Breast Milk Samples Research Articles

Exploring Machine Learning Methods for Aflatoxin M1 Prediction in Jordanian Breast Milk Samples

Exploring Machine Learning Methods for Aflatoxin M1 Prediction in Jordanian Breast Milk Samples

Quantification of persistent organic pollutants in breastmilk and estimated infant intake, Norway.

Persistent organic pollutants (POPs) are environmental contaminants that can accumulate in human tissues and pose potential health risks. Despite global efforts to reduce their prevalence, follow-up studies are needed to see if the measures are successful. Since most infants in Norway are breastfed for the first 6 months of life, monitoring POP contamination in breastmilk is important for children's health and development. This study aims to evaluate the current levels of various POPs in women's breastmilk in Innlandet County, Norway. A cross-sectional study was conducted measuring concentrations of 35 different POPs, including polychlorinated biphenyls (PCBs), chlordanes (ChlDs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), Mirex, and brominated flame retardants in 120 breastmilk samples. The study analysed the impact of maternal age, parity, pre-pregnancy BMI, and infant age on POPs levels and compared the estimated daily intake per body weight of infants to existing health guidelines. The detected percentages for PCBs were 100%, for DDTs 98.3%, and for ChlDs 98.3%. The highest median concentration was found for ΣPCBs (26.9 ng/g lw). Maternal age, parity, and infant age were significant determinants of POP concentrations. Most infants exceeded the health-based guidance values for ΣPCB, and 6.4% percent did so for ΣHCHs. Despite lower POPs concentrations in breastmilk than in earlier studies, many breastfed infants are still exposed to levels exceeding health-based guidance values. Although the study's design had limitations, the study provides updated population-based data on POPs in breastmilk. Continued monitoring and research are necessary to understand and mitigate potential health risks associated with POPs.

Population pharmacokinetic modelling of cetirizine concentrations in human breast milk-A contribution from the ConcePTION project.

Cetirizine is an antihistamine commonly used to treat allergic rhinitis and other allergic conditions. Cetirizine is often prescribed to breastfeeding mothers although there is limited information on infant exposure via breast milk. The aim of this study was to develop a popPK model based on data from a lactation study to predict cetirizine breast milk concentrations and estimate the relative infant dose (RID) in a breastfed infant. A popPK model was developed in NONMEM on data from a human lactation study including 35 women using cetirizine or levocetirizine while breastfeeding. Serial samples of breast milk were collected (n = 205) and the cetirizine concentrations quantified using a validated LC-MS/MS method. A one-compartment model of cetirizine in breast milk was developed and employed to calculate the relative infant dose (RID). Covariates related to the maternal characteristics and breastfeeding patterns were evaluated in the model; only milk sampling pumping duration was found to be a significant covariate, with an increasing pumping duration leading to an increased apparent milk volume of distribution (Vm). The mean RID was 1.99% with the highest RID being 3.36% at Cmax. PopPK modelling could be used to estimate infant exposure to cetirizine via breast milk. The low predicted exposure in infants supports that cetirizine is compatible with breastfeeding.

Determination of PAH Contamination in Breast Milk Samples from Hungarian Volunteering Mothers, Using HPLC–FLD

(1) The evidence is mounting that polycyclic aromatic hydrocarbons (PAHs) are a class of hazardous organic compounds with established carcinogenic and toxic properties. Humans may be exposed to PAHs through several different routes, including diet, inhalation, and dermal contact. There is also a possibility that they could transfer into breast milk following maternal exposure, which could potentially endanger breastfeeding infants. (2) The objective of this study was to ascertain the concentration of polycyclic aromatic hydrocarbons (PAHs) in breast milk samples from 50 Hungarian mothers, employing high-performance liquid chromatography with fluorescence detection (HPLC–FLD). An Incremental Life Risk Calculation (IRCL) model estimated the carcinogenic risk to infants. (3) Total PAH concentrations ranged from 0 to 78 ng/mL, with fluorene (5.3 ng/mL), phenanthrene (3.2 ng/mL), and pyrene (2.5 ng/mL) being the most abundant. PAHs were detected in 48 of the 50 samples, with phenanthrene present in 92% of samples. Dibenzo (a,h)anthracene was not detected. (4) According to the model measurements, most of the samples were within acceptable risk levels; however, 2 samples out of 50 posed a higher risk. Statistical analysis of questionnaires completed by the mothers indicated that factors such as diet, residence, and education may influence PAH levels in breast milk.

