Perchlorate: water and infant formulae contamination in France and risk assessment in infants

Dietary exposure assessment of perchlorate and chlorate in infant formulas marketed in Shanghai, China

Perchlorate and chlorate are ubiquitous pollutants that can adversely affect the thyroid function in humans. This study assessed the potential health risks associated with the dietary exposure of infants and young children to perchlorate and chlorate present in infant formulas available in Shanghai. The assessment was based on risk monitoring data from 150 samples of infant formulas in Shanghai between 2020 and 2022, along with the dietary consumption data of infants and young children. The detection rates of perchlorate and chlorate in infant formulas were 46.0% and 98.7%, with mean contents of 9.98 μg/kg and 112.01 μg/kg, and the maximum values of 151.00 μg/kg and 1475.00 μg/kg, respectively. The mean and 95th percentile (P 95) values of daily perchlorate exposure of 0-36-month-old infant and young children via infant formulas were 0.07 and 0.17 μg/kg body weight (bw) per day, respectively, which were lower than the tolerable daily intake (TDI) of perchlorate (0.3 μg/kg bw per day). The mean and P 95 values of chlorate exposure via infant formulas in 0-36-month-old infants and young children were 0.83 and 1.89 μg/kg bw per day, which were lower than the TDI of chlorate (3 μg/kg bw per day). The P 95 exposure of different age groups (0-6 months, 7-12 months and 13-36 months) of infants and young children to perchlorate and chlorate in infant formulas was below the TDI. Therefore, the risk associated with the exposure of 0-36-month-old infants and young children to perchlorate and chlorate from infant formulas in Shanghai is considered acceptable. Prioritizing environmental pollution control efforts to reduce the levels of perchlorate and chlorate in food products is important to safeguard the health of the infants and children under the One Health concept.

Additives in Children's Nutrition-A Review of Current Events

Additives are defined as substances added to food with the aim of preserving and improving safety, freshness, taste, texture, or appearance. While indirect additives can be found in traces in food and come from materials used for packaging, storage, and technological processing of food, direct additives are added to food with a special purpose (canning). The use of additives is justified if it is in accordance with legal regulations and does not pose a health or danger to consumers in the prescribed concentration. However, due to the specificity of the child's metabolic system, there is a greater risk that the negative effects of the additive will manifest. Considering the importance of the potential negative impact of additives on children's health and the increased interest in the control and monitoring of additives in food for children, we have reviewed the latest available literature available through PubMed, Scopus, and Google Scholar. Expert data were taken from publicly available documents published from January 2010 to April 2022 by internationally recognized professional organizations. It was found that the most frequently present additives in the food consumed by children are bisphenols, phthalates, perfluoroalkyl chemicals, perchlorates, pesticides, nitrates and nitrites, artificial food colors, monosodium glutamate, and aspartame. Increasing literacy about the presence and potential risk through continuous education of parents and young people as well as active monitoring of newly registered additives and harmonization of existing legal regulations by competent authorities can significantly prevent the unwanted effects of additives on children's health.

Integration of probabilistic exposure assessment and risk characterization for perchlorate in infant formula and supplementary food

Infants are the primary susceptible population to perchlorate exposure-related adverse health effects, while information on their dietary intake of perchlorate via infant food remains limited. This study determined perchlorate in six categories of baby food commodities commonly consumed by 0-36 months infants. A probabilistic approach with Monte Carlo simulation was used to estimate perchlorate's daily intake (EDI) considering uncertainty and variability. Results showed that the average perchlorate concentration in infant food ranged from 3.42 to 22.26 μg/kg. The mean (SD) EDIs of perchlorate were 0.42(0.20), 0.62(0.20), and 0.46(0.14) μg/kg-bw/day for 0-6, 7-12, and 13-36-months infants, respectively. Infant formula was the major contributor (34%-74%) to EDIs of perchlorate in all age groups. Probabilistic risk characterization showed the cumulative probability of EDIs exceeding the RfD (0.70 μg/kg-bw/day) were 6.5%, 37.9%, and 4.5% for 0-6, 7-12, and 13-36-months infants, respectively. The cumulative risk of perchlorate exposure from different infant food intake should be noted.

Perchlorate and chlorate in breast milk, infant formulas, baby supplementary food and the implications for infant exposure

Perchlorate and chlorate are ubiquitous pollutants in various types of foodstuffs, drinking water and environmental compartments. They have raised great concerns due to potential adverse effects on human thyroid functions. Dietary intake is considered as the predominant pathway for human exposure to perchlorate and chlorate. Nevertheless, data on human exposure to the chemicals above remain limited, particularly for the most vulnerable populations such as infants. In the present study, 62 breast milks, 53 infant formulas, 88 baby supplementary food and 50 tap water samples were collected in South China and the levels of perchlorate and chlorate were measured in these samples. Perchlorate and chlorate were frequently detected in more than 90% of measured samples. In these different types of samples, the median concentrations of perchlorate were 0.65 μg/L, 0.61 μg/kg, 0.56 μg/kg and 1.18 μg/L, respectively, while the median concentrations of chlorate were 1.73 μg/L, 2.48 μg/kg, 2.67 μg/kg and non-detected, respectively. Health risk assessment using hazard quotient suggested that perchlorate and chlorate exposure in the sampled baby food are not expected to increase the risk of an adverse health effect. To our knowledge, this is the first study simultaneously investigating perchlorate and chlorate exposure in Chinese infants via food intake.

