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Background Exposure to ambient nitrogen dioxide (NO2) could increase the risks of small for gestational age (SGA) and large for gestational age (LGA). Nevertheless, previous published studies usually use a time period over relatively long durations as the exposure window, such as trimester-specific or gestational months, to identify adverse pregnancy outcomes related susceptible exposure windows for ambient air pollution. At present, no study has explored associations of weekly-specific ambient air NO2 exposure around pregnancy with SGA and LGA. Objective To evaluate the associations of exposure to ambient NO2 over the preconception and entire pregnancy period with risks of SGA and LGA, as well as to explore critical windows of NO2 exposure by refining exposure period to specific weeks. Methods Based on a birth cohort established by the project Environmental and LifEstyle FActors iN metabolic health throughout life-course Trajectories (ELEFANT) situated in Tianjin, 10 916 singleton pregnant women whose dates of the last menstrual period and delivery were both between June 2014 and June 2016, and whose gestational age were within 24-42 completed gestational weeks were included in this study. Each pregnant woman's exposures to ambient NO2 throughout 12 weeks before pregnancy and pregnancy period were matched with daily average NO2 concentrations obtained from the Chinese air quality reanalysis datasets (CAQRA). Distributed lag models incorporated in Cox proportional hazard regression models were applied to explore the associations of maternal exposure to weekly ambient NO2 throughout 12 weeks before pregnancy and pregnancy period with risks of SGA and LGA after controlling for potential confounders including maternal age, ethnicity, educational level, occupation, body mass index before pregnancy, residence, times of gravidity and parity, smoking, alcohol consumption, husband smoking, and season of conception. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated per 3 μg·m−3 increase in ambient NO2 concentrations. Results The average levels of maternal exposure to NO2 over the preconception, first trimester, second trimester, third trimester, and entire pregnancy periods were (39.6±10.8), (42.7±10.5), (44.8±12.7), (37.7±11.1), and (41.6±4.8) μg·m−3, respectively. For a 3 μg·m−3 increase in NO2 over the first trimester, the risk of SGA increased by 19.0% (95%CI: 8.0%-32.0%). For a 3 μg·m−3 increase in NO2 over the preconception, first trimester, and entire pregnancy, the associated risks of LGA increased by 7.0% (95%CI: 1.0%-13.0%), 37.0% (95%CI: 29.0%-46.0%) and 19.0% (95%CI: 9.0%-31.0%), respectively. For SGA, the susceptible exposure windows for NO2 were observed during the 7th to 12th preconceptional weeks and the 6th to 12th gestational weeks, with the strongest association found at the 12th preconceptional week, when the risk of SGA increased by 6.0% (95%CI:3.2%-8.9%) for a 3 μg·m−3 increase in NO2. For LGA, the susceptible exposure windows for NO2 were observed during the 1st to 12th preconceptional weeks and the 1st to 6th gestational weeks, with the strongest association found at the 12th preconceptional week, when the risk of LGA increased by 6.1% (95%CI: 4.5%-7.8%) for a 3 μg·m−3 increase in NO2. Conclusion Exposure to ambient NO2 is associated with increased risks of both SGA and LGA, and the most susceptible weekly exposure windows are nested within the 12 weeks before pregnancy and early pregnancy.
