Indoor air quality in the primary school of China-results from CIEHS 2018 study.

Indoor air quality ((IAQ) in classrooms was associated with the daily exposure of school-age children who are particularly vulnerable to air pollutants exposure, while few data exist to evaluate classroom indoor air quality nationwide in China. The subsample of the CIEHS 2018 study was performed in 66 classrooms of 22 primary schools nationwide in China. Temperature, relative humidity, PM2.5, PM10, CO2, CO, formaldehyde concentrations, bacteria and fungi were detected in all classrooms by using the instruments that meet the specified accuracy. The ratios of indoor to outdoor (I/O) of PM2.5 were calculated in each classroom to identify whether the indoor environment the pollutants comes from outdoors. The indoor PM2.5, PM10, CO, HCHO, bacteria and fungi GM concentration are 47.40 µg/m3, 72.91 µg/m3, 0.37 mg/m3, 0.02 mg/m3, 347.51 CFU/m3 and 362.76 CFU/m3, respectively. We observed that there were 66.5%, 52.6%, 22.4%, 1.8%, and 9.6% of the classrooms that exceeded the guideline values of PM2.5, PM10, CO2, HCHO, and bacteria, respectively. It should be attention that all of the classroom's PM2.5 concentrations in Shijiazhuang and Nanning, PM10 concentrations in Nanning, CO2 concentration in Lanzhou were exceeded the suggested values. Bacteria contamination in Shijiazhuang's classrooms is also serious. All classroom CO concentrations meet the requirement. The results indicated that classroom indoor PM2.5 was significantly positively correlated with indoor PM10 and CO2, while was negative correlated with temperature, CO, and fungi. Our results suggest that indoor air pollution in classrooms was a severe problem in Chinese primary schools. It is necessary to strengthen ventilation in the classroom to improve indoor air quality. What's more, a healthy learning environment should be created for primary school students.

Spatiotemporal variation in residential PM2.5 and PM10 concentrations in China: National on-site survey.

BACKGROUND: Significant efforts have been directed toward addressing the adverse health effects of particulate matter, while few data exist to evaluate indoor exposure nationwide in China. OBJECTIVES: This study aimed to investigate dwellings particulate matter levels in the twelve cities in China and provide large data support for policymakers to accelerate the legislative process. METHODS: The current study was based on the CIEHS 2018 study and conducted in 12 cities of China. A total of 2128 air samples were collected from 610 residential households during the summer and winter. Both PM10 and PM2.5 were detected with a light-scattering dust meter in both the living room and bedroom. The Wilcoxon rank-sum test was performed to evaluate the correlations between PM2.5 and PM10 concentrations and both sampling season and site. Ratios of the living room to bedroom were calculated to evaluate the particulate matter variation between rooms. Hierarchical clustering was used to probe the question of whether the concentration varies between cities throughout China. RESULTS: The geometric means of the PM2.5 in living rooms and bedrooms were 39.80 and 36.55 µg/m3 in the summer, and 70.97 and 67.99 µg/m3 in the winter, respectively. In the summer, approximately 70 % of indoor dwelling PM2.5 exceeded the limit of 25 µg/m3, and for PM10 approximately 60 % of dwellings demonstrated levels higher than 50 µg/m3; the corresponding values were over 90 % and 80 % in winter, respectively. In Shijiazhuang, Lanzhou, Luoyang and Qingdao, the geometric means of the PM2.5 concentrations were observed to be 1.5 to 4.3 times higher during winter than during summer; similar concentrations in summer and winter were observed in Harbin, Wuxi, and Shenzhen, while the PM2.5 concentrations in Panjin were approximately 1.5 times higher in summer than in winter. There was no significant difference in particulate matter concentrations between the living rooms and bedrooms. Scatter plots showed that cities with low GDP and a small population had higher concentrations, while Shenzhen, which has a higher GDP and a large permanent population, had a relatively low concentration of particulate matter. CONCLUSIONS: Our results suggest that indoor air pollution is a severe problem in China. It is necessary to continue monitoring indoor air quality to observe the changing trend under the tremendous effort of the Chinese government.

Burden of Outpatient Visits Attributable to Ambient Temperature in Qingdao, China.

Climate change has been referred to as one of the greatest threats to human health, with reports citing likely increases in extreme meteorological events. In this study, we estimated the relationships between temperature and outpatients at a major hospital in Qingdao, China, during 2015-2017, and assessed the morbidity burden. The results showed that both low and high temperatures were associated with an increased risk of outpatient visits. High temperatures were responsible for more morbidity than low temperatures, with an attributed fraction (AF) of 16.86%. Most temperature-related burdens were attributed to moderate cold and hot temperatures, with AFs of 5.99% and 14.44%, respectively, with the young (0-17) and male showing greater susceptibility. The results suggest that governments should implement intervention measures to reduce the adverse effects of non-optimal temperatures on public health-especially in vulnerable groups.

Characterization and exposure assessment of household fine particulate matter pollution in China.

Household fine particulate matter (PM2.5 ) pollution greatly impacts residents' health. To explore the current national situation of household PM2.5 pollution in China, a study was conducted based on literature published from 1998 to 2018. After extracting data from the literature in conformity with the requirements, the nationwide household-weighted mean concentration of household PM2.5 (HPL) was calculated. Subgroup analyses of spatial, geographic, and temporal differences were also done. The estimated overall HPL in China was 132.2 ± 117.7 µg/m3 . HPL in the rural area (164.3 ± 104.5 µg/m3 ) was higher than that in the urban area (123.9 ± 122.3 µg/m3 ). For HPLs of indoor sampling sites, the kitchen was the highest, followed by the bedroom and living room. There were significant differences of geographic distributions. The HPLs in the South were higher than the North in four seasons. The inhaled dose of household PM2.5 among school-age children differed from provinces with the highest dose up to 5.9 µg/(kg·d). Countermeasures should be carried out to reduce indoor pollution and safeguard health urgently.

[Development and performance evaluation for a solid phase adsorption gas sampler of formaldehyde in indoor air].

OBJECTIVE: We developed a solid phase adsorption gas sampler, which is suitable for collection and analysis of indoor air formaldehyde. METHODS: This solid phase adsorption gas sampler is composed of two parts, a support part made of a glass tube covered silica-gel stopper on ports, an absorbent part in glass tube made of surface denatured synthetic fibre coated formaldehyde absorbent. We evolved its performance, and established an method for sampling and determination formaldehyde in indoor air with the gas sampler. RESULTS: For the solid phase adsorption gas sampler, the collection efficiency was 98.7%, and the desorption efficiency was 98.6%. The variation coefficients of sampling was 4.02% (n = 10). The above method was compared with the standard method (GB/T 16129-1995 ), the results showed no significant difference between the two methods. CONCLUSION: This solid phase adsorption gas sampler can be used for sampling and determination formaldehyde in indoor air.