ISSN 1001-5914 CN 12-1095/R
国家疾病预防控制局 主管
中华预防医学会、天津市疾病预防控制中心 联合主办
国家疾病预防控制局 主管
中华预防医学会、天津市疾病预防控制中心 联合主办
Objective To understand the differences in the levels of inflammatory factors among patients with obstructive sleep apnea-hypopnea syndrome（OSAHS） of different degrees，and to know the effects on the severity of OSAHS and the expression of myocardial enzymes. Methods A total of 225 OSAHS patients admitted to the First People’s Hospital of Huzhou from June 2021 to August 2025 were chosen as the research objects. According to apnea-hypopnea index（AHI），the patients were divided into mild group（AHI 5-15 times/h，n=48），moderate group（AHI>15-30 times/h，n=92） and severe group（AHI>30 times/h，n=85）. The patients were also divided into normal myocardial enzyme group（n=97） and elevated myocardial enzyme group（n=128） based on the expression level of myocardial enzymes. Compare the general data of patients in different AHI groups and myocardial enzyme groups. Multiple linear regression was used to analyze the correlation between AHI level and inflammatory factor level of the patients. Multivariate Logistic regression was used to analyze the influencing factors of elevated myocardial enzyme expression level of the patients. Two-way ANOVA was used to analyze the effects of OSAHS severity and inflammatory factor level on myocardial enzyme expression. Restricted cubic spline（RCS） was used to analyze the dose-response relationship between inflammatory factors and elevated myocardial enzyme expression level. A mediation effect model was constructed to analyze the mediating role of inflammatory factors in the relationship between OSAHS severity and elevated myocardial enzyme expression level. Results As the severity of OSAHS increased，the levels of procalcitonin（PCT），interleukin-6（IL-6），high-sensitivity C-reactive protein（hs-CRP），neutrophil-to-lymphocyte ratio（NLR），creatine kinase isoenzyme（CK-MB），creatine kinase（CK） and L-lactate dehydrogenase（LDH） in the three groups of patients gradually increased（P<0.05）. The apnea-hypopnea index（AHI） level was positively correlated with PCT，IL-6，hs-CRP and NLR（P<0.05）. The age，PCT，IL-6，hs-CRP，NLR，AHI were independent risk factors for elevated myocardial enzyme expression levels in patients，while LSaO2 was a protective factor（P<0.05）. With the increase in the severity of OSAHS，the levels of CK-MB，CK and LDH in patients with different levels of inflammatory factors all increased（P<0.001）. There was a nonlinear dose-response relationship between the levels of PCT，IL-6，hs-CRP and NLR and the risk of elevated myocardial enzyme levels. As the levels of PCT，IL-6，hs-CRP and NLR increased，the risk of elevated myocardial enzyme levels also increased（P<0.05）. The inflammatory factors played a mediating role between the severity of OSAHS and the expression level of myocardial enzymes（P<0.001）. Conclusion As the severity of OSAHS increases，the levels of inflammatory factors and the expression levels of myocardial enzymes in patients also increase. Clinically，by monitoring and controlling the levels of inflammatory factors in patients early，the risk of elevated expression levels of myocardial enzymes can be reduced，providing a theoretical basis and potential targets for clinical prevention and treatment of OSAHS-related myocardial damage.