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Background The health effects of forest therapy have been widely recognized, while the previous studies mostly focused on a single activity mode of forest walks. The effects of different types of forest therapy activities remain unclear. Objective To explore the effects of short-term forest therapy on cardiopulmonary health, psychological health, and sleep quality, and the health effects of different types of forest therapy activities, aiming to provide population empirical study data for the development of forest therapy. Methods A self-control study was conducted in a national forest park in suburb of Beijing from August to September 2018. A total of 31 healthy college students were recruited as the study subjects, with a total forest stay for 3 days and 2 nights. During the period of study, each subject practiced walking therapy, sitting therapy with five senses experience (sitting therapy thereafter), and handmade work therapy, successively. Each type of forest therapy lasted about 2 h. Changes of blood pressure, oxygen saturation (SpO2), lung function, and fractional exhaled nitric oxide (FeNO) were estimated by measuring corresponding indicators before and after the forest therapy. Psychological health and sleep quality were assessed by Profile of Mood States and Pittsburgh Sleep Quality Index respectively at the same time. Mixed effects models were used to analyze the changes of these health indicators. The health effects of different types of forest therapy activities were further analyzed. Results The average age and body mass index of subjects in this study were (24.5±2.6) years and (20.7±1.7) kg·m−2, respectively. After a short-term forest therapy, the selected indicators of cardiopulmonary health, psychological health, and sleep quality of subjects were all improved. In particular, the pulse pressure (PP) and FeNO decreased by 3.02 mmHg and 1.10 ppb, respectively, while the SpO2 and peak expiratory flow (PEF) increased by 0.65% and 0.50 L·s−1, respectively, and the negative emotion and global sleep quality also presented significant positive changes (all P<0.05). Furthermore, different therapy activities presented differential effects in the health indicators. Walking therapy significantly improved pulmonary function, SpO2, and confusion (CON) emotion, in which the SpO2, forced expiratory volume in the first second (FEV1), and forced vital capacity (FVC) increased by 0.48%, 0.14 L, and 0.12 L, respectively, and the score of CON decreased by 0.97 (all P<0.05). Sitting therapy significantly reduced blood pressure and tension (TEN) emotion of subjects, including a decrease of the systolic blood pressure (4.45 mmHg), PP (4.19 mmHg), and the score of TEN (0.84) (all P<0.05). The diastolic blood pressure (DBP) increased slightly after handmade work therapy (ΔDBP=2.44 mmHg, P=0.016), but there were no significant changes in other indicators. Conclusion Short-term forest therapy could significantly improve cardiopulmonary health, psychological health, and sleep quality of young healthy individuals, and different types of forest therapy activities may have differential health effects.
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Objective@#To assess the associations of indoor fine particulate matter (PM2.5) from outdoor and indoor sources with heart rate (HR) and heart rate variability (HRV) in patients with chronic obstructive pulmonary disease (COPD) of Beijing.@*Methods@#A total of 40 male patients in a stable stage of COPD were recruited from a hospital in a panel study in Beijing with 5 consecutive days of measurement for each subject. General information and disease history of the participants from questionnaires were obtained prior to the study. HR and HRV were repeatedly examined using dynamic electrocardiograph. HRV included standard deviation of all NN intervals (SDNN), root mean square of successive differences between adjacent NN intervals (rMSSD), total power (TP) power in the low-frequency band (LF) and the high-frequency band (HF). Iron was used as tracer element to separate indoor-originated PM2.5 and outdoor-originated PM2.5. Mixed-effect models were applied to assess the associations of outdoor-originated PM2.5 or indoor-originated PM2.5 and health effects.@*Results@#The P50 (P25, P75) values of daily indoor PM2.5, indoor-originated PM2.5 and outdoor-originated PM2.5 were 50.9 (26.8, 122.7), 16.0 (1.9, 43.7) and 27.3 (13.5, 61.8) μg/m3, respectively. The mean±SD of concentrations of real-time indoor PM2.5, indoor-originated PM2.5 and outdoor-originated PM2.5 were (61.5±58.8), (25.3±39.1) and (36.2±42.7) μg/m3, respectively. Compared with outdoor-originated PM2.5, indoor-originated PM2.5 had significant associations with HRV and HR. Each 10 μg/m3 increase at 4 h indoor-originated PM2.5 and outdoor-originated PM2.5 moving average was associated with 3.4% (95%CI: -4.7%, -2.1%) and 0.6% (95%CI: -2.0%, -0.8%) reduction in TP (P<0.001). Each 10 μg/m3 increase at 12 h indoor-originated PM2.5 moving average was associated with 7.6% (95%CI: -10.1%, -5.1%), 4.7% (95%CI: -6.7%, -2.7%), 3.3% (95%CI: -4.2%,-2.4%) and 3.0% (95%CI: -4.5%, -1.5%) reduction in HF, LF, SDNN and rMSSD, respectively. Each 10 μg/m3 increase at 12 h outdoor-originated PM2.5 moving average was associated with 0.7% (95%CI: -2.7%, -1.4%), 0.2% (95%CI: -1.9%, 1.4%), 0.7% (95%CI: -1.4%, -0.1%) and 0.2% (95%CI: -1.3%, 0.9%) reduction in HF, LF, SDNN and rMSSD, respectively (P<0.001). Each 10 μg/m3 increase at 8 h indoor-originated PM2.5 and outdoor-originated PM2.5 moving average was associated with 0.7% (95%CI: 0.4%, 1.0%) and 0.4% (95%CI: 0.2%, 0.6%) increase in HR.@*Conclusion@#Exposure to indoor-originated PM2.5 was more strongly associations with HRV indices and HR compared with outdoor-originated PM2.5 in male COPD patients.
