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Background Polycyclic aromatic hydrocarbons (PAHs) are one of the most widely distributed and harmful organic pollutants in the atmosphere. Objective To investigate the distribution characteristics and composition sources of PAHs in the atmosphere of two districts of Lanzhou from 2019 to 2020 and evaluate the health risks of PAHs via inhalation to different populations. Methods The PAHs concentrations in two urban areas (Chengguan District and Xigu District) of Lanzhou City from January 2019 to December 2020 were regularly monitored. Mann-Whitney U test was used to compare differences in target pollutant concentrations between the two areas. Diagnostic ratio method and principal component analysis were adopted for source identification. Incremental lifetime cancer risk (ILCR) model was applied to evaluate the health risks of PAHs. Results The M (P25, P75) PAHs concentrations in Chengguan District and Xigu District were 24.04 (14.59, 41.81) ng·m−3 and 25.97 (18.59, 42.56) ng·m−3, respectively, with no significant difference (Z=−0.970, P>0.05). As to seasonal distribution, most PAHs monomer concentrations in Chengguan District were higher than those in Xigu District in summer, and the concentrations of benzo[a]anthracene and benzo[g,h,i]perylene in Chengguan District were also higher than those in Xigu District in spring and autumn (P<0.05), but there were no significant differences in PAHs monomer concentrations between the two urban areas in winter (P>0.05). Ring number of PAHs exhibited seasonal fluctuations. In winter and spring, the highest proportions in Chengguan District and Xigu District were both 4-ring PAHs (37.32%-41.73%, 35.20%-39.66%), and in summer and autumn, the highest proportions were both 2- and 3-ring PAHs (39.38%-49.54%, 47.17%-51.23%). The results of diagnostic ratio method revealed mixed atmospheric PAHs sources in the two urban areas, including fossil fuel, coal, and biomass combustion. The results of principal component analysis showed that the cumulative contribution rate of the four principal component factors reached 79.54%. Principal component 1 included phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene; principal component 2 included acenaphthene and dibenzo[a,h]anthracene; principal component 3 was fluorene; principal component 4 was naphthalene. The results of health risk assessment showed that the ILCR values of adult males, adult females, and children in Chengguan District were 2.30×10−6, 2.16×10−6, and 1.73×10−6, respectively; and those in Xigu District were 1.58×10−6, 1.48×10−6, and 1.19×10−6, respectively; all were greater than 10−6. Conclusion PAHs pollution exists in the atmosphere of the two urban areas of Lanzhou City, mainly comes from mixed sources of fossil fuels, coal, and biomass burning, and may pose potential carcinogenic risks to the population.
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Background Because of high working intensity, high responsibility, and unexpected situations, health care workers may suffer great work pressure, which may lead to health damage. Objective To explore the self-rated health status and its influencing factors such as demographic and occupational-related factors of medical staff in Lanzhou. Methods In-service medical staff were selected by using cluster random sampling method from 18 public hospitals in Lanzhou City and were investigated with a self-made questionnaire and the Self-rated Health Measurement Scale (SRHMS). SRHMS includes 48 items in 10 dimensions, which are divided into three sub-scales of physical health, mental health, and social health, and another independent dimension is overall health. The scores were converted into a percentage scale and expressed as the percentage of measured score to full score; a higher score indicated better health, and >70% was considered good health status. t test, Kruskal-Wallis H test, and Spearman correlation were used to analyze the scores of SRHMS and the demographic and occupational-related factors affecting the scores of physical, mental, and social health sub-scales. Results A total of 2989 valid questionnaires were recovered. There were statistically significant differences in total score and the scores of physical, mental, and social health among medical staff of different age, educational background, length of service, and weekly working hours groups (P < 0.05). The percentage of total score to full score in the medical staff was 71.41%, but the scores of physical, mental, and social health sub-scales and total scale of selected participants were all lower than the corresponding domestic norms (t=−3.323, −12.283, −7.157, −9.659, P < 0.05); the percentage of psychological symptoms and negative emotions in mental health scale to full score was the lowest, only 58.39%. Educational background, length of service, and weekly working hours were negatively correlated with physical health score (r=−0.061, −0.060, −0.165, P < 0.05); professional title was positively correlated with mental health score (r=0.045, P < 0.05), while educational background and weekly working hours were negatively correlated with it (r=−0.051, −0.172, P < 0.05). Monthly income, professional title, and length of service were positively correlated with social health score (r=0.040, 0.049, 0.071, P < 0.05), while educational background and weekly working hours were negatively correlated with it (r=−0.038, −0.110, P < 0.05). Conclusion The self-rated health status of selected medical staff in Lanzhou is generally good, but lower than that of the norm, especially the mental health score is the lowest. The self-rated health score of total scale is correlated with education, length of service, professional title, and working time per week.
