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Water eutrophication caused by nitrogen pollution is an urgent global issue that requires attention. The Qingyi River is a typical micro-polluted river in China. In this study, we took this river as the research object to investigate the nitrogen pollution purification capacity of a herbaceous plant, Rumex japonicus Houtt. (RJH). Compared to nitrate nitrogen (NO 3 −-N) and nitrite nitrogen (NO 2 −-N), RJH showed better purification performance on total nitrogen (TN), total phosphorus (TP) and ammonia nitrogen (NH 4 +-N), with a highest removal rate of 37.22%, 52.13%, and 100%, respectively. RJH could completely remove ammonia nitrogen and exhibit excellent resistance to pollutant interference when the initial concentration of ammonia nitrogen in the cultivation devices increased from 1 mg/L to 10 mg/L or in the actual river. This indicated the great application potential of RJH in ammonia nitrogen removal from natural micro-polluted rivers. In addition, combined effects of nitrification of roots, absorption of self-growth, stripping, and others contributed to nitrogen removal by RJH. Particularly, the nitrification of roots played a dominant role, accounting for 73.85% ± 8.79%. High-throughput sequencing results indicate that nitrifying bacteria accounted for over 75% of all bacterial species in RJH. Furthermore, RJH showed good growth status and strong adaptability. The correlation coefficients of its relative growth rate with chlorophyll A and the degradation rate of absorption were 0.9677 and 0.9594, respectively. Our research demonstrates that RJH is one of the excellent varieties for ammonia removal. This provides a very promising and sustainable method for purifying micro-polluted rivers. [Display omitted] • A Rumex japonicus Houtt.(RJH)-based phytoremediation technology was proposed. • Nitrification, absorption, stripping and other effects influenced ammonia removal. • Nitrification of roots accounted for 73.85% ± 8.79% of the total degradation rate. • The good growth status and strong purification ability of RJH were verified. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants in the environment, which are teratogenic, carcinogenic, and mutagenic. Co-contamination of PAHs and heavy metal commonly exists in soil. In this study, 20 types of soils with different properties in China were collected and comprehensively characterized. Phenanthrene (Phe) and Cu (II) were selected as representatives of PAHs and heavy metals, respectively. The adsorption-desorption behaviors of Phe under Phe contamination and Cu (II)-Phe co-contamination in 20 types of soils were studied. The adsorption-desorption behaviors of Phe in 20 types of soils varied greatly, and adsorption of Phe in the soils followed both linear partitioning and nonlinear surface adsorption. Soil organic matter (SOM) plays an important role in the adsorption-desorption behavior of Phe. When the concentrations of Phe were >50 μg/L, soft carbon (SC) fraction of SOM not black carbon (BC) contributed more to the adsorption of Phe. Soil dissolved organic matter (DOM), especially fulvic acid and humic acid fractions, contributes to the adsorption of Phe. Under the effect of Cu (II) (60 mg/L in solution), the adsorption capacity of soil for Phe increased, which possibly resulted from lowered pH, the existence of the cation-π bonding and the "bonding bridge" effect. The systematic investigation of adsorption-desorption behaviors of Phe in soils under heavy metal-PAHs co-contamination will provide a scientific basis for the calculation of soil environmental capacity in the future. [Display omitted] • Adsorption of Phe in soils with Cu (II)-Phe co-contamination exhibits both partitioning and surface adsorption. • The adsorption capacity of soil for Phe increases under co-contamination of Cu (II)-Phe. • Significant positive correlations were observed between Phe adsorption and SOM, SC in soils. [ABSTRACT FROM AUTHOR]

Nonylphenol (NP) contamination in the coastal environment of China poses ecological risks to aquatic organisms. However, the endocrine disruptive impacts of NP on bivalves, particularly on ovarian development, remain poorly understood. In this study, Manila clams Ruditapes philippinarum at the developing stage of gonad were exposed to 1.0 μg/L NP for 21 days. Utilizing RNA interference (RNAi) to suppress ER gene expression, we observed a delay in ovarian development as evidenced by histological observations under both NP and NPRi (NP with ER-RNAi) treatment, with Vtg elevation exclusive to the NP group. Comprehensive analyses encompassing transcriptomics, real-time quantitative PCR, and steroid hormone measurement revealed significant alterations in aldosterone synthesis, estrogen signaling, and thyroid hormone synthesis. These pathways showed similar perturbations in both NP and NPRi groups compared to controls. Notably, the NPRi group exhibited distinct enrichment in PPAR and insulin signaling pathways, may implicating these in ER function suppression. Steroid hormone biosynthesis was notably reduced in both treatments, pointing to a profound impact on hormone synthesis. The contrast between in vivo and in vitro findings suggests that NP's detrimental effects on ovarian development may primarily involve neuroendocrine regulation of steroidogenesis. This investigation highlights the complex dynamics of NP-induced endocrine disruption in bivalves, emphasizing the pivotal role of ER and associated pathways. [Display omitted] • NP accumulation leads to delayed ovarian development in clams. • NP accumulation induces the expression of ER and Vtg. • ER-RNAi clams shows no increased expression of Vtg after NP exposure. • Ovarian development cease may due to depressed steroids biosynthesis caused by NP exposure. [ABSTRACT FROM AUTHOR]

In recent years, the incidence of thyroid cancer has been on a significant rise worldwide, and a number of environmental factors have been suspected to be risk factors for thyroid cancer, especially the relationship between iodine intake and thyroid cancer has attracted attention. In this study, we want to assess the relationship between different water iodine exposures and thyroid cancer incidence before and after water alteration in areas with high water iodine in China. Thyroid cancer patients (2009–2020) were enrolled at two hospitals, both in Heze City, Shandong Province, an area with high water iodine levels. According to the criteria of the study, 5826 cases out of 8785 cases were selected for inclusion in the study. Before and after water alteration, the incidence of thyroid cancer was highest in areas with water iodine concentrations of 200–300 μg/L in high iodine areas. In areas where water iodine decreased to adequate iodine levels, there was a strong negative correlation between the decreased level of water iodine and the incidence of thyroid cancer. In addition, in cases with pathology reports, we found that the greater the decrease in water iodine values, the markedly smaller the maximum diameter of the thyroid cancer lesions. Taken together, these findings suggest that we should continue to monitor the incidence of thyroid cancer in areas with high water iodine and continue to optimize population iodine intake to reduce the incidence of thyroid cancer. [Display omitted] • Highest incidence of thyroid cancer found in areas with 200–300 μg/L water iodine. • Water iodine decline values negatively correlated with thyroid cancer incidence. • The lower water iodine levels, the smaller the diameter of thyroid cancer lesions. [ABSTRACT FROM AUTHOR]