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Objective To explore the effect of carbon monoxide (CO) and ozone (O3) in the air on the myocardial infarction mortality in Ningbo,Zhejiang province,from 2011 to 2015.Methods The data of daily air quality surveillance and the causes of deaths in Ningbo from January 1,2011 to December 31,2015 were collected and the time series study using a generalized additive model was conducted to evaluate the relationship between the mortality of myocardial infarction and the air pollutants after adjustment for the long-term trend of death,weather conditions,"days of the week" and other confounding factors.Results The daily average concentrations of CO and O3 in Ningbo during 2011-2015 were 0.90 (0.02-3.31) mg/m3 and 82.78 (4-236) μg/m3,respectively.A total of 5 388 myocardial infarction deaths occurred,with a daily average of 3 deaths.In single-pollutant model,an increase of 0.1 mg/m3 in average concentration of CO could increase the risk of myocardial infarction mortality by 1.06％ (95％ CI:0.29％-1.93％) in general population,and by 1.26％ (95％ CI:0.28％-2.24％) in aged people aged ≥65 years in lagged 6 days,but the influence was not significant in people aged ＜65 years.The influence had no significant difference in males,but it increased the risk of myocardial infarction mortality by 1.77％ in females (95％ CI:0.44％-3.13％).In multipollutant model,CO did remain robust after adjusting for other co-pollutants.Whereas the effect of O3 had no significant influence.Conclusion These findings suggested that the increased risk of daily myocardial infarction mortality was associated with the increase of CO concentration,but no such association was found for O3 in Ningbo.
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Objective: To investigate the effect of silver nanoparticles (AgNPs) on hemichannel activity in human skin keratinocytes (HaCaT) and to explore the role of hemichannel in AgNP-induced anti-proliferative effect on HaCaT cells.Methods: HaCaT cells were exposed to 0, 0.1, 0.2, 1.0, 5.0, 10.0, 15.0 and 20.0 μg/cm2 of AgNPs for 24 h and cell viability was assessed by propidium iodide (PI) staining with flow cytometry.Hemichannel activity was examined by ethidium bromide (EB) uptake experiments in cells exposed to AgNPs with and without hemichannel inhibitor carbenoxolone (CBX).Afterward, HaCaT cells were seeded at a low density of 1×104cell /cm2 or a normal density of 4×104cell /cm2 and cultured for 24 h.Cell proliferation was measured by cell counting kit-8 (cck-8) in low-or normal-density cultured cells exposed to AgNPs for 24 h with and without 100 μmol/L CBX.Results: Cell viability showed no significant differences between the control and AgNP-exposed groups with the concentration less than 10 μg/cm2.Exposure to AgNPs increased EB uptake in a time-and dose-dependent manner in HaCaT cells and EB fluoresce density was increased to 116.67%, 124.85% and 139.53% of the control after exposure to 10 μg/cm2 AgNPs for 2 h, 12 h and 24 h.After being treated with 25, 50 and 100 μmol/L CBX, 10 μg/cm2 AgNP-induced increase in EB uptake was significantly reduced in HaCaT cells (P<0.01).The cellular proliferation rate was increased inlow-and normal-density cultured cells after AgNPs exposure with 100 μmol/L CBX.After being treated with 100 μmol/L CBX, 10 μg/cm2 AgNP-induced anti-proliferation in low-density cultured cells was significantly restrained (P<0.01).Conclusion: AgNPs could enhance hemichannel activity of HaCaT cells.Hemichannel activation was involved in AgNP-induced anti-proliferative effect.