Influence of Early Life Factors on the Breast Milk and Fecal Microbiota of Mother–Newborn Dyads

Maternal gut and breast milk (BM) are key in vertically transmission bacteria to infants, shaping their gut microbiota in early life. Although the establishment of early gut microbiota is known, the role of the combined influence of maternal factors and newborn characteristics is not explored. In this study, we aimed to assess the influence of maternal BMI and total body fat, age, delivery mode, and newborn sex on the diversity and composition of the BM and gut microbiota (GM) in mother–newborn dyads. In this cross-sectional study, of the 986 pregnant women candidates, 53 participated, and, finally, 40 mother–newborn dyads exclusively breastfeeding at 20–28 days postpartum were included. Metataxonomic profiling of DNA extracted from BM and fecal samples was conducted using 16S rRNA sequencing. Globally, the findings offer valuable insights that excessive adiposity, age, and C-section delivery influence a lower abundance of specific taxa in the BM, maternal gut, and gut of newborns. Also, the simultaneous analysis of maternal factors and newborn characteristics shows that maternal age and newborn sex explain an important variation in the microbiota composition. These results add to the understanding of the intricate interplay between maternal factors and the microbial communities that influence early-life gut and BM microbiota.

Metabolomics Approach to Identify Biomarkers of Acute and Subacute Mastitis in Milk Samples: A Pilot Case-Control Study.

Background and aims: Mastitis is one of the main complications during breastfeeding and contributes to the cessation of breastfeeding. However, the etiopathogenesis and diagnosis of mastitis are complex and not yet well defined. We aimed to identify metabolic and lipidic changes in human milk during acute and subacute mastitis in order to detect potential biomarkers of mastitis. Methods: We conducted a pilot case-control study including 14 breastfeeding women with acute mastitis, 32 with subacute mastitis symptoms, and 19 without any mastitis symptoms (control). Milk samples were collected and analyzed by proton nuclear magnetic resonance (H-NMR) for metabolomics analysis. To assess the association between the significant metabolites and lipids and the development of acute and subacute mastitis, multi-adjusted logistic regression models were developed. Results: The NMR-based metabolomics approach was able to identify and quantify a total of 40 metabolites in breast milk samples. After adjusting for confounding variables, acute mastitis was significantly associated with acetate (OR 3.9 IC 1.4-10.8), total cholesterol (OR 14 CI 3.2-62), esterified cholesterol (OR 3.3 CI 1.9-5.8), and sphingomyelin (OR 2.6 CI 1.2-5.8). The other metabolites presented weak association (OR < 2.5). Subacute mastitis was significantly associated with glutamine, lysophosphatidylcholine, phosphatidylcholine, plasmalogen, and total polyunsaturated fatty acids, but only cholesterol showed a strong association (OR > 2.5) with an OR of 2.6 (IC 1.1-6.6). Conclusions: Metabolic alteration in breast milk occurs during a process of both acute and subacute mastitis. Acetate, esterified cholesterol, lysophostidylcholine, and polyunsaturated fatty acids increased in both acute and subacute mastitis. However, according to the multi-adjusted regression logistic models, the candidate biomarkers for acute and subacute mastitis are cholesterol, lysophosphatidylcoholine, phosphatidylcholine, plasmalogen, and polyunsaturated fatty acids.

Influence of Lactation Stage on Content of Neurotrophic Factors, Leptin, and Insulin in Human Milk.

