Preliminary study on bisphenol A levels and possible exposure history of mother and exclusively breastfed infant pairs

The Early Appearance of Asthma and Its Relationship with Gut Microbiota: A Narrative Review

Asthma is, worldwide, the most frequent non-communicable disease affecting both children and adults, with high morbidity and relatively low mortality, compared to other chronic diseases. In recent decades, the prevalence of asthma has increased in the pediatric population, and, in general, the risk of developing asthma and asthma-like symptoms is higher in children during the first years of life. The "gut-lung axis" concept explains how the gut microbiota influences lung immune function, acting both directly, by stimulating the innate immune system, and indirectly, through the metabolites it generates. Thus, the process of intestinal microbial colonization of the newborn is crucial for his/her future health, and the alterations that might generate dysbiosis during the first 100 days of life are most influential in promoting hypersensitivity diseases. That is why this period is termed the "critical window". This paper reviews the published evidence on the numerous factors that can act by modifying the profile of the intestinal microbiota of the infant, thereby promoting or inhibiting the risk of asthma later in life. The following factors are specifically addressed in depth here: diet during pregnancy, maternal adherence to a Mediterranean diet, mode of delivery, exposure to antibiotics, and type of infant feeding during the first three months of life.

Environmental phenol exposures in 6- to 12-week-old infants: The Infant Feeding and Early Development (IFED) study

BACKGROUND

Exposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6-12 weeks.

METHODS

The Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010-2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level.

RESULTS

Median concentrations (μg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3-5 and 6-11 years, while propylparaben concentrations were 3-4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (-77%) and triclosan (-53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (-62%). Phenol concentrations were generally higher in summer samples.

CONCLUSIONS

Widespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development.

Estimated exposure to bisphenol A in breastfed and breastfed plus formula-fed infants in Turkey: a comparison study

This study aimed to estimate and compare dietary exposure to bisphenol A (BPA) in exclusively breastfed (EBF) and breastfed plus formula-fed (BF + FF) infants. A total of 70 mothers and their 0-6 month-old infants (40 in the EBF group and 30 in BF + FF group) were included in the study. After the questionnaire form was applied to the mothers, maternal breast milk, infant formula, and infant urine were collected from mother-infant dyads. Total BPA levels in breast milk, infant formula, and infant urine samples were analyzed by the high-pressure liquid chromatography (HPLC). While BPA was detected in 92.5% of the breast milk samples in the EBF group (mean ± SD = 0.59 ± 0.29 ng/mL), BPA was detected in all of the breast milk samples in the BF + FF group (mean ± SD= 0.72 ± 0.37 ng/mL) (p < 0.05). Similarly, 100% of the infant formula samples in the BF + FF group had detectable levels of BPA (mean ± SD = 7.54 ± 1.77 ng/g formula). The mean urinary BPA levels in the EBF infants (4.33 ± 1.89 µg/g creatinine) were not statistically different from the BF + FF infants (5.81 ± 0.11 µg/g creatinine) (p > 0.05). The average daily BPA intake in EBF infants (0.18 ± 0.13 µg/kg body weight (bw)/day) was found to be significantly higher than in BF + FF infants (0.12 ± 0.09 µg/kg bw/day) (p < 0.05). The estimated dietary intakes of BPA for infants in both groups were below the temporary tolerable daily intake (t-TDI) (4 µg/kg bw/day). Consequently, BPA intake of EBF and BF + FF infants were within safe daily limits during the first six months of life.

Association of bisphenol A with 25(OH)D, 1,25(OH)2D levels and 1,25(OH)2D/25(OH)D ratio in cord blood

The aim was to investigate the association between bisphenol A (BPA), 25-hydroxy vitamin D [25(OH)D], and 1α,25 dihydroxy vitamin D [1,25(OH)2D] levels in the cord blood of newborn babies. BPA was measured by high pressure liquid chromatography (HPLC) and vitamin D levels by commercial ELISA or ECLIA kits. BPA and Vitamin D levels were grouped according to tertile values. In the cord blood, the median 25(OH)D level was 14.9 ng/mL (IQR: 8.5-20.8) and median 1,25(OH)2D level was 53.3 pg/dL (IQR: 42.3-98.4). 25(OH)D levels were < 20 ng/mL in 76.5% of the babies. BPA was detectable in 72.4% of the cord blood samples; median BPA level was 1.57 ng/mL (IQR: < DL-4.05 ng/mL). Frequencies of vitamin D deficiency and frequencies of cases having the highest tertile active vitamin D levels were similar in groups of BPA tertiles in both univariate and multivariate analysis. In conclusion, both BPA exposure and insufficient vitamin D transfer via cord blood are common in newborns. Bisphenol A levels were not correlated with vitamin D levels in cord blood of healthy mother-fetus pairs.

