Temporal and spatial variation of microplastics in Baotou section of Yellow River, China.

Freshwater rivers play the key role in providing drinking water sources and building the bridge of oceans and lands. Hence, environmental pollutants can be transferred into drinking water through a water treatment process and transported land-based microplastics into the ocean. Microplastics are considered a new pollutant that is becoming a threat to freshwater ecosystems. The present study investigated the temporal and spatial variation of microplastics abundance and their characteristics of occurrence in surface water, sediment and soil samples of Baotou section of Yellow River in China in March 2021 and September 2021. According to the LDIR analysis, the average abundances of microplastics in wet season (surface water 2510.83 ± 2971.27n/L, sediment 6166.67 ± 2914.56n/kg) were higher than that in dry season（surface water 432.5 ± 240.54n/L, sediment 3766.67 ± 1625.63n/kg), particularly being significant difference in the dry and wet seasons of surface water. The predominant polymer types in surface water (PBS and PET during the dry season, PP during the wet season) demonstrated that the temporal variation of microplastics abundance in surface water could be attributed to the combined effect of the regional precipitation, fishing activities and improper disposal of plastic waste. And the results of spatial abundances of microplastics showed that the microplastics abundance of soil and sediment was higher than that in river water and microplastics abundance in the river of the south side was the higher than other water sampling sites, revealing the differences of microplastics burden at the different sampling sites. Moreover, it is worth noting that a large amount of PAM was detected in sediments and soil, but not in water, and the biodegradable plastics PBS and PLA were also detected in the Yellow River. It was a very useful information for evaluating environmental impacts and ecological effects of degradable plastics compared to the traditional plastics after the implementation of a new environmental policy in the future. Thus, this study provided insights into the temporal-spatial characteristics of microplastics in an urban river and raised environmental management awareness of the long-term threat to drinking water safety by microplastics.

The developmental toxicity and transcriptome analyses of zebrafish (Danio rerio) embryos exposed to carbon nanoparticles.

Long-term and short-term exposure to carbon nanoparticles (CNPs) can affect fetal development and subsequent adverse outcomes including preterm delivery, intrauterine growth restriction, low birth weight, increased health risk linked to cardiovascular, respiratory and nervous systems in adulthood. The adverse developmental outcomes of CNPs were well known, but the underlying mechanisms remain unresolved. In this study, zebrafish embryos were treated with CNPs of 50,100,200 µg/mL and the toxic effects were observed. Using the RNA-seq analysis approach, we examined the effects of CNPs (200 µg/mL) on gene expression in zebrafish embryos exposed from 4 to 96 h-post-fertilization (hpf). We observed that CNPs-treated embryos exhibited increased malformations and decreased hatching. A total of 236 differentially expressed genes were detected by transcriptome analyses, which were associated with phototransduction, amino acid metabolism, steroid and steroid hormone biosynthesis. Transcriptome results were verified by real-time fluorescence quantitative PCR (RT-qPCR). Our results indicated that CNPs exposure was most likely to lead to differential gene changes in steroid and hormone biosynthesis pathways, thus inducing developmental toxicity such as delayed incubation of zebrafish embryos, increased malformation rate and multiple malformation phenotypes.

[TH1/TH2 type cytokine expression and DNA aberrant methylation analysis in peripheral blood of coke oven workers].