Human milk comprehensively meets the nutritional needs of a child, providing not only structural and energy components but also various bioactive factors. Among these, neurotrophic factors and hormones involved in metabolic processes deserve special attention. Studies using enzyme-linked immunosorbent assays compared the content of neurotrophic factors-CNTF, NT-3, and NGF-and hormones, leptin and insulin, in two groups of breast milk samples: early lactation (1-3 months) and extended lactation (>6 months, up to 12 months). The results indicated changes in leptin and insulin levels as the lactation period extended. NGF, leptin, and insulin were present in milk samples from both study groups, with leptin and insulin levels being higher in the early lactation group. CNTF and NT-3 were not detected in any of the samples from either study group. The analyses confirmed that human milk from women who breastfeed for extended periods remains a source of biologically active components and macronutrients that support a child's development and health.

Farm exposure is associated with human breast milk immune profile and microbiome.

Prenatal and early life farm exposure, and breastfeeding, are associated with protection from allergic diseases. We hypothesize that farm exposure influences the human breast milk microbiome and immune proteins. The immune protein profiles and microbial communities of 152 human breast milk samples were compared among three maternal farm exposure groups (traditional agrarian, farm, and non-farm) in rural Wisconsin to identify signatures associated with farm status and atopic disease. We found significant differences between farm groups for 23 immune proteins (p-adj<0.05), microbiome diversity (p=2.2E-05), and microbiome richness (p=8.0e-06). Traditional agrarian human breast milk had the highest immune protein levels and microbiome diversity and richness, followed by farm and non-farm human breast milk. Furthermore, Gram-positive bacterial species correlated with IL-23 mediated signaling events (p-adj<1.0E-05). These data suggest that increased farm exposures promotes human breast milk that is more microbially-diverse and rich in immune-associated proteins, ultimately influencing immune development in the infant.

Fatty acids from nutrition sources for preterm infants and their effect on plasma fatty acid profiles

BackgroundIn preterm infants, IV administration of fat is less well tolerated compared to intake via the enteral route, often resulting in hypertriglyceridemia. It is therefore recommended that parenteral fat intake should not exceed 3.5 to 4.0 g/kg/d whereas human milk can provide up to 8 g/kg/d. It is unknown whether such hypertriglyceridemic conditions are caused by a uniform increase of all fatty acids or it is linked to an elevation of distinct fatty acids due to an unbalanced intake. Obviously, both scenarios could potentially influence the formulation of novel lipid solutions for preterm infants. Objective of this exploratory study was to compare fatty acid profiles between a) different nutritional sources and corresponding plasma samples, b) plasma of infants fed breast milk versus those receiving lipid emulsion, and c) plasma of infants with normal versus elevated triglyceride levels.MethodsForty-seven preterm infants < 36 weeks of gestation were included; fatty acid profiles were measured in serum samples and corresponding nutritional sources (breast milk and lipid emulsion) using gas chromatography/mass spectrometry.ResultsCompared to breast milk levels, plasma contained significantly lower C8:0, C10:0, C12:0, C14:0, C19:1n9, C18:3n3 (p < 0.0001). In contrast, relative abundance of C16:0, C18:0 and C20:4n6 was higher in plasma than in corresponding breast milk samples (p < 0.001) and lipid emulsion (p < 0.01). Compared to the corresponding lipid emulsion, the abundance of C18:2n6 and C18:3n3 was significantly lower in plasma (p < 0.001). Fatty acid profiles in plasma of infants fed breast milk compared to lipid emulsion were not markedly different. Hypertriglyceridemic samples showed elevated levels for C18:1n9 and C16:0 when compared with normotriglyceridemic samples.ConclusionsOur study reveals that lipid levels in plasma show both depletion and enrichment of distinct fatty acids which do not seem to be closely related to dietary intake. A more detailed understanding of fatty acid flux rates is needed, like the understanding of amino acid metabolism and is supported by the finding that hypertriglyceridemia might be a state of selective fatty acid accumulation. This would allow to develop more balanced diets for intensive care and potentially improve clinical outcomes.

