 176.7 ng g^-1). It may be present as a degradation product, but also, it can be released from vegetables and fruits during food processing. It is recommended to collect more data on natural vs non-natural occurrence of parabens and metabolites to evaluate the exposure of sensitive population vs ADI published by the European Food Safety Authority and European Medicines Agency.