Perchlorate contamination of tea leaves and a corresponding probabilistic dietary risk assessment using Monte Carlo simulation

Perchlorate is known as a thyroid disrupter. Its contamination in various tea samples was monitored, and 286 samples belonging to four types of tea leaves were analysed. The detection rate of perchlorate in tea was 99.3%. The mean concentration in different tea types decreased in order from green tea, oolong tea, white tea to black tea. A probabilistic approach was performed to evaluate the dietary exposure of perchlorate for six different subpopulations. The daily intakes (EDIs) for consumers over the age of 41 were higher than that of other subpopulations. The hazard quotient for six groups was lower than 1 even at the extreme percentile (P99). It indicates that the risk of dietary exposure to perchlorate from tea consumption for Fujian people is acceptable without considering other foodstuffs. However, the high occurrence of perchlorate in tea samples suggested that the actual source of this contaminant should be further investigated.

The contamination and estimation of dietary intake for perchlorate and chlorate in infant formulas in China

The contents of perchlorate and chlorate were determined in a total of 278 samples of infant formulas marketed in China. The associated health risk via infant and young child formulas consumption for 0-36 month old children in China was also assessed. The contents of perchlorate and chlorate were measured by a validated method with LC-MS and the limit of detection (LOD) was 1.5 μg kg^-1 and 3.0 μg kg^-1 for perchlorate and chlorate, respectively. Perchlorate and chlorate were detected in about 85.8% (median 6.92 μg kg^-1, maximum 74.20 μg kg^-1) and 99.3% (median 52.80 μg kg^-1, maximum 2780 μg/kg) of the samples. The exposures of infant and young children to perchlorate from formulas were lower than the provisional maximum tolerable daily intake (PMTDI, 0.7 μg/kg bw/day), which was established by U.S. Environmental Protection Agency (EPA). The European Food Safety Authority (EFSA) in 2015 also proposed a tolerable daily intake (TDI) of 3 μg/kg bw/day for chlorate based on the mean and average concentrations. Only for infants 0-6 month at the 95th percentile did exposures exceed the TDI of 3 μg/day for chlorate. Therefore, the safety of infant and young child formulas is excellent. To our knowledge, this is the first report to assess the exposure of infant and young child formulas in China to perchlorate and chlorate.

Studies on perchlorate levels in powdered infant formulas available on the Polish market

Perchlorate has been acknowledged as a health threat due to its ability to interfere with iodine uptake by the thyroid gland. Infants and developing newborns have been considered as the most vulnerable groups to the perchlorate toxicity. A crucial source of perchlorate ingestion are powdered infant formulas. This study was designed to measure perchlorate content in thirty-one powdered infant formulas available on the Polish market. A rapid and sensitive ion chromatography method – conductivity cell detection – was applied to determine ClO 4 − {\rm{ClO}}_4^ - content. Limit of detection (0.150 µg/L) and limit of quantification (0.450 µg/L) were assessed. Collected samples were classified by the age of consumers: first stage, until the baby is six months old and follow-on formula for older children. Geometric mean of perchlorate concentration of 1.041 µg/L and 0.857 µg/L in the groups of the first stage and follow-on formulas were calculated, respectively. A health risk assessment revealed that the Tolerable Daily Intake (TDI) for perchlorate (0.3 µg/kg body weight/day) was exceeded only in a few milk samples. The findings suggest that perchlorate contamination of powdered infant formulas may not to be an immediate health issue, yet testing for ClO 4 − {\rm{ClO}}_4^ - should continuously be conducted. To the best of our knowledge, this is the first study concerning perchlorate content in infant formulas in Poland.