OBJECTIVE: To understand the exposure levels of polycyclic aromatic hydrocarbons(PAHs) and the expression of interleukin-2(IL-2), interferon-γ(IFN-γ), interleukin-4(IL-4), interleukin-10(IL-10) in peripheral blood of coke oven workers exposed to coke oven emissions(COEs). The other purpose of this study was to understand the performance of IFN-γ and IL-10 epigenetic mechanisms in COEs exposure damage. METHODS: The 85 workers exposed to COEs in a coking plant were randomly selected as the exposure group. The 47 workers who were exposed to non-COEs in the coking plant were used as the control group. The morning urine of the exposure group and the control group were subjected to detection of 1-OHPyr levels with alkaline hydrolysis High-performance liquid chromatography fluorescence, urine creatinine correction. The peripheral venous blood were subjected to detection of the expression of IL-2, IFN-γ, IL-4 and IL-10 with enzyme-linked immunosorbent assay. And methylation levels of IFN-γ and IL-10 were analyzed by time of flight mass spectrometry. RESULTS: The urine 1-hyroxy-pyrene(1-OHPyr) content of coke oven workers was higher than that of the control group(F=12. 446, P<0. 05). The urine 1-OHPyr content of the furnace side and the furnace top were higher than the control group, and the differences were statistically significant. Compared with the control group, serum IL-2 content of coke oven workers decreased(F=14. 774, P<0. 05), and serum IFN-γ content of coke oven workers decreased(F=46. 379, P<0. 05), the serum IL-4 content of coke oven workers increased(F=17. 426, P<0. 05), the serum IL-10 content of coke oven workers increased(F=33. 515, P<0. 05), and the TH1/TH2 ratio of coke oven workers decreased(F=21. 677, P<0. 05). In the exposed group, the level of IFN-γ in the top of the furnace was higher than that in the bottom of the furnace. The difference was statistically significant. The level of IL-10 in the top and bottom of the furnace was lower than that in the furnace. The difference was statistically significant. The IL-10 CpG-11, CpG-15 and mean methylation rates in the exposed group were lower than those in the control group, and the differences were statistically significant. The methylation rate of IFN-γ CpG-5 in the exposed group was higher than that in the control group, and the difference was statistically significant. The urine 1-OHPyr content of coke oven workers was negatively correlated with TH1/TH2 ratio and IFN-γ expression level, and positively correlated with IL-4 and IL-10 levels. The IL-10 CpG-11, CpG-15 methylation rate decreased with increasing urine 1-OHPyr concentration. CONCLUSION: The side and top of the furnace worker exposed to COEs were the key targets for occupational health. The exposure of coke oven workers to COEs affected the expression of immunoregulatory cytokines. The exposure of COEs caused the change of IL-10 methylation rate.

[Effects of the inhalable particle (PM10) on secretion of inflammatory factors in human lung fibroblasts and mouse alveolar macrophage cell].

OBJECTIVE: To study the effects of PM10 and the concentrated culture suspension of RAW264.7 cells treated with PM10 on the secretion of tumor necrosis factor-alpha (TNF-alpha), interleukin-6(IL-6) and interleukin-8(IL-8) in the human lung fibroblasts( HLF). METHODS: PM10 were collected during heating period in the urban area of Beijing. HLF and mouse alveolar macrophage cell (RAW264.7) were used. The two ways of exposed cells to PM10 were used: (1) HLF were treated with the different concentration of PM10 for 24h. (2) HLF were stimulated by the added the suspension of RAW264.7 cell exposed to different concentrations of PM10. Cytotoxicity of PM10 was measured by MTT assay. The levels of inflammatory cytokines TNF-alpha, IL-6 and IL-8 were determined by the radioimmunity assay. RESULTS: After treated for 24h, PM10 showed the cytotoxicity in HLF and RAW264.7 cells, which was characterized by increase of the viability of cells at low concentration of PM10, and decrease at high doses. PM10 induced the secretion of TNF-alpha, IL-6 and IL-8 in HLF in a dose-dependent manner. The concentrated culture medium of RAW264.7 cells treated with PM10 also stimulated the secretion of TNF-alpha, IL-6 and IL-8 in HLF. CONCLUSION: PM10 is cytotoxic to HLF and RAW264.7 cells. PM10 induced the secretion of TNF-alpha, IL-6 and IL-8 in HLF. This effect was also observed by treatment of HLF with the concentrated culture medium of RAW264.7 cell exposed to PM10.