Mixture of environmental pollutants in breast milk from a Spanish cohort of nursing mothers

Breastfeeding is one of the most effective ways to ensure child health and survival, with several benefits for both the infants and their mothers. However, breast milk can contain environmental pollutants with endocrine disruption capacity, neurotoxicity and/or potential to alter microbiota. Monitoring breast milk provides information on the current chemical exposure of breastfed infants and, in addition, on the current and historical exposure of nursing mothers. In this study, the levels of a wide range of pollutants were measured in breast milk of Spanish nursing mothers. Target chemicals were dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), oxy-chlordane, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), per- and poly-fluoroalkyl substances (PFASs) (including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)), chlorpyrifos, bisphenol A (BPA), tetrabromobisphenol A (TBBPA), and a number of toxic and essential elements. Traces of most chemicals were found. A correlation between the levels of some persistent organic pollutants (POPs) and maternal characteristics (age and body mass index) was observed, while smoking was associated to higher concentrations of some toxic elements. Higher levels of PCBs were detected in samples from Spanish primiparous mothers compared to non-Spanish multiparous women. Breast milk from low-income mothers showed higher content of DDT and DDE than high-income mothers. Although breastfeeding is clearly beneficial for babies, the exposure to this mixture of hazardous substances, as well as their interaction and combined effects must not be disregarded.

Biomonitoring of bisphenol A, 4-nonylphenol, and 4-t-octylphenol in Turkish population: exposure and risk assessment

Biomonitoring studies are important tools to understand the effects of endocrine-disrupting compounds on human health. Up to now, there have been no biomonitoring and risk assessment studies conducted in Turkish population in which urinary bisphenol A (BPA), 4-nonylphenol (4-NP), and 4-t-octylphenol (4-t-OP) levels were measured simultaneously. The aim of this study is to measure urinary BPA, 4-NP, and 4-t-OP on Turkish population and conduct a risk assessment using urinary levels of chemicals of interest. During the study, liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to measure urinary levels of above-mentioned chemicals, and human biomonitoring was used as a risk assessment tool in 103 volunteers, living in Mersin Region, Turkey. Urinary BPA, 4-NP, and 4-t-OP were founded as 0.0079 μg/g creatinine, 0.0177 μg/g creatinine, and 0.0114 μg/g creatinine, respectively. The obtained estimated daily intakes (EDIs) were calculated as 0.095 μg/kg bw/day, 0.041 μg/kg bw/day, and 0.091 μg/kg bw/day, for BPA, 4-NP, and 4-t-OP, respectively. In conclusion, although no potential health risk due to BPA and 4-NP exposure was observed, there might be health risks associated with 4-t-OP exposure in the Turkish population.

Estimation of lactating mothers' daily intakes of bisphenol A using breast milk

Breast milk is a unique biological sample that reflects the exposure levels of both lactating mothers and infants. The exposure levels of BPA due to breast milk consumption for infants can be estimated easily, but the method to estimate the total daily intake (TDI) of lactating mothers from breast milk has not yet been established. In this study, BPA concentrations were detected in breast milk samples from 149 lactating mothers from Hunan, China. The median concentration of BPA in breast milk was 0.053 μg/L with a range of 0.001-2.535 μg/L, and a temporal decline trend was found for BPA concentrations in breast milk (p < 0.05). The median intake of BPA via breast milk was 26.8 ng/kg bw/day for 0-3-month-old infants and 7.0 ng/kg bw/day for 4-12-month-old infants. Based on the predicted concentrations of BPA in urine and blood via the conversion coefficients from breast milk, the TDIs of lactating mothers were estimated. The TDIs estimated from the simulated urine concentration were 84.0 ± 175.2 ng/kg bw/day for 0-3-month-old infants' mothers and 36.9 ± 80.8 ng/kg bw/day for 4-12-month-old infants' mothers. The dietary daily intakes estimated from the simulated blood concentration were 579.6 ± 370.8 ng/kg bw/day for 0-3-month-old infants' mothers and 280.1 ± 195.2 ng/kg bw/day for 4-12-month-old infants' mothers. When assuming the dietary daily intakes in Hunan of the fifth total diet study (TDS) as the "true" total dietary intake of our population, the contribution of diet was estimated to be 63.7%, which suggested that non-dietary BPA exposure may be underestimated.

Plastics in our water: Fish microbiomes at risk?

