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Background The safety of drinking water is closely related to people's health. In recent years, relevant studies have identified some health related problems with drinking water in Inner Mongolia Autonomous Region. The complex and diverse natural environment embraced by the vast jurisdiction of the region may lead to uneven drinking water quality across the region. Objective To evaluate eight chemicals including arsenic, cadmium, chromium (hexavalent), lead, mercury, fluoride, trichloromethane, and carbon tetrachloride in urban drinking water in Inner Mongolia Autonomous Region in 2021, and to provide reference for optimizing urban water supply system and ideas for further developing strategies to promote population health. Methods A total of 1228 monitoring sites were set up in urban areas of Inner Mongolia, and water samples were collected once in dry season (May) and once in wet season (August−September). Eight chemicals of interest in drinking water were detected according to the Standard examination methods for drinking water, and assessed for health risks using the health risk assessment model recommended by the United States Environmental Protection Agency (USEPA) and following the Technical guide for environmental health risk assessment of chemical exposure. Mann-Whitney U test was used to compare the concentrations of eight chemicals in urban drinking water by water seasons and water sample types. Results In 2021, a total of 2381 samples of urban drinking water were tested in the Inner Mongolia Autonomous Region, including 1195 samples in wet season and 1186 samples in dry season; 389 samples of finished water and 1992 samples of tap water. The positive rates of arsenic and fluoride were 26.25% and 96.77%, respectively. The positive rates of cadmium, chromium (hexavalent), lead, mercury, trichloromethane, and carbon tetrachloride were 6.22%, 16.63%, 6.09%, 16.67%, 18.98%, and 8.36%, respectively. The exceeding standard rate of fluoride was 4.87%. Trichloromethane and carbon tetrachloride were qualified in all samples. There were statistical differences in the concentrations of arsenic, cadmium, chromium (hexavalent), lead, and carbon tetrachloride in urban drinking water between water seasons (Z=−3.847, P<0.05; Z=2.464, P=0.014; Z=−3.129, P=0.002; Z=4.341, P<0.05; Z=4.342, P<0.05). Only fluoride concentration was found statistically different among different water sample types (Z=−2.287, P=0.022). The non-carcinogenic risks of ingestion and dermal exposure to each chemical in drinking water by water seasons and water sample types were all less than 1, but the P95 total non-carcinogenic risks of oral exposure were greater than 1. The P95 carcinogenic risks of oral exposure to some chemicals in drinking water by water seasons and water sample types were>10−4, which suggested carcinogenic risks, while the carcinogenic risks of dermal explore to chemicals were all less than 10−6. Conclusion In 2021, urban drinking water in Inner Mongolia Autonomous Region is generally safe, but arsenic, cadmium, chromium (hexavalent), lead, mercury, and fluoride still exceed the national limits, posing certain health risks.
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<p><b>OBJECTIVE</b>The aim of this study was to establish a standard protocol for detection of EGFR mutations in cytologic specimens.</p><p><b>METHODS</b>287 cytologic samples were collected from the patients who were suspected of having lung cancer at six hospitals in Beijing. A detection protocol for EGFR mutations was designed. Two comparative experiments were carried out for the coincidence in EGFR mutation rates between direct sequencing (Seq) and amplification refractory mutation system (ARMS) methods, and between 40 matched cytologic samples with formaldehyde-fixed paraffin embedded (FFPE) cytologic blocks and cytospin slides.</p><p><b>RESULTS</b>Tumor cells were found in 236 out of 287 cases (82.2%, 236/287) . Among them, there were 31 cases (13.1%, 31/236) of low tumor cell content samples and 205 cases (86.9%, 205/236) of high tumor cell content samples. 180 cases in the high tumor cell content samples (87.8%, 180/205) were diagnosed to be consistent with NSCLC. 25 out of 194 cases were ruled out or indefinite to be diagnosed as NSCLC by immunohistochemistry. By direct sequencing, the mutation rate of EGFR was 27.8% (50/180) in NSCLC samples and 28.2% (50/177) in adenocarcinoma samples (high tumor content samples) . By ARMS, the mutation rate of EGFR was 45.6% (82/180) in NSCLC samples and 46.3% (82/177) in adenocarcinoma samples (high tumor content samples). The EGFR mutation rate in low tumor content samples was 38.7% (12/31) , there was no significant difference in EGFR mutation rates between the groups of low tumor cell content samples and high tumor cell content samples (P = 0.12). The concordance rate of EGFR mutation rates was 100% between scraping tumor cells from slides samples and from FFEP blocks in the 40 matched samples. Forty-eight out of 180 definitive NSCLC patients received Gefitinib therapy. The FPS was 12 months in the gefitinib-treated ARMS⁺ group and 2 months in the ARMS⁻ group (P < 0.001), and the OS was 19 months in the gefitinib-treated ARMS⁺ group and 7 months in the ARMS⁻ group (P = 0.003), but no significant differences were found in the efficacy (PFS and OS) of Gefitinib between Seq⁺ and Seq⁻ groups (P = 0.227, P = 0.510, respectively), and Seq⁺/ARMS⁺ and Seq⁻/ARMS⁺ groups (P = 0.354, P = 0.334, respectively).</p><p><b>CONCLUSIONS</b>The detection protocol for EGFR mutations in cytological specimens introduced in this study is tested to be reliable and feasible. Pathological evaluation and immunohistochemistry are important in the detection procedure of EGFR mutations in cytologic specimens. High sensitivity methods should be selected for detection of EGFR mutations in cytologic samples.</p>