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Objectives@#To investigate the effect of short-term exposure to ambient NO2 has influence on lung function and fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) patients.@*Methods@#A panel of doctor-diagnosed stable COPD patients (n=33) were recruited and repeatedly measured for lung function and FeNO from December 2013 to October 2014. The patients who lived in Beijing for more than one year and aged between 60 and 85 years old were included in the study. We excluded patients with asthma, bronchial tensor, lung cancer and other respiratory disorders other than chronic obstructive pulmonary disease and occupational exposure and chest trauma surgery patients. Because the frequency of each subject visiting to the hospital was different, a total of 170 times of lung function measurements and 215 times of FeNO measurements were conducted. At the same time, the atmospheric NO2 data of Beijing environmental monitoring station near the residence of each patient during the study period were collected from 1 day to 7 days lag before the measurement. Effects of short-term NO2 exposure on lung function and FeNO in COPD patients were estimated by linear mixed-effects models.@*Results@#The subjects' forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), and exhaled NO of subjects were (3.26±0.83) L, (1.66±0.61) L, (4.13±1.77) L/s, and (48.99±14.30) μg/m3, respectively. The concentration of NO2 was (70.3±34.2) μg/m3 and the interquartile range (IQR) was 39.0 μg/m3. Short-term exposure to NO2 resulted in a significant decrease in FVC among COPD patients' which was most obvious in 2 days lag. Every quartile range increased in NO2 (39 μg/m3, 2 day) would cause a 1.84% (95%CI: -3.20%- -0.48%) reduction in FVC. The effects of exposure to higher concentration of NO2 (≥58.0 μg/m3) on FVC estimate was -2.32% (95%CI: -4.15%- -0.48%)(P=0.02). No significant relevance of FeNO and NO2 was observed in this study.@*Conclusions@#Short term exposure to ambient NO2 may bring down pulmonary function in COPD patients.
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Objective To explore the effect of carbon monoxide (CO) and ozone (O3) in the air on the myocardial infarction mortality in Ningbo,Zhejiang province,from 2011 to 2015.Methods The data of daily air quality surveillance and the causes of deaths in Ningbo from January 1,2011 to December 31,2015 were collected and the time series study using a generalized additive model was conducted to evaluate the relationship between the mortality of myocardial infarction and the air pollutants after adjustment for the long-term trend of death,weather conditions,"days of the week" and other confounding factors.Results The daily average concentrations of CO and O3 in Ningbo during 2011-2015 were 0.90 (0.02-3.31) mg/m3 and 82.78 (4-236) μg/m3,respectively.A total of 5 388 myocardial infarction deaths occurred,with a daily average of 3 deaths.In single-pollutant model,an increase of 0.1 mg/m3 in average concentration of CO could increase the risk of myocardial infarction mortality by 1.06％ (95％ CI:0.29％-1.93％) in general population,and by 1.26％ (95％ CI:0.28％-2.24％) in aged people aged ≥65 years in lagged 6 days,but the influence was not significant in people aged ＜65 years.The influence had no significant difference in males,but it increased the risk of myocardial infarction mortality by 1.77％ in females (95％ CI:0.44％-3.13％).In multipollutant model,CO did remain robust after adjusting for other co-pollutants.Whereas the effect of O3 had no significant influence.Conclusion These findings suggested that the increased risk of daily myocardial infarction mortality was associated with the increase of CO concentration,but no such association was found for O3 in Ningbo.
