Associations between indoor volatile organic compounds and nocturnal heart rate variability of young female adults: A panel study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults.@*METHODS@#This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results.@*RESULTS@#The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m2. During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m3, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m3, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m3 increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m3. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter.@*CONCLUSION@#Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.

Association of ambient fine particulate air pollution with hospitalization costs and stays for depression in China: a multicity analysis / 中华预防医学杂志

Objective: To explore the effect of fine particulate matter (PM2.5) pollution on depression hospitalization cost and length of stay in 57 cities of China. Methods: A total of 84 207 patients with depression in 57 cities of China from January 2013 to December 2017 were selected as the subjects. The demographic characteristics and hospitalization status of the patients were obtained from the database of basic medical insurance for urban workers and urban residents in China. The environmental exposure data of the same period were obtained from the national air quality real-time release platform of China Environmental Monitoring Station. A generalized additive model based on quasi-Poisson distribution was used to analyze PM2.5 exposure effect in each city, and the nonlinear mixing of moving average temperature, relative humidity and date was controlled by natural smooth spline function. Results: Among the included cities, southern cities accounted for 50.88% (29), and the number of female inpatients, hospitalization costs and hospitalization days accounted for 62.65%, 63.50% and 60.85% (42 735 cases, 567.78 million yuan and 1.14 million days, respectively). The proportion of hospitalized cases, hospitalization cost and length of stay in the age group of 40 to 64 years old were 59.15% (40 346 cases), 53.92% (482.15 million yuan) and 52.07% (0.98 million days), respectively. PM2.5 level was positively correlated with the number of hospitalized cases with depression, hospitalization cost and length of stay. When the 3-day moving average of PM2.5 exposure level increased by 10 μg/m3, the number of hospitalization cases increased by 0.64%. The attributed percentage (95%CI) of hospitalized cases, hospitalization costs and length of stay were 3.35% (0.57%-6.04%), 3.04% (0.52%-5.48%) and 3.07% (0.49%-5.56%), respectively. Subgroup analysis showed that the attributed percentage of hospitalization cases, hospitalization cost and length of stay to PM2.5 exposure ranged from 3.97% to 4.68%, 4.04% to 4.33% and 4.13% to 4.30% in northern China, male and cold season, respectively. Conclusion: PM2.5 exposure is associated with the increase of hospitalization cost and length of stay among Chinese urban population with depression.

Monitoring metrics for short-term exposure to ambient ozone and pulmonary function and airway inflammation in healthy young adults / 北京大学学报(医学版)

OBJECTIVE@#To assess the associations of different monitoring metrics for short-term exposure to ambient ozone (O3) with pulmonary function and airway inflammation in healthy young adults.@*METHODS@#A total of 97 healthy young college students were recruited and followed in a panel study conducted from December 2017 to June 2018. Each participant underwent 3 follow-up visits, and lung function and fractional exhaled nitric oxide (FeNO) were measured at each visit. Ambient air pollutant concentrations were obtained from the environment monitoring station of Beijing closest to the participant residences, and meteorological data were collected from China Meteorological Data Service Center. Linear mixed-effect models were applied to assess the associations between different monitoring metrics for ambient O3 short-term exposure with pulmonary function or airway inflammation in the healthy young adults.@*RESULTS@#During the study period, the P50 (P25, P75) values for ambient O3 concentration expressed as daily 1-hour maximum (O3-1 h max), daily maximum 8-hour average (O3-8 h max) and 24-hour average (O3-24 h avg) were 102.5 (76.8, 163.0) μg/m3, 91.1 (68.3, 154.3) μg/m3 and 61.6 (36.9, 81.7) μg/m3, respectively. The different monitoring metrics for short-term exposure to ambient O3 were significantly associated with reduced forced expiratory volume in the first second (FEV1) and increased FeNO. An interquartile range (IQR) increase in 6-d moving average of O3-1 h max (IQR=71.5 μg/m3) was associated with a 6.2% (95%CI: －11.8%, －0.5%) decrease in FEV1 and a 63.3% (95%CI: 13.8%, 134.3%) increase in FeNO. An IQR increase in 7-d moving average of O3-8 h max (IQR=62.0 μg/m3) was associated with a 6.2% (95%CI: －11.6%, －0.7%) decrease in FEV1and a 75.5% (95%CI: 19.3%, 158.0%) increase in FeNO. An IQR increase in 5-d moving average of O3-24 h avg (IQR=32.9 μg/m3) was associated with a 3.7% (95%CI: －7.1%, －0.2%) decrease in FEV1and a 25.3% (95%CI: 3.6%, 51.6%) increase in FeNO. There was no significant association between the three monitoring metrics for O3 exposure and peak expiratory flow (PEF).@*CONCLUSION@#Short-term exposure to ambient O3 was associated with decreased lung function and increased airway inflammation among the healthy young adults, and daily 1-hour maximum was more sensitively to the respiratory effects of O3.