Occurrence, sources, and pathways of chemical contaminants in infant formulas

Infant formulas are manufactured products to meet specific nutritional requirements for infants. However, infant formulas can contain harmful substances, such as chemical contaminants and residues, normally due to possible contamination of the raw material or from the production chain. Some studies have demonstrated that veterinary drugs, pesticides, mycotoxins, heavy metals, packaging materials, within other chemicals are found in infant formulas from different sources of contamination. It is known that some of these substances can be hepatotoxic, carcinogenic, teratogenic, mutagenic, immunotoxic, contributing to antibiotic resistance, among other detrimental consequences for consumers' health. The purpose of this review is to assess the scientific evidence concerning the occurrence, sources, and pathways of contamination, as well as the detrimental impacts on infant health due to the possible presence of chemical contaminants and residues in infant formulas. Moreover, strategies to reduce the risk of contamination of infant formulas are presented to ensure the highest standards of quality of infant formulas. The entire infant formula manufacturing process should be monitored and controlled to minimize the risk of contamination during processing, storage, and distribution, besides ensuring the use of raw materials with as low as acceptable levels of harmful substances in order to assure that the final product shall comply with the maximum levels and maximum residue limits, when established, for residues and contaminants in the final product.

Worldwide occurrence and origin of perchlorate ion in waters: A review

Perchlorate (ClO₄^-) is a persistent water soluble oxyanion of growing environmental interest. Perchlorate contamination can be a health concern due to its ability to disrupt the use of iodine by the thyroid gland and the production of metabolic hormones. Its widespread presence in surface water and groundwater makes the aquatic environment a potential source of perchlorate exposure. However, the amount of published data on perchlorate origins and water contamination worldwide remains spatially limited. Here, we present an overview of research on perchlorate origins and occurrences in water, and the methodology to distinguish the different perchlorate sources based on isotope analysis. All published ranges of isotopic content in perchlorate from different sources are presented, including naturally occurring and man-made perchlorate source types, as well as the effects of isotope fractionation that accompanies biodegradation processes. An example of a case study in France is presented to emphasize the need for further research on this topic.

Environmentally safe (chlorine-free): new green propellant formulation based on 2,2,2-trinitroethyl-formate and HTPB

A new green (chlorine-free) high energy dense oxidizer (HEDO) 2,2,2-trinitroethyl-formate (TNEF) and its propellant formulation based on the hydroxyl-terminated polybutadiene (HTPB) as a binder was prepared and studied. The new oxidizer TNEF was successfully prepared and characterized by nuclear magnetic resonance (NMR) and FTIR spectrometer. Scanning electron microscopy (SEM) was used to check the crystal morphology of the oxidizer. A high specific impulse (I_s = 250.1 s) was obtained from the characteristics calculation of the new oxidizer instead of (I_s = 156.9 s) for the commonly used ammonium perchlorate (AP) by using EXPLO5_V6.03 software. The burning behavior and the burning rate were determined by using a high speed camera. TNEF and the propellant formulations were studied by using nonisothermal thermogravimetric analysis (TGA) and the kinetic parameters of the studied samples were determined by using isoconversional (model-free) methods “Kissinger, Ozawa and Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS)”. The results proved that the new oxidizer and its formulation based on HTPB have chlorine-free decomposition products and have higher performance characteristics than the traditional propellants.

Burning behavior of a traditional (AP/HTPB) and new (TNEF/HTPB) propellants.

37Cl/35Cl isotope ratio analysis in perchlorate by ion chromatography/multi collector -ICPMS: Analytical performance and implication for biodegradation studies

In the present study we propose a new analytical method for ³⁷Cl/³⁵Cl analysis in perchlorate by Ion Chromatography(IC) coupled to Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS). The accuracy of the analytical method was validated by analysis of international perchlorate standard materials USGS-37 and USGS -38; analytical precision better than ±0.4‰ was achieved. ³⁷Cl/³⁵Cl isotope ratio analysis in perchlorate during laboratory biodegradation experiment with microbial cultures enriched from the contaminated soil in Israel resulted in isotope enrichment factor ε³⁷Cl = -13.3 ± 1‰, which falls in the range reported previously for perchlorate biodegradation by pure microbial cultures. The proposed analytical method may significantly simplify the procedure for isotope analysis of perchlorate which is currently applied in environmental studies.

A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway

Rapid reduction of aqueous ClO4(-) to Cl(-) by H2 has been realized by a heterogeneous Re(hoz)2-Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx(-) intermediates formed during reactions with concentrated ClO4(-) promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4(-) reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2(-) intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4(-) reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx(-) scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significantly mitigate Re complex decomposition by slightly lowering the OAT activity when immobilized in Pd/C. Further stability enhancement is then obtained by switching the nanoparticles from Pd to Rh, which exhibits high reactivity with ClOx(-) intermediates and thus prevents their deactivating reaction with the Re complex. Compared to Re(hoz)2-Pd/C, the new Re(hoz)(htz)-Rh/C catalyst exhibits similar ClO4(-) reduction activity but superior stability, evidenced by a decrease of Re leaching from 37% to 0.25% and stability of surface Re speciation following the treatment of a concentrated "challenge" solution containing 1000 ppm of ClO4(-). This work demonstrates the pivotal roles of coordination chemistry control and tuning of individual catalyst components for achieving both high activity and stability in environmental catalyst applications.