Pollution levels and risk assessment of perfluoroalkyl acids (PFAAs) in beef muscle and liver from southern Xinjiang.

The presence of perfluoroalkyl acids (PFAAs) in animal foods is worldwide, and their fate and spatial distribution in Xinjiang are not well understood. In this study, beef muscle and liver collected from five major cities in southern Xinjiang were analyzed (n = 70) for 13 PFAAs using an ion-pairing method combined with HPLC-MS/MS. Overall, PFAA contamination was widespread, exceeding 50% of samples with concentrations ranged from below the limits of detection to 6.118 ng/g. Perfluorooctane sulfonate, perfluorooctanoic acid, and perfluoroundecanoic acid were the predominant PFAAs of ten detected compounds, with maximum concentrations in Korla liver samples of 2.543, 0.856, and 1.386 ng/g, respectively. When comparing the five cities, the highest levels and detection frequencies were observed in samples from Korla (muscle, 0.013 ng/g; liver, 3.336 ng/g), followed by Yanqi, Akesu, Kashgar, and Hotan. The different pollution patterns and distribution profiles of PFAAs among cities were significantly related to local economy and geographical conditions. In addition, the dietary intake assessments for PFAAs showed that samples originating from Korla had the greatest impact on human health, but the total hazard ratio was 0.814 × 10-3, which is far less than 1, indicating that consumption of beef muscle and liver poses no immediate harm to local residents.

Assessment of microbial communities in PM1 and PM10 of Urumqi during winter.

Recently, inhalable particulate matter has been reported to carry microorganisms responsible for human allergy and respiratory disease. The unique geographical environment and adverse weather conditions of Urumqi cause double pollution of dust and smog, but research on the microbial content of the atmosphere has not been commenced. In this study, 16S and 18S rRNA gene sequencing were conducted to investigate the microbial composition of Urumqi's PM1 and PM10 pollutants in winter. Results showed that the bacterial community is mainly composed of Proteobacteria, Firmicutes and Actinobacteria, Proteobacteria accounted for the most proportion which was significant difference in some aforementioned studies. Ascomycota and Basidiomycota constitute the main part of the fungal microbial community. The difference of bacterial relative abundance in sample point is greater than in particle sizes. The sequences of several pathogenic bacteria and opportunistic pathogens were also detected, such as Acinetobacter, Delftia, Serratia, Chryseobacterium, which may impact on immunocompromised populations (elderly, children and postoperative convalescence patients), and some fungal genera may cause several plant diseases. Our findings may serve an important reference value in the global air microbial propagation and air microbial research in desert.