[Simulation and Analysis of Ozone Pollution Process in Shijiazhuang Based on CMAQ-ISAM Model].

In Shijiazhuang City, ozone （O3） pollution occurs frequently in June every year. In June 2023, the average O3 8 h concentration （O3-8h） pollution exceeded 80% of the days in the month, and O3 was the primary pollutant, accounting for 100%. For an O3 heavy pollution process from June 11 to 18, the air quality model WRF-CMAQ was used for simulation, and the average error data MFB and MFE were -10.47% and 17.96%, respectively, which was within the ideal error range. The CMAQ process analysis module was used to simulate the physical and chemical processes in Shijiazhuang City, and the dry deposition （DDEP） contribution concentration was -23.88 µg·m-3, which was the main process of O3 consumption, whereas the transport process （TRAN） was the main source of O3, among which the contribution was more significant in vertical transport （VTRA）. At the same time, the source analysis module （ISAM） was used to analyze the O3 contribution of local and surrounding areas in Shijiazhuang City. The results showed that the contribution rate of local industry sources in Shijiazhuang City was as follows： traffic source （12.54%） > industrial source （6.94%） > residential source （6.56%） > power source （4.75%）. The long-distance transmission source （BCON） continued to be in the first place with a high contribution rate of 63.31%. In the heavy pollution period under stable weather, the contribution concentration of BCON in the D02 layer of the nested domain to Shijiazhuang City was lower than the sum of the marked area. Among the surrounding cities, Baoding City had the highest contribution rate under stable weather, accounting for 26.21%. In the late period, the contribution concentration of Xingtai City increased rapidly under the action of high-value southwest wind. To effectively reduce O3 pollution, it is necessary to reduce emissions in the city and to control the upwind cities in advance, and the implementation of inter-regional joint prevention and control is the key.

[Ozone Sensitivity Analysis and Control Strategy in Shijiazhuang City in July 2019].

The pollution characteristics of surface ozone and its response to meteorological factors were studied based on monitoring in July 2019 in Shijiazhuang City, China. Furthermore, the WRF-CMAQ model coupled with O3 isopleths (EKMA curves) were applied to explore the non-linear response relationship of O3 to precursors VOCs and NOx, aiming to identify a suitable precursor control strategy. The results showed that the days with the maximum daily 8-hour average ozone concentration (MDA8 O3) exceeded the standard by 70.9%. The nonattainment days were usually accompanied by higher temperature, lower relative humidity, and low winds, and the south and southeast winds occurred frequently. The O3 formation was in the strong VOC-limited regime in the urban area of Shijiazhuang, whereas it was in the NOx and VOCs transition regime in suburban areas. As for the urban area, under the condition of single NOx emission reduction, O3 pollution improved when continuous NOx emission reduction was higher than 50% during the nonattainment days. By contrast, during the non-polluted days, O3 concentrations would not rebound when the reduction ratio of NOx and VOCs was higher than 1. In conclusion, VOCs reduction should be the priority for emission reduction plans in urban areas, whereas all different NOx and VOCs ratios led to a decline in O3 concentration in the suburban areas, and a VOCs:NOx of 1:2 was recommended.

[Analysis of Pollution Characteristics and Sources of PM2.5 During Heavy Pollution in Shijiazhuang City Around New Year's Day 2019].

We report on successive haze weather that occurred in Shijiazhuang City, China, from December 30, 2018 to January 15, 2019. There were 12 days of heavy atmospheric pollution during this period, which primarily involved aerosol fine particulate matter (PM2.5). This study analyzes the causes of the pollution using component analysis and by assessing pollution evolution, spatial and temporal distributions of PM2.5, pollution sources, and meteorological factors. The results showed that PM2.5 was mainly composed of secondary inorganic ions (65.4%) that were mainly sourced from coal combustion (24.4%) and industrial sources (23.7%). The contributions of sulfate and secondary inorganic sources increased significantly with increasing pollution. Pollution was affected by unfavorable meteorological conditions (e.g., a low air mass) and by the particular local terrain, static stability, high humidity, and near-ground reverse temperatures from the south-southeast and west-southwest directions. Contaminants from primary sources including coal combustion, industry, and motor vehicle exhausts accumulated quickly in front of the Taihang Mountains. Secondary transformation of gaseous pollutants and increasing moisture absorption of particulate matter increased PM2.5 concentrations. Sulfate explosion also increased pollution. We recommend that as part of emergency responses to heavy pollution events, emissions reduction measures should be implemented to strengthen the control of SO2, NOx, and NH3 emission sources of secondary inorganic precursors, especially SO2 emission sources (i.e., coal etc.). We further propose a strengthen of the management of atmospheric emission sources in Xinle, Wuji, Shenze, Jinzhou, and Xingtang counties in the northeast of the city to reduce the impact of local transmission.

[Analysis of overseas imported malaria and implication for prevention and control strategy in Shijiazhuang City from 2012 to 2015].

