Short-term effects of air pollutants on outpatient volume of respiratory diseases in Guiyang / 环境与职业医学

Background Affected by concentration, composition, and population tolerance of air pollutants, the relationship between air pollutants and population health has regional differences. There is still a research gap in Guiyang. Objective To explore the short-term effects of air pollutant concentrations in low-pollution areas on the outpatient volume of respiratory diseases. Methods Spearman correlation analysis was used to evaluate the correlation between air pollutants, meteorological factors, and respiratory outpatient volume from January 1, 2013 to December 31, 2020 in Guiyang City. A single pollutant distribution lag nonlinear model and a multi-pollutant interaction model were established based on Poisson distribution. A three-dimensional diagram was drawn to display the relationship between air pollutants and respiratory outpatient volume. Quantitative analysis was conducted on the attribution risk and lag effect of air pollutant concentration on outpatient volume of respiratory diseases in Guiyang City. Results The results of the single pollutant model showed that fine particulate matter (PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2) elevated the outpatient volume of respiratory diseases. The maximum relative risk (RR) and 95%CI values of PM2.5, NO2,CO, and SO2 appeared on Day 2, 0, 5, and 6, respectively, which were 1.019 (1.015, 1.023), 1.146 (1.122, 1.171), 1.129 (1.116, 1.143), and 1.046(1.040, 1.052), respectively. For every quartile concentration increment of PM2.5, NO2, CO, or SO2, the outpatient volume of respiratory diseases increased by 0.943% (0.111%, 1.782%), 4.050% (3.573%, 4.529%), 0.595% (0.317%, 0.874%), or 0.667% (0.235%, 1.100%), respectively. The maximum RR (95%CI) of O3 was 1.015 (1.007, 1.023) and appeared on Day 0. The results of multi-pollutant model showed that PM2.5, NO2, CO, SO2, and O3 all elevated the outpatient volume of respiratory diseases. The maximum RR values of PM2.5, NO2, CO, SO2 and O3 appeared on Day 14, 0, 5, 7 and 0, respectively, which were 1.027 (1.021, 1.034), 1.213 (1.179, 1.248), 1.059 (1.043, 1.074), 1.016 (1.005, 1.026), and 1.024 (1.015, 1.033), respectively. Compared with the single pollutant model, the RR values of PM2.5, NO2, and O3 on the outpatient volume of respiratory diseases in the multi-pollutant model showed an upward trend, while the RR values of CO and SO2 in the multi-pollutant model showed a downward trend. Conclusion The impact of low concentrations of PM2.5, NO2, CO, and SO2 on human health cannot be ignored.

Individual and interactive effects of atmospheric PM2.5 and O3 on mortality of circulatory system diseases in Ningxia / 环境与职业医学

Background The impact of atmospheric fine particulate matter (PM2.5) and ozone (O3) on the mortality of circulatory system diseases cannot be ignored. However, whether the interaction between PM2.5 and O3 can affect population health is rarely reported and requires study. Objective To investigate the individual and interactive impacts of atmospheric PM2.5 and O3 on the mortality of circulatory system diseases in the population of Ningxia region. Methods The data of 119647 deaths due to circulatory system diseases, daily average concentrations of atmospheric pollutants, and meteorological data in Ningxia from 2013 to 2020 were retrieved. PM2.5 was divided into low, medium, and high concentrations according to the primary and secondary national limits (35 and 75 μg·m−3) of the Ambient air quality standards. Similarly, O3 was divided into low, medium, and high concentrations according to the national limits (100 and 160 μg·m−3). Using a generalized additive mixed model based on quasi Poisson distribution, the impacts of atmospheric PM2.5 and O3 as well as their interaction on the mortality of circulatory system diseases were analyzed using the population data of Ningxia region. Results During the target period, males and the ≥ 65 year group accounted for larger proportions of deaths due to circulatory system diseases (55.47% and 79.87% respectively). The daily average concentration of PM2.5 (40.25 μg·m−3) exceeded the national primary limit. In the single pollution model, the highest cumulative lag effects for mortality from circulatory system diseases were PM2.5 exposure over previous 1 d (lag01) and O3 exposure for previous 2 d (lag02), and their excess risk (ER) values were 1.03% (95%CI: 0.67%, 1.40%) and 1.02% (95%CI: 0.57%, 1.50%), respectively. The results of concentration stratification analysis showed that the most significant risks of death from circulatory system diseases [ER (95%CI): 1.12% (0.32%, 1.92%) and 0.95% (0.13%, 1.79%) respectively] were found at medium PM2.5 and O3 concentrations. The interaction analysis revealed that under, a synergistic effect on the risk of death from circulatory system diseases was identified (relative excess risk due to interaction=3.08%, attributable proportion of interaction=2.90%, synergy index=1.89) when considering the coexistence of PM2.5 and O3 above the primary limit. As the concentrations of PM2.5 and O3 increased, the synergistic effect increased the risk of death from circulatory system diseases in the general population, men, women, and the ≥ 65 years group. Conclusion Both atmospheric PM2.5 and O3 can increase the risk of death from circulatory system diseases, and the two pollutants have a synergistic effect on the risk of death from circulatory system diseases.

