Advances in research on relationship between indoor artificial light at night and human health / 环境与职业医学

With the acceleration of global urbanization, the intensity and coverage of artificial light at night (ALAN) are increasing, and its service duration is obviously prolonged. ALAN exposure is not only related to the occurrence and development of cardiovascular, metabolic, sleep, myopia, and mental diseases, but also may induce cancer. Previous studies have focused on the health effects of outdoor ALAN, but people spend more than 80% of their lives indoors, hence it is of great significance to understand the relationship between indoor ALAN and population health to create a healthy indoor environment and protect the health of the population.

Effects of cord blood element levels on neurodevelopment of preterm and full-term children: A cohort study / 环境与职业医学

Background Essential and non-essential elements have an important impact on the development of the central nervous system during fetal development. Due to their less developed brain, preterm infants are more sensitive to element exposure, and are high-risk groups of neurodevelopmental abnormalities. However, it is not clear whether the effects of element exposure in utero on postpartum neurodevelopment are different between full-term infants and preterm infants. Objective To evaluate the effects of element exposure levels during pregnancy on neurodevelopment of children aged 6-24 months (of corrected age), and compare the effects between preterm and full-term children. Methods A prospective study design was adopted and this study was conducted based on the Maoming Birth Cohort Study (MBCS) in Maoming City, Guangdong Province. Twenty elements in cord blood of 197 preterm infants and 297 full-term infants were measured, including 11 essential trace elements [vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), strontium (Sr), tin (Sn), and iron (Fe)], and 9 non-essential trace elements [aluminum (Al), arsenic (As), thallium (Tl), lead (Pb), uranium (U), cerium (Ce), antimony (Sb), cadmium (Cd), and yttrium (Y)]. The neurodevelopment of the children at 6, 12, and 24 months were evaluated by the Ages and Stages Questionnaires-the Third Edition (ASQ-3). A generalized estimating equation (GEE) model was adopted to evaluate the associations between elements and neurodevelopment in full-term and preterm children separately. Results The positive rates of 10 elements (Mn, Cu, Zn, Se, Sr, Fe, Sb, Tl, Pb, and As) in cord blood were greater than 80%. Among the preterm birth children, the results of GEE analysis showed that after adjusting for the covariates, for each increase of interquartile range (IQR) in ln-transformed concentration, As was associated with problems/delay in the communication and problem-solving sub-scales, with the adjusted odds ratios (OR) and 95% confidence intervals (CI) of 1.36 (1.03-1.80) and 1.55 (1.10-2.20), respectively; the adjusted OR (95%CI) of problems/delay in the fine motor and problem-solving sub-scales were 1.44 (1.00-2.07) and 1.76 (1.09-2.84) for Sb, respectively; the adjusted OR (95%CI) of problems/delay in the communication sub-scale was 1.37 (1.09-1.74) for Se. No statistically significant associations between umbilical cord blood element concentrations and neurodevelopment indicators were observed among full-term children. The results of stratified analysis by sex showed that the associations between umbilical cord blood element concentrations and neurodevelopment problems/delay were only significant among female preterm children. Conclusion Exposures to As, Se, and Sb during pregnancy may increase the risk of neurodevelopment problems/delay in preterm children aged 6-24 months, and female seem to be more vulnerable.

Identifying susceptible exposure windows for ambient nitrogen dioxide before and during pregnancy and increased risks of small/large for gestational age / 环境与职业医学

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.

Effects of short-term forest therapy on selected physical and mental health indicators of young healthy individuals / 环境与职业医学

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.

Forest therapy and population health / 环境与职业医学

Prosperity for all is impossible without health for all. In recent years, following with the development of national land greening, forest resources have greatly increased in China. It is one of the effective ways to realize the Healthy China strategy to develop and perfect forest rehabilitation and forest therapy with forest resources. Forest therapy has gradually become a new interdisciplinary science and a focus of public attention. This paper reviewed the development of forest therapy in some countries in the world, summarized the health effects of forest therapy on cardiovascular, respiratory, immune, and mental system, pointed out the limitations of the research work at present on forest therapy and population health, and discussed the outlook of forest therapy and population health in China.

Short-term effects of household indoor- and outdoor-originating fine particulate matters on heart rate and heart rate variability in chronic obstructive pulmonary diseases patients, Beijing / 中华预防医学杂志

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.

Review on methods in the disease burden assessment attributable to household air pollution / 中华预防医学杂志

In the past decades, people's work and life styles have dramatically changed during the rapid economic development and urbanization in China. A national survey reported that Chinese adults spend an average of 81% of daily time in indoor environment. Exposure to indoor air pollution plays key roles for human health but is likely to be neglected due on the relatively lower concentration levels and lower awareness among common people. Till now, published studies focus more on the pollution levels or the toxicological effects of indoor air pollutants but there is a lack of disease burden assessment attributable to indoor air pollution. In this review, several international studies were introduced on the disease burden estimation attributable to indoor air pollution, as well as the estimation methods. The current situation of national study was also reviewed. The strengths and limitations of the representative international studies were discussed. This review is helpful in providing data to guide the research on disease burden assessment attributable to indoor air pollution in China, and further helps to prioritize the indoor air pollution control based on disease burden ranking among pollutants and motivate public policies to protect the public health.

