Effects of pollen concentration on allergic rhinitis in children: A retrospective study from Beijing, a Chinese megacity.

With global climate change and rapid urbanization, the prevalence of allergic diseases caused by pollen is rising dramatically worldwide with unprecedented complexity and severity, especially for children in mega-cities. However, because of the lack of long time-series pollen concentrations data, the accurate evaluation of the impact of pollen on allergic rhinitis (AR) was scarce in the Chinese metropolis. A generalized additive model was used to assess the effect of pollen concentration on pediatric AR outpatient visits in Beijing from 2014 to 2019. A stratified analysis of 10 pollen species and age-gender-specific groups was also conducted during the spring and summer-autumn peak pollen periods separately. Positive associations between pollen concentration and pediatric AR varied with the season and pollen species were detected. Although the average daily pollen concentration is higher during the spring tree pollen peak, the influence was stronger at the summer-autumn weed pollen peak with the maximum relative risk 1.010 (95% CI 1.009, 1.011), which was higher than the greatest relative risk, 1.003 (95% CI 1.002, 1.004) in the spring peak. The significant adverse effects can be sustained to lag10 during the study period, and longer in the summer-autumn peak (lag13) than in the spring peak (lag8). There are thresholds for the health effects and they varied between seasons. The significant effect appeared when the pollen concentration was higher than 3.74 × 105 grain·m-2·d-1 during the spring tree pollen peaks and 4.70 × 104 grain·m-2·d-1 during the summer-autumn weed pollen peaks. The stratified results suggested that the species-specific effects were heterogeneous. It further highlights that enough attention should be paid to the problem of pollen allergy in children, especially school-aged children aged 7-18 years and weed pollen in the summer-autumn peak pollen period. These findings provide a more accurate reference for the rational coordination of medical resources and improvement of public health.

Influence of Urbanization on the Spatial Distribution of Associations Between Air Pollution and Mortality in Beijing, China.

This study investigated the influence of urbanization on the intra-city spatial distribution of associations between air pollution and mortality in Beijing, China. First, we utilized the generalized additive model to establish the exposure-response associations of PM2.5, O3, with nonaccidental and cardiorespiratory mortality between urban and suburban areas. Second, we assessed district-specific air pollution-related mortality and analyzed how these associations were affected by the degree of urbanization. Finally, we analyzed the changes in air pollution-related mortality before and after the enforcement of the Air Pollution Prevention and Control Action Plan (referred to as the Action Plan). The effect estimates of PM2.5 for nonaccidental mortality were 0.20% (95% CI: 0.12-0.28) in urban areas and 0.46% (95% CI: 0.35-0.58) in suburban areas per 10 µg/m3 increase in PM2.5 concentrations. The corresponding estimates of O3 were 0.13% (95% CI: -0.04-0.29) in urban areas and 0.34% (95% CI: 0.12-0.56) in suburban areas per 10 µg/m3 increase in O3 concentrations; however, the difference between the estimates of O3 in urban and suburban areas was not statistically significant. The district-specific results suggested that the estimated risks increased along with urban vulnerability levels for the effects of PM2.5. Implementing the Action Plan reduced the mortality risks of PM2.5, but the risks of O3 increased in some districts. However, the difference in the estimates between the pre- and post-emission reductions was not statistically significant. Our study indicated that populations living in less urbanized areas are more vulnerable to the adverse effects of air pollution in Beijing, particularly for PM2.5.

Upper respiratory tract microbiota is associated with small airway function and asthma severity.

BACKGROUND: Characteristics of airway microbiota might influence asthma status or asthma phenotype. Identifying the airway microbiome can help to investigate its role in the development of asthma phenotypes or small airway function. METHODS: Bacterial microbiota profiles were analyzed in induced sputum from 31 asthma patients and 12 healthy individuals from Beijing, China. Associations between small airway function and airway microbiomes were examined. RESULTS: Composition of sputum microbiota significantly changed with small airway function in asthma patients. Two microbiome-driven clusters were identified and characterized by small airway function and taxa that had linear relationship with small airway functions were identified. CONCLUSIONS: Our findings confirm that airway microbiota was associated with small airway function in asthma patients.