Objective To understand the correlation between systemic inflammation and sarcopenia in long-term bedridden patients with Type 2 diabetes mellitus（T2DM）. Methods A total of 155 stroke patients admitted to the People’s Hospital of Guyuan City，Ningxia，during January 2021 and March 2024 were enrolled as the study participants. Based on the presence or absence of type 2 diabetes mellitus（T2DM），the patients were categorized into the stroke with T2DM group（n=72） and the stroke-only group（n=83）. Additionally，according to sarcopenia status，they were further classified into the sarcopenia group（n=64） and the non-sarcopenia group（n=91）. Pearson correlation analysis was performed to examine the association between systemic inflammatory markers and blood glucose levels. Multivariate logistic regression analysis was conducted to identify factors associated with sarcopenia. The dose-response relationship between systemic inflammatory indicators and the risk of sarcopenia was assessed by using restricted cubic splines. Subgroup analyses of sarcopenia were carried out incorporating systemic inflammatory markers as the covariates. Furthermore，the potential interaction effect between systemic inflammatory indicators and blood glucose levels on sarcopenia was evaluated through logistic regression modeling. Results The platelet-to-lymphocyte ratio（PLR） and neutrophil-to-lymphocyte ratio（NLR），as well as the systemic immune-inflammation index（SII），were significantly higher in patients with stroke combined with type 2 diabetes mellitus（T2DM） compared to those with stroke alone，whereas the lymphocyte-to-monocyte ratio（LMR） was significantly lower in the former group（P<0.05）. Pearson correlation analysis revealed a statistically significant linear association between fasting blood glucose（FBG） levels and PLR，NLR，LMR，SII（P<0.05）. In addition，patients in the sarcopenia group exhibited higher PLR，NLR，SII values and lower LMR values compared to those in the non-sarcopenia group（P<0.05）. Multivariate regression analysis identified age，National Institutes of Health Stroke Scale（NIHSS） score，FBG，PLR，NLR，and SII as independent risk factors for sarcopenia，while body mass index（BMI） and LMR were found to be protective factors. Restricted cubic spline modeling demonstrated a significant nonlinear dose-response relationship between PLR，NLR，LMR，SII，and the incidence of sarcopenia（P<0.05）. Subgroup analysis indicated that the incidence of sarcopenia was markedly increased in patients with stroke complicated by T2DM. Furthermore，sarcopenia was more prevalent among individuals with PLR≥142.58，NLR≥3.17，LMR≤2.79，and SII≥623.72. Interaction analyses showed that each of these cutoff values（PLR≥142.58，NLR≥3.17，LMR≤2.79，SII≥623.72） significantly interacted with FBG≥7.83 mmol/L，respectively（P<0.05）. Conclusion An increase in PLR，NLR，SII along with a decrease in LMR is associated with an elevated risk of sarcopenia among stroke patients suffering from long-term bed rest due to T2DM while abnormal systemic inflammatory markers coupled with dysregulated blood glucose levels may exacerbate this risk.
Objective To understand the correlation between the characteristics of pulmonary ultrasound（LUS） and the microscopic changes of airway under fiberoptic bronchoscopy（FB） in children with severe pneumonia（SP），and to evaluate the predictive value of LUS for the poor prognosis，so as to provide a basis for the application of non-invasive monitoring tools. Methods 200 cases of SP children admitted from February 2021 to December 2024 were retrospectively included. They were divided into infant group（<3 years old，n=60），preschool group（3-6 years old，n=80） and school-age group（7-14 years old，n=60）. All children received FB examination to evaluate airway lesions（mucosal congestion，secretion，stenosis，etc.），and 12-zone LUS examination（score range 0-36，graded according to ventilation degree）. The clinical data，laboratory inflammatory indicators（IL-10，TNF-α，CRP，etc.） and prognosis information（respiratory failure，mechanical ventilation or death within 30 days） were collected. Logistic regression was used to analyze the influencing factors of prognosis，and restricted cubic spline（RCS） model was used to evaluate the dose-effect relationship between LUS score and prognosis. Results The characteristics of FB airway were related to age，the school-age group was more likely to have increased secretion（33.33% vs 8.33% for infants） and mucus plug obstruction（35.00% vs 3.33%）. The incidence of inflammatory stenosis in preschool group was the highest（37.50%）. Intraluminal softening was more common in the young age group（20.00% in infants，23.75% in preschool age and 5.00% in school age）（all P<0.05）. The LUS score was significantly correlated with airway changes：the higher the LUS score，the higher the incidence of mucus embolism（>4 group 33.3% vs <3 group 2.0%），lobar/segmental bronchitis stenosis（40.0% vs 13.0%） and lumen softening（33.3% vs 6.0%）（all P<0.001）. The infant group had the highest baseline LUS score（3.54±0.52，P<0.001）. LUS score was an independent predictor of poor prognosis. The baseline LUS score of poor prognosis group（n=34，4.39±0.63） was significantly higher than that of good prognosis group（n=166，2.89±0.54）（P<0.001）. Before treatment，LUS score（OR=3.334， 95%CI：2.434-4.514， P=0.003）， age（OR=1.652， 95%CI：1.182-2.118， P=0.024） and IL-10（OR=1.767， 95%CI：1.122-2.523， P=0.029）， TNF-α（OR=3.188， 95%CI：1.411-3.623， P=0.027）， CRP（OR=2.266， 95%CI：0.832-3.112， P=0.018） were the independent risk factor for poor prognosis. When the LUS score was ≥3，the risk of poor prognosis significantly increased with the increase of the score（nonlinear test P<0.001）. Conclusion LUS score is correlated with key inferior airway lesions under fiber bronchoscope（especially mucus plug obstruction，inflammatory stenosis and lumen softening） in children with severe pneumonia，and it is a powerful independent index to predict 30-day adverse prognosis. LUS score ≥3 can be used as an early warning threshold for the sudden increase of prognosis risk.
