| Objective:Due to its special geographical conditions and industrial structure,Shijiazhuang has serious air pollution problems.Besides,the incidence of tuberculosis（TB）in Shijiazhuang ranks first in the Beijing-Tianjin-Hebei region.Therefore,it is urgent to carry out more epidemiological studies to clarify the distribution characteristics of pulmonary tuberculosis in Shijiazhuang and to further evaluate the risk of pulmonary tuberculosis caused by meteorological and atmospheric pollutants.It provides the possibility to establish an early warning system for pulmonary tuberculosis,and at the same time provides reasonable suggestions for preventing the occurrence of pulmonary tuberculosis,and guides the formulation of health policies.Methods:1.The data of TB cases in Shijiazhuang City from 2014 to 2018 comes from the National Notifiable Disease Information System.Meteorological data is obtained from the China Meteorological Data Sharing Service Network.The daily average concentration of air pollutants comes from the national urban air quality real-time release platform.The demographic information comes from the Hebei Statistical Yearbook.2.First,descriptive analysis was conducted to describe the distribution characteristics of TB in Shijiazhuang in the past five years.The Spearman correlation matrix was constructed to explore the correlation between TB and various environmental factors（weather,air pollutants）,and to determine the variables included in the models.3.The moving average method is used to eliminate part of the noise in the original data.Through the generalized linear regression model（GLM）and the generalized additive model（GAM）,the risk factors that affect the incidence of TB are screened.A combination of GLM and distribution lag nonlinear model（DLNM）was used to evaluate the lag effect of environmental factors on the TB.Results were tested for robustness by sensitivity analysis.4.All analyses in this study were completed by R software（version 3.6.2）,and the main model construction was achieved through the"dlnm","ts Model"and"splines"packages.Results:1.A total of 21,205 cases of TB were reported in Shijiazhuang from 2014to 2018.The incidence is declining year by year,with obvious seasonality and periodicity;the peak incidence occurred in January to May（the sudden drop in February may be due to the delay in reporting the incidence of the Spring Festival）,and a small peak appeared in September（autumn）;the incidence generally increases with age,but the incidence in the 15-34 years group is significantly higher than that in neighboring age groups;the incidence in men is much higher than that in women;the occupations are mainly farmers and students.2.There was a linear relationship and lag effect between PM10 and TB.The effect of every 10μg/m3 increase of PM10 on the whole population was the largest on the second and 15th days of lag,with RR values were 1.00166（95%CI:1.00023-1.00390）and 1.00209（95%CI:1.00076-1.00341）,respectively.The RR distribution of the lag effect exhibits a bimodal distribution with the lag time.Both peaks of the lag effect are statistically significant.The cumulative lag effect of every 10μg/m3 increase in PM10showed a similar bimodal distribution.Time zones where the RR makes sense are days 4-6 and 13-20,and maximum lag effect occurred at the 18th day of cumulative exposure.The RR is 1.02239（95%CI:1.00623-1.03882）.3.No evidence of the influence of meteorological factors and other air pollutants on the incidence of tuberculosis has been found.Conclusion:1.This study conducted a descriptive analysis of the epidemiological characteristics of TB in Shijiazhuang City from 2014 to 2018,and showed that the incidence of TB in Shijiazhuang City has obvious seasonal fluctuations,and the peak incidence is concentrated in January to May（except February）,September Increased volatility;the incidence of men is much higher than that of women;the distribution of occupations is significantly different,mainly in farmers and students.2.The distribution lag model shows that PM10is likely to be an important risk factor affecting the onset of TB,and short-term exposure to PM10will increase the risk of TB in Shijiazhuang City.The application of the smoothing function greatly improves the robustness of the model and the reliability of the conclusions.3.Meteorological factors and other pollutants have not been found to be associated with the incidence of tuberculosis.4.Strengthening the monitoring and emission management of air pollutants,taking appropriate measures for the special behaviors and lifestyles of high-risk groups,and protecting susceptible groups during the high-incidence season is of great significance to reduce the incidence of TB.The delayed effect of air pollutants on the incidence of TB deserves further study.We hope that this research can provide new ideas for mitigating or eliminating TB in the future,and provide a scientific basis for establishing an early warning system to improve early warning capabilities. |