Identification of Health Effects of Complex Air Pollution in China.

After the Chinese government introduced a series of policies to strengthen the control of air pollution, the concentration of particulate matter has decreased, but the concentration of ozone has increased, and the problem of complex air pollution still exists, posing a serious threat to public health. Therefore, disentangling the health effect of multi-pollutants has been a long-discussed challenge in China. To evaluate the adverse effects of complex air pollution, a generalized additive model was used to assess the health risks of different pollution types in eight metropolises in different climates in China from 2013 to 2016. Instead of directly introducing multiple pollutant concentrations, we integrated the concentration levels of PM2.5, NO2, and O3 into a set of predictors by grouping methods and divided air pollution into three high single-pollutant types and four high multi-pollutant types to calculate mortality risk in different types. The comprehensive results showed that the impact of high multi-pollutant types on mortality risk was greater than that of high single-pollutant types. Throughout the study period, the high multi-pollutant type with high PM2.5, NO2, and O3 and the high multi-pollutant type with high PM2.5 and NO2 were more associated with death, and the highest RRs were 1.129 (1.080, 1.181) and 1.089 (1.066, 1.113), respectively. In addition, the pollution types that most threaten people are different in different cities. These differences may be related to different pollution conditions, pollutant composition, and indoor-outdoor activity patterns in different cities. Seasonally, the risk of complex air pollution is greater in most cities in the warm season than in the cold season. This may be caused by the modifying effects of high temperature on pollutants in addition to different indoor-outdoor activity patterns in different seasons. The results also show that calculating the effect of individual air pollutants separately and adding them together may lead to an overestimation of the combined effect. It further highlights the urgency and need for air pollution health research to move towards a multi-pollutant approach that considers air pollution as a whole in the context of atmospheric abatement and global warming.

Acute effects of black carbon on mortality in nine megacities of China, 2008-2016: a time-stratified case-crossover study.

Black carbon (BC) may have more adverse effects on human health than other constituents of PM2.5. The daily mean concentrations of BC in China are much higher than those in developed countries and are estimated to account for more than a quarter of global anthropogenic BC emissions. However, reports on the health effects of BC in China have been limited. Thus, a time-stratified case-crossover study was conducted to evaluate the impacts of BC on daily mortality risk in nine Chinese megacities from 2008-2016. Our results show that for all-cause mortality, when compared to the interquartile range (IQR) of BC concentration increased, odds ratios (ORs) were in the range of 1.01-1.06 (95% CIs: 0.99-1.10). For cardiovascular mortality, ORs were in the range of 1.02-1.07 (95% CIs: 1.003-1.12), and for respiratory mortality, ORs were in the range of 1.01-1.15 (95% CIs: 1.00-1.18). The effects of BC in the nine cities were robust after adjusting for PM2.5, or even became more prominent. Furthermore, BC had stronger effects in spring and winter in northern cities, whereas in mid-latitude cities, BC had stronger effects in the warm seasons. In southern cities, BC had stronger effects in the cool and dry seasons. Our findings support an association between residential exposure to BC and mortality and thus provide further evidence that BC negatively impacts human health and is helpful for decision-making.

Assessment of black carbon exposure level and health economic loss in China.

Based on the geographic information system (GIS) software and the application of the black carbon (BC) and fine particulate matter ([Formula: see text]) ratio method, this paper analyzed and calculated the national BC distribution from 2015 to 2017 and evaluated the national human exposure to BC. The results showed that from 2015 to 2017, 2/3 of the national land area and nearly half of the population were exposed to 1-3 [Formula: see text], and the area and population exposed to a concentration less than 2 [Formula: see text] increased yearly, while the area and population exposed to a concentration higher than 9 [Formula: see text] decreased yearly. The estimated economic loss showed that 77.3% of the targeted districts or counties claimed a loss per square kilometer of 50 million Chinese Yuan (CNY) or less from the perspective of annual changes, and districts and counties in Beijing-Tianjin-Hebei and Hunan with annual losses between 50 and 500 million CNY showed an increasing trend. The BC ratio (the proportion of BC economic loss to GDP) of Beijing-Tianjin-Hebei and Hunan also showed an increasing trend yearly.

