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A high concentration of arsenic in groundwater is a worldwide problem, high concentration of arsenic in groundwater has been documented as a major health issue around the globe. According to WHO standard, the maximum contamination level for total arsenic in water is 10 μg/L. China is one of the most affected country facing health issues because of arsenic contamination in groundwater that is often greater than established limits for human health. Although arsenic is present in several geographical regions in mainland China, Northern China has been identified as high-risk area. It has been estimated that 19.6 million people are at risk of being exposed to arsenic contaminated groundwaterespecially rural areas, as those communities use groundwater for drinking water and household chores. To overcome the aforementioned problem, it is important to know the actual concentration level of arsenic in China and introduce a strategy to remove arsenic contamination. This paper provides a comprehensive overview on arsenic contamination status, sources and exposure pathways in China. It also aims to review the arsenic removal technologies which are easily available. Furthermore, it can be a useful resource for researchers as well as policy makers to identify and investigate useful treatment options.

The prohibition of the use of growth-promoting drug additives in feeds was implemented in China in 2020. However, rabbits can experience symptoms of intestinal disease, such as diarrhea and flatulence, when switching from standard normal diets with antibiotics to antibiotic-free diets. The molecular mechanisms related to the occurrence of these diseases as well as associated physiological and metabolic changes in the intestine are unclear. Thus, the objectives of this study were to study the pathogenesis of intestinal inflammation using untargeted metabolomics. This was done to identify differential metabolites between a group of antibiotic-free feed Hyplus rabbits (Dia) whose diet was abruptly changed from a standard normal diet with antibiotics to an antibiotic-free diet, and an antibiotic diet group Hyplus rabbits (Con) that was fed a standard normal diet with antibiotics. Morphological damage to the three intestinal tissues was determined through visual microscopic examination of intestinal Dia and Con tissue samples stained with hematoxylin and eosin (HE). A total of 1969 different metabolites were identified in the three intestinal tissues from Dia and Con rabbits. The level of 1280 metabolites was significantly higher and the level of 761 metabolites was significantly lower in the Dia than in the Con group. These differential metabolites were involved in five metabolic pathways associated with intestinal inflammation (tryptophan metabolism, pyrimidine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, lysine degradation, and bile secretion). Rabbits in the Dia group developed metabolic disorders that affected the intestinal microbiota and changed the permeability of the intestinal tract, thereby triggering intestinal inflammation, affecting feed utilization, reducing production performance, and activating the intestinal tract self-repair mechanism. Thus, the abrupt transition from a diet with antibiotics to an antibiotic-free diet affected the structure and metabolism of the intestinal tract in Hyplus rabbits. Consequently, to avoid these problems, the antibiotic content in a rabbit diet should be changed gradually or alternative antibiotics should be found.

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