Water contaminated with plastic debris and leached plasticizers can be ingested or taken up by aquatic invertebrates and vertebrates alike, exerting adverse effects on multiple tissues including the gastrointestinal tract. As such, gut microbiomes of aquatic animals are susceptible targets for toxicity. Recent studies conducted in teleost fishes report that microplastics and plasticizers (e.g., phthalates, bisphenol A) induce gastrointestinal dysbiosis and alter microbial diversity in the gastrointestinal system. Here we synthesize the current state of the science regarding plastics, plasticizers, and their effects on microbiomes of fish. Literature suggests that microplastics and plasticizers increase the abundance of opportunistic pathogenic microorganisms (e.g. Actinobacillus, Mycoplasma and Stenotrophomonas) in fish and reveal that gamma-proteobacteria are sensitive to microplastics. Recommendations moving forward for the research field include (1) environmentally relevant exposures to improve understanding of the long-term impacts of microplastic and plasticizer contamination on the fish gastrointestinal microbiome; (2) investigation into the potential impacts of understudied polymers such as polypropylene, polyamide and polyester, and (3) studies with elastomers such as rubbers that are components of tire materials, as these chemicals often dominate plastic debris. Focus on both microplastics and the gut microbiota is intensifying in environmental toxicology, and herein lies an opportunity to improve evaluation of global ecological impacts associated with plastic contamination. This is important as the microbiota is intimately tied to an individual's health and fragmentation of microbial community networks and gut dysbiosis can result in disease susceptibility and early mortality events.

Bisphenol analogue concentrations in human breast milk and their associations with postnatal infant growth

Many studies show that bisphenol A (BPA) is widespread in human breast milk. However, the occurrence of other bisphenol analogues (BPs), including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), in breast milk is still not well known. In this study, breast milk samples were collected from 190 women in Hangzhou, China, with the aims to characterize the occurrence of BPA, BPS, BPF, and BPAF in these samples and to investigate their effects on postnatal growth of infants through breast milk consumption. BPA (mean 2.5 ng/mL, range < LOD-15 ng/mL) was the most abundant BP in breast milk, followed by BPS (0.19 ng/mL, <LOD-1.3 ng/mL) and BPAF (0.092 ng/mL, <LOD-0.58 ng/mL). BPF was not detected in all breast milk samples. We firstly found that breast milk concentrations of BPA were negatively correlated with infant's weight or length gain rate. Daily intakes (DIs) of BPs via the consumption of breast milk were calculated for infants, and the mean DI values were 531 ng/kg/day, 53 ng/kg/day, and 24 ng/kg/day for BPA, BPS, and BPAF, respectively. Overall, this study firstly demonstrats that the lactation exposure to BPA through breast milk consumption may affect the postnatal growth of infants.

Assessment of Bisphenol A Levels in Preschool Children: Results of a Human Biomonitoring Study in Ankara, Turkey

OBJECTIVE

There is general concern regarding environmental chemical exposure and the impact it may have on human health. This is particularly important for vulnerable populations such as infants and children during critical periods of development. Bisphenol A (BPA) is an endocrine disrupting chemical used worldwide over the last 30 years in many consumer products. Evidence points to widespread human exposure to BPA. The aim of this study was to evaluate the exposure of Turkish preschool children to BPA.

METHODS

This study was conducted as a preliminary investigation of BPA in urine, collected from 3-6 year old children living in Ankara. After spot urine samples were taken from preschool children, free BPA, β-D-glucuronide and total BPA were determined using high-performance liquid chromatography tandem mass spectrometry and adjusted by creatinine concentration.

RESULTS

Preschool children from Ankara (n=125; males n=70, females n=55; mean age: 4.50±1.26) were recruited. BPA was detected in 76.8% of children from Ankara city, with urinary concentrations ranging from < limit of quantification to 18.36 μg/g creatinine. Total BPA levels were not statistically different between boys (1.26 μg/g creatinine) and girls (2.24 μg/g creatinine) (p>0.05).

CONCLUSION

This study is an important contribution to the limited information about childhood exposure to BPA. The estimated daily BPA intake in this study is substantially lower than the European Food Safety Authority derived tolerable daily intake of 4 μg/kg BW/day.

An electrochemical aptasensor based on eATRP amplification for the detection of bisphenol A

Herein, a novel aptasensor was constructed for ultrasensitive detection of bisphenol A (BPA). In this method, an electrochemically mediated atom transfer radical polymerization (eATRP) signal amplification strategy was applied to BPA detection for the first time. The 5'-end modified sulfhydryl group and the 3'-end modified azide group hairpin DNA were immobilized on a gold electrode through an Au-S bond. The double-stranded DNA was formed by the hybridization of an aptamer and a single-stranded DNA partially paired with the hairpin DNA. In the presence of BPA, the aptamer combined with BPA and the single-stranded DNA was released to open the hairpin structure, making the azide groups at the 3' end exposed. Subsequently the initiator of eATRP was introduced into hairpin DNA through click chemistry reaction and eATRP was conducted for the polymerization of the electroactive probe ferrocene methyl methacrylate (FMMA). As a result, the ultrasensitive detection of BPA was realized, and the detection limit of this aptasensor was as low as 59 aM and a good selectivity was obtained in the presence of 100-fold structural analogs. The application of this aptasensor was evaluated by detecting BPA in pure water samples, and recoveries were in the range of 95.23-98.40%, holding promising applications in biological analysis.