Unveiling connections: bisphenol A and vitamin D dynamics in breast milk among healthy lactating mothers

ABSTRACT Bisphenol A (BPA) has negative impact on human health. This study aims to explore the association between the levels of BPA and 25(OH) vitamin D in breastmilk. BPA exposure and vitamin D sources were recorded on the study form. Breastmilk 25(OH) vitamin D was measured by the competitive enzyme-linked immunosorbent assay method, and BPA was analyzed by fluorescence detector high pressure liquid chromatography technique. Multiple logistic regression analysis were performed for association. Among 70 lactating mothers, the median 25(OH) vitamin D level was 12.6 ng/mL. In 92.9% of breastmilk samples, detectable levels of BPA were found, with a median BPA concentration of 2.56 ng/mL. However, both univariate and multivariate analyses failed to reveal any association between breastmilk BPA and 25(OH) vitamin D levels. This lack of association in healthy lactating mothers, highlighting the need for further research to comprehensively understand the intricate dynamics of these factors.

Heavy Metal Nanoparticle Detection in Human and Formula Milk.

Breast milk is the natural source of nutrition for infants, but while it supports their health, it can also be a potential source of toxic inorganic particulate matter, and this applies to both breast milk and industrially produced milk. The aim of the present study was to evaluate the presence of nanoparticles in both breast milk and formula milk samples. We collected and analyzed, via a new electron scanning microscopic procedure, 19 samples of breast milk from Italian women and 19 formula milk samples produced by different companies. Organic-inorganic agglomerates were detected in 58% of formula and in 63% of breast milk samples, respectively. In addition, a significantly (p < 0.05) greater size of nanoparticles was observed in formula milk samples. The results, showing the presence of inorganic nanosized particles in breast and artificial milk, may lead to future studies aimed at investigating possible nanosized contamination of milk and identifying early prevention strategies for women and animals involved in the food chain.

Interim analysis, a tool to enhance efficiency of pharmacokinetic studies: Pharmacokinetics of rifampicin in lactating mother-infant pairs.

Pharmacokinetic studies are important for understanding drug disposition in the human body. However, pregnant and lactating women are often excluded from primary pharmacokinetic studies and as such there is often limited dosing information regarding drug use in pregnant and/or lactating women. The objectives of this interim analysis were to define the transfer of rifampicin to a breastfed infant and to determine the area under the concentration-time curve of rifampicin in maternal plasma, breastmilk and infant plasma. Performing this interim analysis enabled us to substantiate whether prior assumptions we made on several study design issues including patient sample size and pharmacokinetic sampling times held and whether we needed to amend our protocol or not. We enrolled lactating mothers on treatment for tuberculosis with their breastfeeding infants (below 12 months of age), performed intensive pharmacokinetic sampling (0-24 h post-dose) on plasma samples from both the mother, infant(s) and breastmilk samples from the mother on two separate occasions (once during the initiation phase and another during the continuation phase of tuberculosis treatment). The initial study design, including sampling times, was informed by a stochastic simulation and estimation exercise, with very limited prior breastmilk data. An interim analysis after recruiting 6 mother-infant pairs ascertained that our initial assumptions were ideal for achieving our study objectives and no amendments to the sampling times were necessary. Initial data from 6 mother-infant pairs show that rifampicin penetrates breastmilk with an approximate milk-to-plasma ratio of 0.169 and 0.189 on two separate visits. However, it was undetectable in most infants.

