Indoor PM2.5 Mortality in China when Outdoor Air Meets 2021 WHO AQG

The World Health Organization (WHO) Air Quality Guidelines (AQG) 2021 for PM2.5 is tightened to be 5 μg/m3. We firstly estimated deaths attributable to human exposure to PM2.5 (DAHP) to be 455 thousand (372-527) in urban China in 2019, of which indoor sources contributed 253 thousand (207-294) deaths. The economic losses related to PM2.5 from indoor sources were 0.98 trillion (0.80-1.14) RMB, accounting for 56% of the total economic losses. We then further projected the DAHP at 328 thousand (260-392) when the outdoor PM2.5 concentration is 5 μg/m3, while PM2.5 from indoor sources still causes 297 thousand (235-355) deaths and 1.27 trillion (1.00, 1.51) in economic losses each year. There are significant health hazards and economic losses caused by indoor PM2.5, even the outdoor air is clean enough. The formulation and implementation of more air pollution policies are therefore in urgent need to control indoor sources of PM2.5.

Exposure to Particles and Gases in a Shopping Mall: Spatial Heterogeneity and Outdoor Infiltration

Shopping malls in Hong Kong are usually located near major roads. Indoor air quality (IAQ) in these buildings is subject to infiltration of outdoor traffic-related pollutants, such as PM10, PM2.5, CO, and NO2. Furthermore, the existence of indoor sources and building geometry added to the complexity of variations in IAQ. To understand outdoor infiltration and spatial heterogeneity of these pollutants, we conducted fixed and cruise indoor sampling, together with simultaneous outdoor measurements, in a typical mall in Hong Kong. The cruise sampling was conducted indoors on a predesigned route and repeated 15 times. Outdoor infiltration was quantified based on regression analysis between indoor and outdoor sampling. Results showed that 75% of PM2.5, 53% of PM10, and 59% of NO2 were infiltrated into the mall during opening hours. Elevated PM2.5 and CO were observed during the dinner period, suggesting an impact from cooking. Substantial spatial variations were observed for PM10, PM2.5, and NO2, particularly at locations near entrances and restaurants. Measures are needed to reduce pollution intrusion from building openings and cooking-related sources to improve air quality in the selected mall. Fixed and cruise sampling methods used in this study provide insights on sensor deployment for future air quality monitoring in buildings.

INDOOR AIR QUALITY REQUIREMENTS FOR CIVIL BUILDINGS IN RUSSIAN REGULATIONS IN COMPARISON WITH INTERNATIONAL GREEN STANDARDS

A new trend combining the concept of "green" buildings with the idea of preserving and strengthening peoples’ health in order to eliminate sick building syndrome and building related illnesses has been observed worldwide. The COVID – 19 pandemic consequences outlined the necessity of updating the regulatory framework considering health preserving built environment principles in order to create sustainable and comfortable living environments. Indoor air quality directly correlates with human health: exposure to polluted air increases the risk of cardiovascular disease, myocardial ischemia, angina pectoris, hypertension and heart disease. It is known that indoor air quality depends not only on ambient air quality, but also on indoor sources of chemical and biological pollutants. Existing regulatory framework does not cover the civil buildings indoor sources of air pollution topic. This article discusses the terms of the Russian national technical and hygienic standards concerning the indoor air quality. A comparative analysis of the Russian Federation regulatory framework that refers the civil buildings indoor air quality with international "green" standards was carried out. Based on the analysis, the necessity to update the Russian regulatory framework is highlighted.

A Preliminary Research Study for Distribution Characteristics and Sources of Indoor Air Pollutants in the Valuable Archive of the National Library of Korea

Important records can be damaged directly and indirectly. Their restoration, if possible, is difficult as it is very time-consuming and costly. Although measures have been taken to permanently preserve records, most studies focus on preventing short-term damage from physical or biological factors and not on preventive measures against chemical damage from long-term polluted air exposure. This study investigated the types, concentrations, and distribution characteristics of hazardous chemicals present in the valuable archive of the National Library of Korea (NLK) and identified the sources of these pollutants. Mean SO2, NOX, CO, CO2, and total volatile organic compound (TVOC) concentrations were 1.49 ± 0.44 ppb, 30.52 ± 19.70 ppb, 0.75 ± 0.21 ppm, 368.91 ± 32.23 ppm, and 320.03 ± 44.20 µg/m3, respectively, meeting the Ministry of the Interior and Safety (MOIS) of Korea standards. Toluene (66.43 ± 10.69 µg/m3) and acetaldehyde (157.23 ± 6.43 µg/m3) were present at the highest concentrations, respectively. Two principal components were extracted via a principal component analysis; the primary component (66%) was closely related to outdoor pollution sources and the secondary component (33%) to indoor sources. Results contribute to establishing air quality standards and management measures for preservation of this archive.

Bioaerosol Contribution to Atmospheric Particulate Matter in Indoor University Environments

Within the framework of the project “Integrated Evaluation of Indoor Particulate Exposure”, we carried out a 4-week field study to determine indoor bioaerosol, and its contribution to particulate matter (PM)10 and organic matter. The study was carried out in university classrooms, where most of the common indoor sources of atmospheric particles are missing. Bioaerosol was determined by a method based on propidium iodide staining, observation by fluorescence microscopy, and image analysis. Indoor bioaerosol concentrations were compared with outdoor values, which were determined simultaneously. The samplings periods were scheduled to divide weekday hours, when the students were inside, from night-time hours and weekends. Very high bioaerosol concentrations were detected inside the classrooms with respect to outdoor values. The mean difference was 49 μg/m3 when the students were inside, 5.4 μg/m3 during the night, and it became negative during the weekends. Indoor-to-outdoor ratios were 6.0, 4.2, and 0.7, respectively. Bioaerosol contributed 26% to organics and 10% to PM10. In indoor samples collected during the day, the microscope images showed numerous skin fragments, which were mostly responsible for the increase in the bioaerosol mass. People’s presence proved to be responsible for a significant increase in bioaerosol concentration in crowded indoor environments.

The contribution of cooking appliances and residential traffic proximity to aerosol personal exposure

Purpose Indoor and outdoor factors affect personal exposure to air pollutants. Type of cooking appliance (i.e. gas, electricity), and residential location related to traffic are such factors. This research aims to investigate the effect of cooking with gas and electric appliances, as an indoor source of aerosols, and residential traffic as outdoor sources, on personal exposures to particulate matter with an aerodynamic diameter lower than 2.5 μm (PM2.5), black carbon (BC), and ultrafine particles (UFP). Methods Forty subjects were sampled for four consecutive days measuring personal exposures to three aerosol pollutants, namely PM2.5, BC, and UFP, which were measured using personal sensors. Subjects were equally distributed into four categories according to the use of gas or electric stoves for cooking, and to residential traffic (i.e. houses located near or away from busy roads). Results/conclusion Cooking was identified as an indoor activity affecting exposure to aerosols, with mean concentrations during cooking ranging 24.7–50.0 μg/m3 (PM2.5), 1.8–4.9 μg/m3 (BC), and 1.4 × 104–4.1 × 104 particles/cm3 (UFP). This study also suggest that traffic is a dominant source of exposure to BC, since people living near busy roads are exposed to higher BC concentrations than those living further away from traffic. In contrast, the contribution of indoor sources to personal exposure to PM2.5 and UFP seems to be greater than from outdoor traffic sources. This is probably related to a combination of the type of building construction and a varying range of activities conducted indoors. It is recommended to ensure a good ventilation during cooking to minimize exposure to cooking aerosols.