Development of GRAPES-CUACE adjoint model version 2.0 and its application in sensitivity analysis of ozone pollution in north China.

We presented the development of the gaseous chemistry adjoint module of the meteorological-chemical model system GRAPES-CUACE (Global/Regional Assimilation and PrEdiction System coupled with CMA Unified Atmospheric Chemistry Environmental Forecasting System) on the basis of the previously constructed aerosol adjoint module. The latest version of the GRAPES-CUACE adjoint model mainly includes the adjoint of the physical and chemical processes, the adjoint of the transport processes, and the adjoint of interface programs, of both gas and aerosol. The adjoint implementation was validated for the full model, and adjoint results showed good agreement with brute force sensitivities. We also applied the newly developed adjoint model to the sensitivity analysis of an ozone episode occurred in Beijing on July 2, 2017, as well as the design of emission-reduction strategies for this episode. The relationships between the ozone concentration and precursor emissions were well captured by the adjoint model. It is indicated that for a case used here, the Beijing peak ozone concentration was influenced mostly by local emissions (6.2-24.3%), as well as by surrounding emissions, including Hebei (4.4-16.8%), Tianjin (1.8-6.6%), Shandong (1.8-2.6%), and Shanxi (<1%). In addition, reduction of NOx, VOCs, and CO emissions in these regions would effectively decrease the Beijing peak ozone concentration. This study highlights the capability of GRAPES-CUACE adjoint model in quantifying "emission-concentration" relationship and in providing guidance for environmental control policy.

Ultrafine black carbon caused mitochondrial oxidative stress, mitochondrial dysfunction and mitophagy in SH-SY5Y cells.

Exposure to ambient ultrafine black carbon (uBC, with aerodynamic diameter less than 100 nm) is associated with many neurodegenerative diseases. Oxidative stress is the predominantly reported neurotoxic effects caused by uBC exposure. Mitochondrion is responsible for production of majority of ROS in cells and mitochondrial dysfunction is closely related to adverse nervous outcomes. Mitophagy is an important cellular process to eliminate dysfunctional or damaged mitochondria. However, the mechanisms that modulate mitophagy and mitochondrial dysfunction initiated by uBC remain to be elucidated. The purpose of this study was to investigate how mitochondrial oxidative stress regulated mitochondrial dysfunction and mitophagy in human neuroblastoma cell line (SH-SY5Y) after uBC treatment. RNA interference was further applied to explore the roles of mitophagy in mitochondrial dysfunction. We found uBC triggered cell apoptosis via ROS-mitochondrial apoptotic pathway. The uBC also caused serious mitochondrial damage and respiratory dysfunction, indicated by the abnormalities in mitochondrial division and fusion related proteins, decreased mitochondria number and ATP level. Increased PTEN induced putative kinase 1 (PINK1) and Parkin protein levels and the autolysosome numbers suggested uBC could promote Pink1/Parkin-dependent mitophagy process in SH-SY5Y cells. Mitophagy inhibition could reserve mitochondria number and ATP activity, but not fusion and division related protein levels in SH-SY5Y cells exposed to uBC. Administration of a mitochondria-targeted antioxidant (mitoquinone) significantly eliminated uBC caused apoptosis, mitochondrial dysfunction and mitophagy. Our data suggested mitochondrial oxidative stress regulated uBC induced mitochondrial dysfunction and PINK1/Parkin-dependent mitophagy. PINK1/Parkin-dependent mitophagy probably participated in regulating uBC caused mitochondrial dysfunction but not by controlling mitochondrial fusion and division related proteins. Our results may provide some new insights and evidences to understand the mechanisms of neurotoxicity induced by uBC.