Advances on associations of exposure to air pollutants during pregnancy with congenital heart disease in offspring / 环境与职业医学

Congenital heart disease (CHD) is the most common birth defect and one of the major causes of neonatal death, with an average prevalence of 9.4‰ worldwide. We reviewed recent epidemiological studies and found that exposure to air pollutants is associated with increased CHD risks, but the associations are inconsistent between exposure to air pollutants and different subtypes of CHD due to developmental and etiological heterogeneity among different subtypes of CHD. It has been reported that air pollutants are associated with increased risks of ventricular septal defect, patent ductus arteriosus, pulmonary stenosis, tetralogy of Fallot, and transposition of the great arteries. However, associations between maternal exposure to air pollutants and atrial septal defect (ASD) are contradictory, with significantly positive associations of inhalable particulate matter and nitrogen dioxide exposure, negative associations of fine particulate matter and carbon monoxide, and mixed associations of sulfur dioxide. Adverse effects of air pollutant on cardiac development cover a wide time window beyond 3-8 weeks during gestation; particulate matter and nitrogen oxide are more likely to affect fetal heart in early pregnancy, while the association strength of carbon monoxide shows a trough in early pregnancy, and sulfur dioxide and ozone affect cardiac health throughout pregnancy. In addition, we discussed the limitations of previous studies on the associations between maternal air pollutant exposure and CHD, and highlighted the application of precise assessment on exposure to air pollutants, the performance of prospective cohort studies and longitudinal studies, and the necessity of studies on CHD subtypes, in order to provide scientific evidence to control exposure to environmental pollutants and CHD occurrence.

Time-series analysis of association between air pollution and hospital outpatient visits in a district of Shanghai from 2015 to 2019 / 上海预防医学

ObjectiveTo explore the association between air pollutants and hospital outpatient visits in a district of Shanghai. MethodsDaily meteorological data， environmental data， data of outpatient visits to two secondary hospitals and two tertiary hospitals in this district from January 1， 2015 to December 31， 2019 were collected. A Poisson regression generalized linear model was used to analyze the exposure-response relationship between the air pollutants and hospital outpatient visits in this area. ResultsDuring the study period， the total number of outpatient visits in the included hospitals was 17 802 634， with an average daily total of （9 750±4 191） outpatient visits，and an average daily of （761±341） respiratory outpatient visits. In the lag effect of single pollutant model， when the concentration of air pollutant increased by 10 μg·m-3， PM2.5， SO2， NO2 had the maximum lag effect on the number of outpatient visits in the department of internal medicine for respiratory diseases on lag day 4， day 5 and day 7， respectively. And the RR values and 95%CI were 1.002 0（1.001 3‒1.002 6）， 1.0154（1.012 3‒1.018 5）， and 1.006 1（1.005 3‒1.006 9）， respectively. ConclusionThere is a exposure-response relationship between air pollutants and the number of outpatient visits in each department of the hospitals， and different pollutants have different degrees of lag effects.