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Background Air pollutants PM2.5 and its adsorbed metal elements are important factors affecting public health. Objective To explore the distribution characteristics and sources of metal elements in atmospheric PM2.5 in Lanzhou from 2019 to 2020, and to assess the health risks of metal elements to different groups of residents through inhalation. Methods From January 2019 to December 2020 in two districts of Lanzhou City (Chengguan District and Xigu District), regular PM2.5 and metal elements [antimony (Sb), aluminum (Al), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se), and thallium (Tl)] were regularly monitored, and their concentrations were described by the median (M) and 25th and 75th percentiles (P25, P75) as not following a normal distribution (because the detection rates of the five elements Be, Cr, Hg, Ni, and Se were less than 70%, the five elements were not included in subsequent analysis), and then compared with the secondary concentration limits in the Ambient Air Quality Standards (GB 3095-2012). The differences between the medians of the two groups were compared by the Mann-Whitney U rank sum test, and the differences among the medians of multiple groups were compared by the Kruskal-Wallis H rank sum test; the enrichment factor (EF) method and principal component analysis were used to evaluate the pollution degree of the metals and their sources; the health risks of five non-carcinogenic metals (Sb, Al, Pb, Mn, and Tl) and two carcinogenic metals (As and Cd) in PM2.5 were evaluated by hazard index (HI) and hazard quotient (HQ) using the incremental lifetime cancer risk (LCR) model and the non-carcinogenic risk assessment model, respectively. Results The PM2.5 concentrations [M (P25, P75)] in Lanzhou City were 38.50 (26.00, 65.00) and 41.00 (29.00, 63.10) μg·m−3 in 2019 and 2020, respectively, and the difference was not statistically significant (Z=−0.989, P > 0.05). The average levels of the metal elements from high to low were: Al > Pb > Mn > As > Cd > Sb > Tl, and the annual average concentration of each metal element in 2019 was higher than that in 2020 (P<0.05). The M ( P25, P75) of PM2.5 concentrations in Chengguan and Xigu districts were 52.98 (17.00, 61.00) and 55.40 (17.00, 67.00) μg·m−3, respectively, with no statistically significant differences (P<0.05); the concentrations of Sb and Al in Chengguan District were lower than those in Xigu District (P<0.05), and the concentrations of other metal elements were not different between the two areas (P>0.05). There were seasonal differences in the concentrations of PM2.5 and seven metal elements in Lanzhou City (except PAl=0.007, the other Ps < 0.001). The results of the enrichment factor method showed that the EF values of the six metals (Sb, Al, As, Cd, Pb and Tl) were all greater than 1. Among them, except As, the EF values of other metal elements were all greater than 10, and the EF values of Al and Cd were both greater than 100. The results of principal component analysis showed that the variance contributions of the three principal components were 45.61%, 24.22%, and 14.42%, and the cumulative contribution reached 84.25%. The principal component 1 included Pb, As, Cd, and Sb, the principal component 2 included Al and Mn, and the principal component 3 contained Tl. The non-carcinogenic risks of the five metals were, in descending order, Al > Mn > Pb > Tl > Sb, among which the HQ values of the remaining four metals were less than 1 for adults and children, except the HQ value of Al for adults, which was greater than 1. The ILC values of carcinogenic metal As for adult males, adult females, and children were 2.68×10−5, 2.51×10−5, and 1.45×10−5, respectively; the ILC values of carcinogenic metal Cd for adult males, adult females, and children were 1.53×10−6, 1.43×10−6, and 8.26×10−7, respectively. Conclusion There is pollution of atmospheric PM2.5 and its adsorbed metal elements in Lanzhou. As and Cd elements may pose potential carcinogenic risks to the residents.
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ObjectiveTo investigate the effect of serum C-peptide level on the progression of liver fibrosis in patients with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD). MethodsA total of 484 patients with T2DM who were admitted to Department of Geriatrics, The Second Hospital of Lanzhou University, from December 2018 to July 2020 were enrolled, and according to the results of abdominal ultrasound examination, they were divided into simple T2DM group with 107 patients and T2DM+NAFLD group with 377 patients. According to NAFLD fibrosis score, the patients with T2DM and NAFLD were divided into fibrosis exclusion subgroup （T2DM+F0） with 136 patients, uncertain subgroup (T2DM+F1) with 146 patients, and fibrosis subgroup (T2DM+F2) with 95 patients. Medical history data and laboratory markers were collected. The chi-square test was used for comparison of categorical data; the t-test or the Mann-Whitney U test was used for comparison of continuous data, and a one-way analysis of variance or the Kruskal-Wallis H test was used for comparison between multiple groups; a logistic regression analysis was used to explore the risk factors for the progression of liver fibrosis; the receiver operating characteristic (ROC) curve was used to analyze the clinical value of serum C-peptide in predicting and diagnosing the progression of liver fibrosis. ResultsCompared with the simple T2DM group, the T2DM+NAFLD group had a significant increase in C-peptide level (Z=-6.040,P＜0.001); compared with the T2DM+F1 and T2DM+F0, the T2DM+F2 had significantly higher C-peptide level ［2.89 (1.84-3.77) vs 1.97 (1.12-2.65)/1.87 (1.25-2.68), H=36.023,P＜0.001) and rate of fasting C-peptide (56.84% vs 23.29%/24.27%, χ2=37.583,P＜0001). The logistic regression analysis showed that C-peptide (OR=1.435, 95% confidence interval: 1.227~1.678， P＜0.001) was a risk factor for liver fibrosis in patients with T2DM and NAFLD, and the ROC curve analysis also showed that C-peptide had great significance in predicting liver fibrosis in such patients, with an area under the ROC curve of 0.814, a sensitivity of 642%, a specificity of 897%, and a Youden index of 0.539 at the optimal cut-off value of 2.405 ng/ml. ConclusionC-peptide is an independent risk factor for the progression of liver fibrosis in patients with T2DM and NAFLD.