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Objective:To study the association of air pollution with health service demand of the elderly and middle-age patients with cardiovascular and cerebrovascular diseases,and to provide a scientific ba-sis for development of environmental protection policy and health service policy of the Chinese govern-ment.Methods:This study included survey data on self-evaluated health,outpatient service demand and inpatient service demand of the patients with hypertension,heart disease and stroke in 62 cities of 1 7 provinces from China Health and Retirement Longitudinal Study(CHARLS)in 201 1 and 201 3,and com-bined it with the data on the annual concentrations of inhalable particulate matter(PM1 0 ),sulfur dioxide (SO2 )and nitrogen dioxide(NO2 )of those provinces and cities.Conditional Logistic regression was car-ried out to assess the possible effects of air pollutants on self-evaluated health and health service utiliza-tion.Results:The results showed that turning points existed in the effects of concentrations of NO2 and SO2 on the health service demand of the patients with hypertension,heart disease and stroke.The inpa-tient service demand of the hypertension patients increased with NO2 concentration when it was lower than 35.1 μg/m3 and decreased with NO2 concentration for higher value.Self-evaluated health of the patients with heart disease and stroke decreased with SO2 concentration when it was lower than 63.8 μg/m3 and increased with SO2 concentration for higher value.In addition,no evidence was found for the association between PM1 0 and health service demand.Conclusion:Air pollution may have effects on health service demand of the patients with hypertension,cardiovascular and cerebrovascular diseases,and different air pollutants at high or low concentration may have different health effects.
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Objective:To compare the differences of children’ s health in different area, and to confirm if the prevalence of respiratory diseases and symptoms among children are closely associated with the air pollution. Methods:A cross-sectional study was conducted in an urban area A and a suburban area B with different levels of air pollution in Beijing. Using a cluster sampling method, we recruited 4 564 chil-dren from 3 primary schools in urban A and 4 primary schools in suburban B. Respiratory symptoms were investigated using an international standardized questionnaire including characteristics of children, living conditions, respiratory diseases and symptoms and situation of parents. The concentrations of air pollu-tants for recent five years were obtained from Reports on the Quality of the Beijing Environment. SPSS 16. 0 was used to analyze data. Results: The prevalence of cough, persistent cough, phlegm, persistent phlegm, wheeze and asthma in A area were higher than those in B area[(62. 2% vs. 59. 9%), (6. 3%vs. 3. 1%), (42. 4% vs. 37. 4%),(3. 6% vs. 2. 4%),(13. 3% vs. 9. 9%) and(9. 5% vs. 5. 4%)]. Except for cough, cough with cold, cough without cold, the prevalence of respiratory diseases and symp-toms in A area were significantly higher than those in B area ( P <0 . 05 ) . Logistic regression analysis showed the prevalence of persistent cough, phlegm without cold, asthma in A area were significantly higher than those in B area ( P<0 . 05 ) . Conclusion:Respiratory diseases and symptoms among school-age children were closely associated with the level of air pollution.
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SUMMARY Traffic noise pollution problem is increasingly emerging with the rapid developmentof urban traffic. Researchers have paid close attention to the health effects of traffic noise. This review has summarized the recent research progress in the health effects of traffic noise both at home and abroad. Traffic noise can have various ad-verse health effects, and most of them are extra-auditory effects. The main aspects include that traffic noise can af-fect the cardiovascular system, which is verified by the evidence that exposure to traffic noise significantly increases the risk for cardiovascular diseases, such as high blood pressure, myocardial infarction, coronary heart disease, and so on. In addition, traffic noise can induce adverse effects on nervous system, leading to the increasing levels of anxiety, noise annoyance, and occurrence of insomnia. Furthermore, traffic noise is significantly associated with adverse pregnant outcomes, and can affect the endocrine system and digestive system. As traffic noise and traffic related air pollutants co-exist in the traffic environment, whether there are joint effects between these two factors have become areas of research focus nowadays. Although there is sufficient evidence that traffic noise has adverse health effects, inadequacies still existe. Analysis of the shortages of current studies and the prospects of the future studies are pointed out in this review.