Systematic review of synergistic effect between air pollutants and temperature on human mortality in China / 环境与职业医学

Background Air pollutants and extreme temperature both pose significant threats to human health, but the synergistic effect between air pollutants and temperature on health is inconsistent. Objective To explore a potential synergistic effect between air pollutants and temperature on the mortality in China through literature review. Methods Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure, VIP Information Chinese Journal Service Platform, PubMed, Web of Science, Science Direct, and Embase databases were searched. "Temperature" "air pollution" "mortality" were selected as keywords to collect literature on synergistic effect between air pollutants and temperature on mortality in China. Literature was published from 2000-01-01 to 2022-07-31 in Chinese or English. Two researchers screened the literature independently according to the inclusion criteria, and the results were integrated and analyzed after data extraction. The "meta" package of R software was used for meta-analysis. Results Twenty-seven studies met the inclusion criteria and associated air pollutants included PM10, PM2.5, O3, SO2, NO2, and CO. The impact of PM10 and PM2.5 on mortality in high temperature days was higher than that in moderate temperature days. In high temperature days, a 10 μg·m−3 increment in PM10 concentration corresponded to pooled estimates of 2.30% (95%CI: 1.34%-3.26%), 1.23% (95%CI: 0.64%-1.82%), and 1.42% (95%CI: 0.63%-2.22%) increase in non-accidental, cardiovascular, and respiratory mortalities, respectively. A 10 μg·m−3 increment in PM2.5 concentration corresponded to pooled estimates of 2.56% (95%CI: 2.00%-3.13%), 2.37% (95%CI: 1.64%-3.12%), and 2.14% (95%CI: 1.03%-3.25%) increase in non-accidental, cardiovascular, and respiratory mortalities, respectively. The synergistic effect of SO2 and NO2 on cardiovascular and respiratory mortalities in low temperature days was higher than that in moderate temperature days. Conclusion The synergistic effects of air pollutants and temperature on mortality in low temperature days or in high temperature days are higher than that in moderate temperature days. The health protection related to these pollutants should be strengthened in these days.

Effect of Air Pollution on Emergency Room Visits for Respiratory Diseases in Lanzhou / 中国医学科学院学报

Objective To explore the effect of air pollution on the number of emergency room visits for respiratory diseases in residents at different ages and its seasonal changes in Lanzhou,so as to provide a scientific basis for the early prevention of respiratory diseases in Lanzhou. Methods The daily number of emergency room visits for respiratory diseases in three class A hospitals in Lanzhou from January 1,2013 to December 31,2017,as well as the air pollutants and meteorological data of Lanzhou in the same period,was collected.After controlling the confounding factors including long-term trend of time,meteorological factors and day-of-week effect using a generalized additive model,we analyzed the relationships between air pollutants and the daily number of emergency room visits for respiratory diseases,and explored whether there was a lag effect of air pollutants.Results From 2013 to 2017,the emergency room visits for respiratory diseases in Lanzhou had a total number of 124 871,with an average of 69(1-367)visits per day.The single pollutant model showed that among the six conventional air pollutants monitored in Lanzhou,PM

Interaction between oxidant pollutants and ambient temperature on cardio-cerebrovascular mortality risks in Guangzhou, China / 环境与职业医学

