Detection of various microplastics in placentas, meconium, infant feces, breastmilk and infant formula: A pilot prospective study.

Pregnancy and infancy are sensitive windows for environmental exposures. However, no study has investigated the presence of microplastics (MPs) in mother-infant pairs, and the exposure sources. Therefore, we aim to assess MPs exposure in placenta, meconium, infant feces, breast milk and infant formula samples, and assess the potential sources of pregnancy and lactational exposure to MPs. A total of 18 mother-infant pairs were recruited, and placentas and meconium samples were collected. Infant feces, breast milk and infant formula samples were collected at 6 months of age. We also collected data on plastic use and feeding habits through two questionnaires to determine the source of exposure. We used an Agilent 8700 laser infrared imaging spectrometer to analyze samples. Sixteen types of MPs were identified, and polyamide (PA) and polyurethane (PU) were dominant. >74 % of the MPs found were 20-50 µm in size. The water intake and usage of scrub cleanser or toothpaste may be exposure sources of pregnant women. The breastfeeding and usage of feeding bottles and plastic toys may be exposure sources for infants. Given the lack of relevant studies, our results highlight the need of investigating the contribution of plastic products to the MPs exposure during the lactational period.

The Association Between Microplastics and Microbiota in Placentas and Meconium: The First Evidence in Humans.

Pregnancy and infancy are vulnerable times for detrimental environmental exposures. However, the exposure situation of microplastics (MPs) for mother-infant pairs and the adverse health effect of MPs are largely unknown. Therefore, we explored MP exposure in placentas and meconium samples, and the potential correlation of MP exposure with microbiota in placentas and meconium. A total of 18 mother-infant pairs were effectively recruited from Shanghai, China. The study required pregnant women to provide placentas and meconium samples. An Agilent 8700 laser infrared imaging spectrometer (LDIR) was applied to identify MPs. Microbiota detection was identified by 16S rRNA sequencing. Sixteen types of MPs were found in all matrices, and polyamide (PA) and polyurethane (PU) were the major types we identified. MPs detected in samples with a size of 20-50 µm were more than 76.46%. At the phylum level, both placenta and meconium microbiota were mainly composed of Proteobacteria, Bacteroidota, and Firmicutes. We also found some significant differences between placenta and meconium microbiota in ß-diversity and gut composition. Additionally, we found polystyrene was inversely related with the Chao index of meconium microbiota. Polyethylene was consistently inversely correlated with several genera of placenta microbiota. The total MPs, PA, and PU consistently impacted several genera of meconium microbiota. In conclusion, MPs are ubiquitous in placentas and meconium samples, indicating the wide exposure of pregnant women and infants. Moreover, our findings may support a link between high concentration of MPs and microbiota genera in placentas and meconium. Additionally, there were several significant associations between the particle size of MPs in 50-100 µm and meconium microbiota.

Exposure to melamine and its derivatives in Chinese adults: The cumulative risk assessment and the effect on routine blood parameters.

Melamine (MEL) and its derivatives, ammeline (AMN), ammelide (AMD), cyanuric acid (CYA) are widely existed in environmental media. Animal studies have reported the cumulative risk assessment (CRA) of simultaneous exposure to MEL and its derivatives and explored the associations between exposure and routine blood parameters. Such information is largely unknown in human studies. In this study, we detected the urinary concentrations of MEL and its derivatives in 239 Chinese adults to conduct the CRA by evaluating their hazard quotients (HQ) and hazard Index (HI), and also explored the possible associations between exposure and measured routine blood parameters in study population. The detectable frequencies of MEL, AMN, AMD and CYA were 96.65%, 41.00%, 97.91% and 97.07%, respectively. The median values of creatinine (Cr)-adjusted MEL, AMN, AMD, CYA and the total concentrations of MEL and its derivatives (∑MEL) were 11.41 µg/g Cr, not detected (ND), 2.64 µg/g Cr, 15.30 µg/g Cr, 35.02 µg/g Cr, respectively. There were 9 (3.77%) participants with estimated daily intakes (EDIs) of CYA exceeding the tolerable daily intake (TDI) of 2500 ng/kg bw/day, and 12 (5.02%) participants with HI of ∑MEL exposure exceeding 1 based on the strictest TDI value. Urinary concentrations of MEL and its derivatives were positively associated with specific routine blood parameters, including hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, white blood cell, neutrophil count (P < 0.05). Meanwhile, exposure to MEL and its derivatives increased the risk of red blood cell abnormality (P < 0.05). Our study is the first study to provide evidence-based data on the CRA of exposure to MEL and its derivatives in Chinese adults, and to propose a possible association between such exposure and routine blood parameters in human.