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Objective:To study the concentrations of fine particulate matters and ultrafine particles and influenced factors during winter in an area of Beijing .Methods:Real-time monitoring of particles ’ mass and number concentrations were conducted in an area of Beijing from February 7th to 27th , 2013.At the same time, the meteorological data were also collected from the Beijing meteorological website .Differences of the particles ’ mass and number concentrations during different periods were analyzed using Mann -Whitney U test.Meanwhile, the influenced factors were also analyzed .Results: The mean concentra-tions of fine particulate matters and ultrafine particles were ( 157.2 ±142.8 ) μg/m3 and (25 018 ± 9 309) particles/cm3, respectively.The particles’ number and mass concentrations in haze days were 1.27 times and 2.91 times higher than those in non-haze days, respectively.The mass concentrations of fine particulate matters in the self-monitoring site were higher than those in the nearest central monitoring sites, and the hourly-average concentrations of particles were significantly consistent with those at the commuter times.Meanwhile, the setting off of fireworks/firecrackers during the Spring Festival could lead to short-term increases of the particles ’ number and mass concentrations .When the wind speed was low and the related humidity was high , the concentrations of particulate matters were relatively high , and the mass concentrations of fine particulate matters were lagged about 1-2 d.Conclusion: The level of the particulate matters in this area was high .Heavy traffic , setting off of fireworks/firecrackers and meteoro-logical factors may be some of the main factors affecting the concentrations of the particulate matters in this area.Among those factors, the effect of setting off of fireworks/firecrackers didn’t last long and the effect of the meteorological factors had a hysteresis effect .
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<p><b>OBJECTIVE</b>This study aims to evaluate the characteristics and the popular themes in the field of air pollution and reproductive and developmental health with the bibliometric approach.</p><p><b>METHOD</b>The articles from the year 1955 to 2013 in this field were retrieved by searching PubMed/MEDLINE using MeSH terms. The bibliographic information was analyzed to summarize the overall research characteristics. MeSH terms were sorted by their normalized frequency (NF) and classified into categories (air pollutants/components, reproductive and developmental outcomes and biological mechanisms) and then analyzed by regressive analysis to investigate the popular themes and their tendency.</p><p><b>RESULTS</b>All 2 315 papers are retrieved in this field, and 52.9% of the papers are published from the year 2004 to 2013. The 84.1% of the studies are conducted on the population, in which 10.9% are cohort studies. The researchers from USA conduct 28.0% of the studies. Only 2.3% of the studies are conducted by researchers from China. In the category of air pollutants/components, the high NF of MeSH terms, tobacco smoke pollutants, dust, carbon monoxide and heavy metals are 46.96%, 15.92%, 5.03% and 7.84% respectively. In the category of reproductive and developmental outcomes, the high NF of abortion, prenatal exposure delayed effects and pregnancy complications are 4.36%, 12.17% and 6.01%. In the category of biological mechanisms, the high NF of maternal-fetal exchange and DNA damage are 6.58% and 1.31%.</p><p><b>CONCLUSION</b>Tobacco smoke pollutants, dust, carbon monoxide and heavy metals are the major concerns of air pollutants/components. Reproductive and developmental outcomes mainly focus on the abortion, prenatal exposure delayed effects and pregnancy complications. Maternal-fetal exchange and DNA damage are mostly concerned as the biological mechanisms.</p>
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Female , Humans , Pregnancy , Abortion, Spontaneous , Air Pollutants , Air Pollution , Bibliometrics , Carbon Monoxide , China , Cohort Studies , DNA Damage , Dust , Maternal-Fetal Exchange , Metals, Heavy , Pregnancy Complications , Prenatal Exposure Delayed Effects , Tobacco Smoke PollutionABSTRACT
ObjectiveTo aim at the deficiencies of existing assessment methods,and put forward ideas,methods and contents to reform experimental course assessment methods for undergraduates.MethodsAll of the fifth-grade preventive medicine undergraduates were divided into experimental group (n=34) and control group(n=31),reformed and conventional assessment methods were used in experimental group and control group respectively.The difference in attendance,experimental skill and reports were compared between two groups.ResultsAttendance,test scores and experimental skill scores of students in experimental group were significantly higher than that in control group and compared with the control group students (P＜0,05),the experimental group students' understanding on the experimental principle,phenomena and data analysis were better.ConclusionReformed assessment methods of experimental course has an improved effect on teaching for undergraduates.