Background The increasing threats of air pollution and extreme weather have been widely recognized in recent years in China, but their individual and joint effects on cardio-cerebrovascular mortality are unclear. Objective This study aims to investigate the individual effects of and potential interactions between oxidant pollutants and ambient temperature on cardio-cerebrovascular mortality risks. Methods We collected daily data on death counts of cardio-cerebrovascular diseases, concentrations of ambient air pollutants, and meteorological parameters in Guangzhou, Chinabetween 1 January 2006 and 31 December 2016. A generalized additive model with a Poisson distribution was conducted to assess the associations of oxidant pollutants and ambient temperature with cardio-cerebrovascular mortality risks. Bivariate response surface models and stratified analyses were further adopted to qualitatively and quantitatively examine the potential interactions between oxidant pollutants and ambient temperature on cardio-cerebrovascular mortality risks. Results During the study period, the daily averages were 60.3 μg·m−3 for ozone (O3), 50.9 μg·m−3 for combined atmospheric oxidant capacity (Ox), 32.5 μg·m−3 for nitrogen dioxide (NO2), and 22.3℃ for ambient temperature. The average daily death counts of coronary and stroke diseases were 20 and 15, respectively. Per 10 μg·m−3 increment in O3, Ox, and NO2 were associated with increased coronary mortality risks (excess risk, ER) of 1.26% (95%CI: 0.79%-1.74%), 1.61% (95%CI: 0.99%-2.23%), and 1.33% (95%CI: 0.59%-2.07%), and with increased stroke mortality risks of 1.56% (95%CI: 1.04%-2.09%), 2.30% (95%CI: 1.60%-3.01%), and 2.93% (95%CI: 2.07%-3.79%) over cumulative lags of 2-5 days, respectively. The exposure-response relationships between ambient temperature and coronary and stroke mortality risks exhibited an inverse "J" shape, with the minimum mortality at temperatures of 25.7℃ for coronary disease and 27.3℃ for stroke. Our results further showed potentially synergic effects of higher temperatures and higher levels of O3 and Ox exposures on coronary mortality risks, and the relative ER due to interactions was 0.103 (95%CI: 0.028-0.178) for O3 and 0.079 (95%CI: 0.004-0.154) for Ox. We didn't find evidence of an interaction between oxidant pollutants and low temperature. Conclusion Short-term exposures to oxidant pollutants are associated with increased cardio-cerebrovascular mortality risks, and the interactive effects of high temperature and oxidant pollutants are synergistic in relation to cardio-cerebrovascular mortality risks.

Atmospheric PM2.5 exposure on semen quality in adult men in Taizhou / 预防医学

Objective@#To explore the effects of ambient fine particulate matter（PM2.5）exposure on semen quality in healthy adult men .@*Methods@#The semen quality data were collected from the pre-pregnancy check outpatient of Taizhou Central Hospital from August 2014 to December 2017,excluding the patients with any disease of reproductive system. The data of daily pollutant concentration of this area during the same period were also collected to estimate the exposures of PM2.5,PM10,SO2,NO2,O3 and CO during 90 days before each semen examination. Logistic regression model was applied to estimate the association between PM2.5 exposure and semen quality .@*Results@#A total of 3 456 healthy adult men were included in this study. The median （interquartile range）of the total sperm count of the 3 456 subjects was 161.00（122.00）×106,and 94.40% of the subjects could reach the lower reference limit for sperm count. The median（interquartile range）of the sperm concentration was 22.20（18.80）×106/mL,and 69.50% of the subjects were qualified. The median（interquartile range）of the sperm vitality was 55.30%（23.37%）,and 44.10% of the subjects were qualified. The median（interquartile range）of daily average concentration of PM2.5 at 0-90 days before semen examination was 37.82（12.33）μg/m3. The results of multivariate logistic regression model showed that,with each 12.33 μg/m3 increase of PM2.5 exposures at 0-90 days before semen examination,the odds ratios of unqualified sperm concentration,sperm motility and sperm vitality were 1.236（95%CI：1.041-1.466）,1.493（95%CI：1.260-1.770）and 1.462（95%CI：1.246-1.715）,respectively .@*Conclusion@#The results suggested that high concentration of ambient PM2.5 exposure during the sperm development period negatively affects sperm concentration,sperm motility and sperm vitality.

Application of a support vector regression on prediction of bacillary dysentery combined with meteorological and air pollutants index / 中华疾病控制杂志

Objective To explore the application of support vector regression (SVR) model combined with meteorological and air pollutants index in the prediction of the cases of bacillary dysentery in Lanzhou City, so as to provide scientific reference for the prevention and control of bacillary dysentery.Methods Time series data of the reported cases of bacillary dysentery from December 2013 to August 2016, combined with the meteorological and air pollutants data, were used as training set to fit support vector regression model. The data from September 2016 to December 2017 was used as validation set to verify the model and compare the effect in fit and prediction with different models. Results A total of 7 192 bacillary dysentery cases were reported in Lanzhou City from 2013 to 2017. The correlation coefficient of meteorological and pollution factors with the cases of bacillary dysentery was more than 0.4, except air pressure. The parameters of the fit model were selected based on the integrated data, acquiring the three parameters with the smallest test error were C=5, γ=0.02 and ε=0.000 1, respectively. The validation set was used to test the different models, which showed that the integrated data model had the best predictive accuracy and robustness . The root mean squared error (RMSE) was 0.164 7 and the mean absolute percentage error (MAPE) was 16.405%. Conclusion SVR model combined with meteorological and air pollutants index is effective in the prediction of bacterial dysentery.