Objective To understand the changes in the disease burden of lower respiratory tract infections attributed to air pollution in China during 1990-2021，and to provide a basis for scientific prevention and control of lower respiratory tract infections. Methods The mortality and disability adjusted life years（DALY） data of lower respiratory tract infections attributed to air pollution in China from 1990 to 2021 were extracted from the Global Burden of Disease Database in 2021. Joinpoint software was used to analyze their trends，and the Bayesian Age Period Queue Model（BAPC） was used to predict the changes in the burden of lower respiratory tract infections attributed to air pollution in China from 2022 to 2030. Results The number of deaths from lower respiratory tract infections attributed to air pollution in China decreased from 20 500 in 1990 to 5 700 in 2021，and the standardized mortality rate decreased from 26.00/100 000 in 1990 to 3.90/100 000 in 2021，with an average annual decrease of 6.27%（95%CI：-6.60%--5.94%）. The DALY attributed to lower respiratory tract infections caused by air pollution in China decreased from 1.420 1 million person years in 1990 to 114 900 person years in 2021，and the standardized DALY rate decreased from 1 360.65/100 000 in 1990 to 98.18/100 000 in 2021，with an average annual decrease of 8.26%（95%CI：-8.56%--7.96%）. The overall burden of lower respiratory tract infections attributed to air pollution in China from 1990 to 2021 showed a decreasing trend followed by an increasing trend，with relatively higher disease burdens among children and the elderly population. The prediction model showed that the burden of lower respiratory tract infections attributed to air pollution in China from 2022 to 2030 was decreasing over time，and the standardized mortality rate and standardized DALY rate may reach 1.93/100 000 and 33.79/100 000 respectively by 2030. Conclusion Although the standardized mortality rate and DALY rate of lower respiratory tract infections attributed to air pollution in China showed a downward trend from 1990 to 2021，the disease burden is still relatively heavy，and there are significant differences between genders and ages. This suggests that early prevention of lower respiratory tract infections in male children and elderly populations should be further strengthened to effectively reduce the burden of lower respiratory tract infections attributed to air pollution in China.
Objective To understand the relationship between apparent temperature（AT）and hand，foot and mouth disease（HFMD） incidence，and its spatial heterogeneity and effect modifying factors in China. Methods The nationwide data of meteorological data from 2015 to 2019，as well as the data on HFMD incidence，economic and social conditions，ecological environment from 2011 to 2020 were collected. The two-stage time series analysis was conducted，distributed lag non-linear models（DLNMs） were fitted to estimate the cumulative effects of AT，and multivariate meta-regression was used to identify effect modifiers. Meanwhile，a hierarchical Bayesian spatiotemporal model was constructed to assess the baseline associations between these factors and HFMD incidence. Results Nationally，higher AT was associated with an increased risk of HFMD in a near-linear trend. Significant spatial heterogeneity was observed across provinces（I2=73.99%）. Meta-regression identified the normalized difference vegetation index（NDVI） as a significant effect modifier. The Bayesian spatiotemporal model revealed positive associations between HFMD incidence and population growth rate（RR=1.119），the number of hospital beds per 10 000 people（RR=1.002），average class size in kindergartens（RR=1.003），and normalized difference vegetation index（NDVI）（RR=2.649），while a negative association was found with the nighttime light index（RR=0.978）. Conclusion The association between AT and HFMD is significant and exhibits spatial heterogeneity. NDVI is a key effect modifier，and multiple socioeconomic and ecological factors are independent determinants of HFMD incidence.
