Long-term degradation characteristics of cyanide in closed monofills and its effects on the environment and human health: Evidence from nine landfill sites in northen China.

Cyanide residues weighing many millions of tons are disposed of in cyanide residue monofills (CRMs) worldwide. The degradation characteristics of cyanide in the anoxic environments of closed landfills may have been overestimated, leading to an underestimation of the long-term risk of cyanide residue landfills. To study the effect, a total of 387 cyanide residue samples were collected for analysis from nine closed CRMs in northen China that have been closed for more than 10 years. The study shows that the probability of achieving the target cyanide concentration (5 mg/L) in the nine sites was only 2.9%. And there is no significant reduction in the overall concentrations compared to the pre-closure period. The effectiveness of the CRM containment barrier needs to be maintained for at least 220 years to allow cyanide concentrations to degrade to harmless levels. Nine CRMs sites, except for CRMs A and B, had a low short-term risk, but in the long term exposure concentrations can exceed the groundwater Class III water quality limit by a factor of 1.64-30, posing a risk of groundwater contamination. This study reveals the risk of cyanide residue degradation in CRMs and its long-term evolution, providing theoretical support for site management and risk control.

Emodin reduces FFAs-induced fatty degeneration in HepG2 cells via the AMPK/SREBP-1 pathway / 中国医师杂志

Objective To investigate the effects of emodin on the triglyceride metabolism and oxidative stress in steatosis in HepG2 cells and possible underlying mechanisms.Methods The appropriate concentration of emodin on HepG2 cells were detected by methyl thiazolyl tetrazolium (MTT) assay.HepG2 cells were induced to fat overaccumulation by 1 mmol/L free fatty acids (FFA) (oleate∶ palmitate =2∶1).The model group exposed to 10 μmol/L,20 μmol/L,40 μmol/L emodin.The intracellular lipid accumulation was documented by Oil Red O staining and the content of triglyceride and total cholesterol was observed.Reactive oxygen species (ROS) was determined by flow cytometry.Western blotting was performed to analyze the protein levels of adenosine monophosphate-activated protein kinase (AMPK),phosphorylated AMPK,and sterol regulatory element-binding protein 1 (SREBP-1).Results Emodin reduced lipid accumulation and triglycerides (TG) content (P ＜ 0.05).At the same time,it significantly reduced ROS production (P ＜ 0.05).Moreover,the levels of AMPK and p-AMPK protein were significantly upregulated,and SREBP-1 protein was significantly downregulated with the treatment of emodin (P ＜ 0.01).Conclusions This study has demonstrated that emodin can reduce fatty degeneration induced by FFAs in hepatocytes,and this effect may be partially mediated by the AMPK/SREBP-1 pathway.