Effects of high-efficiency particulate air purifiers on indoor fine particulate matter and its constituents in a district of Beijing during winter / 北京大学学报(医学版)

OBJECTIVE@#To analyze the effect of domestic high-efficiency particulate air (HEPA) purifiers on the concentrations of indoor fine particulate matter (PM2.5) and its elementary constituents in 20 residences in a district of Beijing during winter.@*METHODS@#From November 2015 to January 2016, 20 residences in a district of Beijing were selected, where indoor and outdoor PM2.5 data were collected simultaneously in three time periods according to the operating of air purifiers (Group 0 h: 24 hours before operating; Group 24 h: 24 hours after operating; Group 48 h: 24 to 48 hours after operating). The content of 21 elements in PM2.5 samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Indoor/outdoor particle concentration ratio (I/O ratios) and ΔI/O ratios were used to describe the pollution levels and the variation range of PM2.5 and its 21 elementary constituents. One-way analysis of variance (ANOVA) for repeated measurement data was applied to compare the I/O ratios of PM2.5 and its elementary constituents among the different groups, and Bonferroni method was used for comparison in pairs. Wilcoxon signed rank test for paired-samples was used to compare ΔI/O ratios of 21 elementary constituents with that of PM2.5.@*RESULTS@#The median I/O ratios of PM2.5 in the three groups were 1.27 (P25-P75: 0.50-2.68), 0.45 (P25-P75: 0.27-1.03) and 0.36 (P25-P75: 0.28-2.48), respectively. Compared with Group 0 h, the I/O ratios of PM2.5 in Group 24 h (P=0.042) and Group 48 h (P=0.006) decreased significantly. However, there was no significant difference between Group 24 h and Group 48 h. Significant differences were found comparing ΔI/O ratios of aluminium, ferrum and titanium to that of PM2.5, in both Group 24 h and Group 48 h (P<0.05). No significant change was found in the I/O ratios of these three elements among the three groups before and after air purifier operating (P>0.05). Distances from residences to traffic arteries could affect I/O ratios of some elements from traffic-related source (P<0.05).@*CONCLUSION@#Domestic HEPA air purifiers could effectively reduce indoor PM2.5 concentration, and the pollution level of PM2.5 tend to be stable after the purifier operating for a time. The purifiers had different effects on different elements, among which most showed statistical significances.

The comparison of the indoor environmental factors associated with asthma and related allergies among school-child between urban and suburban areas in Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the indoor environmental factors associated with the prevalence of asthma and related allergies among school children.</p><p><b>METHODS</b>A cluster sampling method was used and the ISAAC questionnaire was conducted. A total of 4612 elementary students under Grade Five of 7 schools were enrolled in the survey for the impact of indoor environmental factors on the prevalence of asthma and related allergies in several urban and suburban schools of Beijing.</p><p><b>RESULTS</b>A total of 4060 sample were finally analyzed including 1992 urban and 2068 suburban. The prevalence of wheeze, allergic rhinoconjunctivitis and atopic eczema in the past 12 months was 3.1% (61/1992), 5.3% (106/1992), 1.1% (22/1992) among urban children while 1.3% (27/2068), 3.1% (65/2068), 1.0% (22/2068) among suburban children respectively. The prevalence of wheeze and allergic rhinoconjunctivitis of the past 12 months in urban were both significantly higher than that in suburban (χ(2) = 14.77, 11.93, P < 0.01). The incidences of having asthma and eczema ever among urban children (5.3% (105/1992), 29.4% (586/1992)) were significantly (χ(2) = 39.03, 147.22, P < 0.01) higher than that among suburban (1.7% (35/2068), 13.8% (285/2068)). Although the distributions of indoor environmental factors were similar in both areas, passive smoking and interior decoration had different influence on the prevalence of asthma and related allergies among school children in the two areas. The significant impact of passive smoking on having asthma ever among suburban children was observed (OR = 2.70, 95%CI = 1.17 - 6.23) while no significant result in urban (OR = 1.06, 95%CI = 0.71 - 1.58); the percentage of interior decoration was 84.0% (1673/1992) among urban children and 80.0% (1655/2068) among suburban children, there was significant impact of interior decoration on the prevalence of having eczema ever among urban children (OR = 1.57, 95%CI = 1.17 - 2.10) but no significant results were found in suburban sample (OR = 1.06, 95%CI = 0.76 - 1.48).</p><p><b>CONCLUSION</b>The prevalence of asthma and related allergies among school children is much higher in urban areas than that in suburban areas and the indoor environmental factors such as passive smoking and interior decoration may differently explain the prevalence of asthma and related allergies in the two areas.</p>