Objective To know the development status and application progress of convalescent resources in China’s convalescent institutions，and to explore the allocation of convalescent resources and sustainable development strategies for convalescent resources. Methods A random cluster sampling method was adopted. From May to August 2024，70 convalescent institutions across the country were surveyed，and 68 valid institutional samples were retrieved. The convalescent site types，institutional functions and bed distribution，characteristics and structural reform changes of the insured objects，and the dynamic development trends of services were analyzed. Results The results showed that the health resort areas were rich in health resort resources，and the distribution of these resources varied by region. The main functions of health resort institutions included rehabilitation，special duty personnel health resort，health care，employee rest and recuperation，special health resort and health check-ups. Among them，rehabilitation health resort accounted for 23.4% and health care health resort accounted for 22.6%，which were the highest proportions. The allocation of health resort beds in different institutions varied，with more medical beds，health resort beds and rehabilitation beds，but fewer elderly care beds. The main service targets of health resort services were retired cadres（37.4%），military personnel（29.5%），the general public（14.7%） and employees（14.1%），with the age range mainly concentrated between 35 and 70 years old. The average annual growth rate of health resort participants was 10.50%. In the past five years，the reform of health resort institutions presented a diversified trend，moving towards the integration and reorganization of three-level linked health resort centers，rehabilitation hospitals，health management centers，elderly care institutions and enterprise health resort companies for innovative development and transformation. Conclusion China is rich in health resort resources. Facing the need for comprehensive transformation and upgrading of health resort institutions and the health strategy of Healthy China，it is necessary to continuously optimize the allocation of health resort resources，develop the characteristic resources of health resort areas，expand the service groups，strengthen multi-departmental collaboration，carry out health resort ecological protection，and increase efforts to serve the health of the people，providing favorable support for the healthy development of the health resort industry.
Objective To understand the pollution characteristics of metal elements and polycyclic aromatic hydrocarbons in ambient PM2.5 in Ma’anshan City and the health risks to exposed population. Methods 1 126 ambient PM2.5 samples were collected from Huashan District and Yushan District in Ma’anshan City from 2022 to 2024. The concentrations of 12 metal elements and 16 PAHs were determined. The health risk assessment model recommended by the U.S. Environmental Protection Agency was used to assess the health risks via the inhalation pathway. Results During the monitoring period，the average PM2.5 concentration was 0.049 mg/m3，with 15.10% of the samples exceeding the National Ambient Air Quality Standard. The health risk assessment indicated that for metallic elements，the individual carcinogenic risk（CR） values of chromium（Cr），arsenic（As） and cadmium（Cd） in adults，and that of lead（Pb） in children，were between 1.00×10-6 and 1.00×10-4，indicating potential carcinogenic risks that require attention. The non-carcinogenic risks（HI） of the remaining metal elements，as well as both the carcinogenic and non-carcinogenic risks of PAHs，were below the acceptable levels. Conclusion Specific metal elements carried by PM2.5 in Ma’anshan City pose targeted health risks to the population. Cr，As and Cd for adults and Pb for children present potential carcinogenic risks and should be considered priority control pollutants. The current risk levels of PAHs are within the acceptable range.