P-phenylenediamines (PPDs) and PPD-quinones (PPD-Qs) in human urine and breast milk samples: Urgent need for focus on PPD-Qs and the establishment of health threshold criteria

PPDs and their oxidation products, PPD-Qs, are emerging environmental contaminants arising from the addition and oxidation of rubber products. Although numerous studies have been conducted to elucidate their risks, the primary focus has been on 6PPD and 6PPD-Q, with limited attention given to other PPDs and especially other PPD-Qs. This study comprehensively examines the occurrences of frequently used PPDs and their degradation products, PPD-Qs, in human urine and breast milk samples. The average concentrations of ΣPPDs and ΣPPD-Qs in urine were 27 ± 78 ng/mL and 16 ± 12 ng/mL, respectively. IPPD and DNPD were the predominant PPDs, while DPPD-Q, CPPD-Q, and IPPD-Q were the predominant PPD-Qs. Notably, the concentrations of 6PPD, CPPD, and DPPD were significantly lower than their oxidized quinone products. Weak or no correlations were observed between most PPDs and their corresponding PPD-Qs, suggesting that PPD-Qs in the human body are primarily derived from direct environmental intake rather than in vivo conversion of PPDs. PPDs and PPD-Qs were widely detected in breast milk, exhibiting concentrations and patterns similar to those found in urine, with comparable major pollutants. Estimated daily intakes of PPDs + PPD-Qs for infants were several μg/(kg·day), with the 95th percentile intake approaching 10 μg/(kg·day).

Does the Composition of Breast Milk in the First Week Postpartum Differ Due to Maternal Factors or Neonatal Birth Weight and Percent Fat Body Mass?

Background: The composition of breast milk is dependent on numerous factors. However, the precise impact of maternal health conditions on breast milk composition remains to be fully elucidated. Similarly, there is a paucity of evidence regarding the correlation between neonatal body composition and human milk. The objective of the study was to evaluate the macronutrient composition of breast milk collected during the first week postpartum from mothers with gestational diabetes and healthy mothers in terms of selected maternal and neonatal factors. Methods: n = 70 breast milk samples were analyzed for fat, protein, carbohydrate, dry matter, true protein, and energy. The results were evaluated in terms of selected maternal factors, as well as neonatal birth weight (BW) and percent fat body mass (%FBM), which was assessed with a bioimpedance method. Results: Energy of breast milk in the study group was as follows: median 55.5 kcal/dL in GDM G1, median 55.5 kcal/dL in GDM G2, and median 65.0 kcal/dL in non-GDM, which differed significantly in Kruskal–Wallis ANOVA. Neonatal %FBM, but not BW, was found to be significantly related to concentrations of protein, true protein and dry matter. Maternal gestational weight gain, history of hypothyroidism, and classification by study group were identified as factors affecting both breast milk and neonatal body composition. Conclusions: The composition of breast milk in the initial week following childbirth is predominantly determined by maternal factors. The relationship between selected macronutrients and neonatal percent fat body mass was found to be weak, yet the significance of this finding is unclear. Further research is required to ascertain the influence of maternal milk composition on early infantile nutritional programming.

Synthesis of trisaccharide antigens featuring colitose, abequose and fucose residues and assessment of antibody binding on antigen arrays

Deoxy-hexose sugars, such as rhamnose and quinovose, and the dideoxy-hexoses colitose, abequose, and tyvelose are highly antigenic given that they are absent from animal glycoconjugates. To investigate the specificity of antibodies towards structurally similar carbohydrate epitopes found in bacteria, we synthesized trisaccharides containing colitose, abequose, and fucose motifs. Each trisaccharide was designed with a spacer ending with a primary amino group. These trisaccharide constructs were immobilized on O-succinimide coated glass slides alongside bacterial lipopolysaccharides (LPS) containing colitose, abequose, and fucose residues. We compared the recognition of the synthetic trisaccharides and natural LPS including structurally related epitopes by monoclonal and polyclonal antibodies targeting bacterial LPS. Additionally, we used arrays displaying the synthetic trisaccharides and natural LPS to assess the variability of IgA reactivity from breast milk samples towards the carbohydrate antigens. The results obtained underlined the cross-reactivity of polyclonal antibodies towards structurally related carbohydrate antigens and revealed a broad reactivity of breast milk-derived IgA towards the carbohydrate antigens tested. The significant cross-reactivity of antibodies towards structurally related LPS antigens may lead to false-positive detection of bacterial serotypes when used for diagnostic purposes.