Objective To analyze the overseas imported malaria situation of Shijiazhuang City from 2012 to 2015, so as to provide the evidence for exploring the prevention and control strategy. Methods The data of overseas imported malaria were collected and analyzed with the descriptive method including Plasmodium species, population characteristics, epidemic focus distribution, onset time, diagnosis and treatment in Shijiazhuang City from 2012 to 2015, and the time from the onset to first medical visit, time from first medical visit to being diagnosed, and time from onset to being diagnosed of different Plasmodium species were analyzed respectively with the statistical analysis method. Results A total of 92 overseas imported malaria cases were reported in Shijiazhuang City from 2012 to 2015, including 88 cases from African countries (falciparum malaria taking 53.41%), and 4 cases from Southeast Asian and other countries (vivax malaria taking 50%). Eighty-nine cases were distributed in 28 counties (districts) of 6 cities in Hebei Province, except 2 persons with foreign nationalities and 1 with Anhui Province census register. The male and young adults were dominant. The median time from the onset to seeing a doctor was one day and the median time from seeing a doctor to being diagnosed was five days. Most cases were reported by the Fifth Hospital of Shijiazhuang which was the sentinel hospital. Totally 42.39% of the cases were misdiagnosed when the first visit to a doctor. All of the cases were laboratory confirmed and 100% of them received the standard treatment after diagnosis. Conclusions The overseas imported malaria cases are increasing rapidly with years and the malignant malaria cases were more than other malaria cases in Shijiazhuang City. It is necessary to further strengthen the long-term cooperation mechanism between the medical institutions and the entry-exit inspection and quarantine department. The technician training should be strengthened to avoid the severe cases and death cases.

[Online Source Analysis of Particulate Matter (PM2.5) in a Heavy Pollution Process of Shijiazhuang City During Heating Period in 2015].

In recent years, more and more public attention has been paid to the problem of air pollution during the heating period in North China. This article took a heavy pollution process of Shijiazhuang district from Nov.24th to Dec.4th in 2015 as an example, and analyzed comprehensively the source apportionment in different periods, size distribution of the PM2.5 from each source in different periods, the characteristics of mass spectra of the main emission sources and the meteorological conditions with the method of real-time online source analysis. It turned out:the main sources of pollutants were coal combustions, industrial discharges, vehicle exhausts and secondary inorganic reactions. With the help of meteorological condition of low pressure and low wind speed, the PM2.5 mainly produced by coal combustions and industrial discharges accumulated heavily and went through the second stage conversion, leading to this heavy air pollution. The main particulate matters from coal combustions were the mixed carbons; the main particulate matters from industrial discharges were metals; the main particulate matters from vehicle exhausts were elemental carbon and manganese metal; the main particulate matters from pure secondary inorganic sources were secondary inorganic ions; the main particulate matters from dust pollution were aluminum, calcium, iron and silicate minerals; the main particulate matters from biomass fuel combustions were levoglucosan; the feature signal from restaurant discharges was organic acid. Different from the distribution before and after the heavy pollution period, the particulate matters from the 8 pollution sources presented even distribution during the heavy pollution period.

Analysis of overseas imported malaria and implication for prevention and control strategy in Shijiazhuang City from 2012 to 2015 / 中国血吸虫病防治杂志

Objective To analyze the overseas imported malaria situation of Shijiazhuang City from 2012 to 2015,so as to provide the evidence for exploring the prevention and control strategy. Methods The data of overseas imported malaria were collected and analyzed with the descriptive method including Plasmodium species,population characteristics,epidemic focus distribution,onset time,diagnosis and treatment in Shijiazhuang City from 2012 to 2015,and the time from the onset to first medical visit,time from first medical visit to being diagnosed,and time from onset to being diagnosed of different Plasmodium species were analyzed respectively with the statistical analysis method. Results A total of 92 overseas imported malaria cases were reported in Shijiazhuang City from 2012 to 2015,including 88 cases from African countries(falciparum malaria taking 53.41％),and 4 cases from Southeast Asian and other countries(vivax malaria taking 50％). Eighty-nine cases were distributed in 28 counties(districts)of 6 cities in Hebei Province,except 2 persons with foreign nationalities and 1 with Anhui Province cen-sus register. The male and young adults were dominant. The median time from the onset to seeing a doctor was one day and the median time from seeing a doctor to being diagnosed was five days. Most cases were reported by the Fifth Hospital of Shijia-zhuang which was the sentinel hospital. Totally 42.39％of the cases were misdiagnosed when the first visit to a doctor. All of the cases were laboratory confirmed and 100％of them received the standard treatment after diagnosis. Conclusions The overseas imported malaria cases are increasing rapidly with years and the malignant malaria cases were more than other malaria cases in Shijiazhuang City. It is necessary to further strengthen the long-term cooperation mechanism between the medical institutions and the entry-exit inspection and quarantine department. The technician training should be strengthened to avoid the severe cas-es and death cases.