Objective To understand the short-term lag effects of air pollutants on the incidence of influenza-like illness（ILI） in the population of Baoshan District，Shanghai，and to provide the scientific data for formulating relevant prevention and control measures. Methods The daily data of air pollutants（PM2.5，PM10，SO2，NO2，CO，and O3），temperature and ILI from two sentinel hospitals in Baoshan District during 2014-2024 were collected. R 4.4.1 software was used to analyze the correlation between influenza-like illnesses and air pollutants. A generalized summation model fitting poisson distributions was used to analyze the excess risk（ER） and lag effect of various air pollutants on the incidence of ILI. Moreover，stratified analyses by age，sex，flu activity and season subgroups were conducted. Results There was a correlation between atmospheric pollutants（PM2.5，PM10，NO2，CO and O3） and the number of influenza-like cases in Baoshan district，with a lagged effect. For PM2.5，the effect on the incidence of ILI was significant at lag 0，2，3，4，7 day and the strongest effects on daily ILI cases were observed on lag 7 day，with ER（95%CI） of 0.791%（0.198%-1.387%），0.348%（0.047%-0.651%），0.471%（0.166%-0.776%），0.333%（0.028%-0.640%）和0.807%（0.242%-1.373%）；the effect of PM10 on the incidence of ILI was significant at lag 0，3，4 day and the strongest effects on daily ILI cases were observed on lag 0 day，with ER（95%CI） of 0.722%（0.026%-1.424%），0.486%（0.134%-0.838%），0.488%（0.138%-0.840%）. The effects of SO2 on the incidence of ILI was significant at lag 4 day and NO2 on the incidence of ILI was significant at lag 3，4，5 day，both of them were strongest on lag 4 day with ER（95%CI） of 2.350%（0.071%-4.680%） and 0.859%（0.377%-1.344%），respectively. A 10 μg/m3 increase in PM2.5，PM10，SO2 and NO2 were associated with 2.945%，2.116%，6.501% and 4.545% increases of cumulative ILI cases，respectively. Increased NO2 concentrations increased the number of ILI cases in all age groups. A 10 μg/m3 increase in PM2.5，PM10 and NO2 were associated with 4.565%，3.605% and 3.246%，increases of cumulative ILI cases in residents aged 25-59 years and 4.836%，3.955% and 3.553% increases of cumulative ILI cases in residents aged over 60，respectively. In winter，a 10 μg/m3 increase in PM2.5，NO2 and a 0.1 mg/m3 increase in CO，was associated with 2.493%，3.825% and 21.442% increases of cumulative ILI cases，respectively. In period of high flu activity，a 10 μg/m3 increase in PM2.5，NO2 and a 0.1 mg/m3 increase in CO，was associated with 2.185%，2.975% and 12.885% increases of cumulative ILI cases，respectively. Conclusion All the air pollutants studied have short-term effects on the occurrence of ILI，which is varied by age groups，flu activity periods and seasons.
Objective To understand the pollution level and the seasonal distribution characteristics of chemical composition of atmospheric PM2.5 in the urban area of Luoyang City，Henan Province，and to know the main pollution sources and the health risks to the population by the respiratory route. Methods From January 2020 to December 2022，the samples of atmospheric PM2.5 were collected on the rooftops of two buildings located in different districts of Luoyang City，with sampling conducted over a period of 7 to 10 consecutive days each month. The concentrations of PM2.5 and its main chemical components were determined respectively by gravimetric analysis，inductively coupled plasma mass spectrometry（ICP-MS），ion chromatography and high performance liquid chromatography. The primary sources of PM2.5 were identified by using the Positive Matrix Factorization（PMF） model，and the health risks posed by its hazardous components to the population were evaluated with the U.S. Environmental Protection Agency（EPA） health risk assessment model. Results From 2020 to 2022，the annual mean PM2.5 concentrations in urban air were 70.27 μg/m3 and 68.39 μg/m3，respectively，exceeded the National Ambient Air Quality Standard Grade-I limit（35 μg/m3） but remained below the Grade-II limit（75 μg/m3）. The concentration of PM2.5 and its chemical constituents（∑PAHs，metal ions，water-soluble ions） displayed pronounced seasonality（P<0.01），peaking in winter and reaching minima in summer. PMF source apportionment identified coal combustion，traffic and industrial emissions as the dominant contributors，jointly accounting for >70% across the two districts. EF analysis revealed moderate-to-severe enrichment of anthropogenic elements（Sb，As，Cd，Hg，Pb，Se，Tl），indicating a substantial anthropogenic influence. Benzo[a]pyrene（BaP） posed the highest non-carcinogenic risk，with hazard quotients（HQ） of 3.89 and 3.84 in Zone A and B，respectively，followed by As，Cd，Cr and Pb（all HQ>1），signifying non-negligible hazards. For carcinogenic risks，the estimated lifetime carcinogenic risks for chromium（1.42×10-4） and arsenic（3.86×10-5） exceeded the acceptable risk threshold. Conclusion Ambient PM2.5 pollution in urban Luoyang during the study period showed characterized dominant by anthropogenic sources，with particularly severe pollution in winter. Multiple toxic components in PM2.5，especially BaP，As，and Cr posed significant non-carcinogenic and carcinogenic risks to the people. These pollutants should be prioritized for control，and targeted measures should be implemented to strengthen precise regulation of the major source of pollution.