Is Long-term Ambient Air Pollutant Exposure a Risk Factor for Irritable Bowel Syndrome in Children? A 12-year Longitudinal Cohort Study

BACKGROUND/AIMS: Recent studies suggest that air pollution may play a role in gastrointestinal disorders. However, the effect of long-term exposure to air pollution on childhood irritable bowel syndrome (IBS) is unclear. Hence, we conducted a nationwide cohort study to investigate the association between long-term air pollution exposure and the incidence and risk of IBS in Taiwanese children during 2000–2012. METHODS: We collected data from the Taiwan National Health Insurance Research Database, linked to the Taiwan Air Quality-Monitoring Database according to the insurant living area and the air quality-monitoring station locations. Children < 18 years old, identified from January 1st, 2000, were followed-up until IBS diagnosis or December 31st, 2012. The daily average air pollutant concentrations were categorized into 4 quartile-based groups (Q1–Q4). We measured the incidence rate, hazard ratios (HRs), and 95% confidence intervals for IBS stratified by the quartiles of air pollutant concentration. RESULTS: A total of 3537 children (1.39%) were diagnosed with IBS within the cohort during the follow-up period. The incidence rate for IBS increased from 0.84 to 1.76, from 0.73 to 1.68, from 0.85 to 1.98, and from 0.52 to 3.22 per 1000 person-years, with increase in the carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane quartile (from Q1 to Q4) exposure concentration, respectively. The adjusted HR for IBS increased with elevated carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane exposure in Q4 to 1.98, 2.14, 2.19, and 5.87, respectively, compared with Q1. CONCLUSION: Long-term ambient air pollutant exposure is an environmental risk factor for childhood IBS.

Relation of allergic rhinitis, allergen sensitization, and air pollutants in preschool children

PURPOSE: We aimed to investigate the prevalence and allergen sensitization of allergic rhinitis (AR) in preschool children. We assessed the relationship of AR, allergen sensitization, and air pollutants. METHODS: Between 2012 and 2016 in Jincheon, skin prick testing and questionnaire survey were performed on 2,958 children. AR have diagnosed on the basis of current symptoms and sign of AR on the Korean International Study of Asthma and Allergies in Childhood questionnaire and 1 or more proven allergen sensitization. RESULTS: A total of 2,052 children completed survey and skin prick testing, and were included in the analysis. The prevalence of AR symptom within last 12 months and AR were 27.0% and 10.9%, respectively. During study, both prevalences were increased from 20.1% and 8.6%, respectively in 2012 to 29.1% and 12.8%, respectively in 2016. The total inhalant allergen sensitization rate was 32.6%. The most common inhalant allergen was Dermatophagoides farinae (23.1%), followed by Dermatophagoides pteronyssinus (22.5%), tree pollens (5.3%), weed pollens (5.2%), fungi (4.7%), dog hair (4.5%) cat fur (3.6%), grass pollens (1.1%), and cockroach (0.8%). Although there was no difference tree or weed pollen sensitization, pollen seasonal prevalence of current AR symptoms is highest in spring (80%) versus autumn (52.3%). Seasonal PM10 (particulate matter with a median aerodynamic diameter less than or equal to 10 µm in diameter) and SO2 (sulfur dioxide) levels were correlated with the prevalence of seasonal AR symptoms. Pollen seasonal current AR symptoms were significantly related to seasonal pollen sensitization, but not inhalant allergens including dust mites. CONCLUSION: There was a rapid increasing prevalence of AR in preschool children in the areas of urbanization and industrialization. Pollen seasonal current AR symptoms have a close relationship with PM10 and seasonal pollen sensitization.