Evolution of boundary layer ozone in Shijiazhuang, a suburban site on the North China Plain.

The structure of the boundary layer affects the evolution of ozone (O3), and research into this structure will provide important insights for understanding photochemical pollution. In this study, we conducted a one-month observation (from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County, Shijiazhuang (37°53'N, 114°38'E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ±â€¯26.1 and 84.4 ±â€¯22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity (40%-50%) and medium boundary layer heights (1200-1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds (VOC) and nitrogen oxides (NOx) limitations, and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27% ±â€¯7% on average.

Assessment of resident's exposure level and health economic costs of PM10 in Beijing from 2008 to 2012.

Epidemiological studies have asserted a negative association between atmospheric particulates and human health, especially particulate matter (PM10), which can cause a noticeable damage to human health. In recent years, PM10 has become the primary pollutant in major cities in China. It is crucial to evaluate the health impacts of PM10 to make pollution control policies and protect public health. For health-based assessments, human exposure evaluation is a key step, which is related to offering an exact exposure date for assessment. Using high-density PM10 and population data based on the Geographic Information System (GIS), this study estimated the impact of PM10 on human exposure levels and combined the exposure-response function with the health-economic loss relationship to assess the effect of PM10 on human health in Beijing from 2008 to 2012 quantitatively. The results showed that the population distribution was highly centralized in urban areas, especially inside the fifth ring road. A high proportion, 63.4% of the population, was exposed to the range of 120 to 130µg/m(3). Approximately 44.1% of that population was located inside the fifth ring road, and approximately 55.9% of it was located outside of the fifth ring road. The spatial distribution of the economic cost associated with PM10 from 2008 to 2012 was uneven, being highly centralized in urban areas, especially inside the fifth ring road, similar to the population densities. The economic cost increased from 2008 to 2012, similar to GDP. The proportion of economic cost to Beijing's GDP decreased from 2008 to 2012. The average economic cost of 5years inside the fifth ring road was 4.55billion US$; that of the outside was 4.95billion US$. The proportions of average economic losses compared with GDP inside and outside of the fifth ring road changed slightly in the period from 2008 to 2012.

Association between PM10 and respiratory hospital admissions in different seasons in heavily polluted Lanzhou City.

Exposure-response relationship between particulate matter less than 10 µm in diameter (PM10) and human health in different seasons from 2001 to 2005 was examined based on hospital admissions data of respiratory system diseases from four major hospitals in Lanzhou, China. To quantify associations of respiratory system diseases with multiple air pollutants and meteorological conditions, a semiparametric generalized additive model was used in the authors' study by implementing daily ambient sulfur dioxide, nitrogen dioxide, and PM10 data collected from the Lanzhou Environmental Monitoring Station and daily meteorological data from Lanzhou Meteorological Bureau. Results showed that daily averaged PM10 increased per interquartile range the hospital admissions number of respiratory diseases by 3.3% in spring, 1.4% in summer, 3.6% in autumn, and 4.0% in winter from a single-pollutant model, or 3.1%, 1.4%, 3.0%, and 4.0% from a multi-pollutant model, respectively. The effect of PM10 on respiratory hospital admissions was lowest in summer and highest in winter. The relative risks of PM10 on female or the elderly (≥ 65 yrs.) were higher, showing a stronger association of PM10 with respiratory diseases in female and elderly groups than in males and people younger than 65.

Assessment of population exposure to PM10 for respiratory disease in Lanzhou (China) and its health-related economic costs based on GIS.