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Part of undergraduates were recruited from the universities round Xueyuan Road, Haidian district in Beijing. Self-administered questionnaire were conducted, on the basis of the status quo of students in understanding the environmental and health knowledge, attitude, behavior (KAP), to analyse the need for environmental health educational courses setting among undergraduates and to afford related suggestions on contents and methods for the course.
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Objective To estimate the effect of ambient air pollution on cardiovascular related blood indicators in occupational,highly-exposed population in Beijing. Methods The blood samples were collected for twice from 14 taxi drivers in spring(15-16 April) and autumn(17 September) of 2008,respectively. The air pollution index before the sampling days was also collected for three months in each season. Results Ambient air quality was better in autumn than spring of 2008. The level of plasma viscosity was lower and levels of low-/high-density lipoproteins were higher in autumn compared with those of taxi drivers in spring. Conclusion Air pollution is positively associated with plasma viscosity and negatively associated with low-/high-density lipoproteins in occupational,highly-exposed individuals.
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Objective To investigate the effects of PM2.5 on gap junctional intercellular communication (GJIC) between rat cardiomyocytes. Methods Primary cultured cardiomyocytes were prepared from 1-day-old Sprague-Dawley rats and exposed to PM2.5(1,10,100 ?g/ml)for 24 hours. The GJIC between cardiomyocytes was detected by the scrape loading dye transfer assay. The distribution and density of connexin43(Cx43) in the cells was detected by indirect immunofluorescence and the expression of Cx43 was detected by western blotting. Results The gap junctional intercellular communication between cardiomyocytes was significantly inhibited by PM2.5 in a dose-dependent manner. The fluorescence density of Cx43 was significantly decreased in PM2.5-treated cells,and the expression of Cx43 was also slightly decreased. Conclusion PM2.5 can inhibit GJIC between cardiomyocytes,which may be mediated by the decreased expression and aberrant distribution of Cx43 in PM2.5-treated cells.
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About half of the world population and more than 90% of rural households in the developing countries still use unprocessed biomass fuels (wood, dung and crop residues) as the fuels. These substances, burning in the open fire or in the simple stoves, can cause indoor air pollution and the pollutants exposure in women and children is more serious. Biomass smoke contains lots of toxic and harmful substances which may impact the health of human. This article presented a recent research progress in the indoor air pollution and health effects caused by combustion of biomass fuels in China and in the world.
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Objective To investigate the contamination level of environmental tobacco smoke (ETS) in the public places and workplaces in Dongcheng district of Beijing and identify the influencing factors for ETS exposure. Methods The contamination level of ETS in 14 public places and workplaces of Dongcheng district were monitored with passive sampler of vapor-phase nicotine during Apr.-Feb.,2004. Results Nicotine was detected from all monitor sites at the 14 locations. The lowest air nicotine concentration was detected in no smoking places and the highest one was detected in non-regulation places. There were many factors which were found to influence the indoor air nicotine concentration,including legislation,the number of smokers and the room space,etc. The most significant factor was found to be the numbers of smokers. Conclusion Exposure to ETS in the pubic places and workplaces has become a major pubic and occupational health issue at present.
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Objective:To study short-term effects of PM10(particulate matter of aerodynamic diameter
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Objective:To investigate the effects of nanoscale titanium dioxide(Nano-TiO2) on gap junctional intercellular communication(GJIC) between human lung fibroblasts.Methods: Human lung fibroblasts were exposed to two different sizes Nano-TiO2(25 nm and 80 nm) for 24 hours at the concentrations of 0,10,20,40 and 80 mg/L,respectively.The GJIC between cells was measured by using fluorescence redistribution after photobleaching(FRAP) assay.Results: The results showed that GJIC between cells was significantly inhibited both by 25 nm and 80 nm Nano-TiO2 in a dose-dependent manner.The fluorescence recovery rate was 20.81%?1.93% in control group,7.26%?0.91%(P