Objective To understand the associations between atmospheric pollutants and the number of hospital admissions for community-acquired pneumonia（CAP） in children，as well as the lag effects in Shijiazhuang City. Methods The clinical data of 1 776 hospitalized children aged 1-14 years diagnosed with CAP from a top-tier hospital in Shijiazhuang during January 2018 - December 2020 were collected. The daily meteorological and atmospheric pollutant monitoring data during the same period were also obtained. Univariate nonlinear fitting，multiple linear regression and a semi-parametric generalized additive model（GAM） based on Poisson regression were used for the relavant analysis. Results The number of hospitalized CAP children was highest in winter and lowest in summer，with children aged 1-6 years accounting for 93%. The monthly number of hospitalizations was positively correlated with atmospheric pressure，SO2，NO2，CO，PM10 and PM2.5（P<0.01），and negatively correlated with average temperature，precipitation，sunshine duration and O3（P<0.01）. The correlation coefficient between the multiple linear fitting results and the measured values was 0.85，with a mean square error of 15.8. The Poisson regression model showed that the single-day lags of O3（lag1 to lag5） and NO2（lag0，lag1，lag2，lag5，lag6，lag7） were significant. Cumulative lag effects were not significant for PM10，while they became significant after lag0 for NO2，after lag1 for O3，after lag23 for PM2.5，after lag14 for SO2，and after lag25 for CO. Conclusion The number of hospitalized CAP children in Shijiazhuang City is significantly correlated with multiple atmospheric pollutants. NO2，SO2，PM2.5 and CO present positive cumulative lag effects，while O3 presents a negative association. The established multiple linear model demonstrates certain predictive capability for the monthly average number of CAP hospitalizations in children and can provide a reference for environmental health early warning of childhood pneumonia.
Objective To understand the results of indoor environmental hygienic monitoring in hotels in Lu’an City from 2022 to 2024，and provide a basis for hygiene management. Methods A random sampling method was adopted to choose hotels of different star ratings in Lu’an City. The monitoring was conducted twice a year（in summer and winter），with indicators including indoor temperature，humidity，noise，wind speed，formaldehyde，benzene series，CO2，PM10，PM2.5 and total bacterial count. Results A total of 235 points were monitored. The overall qualified rates for wind speed，noise，benzene，towel pH value，temperature，formaldehyde and bacterial count on public elevator buttons were 97.87%，52.77%，99.15%，44.41%，88.51%，94.47% and 91.67%，respectively. The qualified rates for each item varied significantly across different years（all P<0.05），with the qualified rates for formaldehyde，bacterial count on public elevator buttons and temperature showed a year-by-year declining trend. In terms of regional differences，the bacterial counts on towels and mouthwash cups in county areas were higher than those in urban areas（P<0.05）. Regarding differences in hotel star ratings，noise，CO2 and PM2.5 levels in three-star and above hotels were lower than those in below three-star and budget hotels（P<0.05），while formaldehyde levels was higher in the former（P<0.05）. Budget hotels had higher values for multiple indicators，including towel pH and indoor air bacterial count，compared to below three-star and three-star and above hotels（P<0.001）. Below three-star hotels had higher indoor air fungal counts than budget and three-star and above hotels（P<0.001）. Seasonal differences revealed temperature and humidity were higher in summer than in winter（P<0.001），while indoor air toluene was higher in winter than in summer（P<0.05）. In terms of hotel rating differences，multiple indicators，including indoor air benzene，were higher in C-rated hotels than in B-rated，A-rated，and unrated hotels（P<0.05），while indoor air fungal count was higher in B-rated hotels than in C-rated，A-rated，and unrated hotels（P<0.05）. The physical factor of humidity was higher in B-rated hotels than in A-rated，unrated and C-rated hotels（P<0.05）. Regarding differences in hotel operating years，indoor air xylene and formaldehyde levels were higher in the ≤5-year group than in the 6-10-year and >10-year groups（P<0.05），while some indicators，such as indoor air fungal count，were higher in the >10-year group than in the ≤5-year and 6-10-year groups（P<0.05）. PM2.5，was higher in the 6-10-year group than in the ≤5-year and >10-year groups（P<0.05）. Humidity was positively correlated with formaldehyde and negatively correlated with PM10 and PM2.5；benzene was strongly positively correlated with xylene（rs=0.882，P<0.01）；formaldehyde was negatively correlated with fungal count；and PM10 was strongly positively correlated with PM2.5（rs=0.624，P<0.01）. Conclusion The hygienic issues in hotels in Lu’an City include excessive noise，towel pH value exceeding standards and microbial contamination. It is recommended to strengthen hygienic supervision in county areas，budget hotels and C-rated venues under health supervision quantification grading. Additionally，differentiated prevention and control measures should be implemented for venues based on different seasons and operating years.