Multi-residue analysis method based on QuEChERS followed by ultra-high performance liquid chromatography coupled with diode-array detector for pesticides in human serum and breast milk.

Background: Maternal fluids play a key role in the risk assessment regarding early life pesticide exposure as the chemicals can transfer to neonate through prenatal exposure and lactation.Aim: A developed UHPLC-DAD and modified QuChERS methods were validated for human serum and breast milk. Matrix effect of the biological samples were evaluated.Methods & results: Serum was extracted by unbuffered QuChERS method while breast milk was extracted by citrate buffered method with addition of hexane. Remaining lipid in breast milk extract was later removed using lipid-removal sorbent. Sample matrices caused huge impacted on low-sensitivity pesticides.Conclusion: The modified QuEChERS methods coupled with UHPLC-DAD were fully validated. Application in paired-serum and breast milk samples revealed 6 detected pesticides.

Whole-genome sequencing of bacteria accountable for lactational mastitis in humans combined with an examination of their antibiotic resistance profiles.

Lactational mastitis, a common condition affecting nursing mothers, is characterized by mammary gland inflammation during lactation. This inflammatory response typically occurs due to bacterial infection. The discomfort and pain associated with lactational mastitis can significantly impact a mother's ability to breastfeed comfortably and may lead to the cessation of breastfeeding altogether if left untreated. Antibiotics are commonly prescribed to target the bacteria causing the infection and alleviate symptoms, aiming to treat the infection. Nevertheless, a notable worry linked to antibiotic use is the emergence of antibiotic resistance, compounded by the possible persistence of antibiotics in milk. Additionally, lactational mastitis is characterized by its polymicrobial nature. In this study, bacteria were isolated from infected breast milk samples and whole-genome sequencing was performed on eleven isolates to accurately identify the bacteria and assess their antibiotic resistance profiles. Using Galaxy tools and the ResFinder database, we identified Bacillus paraanthracis, Bacillus altitudinis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Alcaligenes faecalis, and Bacillus licheniformis, along with antibiotic-resistant genes like fosB1, cat86, erm (D), blaZ, and mdf (A). ABRicate aided in antimicrobial resistance (AMR) gene analysis, and CARD visualized their distribution. Our study demonstrates that the severity of infection is directly proportional to an increase in somatic cell count (SCC). This research sheds light on microbial diversity in lactational mastitis milk and provides crucial insights into antibiotic-resistance genes. Utilizing bioinformatics tools, such as those employed in this study, can inform the design of effective treatment strategies for lactational mastitis infections.

Exposure and potential risks of thirteen endocrine- disrupting chemicals in pharmaceuticals and personal care products for breastfed infants in China

Ingestion of breast milk represents the primary exposure pathway for endocrine-disrupting chemicals (EDCs) in newborns. To elucidate the associated risks, it is essential to quantify EDC levels in both breast milk and infant urine. This study measured the concentrations of 13 EDCs, including parabens (methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), iso-propyl paraben, butyl paraben, and iso-butyl paraben), bisphenols (bisphenol A (BPA), bisphenol F, bisphenol S, bisphenol AF, and bisphenol Z), triclosan (TCS), and triclocarban, in breast milk and infant urine to assess their potential health effects and endocrine disruption risks. In total, 1 014 breast milk samples were collected from 20 cities across China, along with 144 breast milk samples and 134 urine samples from a mother-infant cohort in Hangzhou. The EDCs were detected using ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry. Endocrine-disrupting potency was evaluated using a predictive method based on EDC affinity for 15 hormone receptor proteins. The toxicological priority index (ToxPi), incorporating population exposure data, was employed to assess health risks associated with exposure to multiple EDCs. Among the 13 EDCs, MP, EP, PP, BPA, and TCS were detected in over 50 % of breast milk samples, with the highest median concentrations observed for MP (0.37 ng/mL), EP (0.29 ng/mL), and BPA (0.17 ng/mL). Across the 20 cities, 0 %–40 % of infants had a hazard index (HI) exceeding 1. Based on affinity prediction analysis and estimated exposure, cumulative endocrine disruption risk intensity was ranked as MP > TCS > BPA > EP > PP. This research highlights the extensive exposure of Chinese infants to EDCs, offering a detailed analysis of their varying endocrine disruption potencies and underscoring the significant health risks associated with EDCs in breast milk.

