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.