Contaminación del aire y enfermedad respiratoria en menores de cinco años de Bogotá, 2007 / Air pollution and respiratory illness in children aged less than 5 years-old in Bogotá, 2007

Objetivos Determinar la relación entre contaminación del aire extra e intramuros por material particulado MP10 con síntomas respiratorios en niños menores de 5 años en tres localidades del Distrito Capital. Métodos Estudio de cohortes. 315 niños y niñas de jardines ubicados en zona de mayor exposición a material particulado MP10, y 304 de jardines en zona de menor exposición. Se siguieron las cohortes por 19 semanas, teniendo en cuenta síntomas respiratorios. Se midió material particulado intramuros y extramuros en los jardines. Se determinaron prevalencias y asociación entre variables. Resultados Hubo una diferencia de promedios de MP intramuros entre mayor y menor exposición de 85.6 μg/m³vs. 61.8 μg/m³ (p<0,05). 74.3 % de los niños presentaron sibilancias en el último año, con diferencia entre mayor y menor exposición de 79,6 % vs 69,0 % (p<0,05). Sibilancias y expectoración estuvieron asociados a mayor exposición a MP10 (RR 1,39 y 1,30). Factores asociados a síntomas respiratorios: tabaquismo pasivo, el antecedente de bajo peso al nacer, el antecedente de sibilancias, la cercanía del jardín o vivienda a menos de 100 metros de chimeneas, vías de alto flujo vehicular, vías en mal estado y colecho. Discusión Un niño menor de 5 años expuesto a MP10 tiene 1,70 veces más riesgo de presentar ausentismo escolar por enfermedad respiratoria aguda, una disminución del MP10 reduciría en un 41,1 % este ausentismo escolar.

Objectives Determining the relationship between indoor and outdoor air pollution caused by particulate matter PM10 and respiratory symptoms in children aged younger than 5 years-old in three locations in Bogota. Methods This was a cohort study, involving 315 children in kindergartens located in the area of greatest exposure to PM10, and 304 in kindergartens located in an area of less exposure. The cohort was followed-up for 19 weeks considering respiratory symptoms. Particulate matter was intramurally and extramurally measured in the kindergartens. Prevalence and association between variables were determined. Results There was a difference regarding average intramural PM between higher and lower exposure (85.6 ug/m³cf 61.8 g/m³; p<0.05); 74.3 % of the children had suffered wheezing during the last year, difference between greater and lesser exposure being 79.6 % cf 69.0 % (p<0.05). Wheezing and coughing were associated with greater exposure to PM10 (RR 1.39 and 1.30). Factors associated with respiratory symptoms concerned passive smoking, having a history of low birth weight, a history of wheezing, a child's kindergarten or home being within 100 meters of (industrial) chimneys, high traffic flow routes, roads in disrepair and bed-sharing. Discussion A child aged less than 5 years-old exposed to PM10 had a 1.7 times higher risk of truancy due to acute respiratory illness; a decrease in PM10 reduced such truancy by 41.1 %.

Health risk represented by inhaling polycyclic aromatic hydrocarbons (PAH) during daily commuting involving using a high traffic flow route in Bogotá / Exposición a hidrocarburos aromáticos policíclicos durante desplazamientos diarios en una vía de alto flujo vehicular en Bogotá

Objective Assessing the risk to health by inhaling particles and particle-bound PAH during daily commuting along a high traffic flow route/corridor in Bogotá. Methods A van was equipped with a PAS2000 photo-electric sensor for real-time measurement of particle-bound PAH and a Dust Trakfor monitoring PM10 concentration; it drove along typical commuting routes in the city. Exposure to particles and particle-bound PAH was assessed by using an inhalation intake model. Results A similar trend was observed for both PM10 and PAH concentration, indicating that traffic was the same source for both contaminants. Extreme PM10 and PAH inhalation concentrations were recorded every time direct bus and microbus emissions were measured by the van. Inhalation model results indicated that exposure was significantly greater when using a venues having mixed traffic use (i.e. buses, microbuses, passenger vehicles, motorcycles) compared to using roads where the TransMilenio system (articulated buses) had been implemented. Conclusions The results may support evaluating bus drivers, commuters and bike users' exposure to toxic compounds in the city.(AU)