High arsenic contamination in the breast milk of mothers inhabiting the Gangetic plains of Bihar: a major health risk to infants

Groundwater arsenic poisoning has posed serious health hazards in the exposed population. The objective of the study is to evaluate the arsenic ingestion from breastmilk among pediatric population in Bihar. In the present study, the total women selected were n = 513. Out of which n = 378 women after consent provided their breastmilk for the study, n = 58 subjects were non-lactating but had some type of disease in them and n = 77 subjects denied for the breastmilk sample. Hence, they were selected for the women health study. In addition, urine samples from n = 184 infants’ urine were collected for human arsenic exposure study. The study reveals that the arsenic content in the exposed women (in 55%) was significantly high in the breast milk against the WHO permissible limit 0.64 µg/L followed by their urine and blood samples as biological marker. Moreover, the child’s urine also had arsenic content greater than the permissible limit (< 50 µg/L) in 67% of the studied children from the arsenic exposed regions. Concerningly, the rate at which arsenic is eliminated from an infant’s body via urine in real time was only 50%. This arsenic exposure to young infants has caused potential risks and future health implications. Moreover, the arsenic content was also very high in the analyzed staple food samples such as rice, wheat and potato which is the major cause for arsenic contamination in breastmilk. The study advocates for prompt action to address the issue and implement stringent legislative measures in order to mitigate and eradicate this pressing problem that has implications for future generations.

Trend analyses of persistent organic pollutants in human milk from first-time mothers in Norway between 2002 and 2021

IntroductionPersistent organic pollutants (POPs) are stable compounds characterized by their resistance to degradation. From the 1960–70's organochlorine pesticides (OCPs), such as DDTs and polychlorinated biphenyls (PCBs) raised concerns regarding health and environmental impacts. This has led to the banning of POPs in the USA and Europe including Norway in 1980 and worldwide under the 2004 Stockholm Convention. The exposure of nursing infants to POPs has been a significant focus, prompting extensive research into the presence of these substances in human breast milk. In this study, we explored the temporal trends of POPs concentrations in breast milk sampled between 2002 and 2021 by comparing the concentration across the mother's year of birth. MethodTwo Norwegian cohorts of lactating women were utilized (the HUMIS study and the “Iodine in Early Life”-Study). Concentrations of 15 different POPs, including PCBs, OCPs, and brominated diphenyl ethers (BDEs) were measured in 513 breast milk samples that had been collected over two decades in a subset of first-time mothers. ResultsTime trend analysis indicated a steady decrease in concentration levels when adjusted for maternal age. The largest reduction was observed in β-HCH, age-adjusted (−17.1%, 95% CI -18.7, −15.4), followed by ∑6BDE (−9.1%, 95% CI -10.5, −7.7), ∑6PCBs (−7.1%, 95% CI -7.7, −6.5), and ∑2DDTs (−7.0%, 95% CI -8.0, −6.0). In contrast, an increasing trend was noted in the median concentrations of β-HCH, ∑2DDTs, and ∑6BDE in the mothers born in 1990–1994 to 1995–2002. ConclusionOur study demonstrates a decline of most POPs in breast milk, likely attributed to international regulatory efforts like the Stockholm Convention. Notably, an increase in the 95th percentile concentrations of β-HCH, ∑2DDTs, and ∑6BDEs was noted in mothers born in 1990–1994 compared to those born in 1995–2002 suggests demographic shifts that may influence exposure levels. Further research is needed to explore and understand the underlying factors for the rise in median concentrations of ∑6BDEs.