BACKGROUND: Evaluation of the adverse health effects of PM10 pollution (particulate matter less than 10 microns in diameter) is very important for protecting human health and establishing pollution control policy. Population exposure estimation is the first step in formulating exposure data for quantitative assessment of harmful PM10 pollution. METHODS: In this paper, we estimate PM10 concentration using a spatial interpolation method on a grid with a spatial resolution 0.01° × 0.01°. PM10 concentration data from monitoring stations are spatially interpolated, based on accurate population data in 2000 using a geographic information system. Then, an interpolated population layer is overlaid with an interpolated PM10 concentration layer, and population exposure levels are calculated. Combined with the exposure-response function between PM10 and health endpoints, economic costs of the adverse health effects of PM10 pollution are analyzed. RESULTS: The results indicate that the population in Lanzhou urban areas is distributed in a narrow and long belt, and there are relatively large population spatial gradients in the XiGu, ChengGuan and QiLiHe districts. We select threshold concentration C0 at: 0 µg m(-3) (no harmful health effects), 20 µg m(-3) (recommended by the World Health Organization), and 50 µg m(-3) (national first class standard in China) to calculate excess morbidity cases. For these three scenarios, proportions of the economic cost of PM10 pollution-related adverse health effects relative to GDP are 0.206%, 0.194% and 0.175%, respectively. The impact of meteorological factors on PM10 concentrations in 2000 is also analyzed. Sandstorm weather in spring, inversion layers in winter, and precipitation in summer are important factors associated with change in PM10 concentration. CONCLUSIONS: The population distribution by exposure level shows that the majority of people live in polluted areas. With the improvement of evaluation criteria, economic damage of respiratory disease caused by PM10 is much bigger. The health effects of Lanzhou urban residents should not be ignored. The government needs to find a better way to balance the health of residents and economy development. And balance the pros and cons before making a final policy.

Emission inventory evaluation using observations of regional atmospheric background stations of China.

Any accurate simulation of regional air quality by numerical models entails accurate and up-to-date emissions data for that region. The INTEX-B2006 (I06), one of the newest emission inventories recently popularly used in China and East Asia, has been assessed using the Community Multiscale Air Quality model and observations from regional atmospheric background stations of China. Comparisons of the model results with the observations for the species SO2, NO2, O3 and CO from the three regional atmospheric background stations of Shangdianzi, Longfengshan and Linan show that the model can basically capture the temporal characteristics of observations such as the monthly, seasonal and diurnal variance trends. Compared to the other three species, the simulated CO values were grossly underestimated by about two-third or one-half of the observed values, related to the uncertainty in CO emissions. Compared to the other two stations, Shangdianzi had poorer simulations, especially for SO2 and CO, which partly resulted from the site location close to local emission sources from the Beijing area; and the regional inventory used was not capable of capturing the influencing factors of strong regional sources on stations. Generally, the fact that summer gave poor simulation, especially for SO2 and O3, might partly relate to poor simulations of meteorological fields such as temperature and wind.

An assessment of China's PM10-related health economic losses in 2009.

Using GIS software and based on exposure-response functions, this paper estimated the health-related economic losses that China suffered in 2009 due to the presence of particulate matter (PM(10)). The results show that China suffered a health-related economic loss due to PM(10) of US$ 106.5 billion, or 2.1% of China's GDP, for the year 2009. Some urban areas, including Beijing, Tianjin, Shanghai, Guangzhou, Chongqing, and Changsha, reported large health-related economic losses due to PM(10), with a value of US$ 1.5 million per square kilometre or greater. Some parts of Beijing, Ji'nan, and Chongqing reported health-related economic losses due to PM(10) as being greater than 4% of the 2009 GDP.

Association between dust weather and number of admissions for patients with respiratory diseases in spring in Lanzhou.

Controlling the confounding factors on respiratory hospitalizations such as long-term trend, meteorological factor, atmospheric pollution, and calendar effect, the research is designed to study the effect of sand-dust weather on respiratory diseases from 2001 to 2005 in Lanzhou City on the basis of the semi-parametric generalized additive model (GAM). The results indicate that there is an association between sand-dust weather and the increase in respiratory hospitalizations, and with lagging effect. There are gender and age differences in the effect of sand-dust weather on health, on male severer than on female (RR value being 1.148 for male, while 1.144 for female without statistical significance), and much greater on the aged ≥ 65 years than on < 65 years (RR value being 1.266 for ≥ 65 yr, and 1.119 for < 65 yr).