Effects of silver nanoparticles on maternal mammary glands and offspring development under lactation exposure.

The widespread applications of silver nanoparticles (AgNPs) throughout our daily lives have raised concerns regarding their environmental health and safety (EHS). Despite an increasing number of studies focused on the EHS impacts of AgNPs, there remain significant knowledge gaps with respect to their potential health impacts on susceptible populations, such as lactating mothers and infants. Herein, we aimed to investigate the deleterious effects of AgNPs with different sizes (20 and 40 nm) and surface coatings (PVP and BPEI) on maternal mice and their offspring following lactation exposure at doses of 20, 100 and 400 µg/kg body weight. We discovered that AgNPs could accumulate in the maternal mammary glands and disrupt the epithelial barrier in a dose-dependent manner. Notably, BPEI-coated AgNPs caused more damage to the mammary glands than PVP-coated particles. Importantly, we observed that, while AgNPs were distributed throughout the blood and main tissues, they were particularly enriched in the brains of breastfed offspring after maternal exposure during lactation, exhibiting exposure dosage- and particle coating-dependent patterns. Compared to PVP-coated nanoparticles, BPEI-coated AgNPs were more readily transferred to the offspring, possibly due to their enhanced deposition in maternal mammary glands. Moreover, we observed reduced body weight, blood cell toxicity, and tissue injuries in breastfed offspring whose dams received AgNPs. As a whole, these results reveal that maternal exposure to AgNPs results in the translocation of AgNPs into offspring via breastfeeding, inducing developmental impairments in these breastfed offspring. This study provides important new insights into the EHS impacts of AgNP consumption during lactation.

Microplastics in household fecal sewage treatment facilities of rural China.

Fecal sewage (FS), composed of human feces and wastewater, potentially contains microplastics (MPs) that are prone to environmental pollution. In this study, 65 FS samples, as collected from 65 villages in 27 Chinese provinces, have been employed to investigate the characteristics of MPs in three kinds of household FS treatment facilities of rural regions, and the possibility of FS irrigation as the source of MPs in farmlands. As a result, seven physicochemical properties and microbial community of FS were detected, and pertinent social statistical data were collected to determine influencing factors of MPs. The abundance of FS-based MPs ranged from 47.16 to 143.05 particles L-1, with an average 90.38 ± 20.63 particles L-1. The FS from northern China had higher MPs abundance than that from southern and northwestern China. Average MPs abundance was cesspit (101.33) > septic tank (86.54) > biogas digester (84.11). The estimated mass of FS-based MPs entering farmlands in China was 7.8 × 103-5.6 × 104 tons a year. Chemical oxygen demand and genus Phascolarctobacterium might mainly affected MPs abundance in FS, while some other factors such as suspended substance, ambient temperature, and medical care spending were also significantly correlated with FS-based MPs abundance.