Objective To understand the contamination status of harmful elements in commercially available pre-made dishes of livestock and poultry meat and the health risks associated with consumption，so as to provide a scientific basis for formulating national food safety standards of prepared dishes. Methods From September to October in 2024，52 samples of commercially available pre-made dishes of livestock and poultry meat were collected from a district of Hangzhou. The contents of five harmful elements were analyzed. The single-factor pollution index（Pi） and the Nemerow comprehensive pollution index（Pc） were used to evaluate the contamination levels of lead（Pb），cadmium（Cd），mercury（Hg），arsenic（As） and chromium（Cr）. The target hazard quotient（THQ and TTHQ） was employed for health risk assessment. Results All five harmful elements were detected in the commercially available pre-made dishes of livestock and poultry meat from a district of Hangzhou，with detection rates as follows：Cr（65.4%） > As（63.5%） > Pb（28.8%） > Cd（19.2%） > Hg（1.9%）. The content of harmful elements was ranked as Cr（0.089 mg/kg） > Pb（0.021 mg/kg） > As（0.003 mg/kg） > Cd（0.002 mg/kg） > Hg（0.001 mg/kg）. The levels of all five harmful elements were below the national standard limits. The Pi and Pc values for the three categories of prepared dishes were all within the safe range，and the TTHQ values were all less than 1，indicating no significant health risk to the consumers. Conclusion The comprehensive analysis indicates that the prepared dishes of livestock and poultry meat sampled in a district of Hangzhou are generally at a safe level with low health risks. However，some individual samples showed varying degrees of contamination by lead，mercury and chromium. The findings of this study will provide safety guidance for the regular consumption of pre-made dishes.
Objective To understand the association between atmosphere PM2.5 components exposure and cardiovascular diseases（CVD），and to provide suggestions for the prevention of CVD. Methods The data of hospitalized patients with CVD in Tianjin Wuqing District People’s Hospital from January 1，2019 to December 31，2020 were collected，and the data of air pollutants and meteorological conditions in Wuqing District during the same period were collected. The association between PM2.5 components and meteorological conditions was analyzed by Spearman rank correlation coefficient. A generalized linear model based on the Poisson distribution was employed for time-series analysis to quantify the excess risk（ER） of CVD incidence per interquartile range（IQR） increase in exposure concentration for each PM2.5 component，considering lags of 0-4 days（lag0-4） and cumulative lags of 1-4 days（lag01-lag04）. Results The short-term exposure of element carbon（EC），Cl-，K and Zn was positively correlated with the morbidity of CVD. When the concentration of EC increased by 1 IQR（1.12 μg/m3），the risk of CVD increased by 2.80%（95%CI：0.63%-5.02%）. When the concentration of Cl- increased by 1 IQR（1.59 μg/m3），the risk of CVD increased by 3.54%（95%CI：0.86%-6.28%）. When K increased by 1 IQR concentration（0.4 μg/m3），the risk of CVD increased by 2.00%（95%CI：0.26%-3.77%）. When the concentration of Zn increased by 1 IQR（0.15 μg/m3），the risk of CVD increased by 5.00%（95%CI：2.41%-7.65%）. Conclusion The increase of EC，Cl-，K and Zn in PM2.5 will increase the risk of CVD.