Effects of silver nanoparticle on hemichannel activation and anti-proliferation in HaCaT cells / 北京大学学报(医学版)

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.

The effect of short-term exposure to ambient NO2 on lung function and fractional exhaled nitric oxide in 33 chronic obstructive pulmonary disease patients / 中华预防医学杂志

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.

Effect of air pollution on health service demand of the elderly and middle-age patients with hypertension,cardiovascular and cerebrovascular diseases:based on analysis of data from CHARLS / 北京大学学报(医学版)

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.

Concentrations of fine particulate matters and ultrafine particles and influenced factors during winter in an area of Beijing / 北京大学学报(医学版)

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 .

Reform of experimental course assessment methods of preventive medicine in undergraduates and its evaluation / 中华医学教育探索杂志

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.

Status of needs, contents and methods of environmental health educational courses among undergraduates / 中华医学教育探索杂志

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.

Acute injury of inhalable particle matters on nasal mucous membrane of rat / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the mechanism of the nasal mucous membrane inflammation induced by the inhalable particle matter (PM10).@*METHOD@#Three dosage PM10 were instilled in rat nasal cavity of different groups for one week. The morphology of nasal mucosa and the numbers of inflammatory cell were observed in each samples.@*RESULT@#The total numbers of inflammatory cells in PM10-treated groups were increased in a dose-respondent manner and significantly different from that in control group. The results of histopathological and scanning electron microscope (SEM) analysis indicated that PM10 caused nasal mucosa injury and pathological changes, such as the damage of cilia and nasal mucosa epithelium in a dose dependent way. The infiltration of inflammatory cells in nasal mucosa epithelium matrix, especially eosinophilia were observed.@*CONCLUSION@#PM10 can cause rat's nasal mucosa inflammation and epithelial injury.

Personal Exposure to PM2.5 of Children Living near Traffic Road and the Influencing Factors in Beijing / 环境与健康杂志

Objective To evaluate personal exposure level to PM2.5 of children living in one of districts of Beijing and to explore the possible influencing factors. Methods Thirty-six pupils were chosen from a primary school in the district. The PM2.5 level of classrooms,campuses and children's living rooms were monitored by Aerosol Monitor and 24 h time-active pattern and environmental information of living room of these pupils were collected at the same time. Each child's exposure level of PM2.5 was calculated by combining the environment PM2.5 monitor data and the children's 24 h time-active pattern. The possible influencing factors were analyzed by single factor analysis(Kruskal-Wall rank sum test and Spearman rank correlation analysis) and multiple linear regression models. Results The 24 h average exposure level of PM2.5 of 36 pupils was 98.13 ?g/m(341.22～121.13 ?g/m3) . The single factor analysis showed that the personal exposure level to PM2.5 was significantly related with air pollution index(API) (r =0.836,P

Effect of Ambient Air Pollution on Cardiovascular Related Blood Indicators in Taxi Drivers / 环境与健康杂志

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.

Effect of PM2.5 on Gap Junctional Intercellular Communication in Neonatal Rat Cardiomyocytes / 环境与健康杂志

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.

Short-time effects of inhalable particles and fine particles on children's lung function in a district in Beijing / 北京大学学报(医学版)

Objective:To study short-term effects of PM10(particulate matter of aerodynamic diameter

Effects of nanoscale titanium dioxide on intercellular gap junction communication in human lung fibroblasts / 北京大学学报(医学版)

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

Effect of PM2.5 Intratracheal Instillation on Heart Rhythm in SHR Rats / 环境与健康杂志

Objective To study the acute effects of PM2.5 on the heart rhythm of spontaneously hypertensive rats(SHR)and the mechanism.Methods Twenty-eight male spontaneously hypertensive rats(SHR)were randomly divided into four groups.PM2.5 was administered by intratracheal instillation at the doses of 0 mg/kg,7.5 mg/kg,15 mg/kg and 30 mg/kg respectively.ECGs were monitored at 30 min,1 h and 24 h later.Results The numbers of the rats with arrhythmia in all groups increased at 30 min after treatment.At 1 h after treatment,in control group the rats recovered,but in PM2.5 groups abnormal ECGs was still showed.However,ECGs of all groups became normal 24 h later.As shown by laser scanning confocal microscope(LSCM),the expression of Cx43 in the heart tissue of rats in 15 mg/kg and 30 mg/kg groups significantly decreased compared with the control group.There was no significant change in content of MDA and SOD in the heart tissue of PM2.5 treated rats.Conclusion PM2.5 exposure through inhalation may induce arrhythmia in SHR rats and the downregulated expression of Cx43 may play an important role in the pathogenesis.