Exposure to pesticides, persistent and non - persistent pollutants in French 3.5-year-old children: Findings from comprehensive hair analysis in the ELFE national birth cohort.

INTRODUCTION: Exposure to endocrine disruptors during early childhood poses significant health risks. This study examines the exposure levels of French 3.5-year-old children to various persistent and non-persistent pollutants and pesticides using hair analysis as part of the ELFE national birth cohort. Differences in sex and geographical location among the children were investigated as ppossible determinants of exposure. METHODS: Exposure biomarkers from 32 chemical families were analyzed using LC-MS/MS and GC-MS/MS in 222 hair samples from children in the ELFE cohort. Of these, 46 mother-child pairs from the same cohort provided unique insight into prenatal and postnatal exposure. Regressions, correlations and discriminate analysis were used to assess relationships between exposure and possible confounding factors. RESULTS AND DISCUSSION: Among the biomarkers tested in children's hair samples, 69 had a detection frequency of ≥ 50 %, with 20 showing a 100 % detection rate. The most detected biomarkers belonged to the bisphenol, organochlorine and organophosphate families. Sex-specific differences were observed for 26 biomarkers, indicating the role of the child's sex in exposure levels. Additionally, regional differences were noted, with Hexachlorobenzene varying significantly across the different French regions. Nicotine presented both the highest concentration (16303 pg/mg) and highest median concentration (81 pg/mg) measured in the children's hair. Statistically significant correlations between the levels of biomarkers found in the hair samples of the mothers and their respective children were observed for fipronil (correlation coefficient = 0.32, p = 0.03), fipronil sulfone (correlation coefficient = 0.34, p = 0.02) and azoxystrobin (correlation coefficient = 0.29, p = 0.05). CONCLUSIONS: The study highlights the elevated exposure levels of young children to various pollutants, highlighting the influence of sex and geography. Hair analysis emerges as a crucial tool for monitoring endocrine disruptors, offering insights into exposure risks and reinforcing the need for protective measures against these harmful substances.

Occurrence and infant exposure assessment of per and polyfluoroalkyl substances in breast milk from South Africa.

The exposure of infants to per and polyfluoroalkyl substances (PFAS) through breast-feeding is of global concern owing to their numerous detrimental health effects. This study investigated the occurrence of eleven perfluorocarboxylic acids (PFCAs) and four perfluorosulfonates (PFSAs) in breast milk of nursing mothers from South Africa. The concentrations of PFAS in these samples were measured by using a validated UHPLC - MS/MS method. The median concentrations of Σ15 PFAS ranged from

Health Risk Assessments of Selected Trace Elements and Factors Associated with Their Levels in Human Breast Milk from Pretoria, South Africa.

While breast milk is the recommended food for infants up to at least six months, exogenously derived compounds such as trace elements have been widely reported in human milk which may make it become toxic or a source of pollutants to the infants. Numerous short- and long-term health effects have been associated with high body-burdens of trace elements, which are amplified in infants. The current study determined the levels and possible contributing factors of six trace elements in breast milk of nursing mothers from a local hospital in Pretoria. Extraction of trace elements employed a digestion technique using perchloric and nitric acid in a ratio of 1:3, while Inductively Coupled Plasma-Membrane Spectrophotometry was used to identify and quantify their levels in breast milk. Concentrations of Cr and Mn were the highest in breast milk, with values ranging from 0.30 to 5.72 µg/L and 0.23 to 5.13 µg/L, respectively. Levels of Co, As, Pb and Cd ranged from

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.

Concentrations and human exposure assessment of per and polyfluoroalkyl substances in farmed marine shellfish in South Africa.

Although the consumption of seafood is a major route of human exposure to perfluoroalkyl substances (PFAS), data on their concentrations in marine shellfish and the exposure of the African population to PFAS through the consumption of shellfish is lacking. In this study, the concentrations of 15 PFAS were measured in four species of farmed marine shellfish by using a validated UHPLC-MS/MS method. These concentrations were used to determine the human daily intake of PFAS through the consumption of marine shellfish and the hazard quotient thereof. PFPeA, PFOS, PFHxA and PFTeDA were the most prevalent compounds with detection frequencies of 94, 88, 76 and 71%, respectively. The Σ11PFAS concentrations (in ng g-1 wet weight (ww)) ranged from 0.12 to 0.49, 4.83-6.43, 0.64-0.66 and 0.22 ng g-1 ww in abalone, mussel, oyster and lobster, respectively. The prevalence of PFCAs reflects the current contamination profile of PFAS in farmed shellfish. The estimated daily intake for Σ10 PFAS through the consumption of marine shellfish ranged from 0.05 to 1.58 ng kg-1 bw d-1. Overall, the hazard quotients for these compounds were low, indicating that these compounds do not pose a health risk to the South African population through shellfish consumption. This study provides background data for future studies on the occurrence of PFAS and other emerging contaminants in the African coastal environment.

Determination and assessment of human dietary intake of per and polyfluoroalkyl substances in retail dairy milk and infant formula from South Africa.

Dairy milk and infant formula play important roles in the diet of adolescents, adults and infants, respectively, in the South African population. However, data on the occurrence of legacy and emerging contaminants such as PFAS in these important food sources is lacking. In this study, the concentration of fifteen PFAS were measured in 23 pooled retail dairy milk and 7 pooled infant formulas by means of an ultrahigh performance liquid chromatography tandem mass spectrometric method. The concentrations of Σ15PFAS ranged from 0.08-15.51 ng mL-1 and 0.42-5.74 ng mL-1 in dairy milk and infant formulas, respectively. PFBA, PFPeA, PFuDA, PFTrDA and PFDoA were the most prevalent PFAS in both matrices with detection frequency > 96%. Highest PFAS concentrations of 2.02 ng ml-1 and 2.76 ng ml-1 were recorded for PFDoA in infant formulas and dairy milk, respectively. The concentrations of legacy PFAS -PFOA and PFOS, shows resemblance with global data, however, elevated concentrations of long chain C9 - C14 PFAS were observed in this study. Though, higher concentrations of PFAS were measured in full cream dairy milk, no statistical significant difference (P = 0.546) was observed for the various classes of dairy milk. The EDI of Σ15PFAS through infant formulas were 184.92, 329.47 and 166 ngkg-1BWday-1 for partially breastfed, exclusively formula fed and older infants, respectively. Similarly, the EDI of PFAS through dairy milk for toddlers, adolescents, female and male adults for the rural population were 14.17, 1.09, 2.59 and 3.16 ngkg-1BWday-1 respectively while they were 20.41, 3.84, 4.13 and 4.26 ngkg-1BWday-1 respectively in the urban population. Although, the EDI of PFAS through the consumption of infant formulas and dairy milk are lower than the daily tolerable limits, the relative importance of long-term exposure and the cumulative effects of multiple exposure pathways cannot be overemphasized.