Shallow lakes, one of the most widespread water bodies in the world, are easily shifted to a new trophic state due to external interferences. Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms (CyanoHABs) in shallow lakes, which pose serious threats to ecological integrity and human health. This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes (Lake Dongting and Poyang) and isolated lakes (Lake Chao and Tai). The results show that (i) chlorophyll-a (Chl-a) concentration tends to decrease exponentially with increasing relative lake level fluctuations (RLLF) and precipitation, but to increase linearly with increasing wind speed and air temperature; (ii) Chl-a concentrations in lakes were significantly higher when RLLF < 100, precipitation < 2.6 mm, wind speed > 2.6 m s⁻¹, or air temperature > 17.8 °C; (iii) the Chl-a concentration of Yangtze-isolated lakes was more significantly affected by water level amplitude, precipitation, wind speed and air temperature than the Yangtze-connected lakes; (iv) the RLLF and the ratio of wind speed to mean water depth could be innovative coupling factors to examine variation characteristics of Chl-a in shallow lakes with greater correlation than single factors.

Polyethylene terephthalate microplastics (PET-MPs) have been detected in the environment and human metabolites or tissues; however, their potential effects on humans under actual exposure doses remain unclear. Herein, male adult mice were exposed to 10 µm PET-MPs at concentrations of 10, 50, and 250 mg/kg per body weight consecutively for 28 days. Changes in blood biochemistry, inflammatory factors, colonic histopathology, colonic mucus gene mRNA levels, and the gut microflora were monitored to study PET-MPs toxicity. The results showed that PET-MPs exposure increased relative serum alanine aminotransferase (ALT) and glucose (GLU) levels in 50 mg/kg bw PET-MPs exposure group, and altered relative levels of inflammatory factors, thereby inducing the inflammatory response. Moreover, PET-MPs exposure increased mRNA expression levels of colonic mucus secretion related and barrier function related genes, indicating intestinal mucus secretion and barrier integrity dysfunction, which was consistent with the results of histopathological results. In addition, gut microbiota analysis revealed that the diversity and community composition were altered after PET-MPs exposure, suggesting a metabolic disorder. Therefore, our results demonstrated that exposure to PET-MPs led to intestinal injury and changes in the gut microbiome composition in mice. Overall, the study findings provided basic data about the health risks of PET-MPs to humans, highlighting that MPs-induced toxicity warrants more concern in the future.

Both fine particulate matter (PM_2.5) and ozone (O₃) may have adverse effects on human health. However, previous studies on the effects of air pollutants mainly have focused on susceptible population, and evidence on healthy young adults is limited. We aimed to examine the associations of the two main air pollutants (PM_2.5 and O₃) with lung function, inflammation and oxidative stress in healthy young adults. We recruited 30 healthy young adults for a longitudinal panel study in Beijing and implemented health examination seven times, including lung function (FEV₁ and PEF) and biomarkers of inflammation and oxidative stress (i.e. C-reactive protein, CRP; interleukin-6, IL-6; malondialdehyde, MDA) from December 2019 to May 2021. Hourly ambient air pollutants data were obtained from the closest air quality monitoring station. Linear mixed-effect model was applied to explore the associations between air pollutants and lung function, inflammation and oxidative stress. We observed higher PM_2.5 exposure was associated with decrement in lung function and increment in CRP and MDA. Each 10 μg/m³ increase in PM_2.5 (lag 2 day) is associated with a 17.06 ml (95% CI: -31.53, -2.58) decrease in FEV₁, 46.34 ml/s (95% CI: -76.41, -16.27) decrease in PEF and increments of 2.86% (95% CI: 1.47%, 4.27%) in CRP, 1.63% (95% CI: 0.14%, 3.14%) in MDA respectively. However, there is no significant association between ozone exposure and health indicators. The study suggested that short-term exposure to PM_2.5 may decrease lung function and induce inflammation and oxidative stress in healthy adults, but there is no association between O₃ and each outcome.

Microplastics in drinking water have attracted increasing global concerns due to their potential adverse impacts on human health. However, there needs to be more knowledge of the occurrence and distribution of microplastics in drinking water systems from water sources to household tap water. Herein, laser direct infrared spectroscopy is used to investigate the occurrence of microplastics in a typical drinking water plant with different water sources. Microplastic information is further used to understand microplastic fates during drinking water supply, including microplastic abundance, size, shape, and polymer type. Overall, the microplastic abundance in treated water ranges from 12.00 to 25.33 particles/L, higher than those in raw water (RW; 2.33–17.33 particles/L) and household water (HW; 8.00–19.67 particles/L), which shows that microplastics are not removed from RW. The main polymers in these microplastics are polyethylene terephthalate, polyvinyl chloride, polyethylene, and polypropylene. At the same time, the main microplastic shapes are fragments and fibers. Small-sized microplastics of 20–100 μm account for up to 76.74% and 79.30% of microplastics during the dry and wet seasons, respectively. Additionally, more microplastics are detected in RW from rivers than those from reservoirs and lakes, and the microplastic abundance in the wet season is higher than that in the dry season. As expected, the potential ecological risk of microplastics in all waters is the I level, which is the lowest level. Most importantly, the annual microplastic intake of an adult via drinking water is 5063–18,301 microplastics, less than that reported in previous studies. These results provide valuable data on the fates of microplastics in drinking water supply systems from water sources to HW and promote authorities to update the treatment technologies for drinking water in the future to remove microplastics efficiently.