Objective To understand the epidemic characteristics of infectious diseases among primary and secondary school students in Changchun City，and to provide the scientific data for controlling and reducing the risks of infectious diseases. Methods The legally notifiable infectious diseases cases reported among primary and secondary school students in Changchun City from 2014 to 2023 were obtained from the Chinese Information System for Disease Control and Prevention，and statistically analyzed from different dimensions through descriptive research methods. Results From 2014 to 2023，22 kinds of infectious diseases were reported in primary and secondary schools in Changchun City，without deaths. These accounted for 11.32% of the total reported cases in the entire population，and the average annual incidence rate was 247.71 per 100 000. There were no reports of Class A infectious diseases. There were 13 kinds of Class B infectious diseases，accounting for 30.01% of the total number of student cases. There were 6 kinds of Class C infectious diseases，accounting for 33.18%. There were 3 other non-statutory infectious diseases such as chickenpox，accounting for 36.81%. From 2014 to 2023，the top 5 diseases reported in primary and secondary schools in Changchun City，ranked as chickenpox，influenza，novel coronavirus infection，hand-foot-mouth disease and mumps，accounting for 86.07% of the total reported cases. During 2014-2023，the disease with the highest incidence rate was chickenpox，except for novel coronavirus infection（in 2022） and influenza（in 2023），all the others were chickenpox. From 2014 to 2023，respiratory infectious diseases accounted for the majority of infectious diseases reported in primary and secondary schools. There were 10 kinds of infectious diseases reported，with a total of 16 638 cases，accounting for 88.42% of the total number of cases，and the average incidence rate was 219.03 per 100 000 people. Conclusion In Changchun City，chickenpox is the most prevalent infectious disease among primary and secondary school students，while the rest are influenza，novel coronavirus infection，hand-foot-mouth disease and mumps. The proportion is relatively high. It is necessary to strengthen the prevention and control measures for key infectious diseases among primary and secondary school students and increase the vaccination rate to effectively reduce the risk of infectious diseases among them.
Objective To explore the feasibility of a measurement method for indoor ventilation and air exchange in public places based on a tracer gas intelligent control system in practical applications. Methods Ten public places equipped with centralized air conditioning and ventilation systems were selected as the experimental subjects. Under the same experimental conditions，paired experiments were conducted respectively by using the traditional fresh air volume measurement method（duct method） and the tracer gas intelligent control system method. The consistency of the measurement results of the two methods was quantitatively evaluated by using the Bland-Altman analysis method. Results The average value of the difference in air change rates measured by the two methods（d1） was 0.167 times/h，the standard deviation of the difference（Sd1） was 0.199 times/h，and the 95% limit of agreement （LoA1：d1±1.96Sd1） was -0.223 to 0.557 times/h. The average value of the difference in fresh air volume（d2） was 2.578 m3/（person·h），the standard deviation of the difference（Sd2） was 1.894 m3/（person·h），and the 95% limit of agreement（LoA2：d2±1.96Sd2） ranged from -1.134 to 6.290 m3/（person·h）. The Bland-Altman diagram results showed that all experimental points were within the 95% limit of agreement，and no obvious systematic trend was observed in the scattered point distribution，suggesting that there was no significant systematic bias in the measurement of air change rate between the two methods. Conclusion The ventilation and air exchange measurement method based on the tracer gas intelligent control system has good consistency with the traditional standard air duct method and can be used according to the requirements of specific application scenarios.
Objective By establishing a standard curve for oxygen，the oxygen content in fixed pollution source exhaust samples is quantitatively analyzed，allowing for more accurate correction of oxygen interference in the samples，thereby improving the accuracy of non-methane total hydrocarbon measurements. Methods High-purity nitrogen gas was used to dilute hydrocarbon-free air，creating standard curves with varying nitrogen-oxygen ratios on the methane and total hydrocarbon columns，and this enabled precise oxygen content analysis and interference subtraction. Instrument settings were injection port 150 ℃，column 75 ℃，detector 200 ℃，carrier gas flow 20.0 mL/min. Results After optimization，the average recovery rates for methane and total hydrocarbons increased to 95.1%-97.0% and 95.2%-96.8%，respectively. The analysis time was reduced to 1.5 minutes. The correlation coefficients for total hydrocarbons and methane were ≥0.999 0. The RSDs for methane and total hydrocarbons were 1.1%-2.1% and 1.9%-2.4% respectively. The limits of detection were methane 0.053 mg/m3，total hydrocarbons 0.060 mg/m3 and non-methane total hydrocarbons 0.060 mg/m3 respectively. Conclusion The modified method offers high sensitivity and accuracy，meeting the requirements for non-methane total hydrocarbon measurement.