Objetivo El presente estudio buscó estimar la exposición a material particulado e Hidrocarburos Aromáticos Poli cíclicos (HAP) asociados a partículas durante el desplazamiento diario de la población en una vía de alto flujo vehicular en Bogotá. Método Se instaló un equipo "dust-track" para la medición de partículas y un equipo fotoeléctrico "PAS2000" para la medición de los HAP, ambos en un vehículo tipo van que replicó el desplazamiento diario de personas de la casa al trabajo y viceversa. Con el fin de valorar la exposición personal a estos contaminantes según el tipo de vía se usó un modelo de inhalación. Resultados Se observó una tendencia similar entre la concentración del material particulado menor a 10 micrómetros (PM10) y los HAP, indicando que ambos provienen del tráfico principalmente. El modelo de inhalación mostró que las concentraciones a las que está expuesta una persona son mayores en vías con diferentes tipologías de vehículos (carros, buses y busetas, camiones, motocicletas) que en vías de uso exclusivo público para el sistema TransMilenio. Conclusiones Los resultados de este estudio son útiles en la evaluación de la población a contaminantes tóxicos del aire y pueden ser utilizados para apoyar políticas públicas destinadas al mejoramiento de la calidad del aire.(AU)

Effects of ozone on influenza virus-induced airway hyperreactivity in rats / 천식및알레르기

BACKGROUND: Ozone is one of the most ubiquitous oxidant in urban air and may exacerbate respiratory diseases such as asthma. OBJECTIVE: We examined whether ozone can influence airway hyperresponsiveness induced by influenza virus-infection. SUBJECT AND METHOD: Rats were exposed to ozone, acutely to 1.0ppm and 0.25ppm for 23.5hrs. At 2hrs post cessation of ozone exposure, animals were infected with rat-adapted influenza virus intra-nasally. On day 3 post-virus inoculation, pulmonary mechanics were measured during an intravenous challenge with acetylcholine . Cumulative doseresponse functions were obtained by doubling the rate of the intravenous infusion every 2min. RESULTS: ACh increased airway resistance in a dose-dependent manner. Neither of the concentrations of ozone altered the airway responses to ACh. Animals infected with virus developed hyperresponsiveness to ACh as was expected. Pre-exposure to 1.0ppm ozone for 23.5hrs aug- mented the virus-induced airway hyperresponsiveness, while 0.25ppm did not. CONCLUSION: Acute exposure to ozone can synergistically act on virus-induced airway hyperreactivity.

Characteristics of Outdoor Air Microbes Pollution in Hefei City / 环境与健康杂志

Objective To understand the air microorganisms pollution and the community structure and distribution characteristics of outdoor airborne microbes in Hefei. Methods Airborne microbes were sampled by fallen plate method at 10 collection sites in the Hefei city. Results The results showed that the average concentration of the bacteria,fungi and total microbes in the outdoor environment were 5.04?104,3.75?103 and 5.41?104 cfu/m3 respectively and the fungi accounted for 6.92%of the total. The preliminary identification showed that the dominant bacteria mainly were Micrococcus, Bacillus, Pseudomonas and Staphylococcus and the average percentage were 37.3%, 21.0%, 10.3% and 9.5% respectively. Of the five fungi the dominant ones were Aspergillum, Penicillium, Mucor and Rhizopu. The average percentage were 42.0%,36.0%,4.4% and 4.2% respectively. Conclusion The outdoor air of Hefei has been polluted by airborne microbes. The distribution of the airborne microbes has the characteristics of time and space.It is affected not only by the environment and pollution,but also by such factors as human activities,animals and plants.

Monitoring of Concentration of Airborne Pollen with Burkard Sampler in Autumn,2007 in Beijing / 环境与健康杂志

Objective The aim of this study was to understand the pollen concentration and the daily variation during 2007 in Beijing by monitoring.Methods Burkard volumetric strap was used for the pollen sampling from August 1st to October 20th.Genus of pollen was identified by light microscope.Results Artemisia and Humulus.L pollen were the dominant airborne pollen in late summer and autumn in Beijing City.The average pollen concentration of Artemisia and Humulus.L were 71 grain/m3, 124 grain/m3.Both of them lasted from the August 8th until October 6th or 8th.Statistical analysis showed that the pollen concentration of Artemisia or Humulus.L at 2:00 pm to 4:00 pm was higher than that at 6:00 am to 8:00 am.Conclusion It is the first work to conduct the monitoring of the concentration of Artemisia and Humulus.L pollen with Burkard sampler in Beijing.Humulus.L is the dominant airborne pollen during August and September.