Pollutions of indoor fine particles in four types of public places and the influencing factors / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the levels of pollutions caused by fine particulate matter (PM(2.5)) in the public places and investigate the possible influencing factors.</p><p><b>METHODS</b>A total of 20 public places in four types such as rest room in bath center, restaurant, karaoke bars and cyber cafe in Tongzhou district in Beijing were chosen in this study; indoor and outdoor PM(2.5) was monitored by TSI sidepak AM510. Data under varying conditions were collected and analyzed, such as doors or windows or mechanical ventilation devices being opened, rooms cramped with people and smoking.</p><p><b>RESULTS</b>The average concentration of indoor PM(2.5) in 20 public places was (334.6 +/- 386.3) microg/m(3), ranging from 6 microg/m(3) to 1956 microg/m(3); while in bath center, restaurant, karaoke bars and cyber cafe were (116.9 +/- 100.1)microg/m(3), (317.9 +/- 235.3) microg/m(3), (750.6 +/- 521.6)microg/m(3) and (157.5 +/- 98.5) microg/m(3) respectively. The concentrations of PM(2.5) in restaurant (compared with bath center: Z = -10.785, P < 0.01; compared with karaoke bars: Z = -10.488, P < 0.01; compared with cyber cafe: Z = -7.547, P < 0.01) and karaoke bars (compared with bath center: Z = -16.670, P < 0.01; compared with cyber cafe: Z = -15.682, P < 0.01) were much higher than those in other two places. Single-factor analysis revealed that the average concentration of indoor PM(2.5) in 20 public places was associated with the number of smokers per cube meters(9.13 x 10(-3); r = 0.772, F = 26.579, P < 0.01) and ventilation score [(2.5 +/- 1.5) points; r = 0.667, F = 14.442, P < 0.01], and there were significant correlation between the average indoor and outdoor levels in restaurant [(317.9 +/- 235.3) microg/m(3), (67.8 +/- 78.9) microg/m(3); r = 0.918, F = 16.013, P = 0.028] and cyber cafe [(157.5 +/- 98.5) microg/m(3), (67.7 +/- 43.7) microg/m(3); r = 0.955, F = 30.785, P = 0.012]. Furthermore, significant correlation was observed between the average concentration of indoor PM(2.5) [(157.5 +/- 98.5) microg/m(3)]and the number of people per cube meters (288.7 x 10(-3)) in cyber cafe (r = 0.891, F = 11.615, P = 0.042). Multiple regression analysis showed that smoking (b' = 0.581, t = 3.542, P = 0.003) and ventilation (b' = -0.348, t = -2.122, P = 0.049) were the major factors that may influence the concentration of indoor PM(2.5) in four public places. With cluster analysis, the results showed that the major factors that influence the concentration of indoor PM(2.5) was the outdoor PM(2.5) levels [(49.6 +/- 39.5) microg/m(3); b = 1.556, t = 3.760, P = 0.007] when ventilation (score > 2) was relatively good. The number of smokers per cube meters (14.7 x 10(-3)) became the major influence factor when the ventilation score </= 2 (b = 140.957, t = 3.108, P = 0.013) and 51.8% increases of indoor PM(2.5) was attributed to smoking.</p><p><b>CONCLUSION</b>This study indicated that smoking was the main source of indoor PM(2.5) in public places. Outdoor PM(2.5) should be correlated with indoor PM(2.5) concentration under drafty situation.</p>

Assessment of Exposure to PM2.5,CO and O_3 for Elders in a Community in Winter in Beijing Using Microenvironment Measurements and Time-Activity Data / 环境与健康杂志

Objective To estimate the exposure level of PM2.5,CO and O_3 in the elders in a community in Beijing.Methods The concentrations of PM2.5,CO and O_3 in 10 main activity sites of the elders were measured and 24 h time-activity data of 30 elders was collected by recording of activity log paper,Nov.28,2007—Jan.17,2008.Results The 24 h average exposure concentrations of PM2.5,CO and O_3 for the elders were(146.54?6.60)?g/m~3,(2.67?0.18)mg/m~3 and(32.30?2.79)?g/m~3, respectively,there was no significant difference in the exposure level of PM2.5 and O_3 between male and female elders except CO (P