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.

Direct and Indirect Effects of Indoor Particulate Matter on Blood Indicators Related to Anemia

Exposure to indoor particulate matter (PM) is a potential risk factor that increases systemic inflammation and affects erythropoiesis. This study investigated the association between exposure to indoor PM and blood indicators related to anemia (BIRA) in housewives. Indoor PM and blood folate status are important factors in the risk of anemia. This was a housewife cohort study; we recruited 284 housewives in Seoul and Ulsan, Republic of Korea. Indoor exposure to PM2.5 and PM10 was measured by gravimetric analysis and sensors. We investigated the BIRA, such as hemoglobin (Hb), hematocrit, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), and mean corpuscular Hb concentration (MCHC). Statistical analysis was performed by multiple linear regression model and mediation analysis. The association between BIRA and PM was assessed by multiple linear regression models fitted by mediation analyses. The increase in the level of indoor PM2.5 was associated with a decrease in MCV (Beta coefficient (B): −0.069, Standard error (SE): 0.022) and MCH (B: −0.019, SE: 0.009) in gravimetric measurements. The increase in the level of indoor PM2.5 was associated with a decrease in Hb (B: −0.024, SE: 0.011), hematocrit (B: −0.059, SE: 0.033), and MCV (B: −0.081, SE: 0.037) and MCH (B: −0.037, SE: 0.012) in sensor measurements (PM2.5-Lag10). Further, we identified a serum folate-mediated PM effect. The indoor PM exposure was significantly associated with decreased Hb, MCV, and MCH in housewives. Taken together, our data show that exposure to indoor PM is a risk factor for anemia in housewives. Blood folate concentration can be a mediating factor in the effect of indoor PM on BIRA. Therefore, folate intake should be recommended to prevent anemia in housewives. Moreover, indoor PM exposure should be managed.

Indoor Air Quality Prior to and Following School Building Renovation in a Mid-Atlantic School District

Children spend the majority of their time indoors, and a substantial portion of this time in the school environment. Air pollution has been shown to adversely impact lung development and has effects that extend beyond respiratory health. The goal of this study was to evaluate the indoor environment in public schools in the context of an ongoing urban renovation program to investigate the impact of school building renovation and replacement on indoor air quality. Indoor air quality (CO2, PM2.5, CO, and temperature) was assessed for two weeks during fall, winter, and spring seasons in 29 urban public schools between December 2015 and March 2020. Seven schools had pre- and post-renovation data available. Linear mixed models were used to examine changes in air quality outcomes by renovation status in the seven schools with pre- and post-renovation data. Prior to renovation, indoor CO measurements were within World Health Organization (WHO) guidelines, and indoor PM2.5 measurements rarely exceeded them. Within the seven schools with pre- and post-renovation data, over 30% of indoor CO2 measurements and over 50% of indoor temperatures exceeded recommended guidelines from the American Society of Heating, Refrigerating, and Air Conditioning Engineers. Following renovation, 10% of indoor CO2 measurements and 28% of indoor temperatures fell outside of the recommended ranges. Linear mixed models showed significant improvement in CO2, indoor PM2.5, and CO following school renovation. Even among schools that generally met recommendations on key guidelines, school renovation improved the indoor air quality. Our findings suggest that school renovation may benefit communities of children, particularly those in low-income areas with aging school infrastructure, through improvements in the indoor environment.

Effects of Exposure to Indoor Fine Particulate Matter on Atopic Dermatitis in Children

This study aimed to investigate the short-term effect of exposure to indoor fine particulate matter (PM2.5) on atopic dermatitis (AD) symptoms in children. Sixty-four children (40 boys and 24 girls) with moderate-to-severe AD, aged under 18 years were enrolled in the study. They were followed up from February 2019 through November 2020. Exposure to indoor PM2.5 in each household of the enrolled children and their AD symptoms were measured daily. The generalized linear mixed model was utilized for statistical analysis. Subdivision analysis was performed by stratifying the patients by age, sex, season, severity, the presence of family allergic diseases, sensitization, and indoor environment conditions including temperature and relative humidity. A total of 9,321 person-days of AD symptom data were collected. The average PM2.5 concentration was 28.7 ± 24.3 µg/m3, with the highest value in winter (47.1 ± 29.6 µg/m3). The overall effect of PM2.5 on AD symptoms was not statistically significant. However, an increase of 10 µg/m3 in indoor PM2.5 concentration increased AD symptom scores by 16.5% (95% CI: 6.5, 27.5) in spring and12.6% (95% CI: 4.3, 21.5) in winter, 6.7% (95% CI: 2.3, 11.3) at indoor temperatures of <25.5 °C, and by 15.0% (95% CI: 3.5, 27.7) with no use of an air purifier. The harmful effect of PM2.5 in boys, in children aged ≥6 years, and in children with inhalant allergen sensitization was significant, showing an increase in AD symptoms of 4.9% (95% CI: 1.4, 8.6), 12.0% (95% CI: 5.3, 19.1), and 7.0% (95% CI: 1.9, 12.3) per 10 µg/m3 of PM2.5, respectively. Furthermore, children with inhalant allergen sensitization plus severe symptoms (SCORing Atopic Dermatitis, SCORAD ≥ 30.7, median value) showed more harmful effects from exposure to PM2.5 (15.7% (95% CI: 4.5, 28.1) increase in AD symptom scores per 10 µg/m3 of PM2.5 increase). Indoor exposure to PM2.5 exacerbated AD symptoms in children in spring, winter, and at indoor temperatures of < 25.5 °C. In particular, this harmful effect was prominent in children with inhalant allergen sensitization and severe symptoms. Minimizing exposure to indoor PM2.5 is needed for the proper management of AD.

Experimnetal Investigation on Outdoor and Indoor PM2.5 and PM10 in Supermarkets in Bandung During Covid-19 Pandemic

During the Covid-19 pandemic, the number of visitor at the trade center in Bandung was much reduced as compared to before pandemic, which was only about 30% of normal conditions. The present study is to investigate particulate concentrations of PM2.5 and PM10 in three supermarkets in Bandung, namely Kosambi, Batununggal Modern and Cinunuk supermarkets during the pandemic of Covid-19. Air sampling was measured using a particulate counter CEM DT96 for 11 hours, from 06:00 AM to 5:00 PM, local time. The results showed that the average of outdoor and indoor concentrations of PM10 in two supermarkets (Batununggal Modern and Griya Cinunuk) was lower than standard during that 11 hours. As for the outdoor concentrations of PM2.5, both markets exceeded the standard for several hours in the morning. In general, it can be concluded that the outdoor and indoor concentrations of PM2.5 and PM.10 during pandemic were below the standard, except in the morning before 10:00 AM

Glutathione (GSH) and superoxide dismutase (SOD) levels among junior high school students induced by indoor particulate matter 2.5 (PM2.5) and nitrogen dioxide (NO2) exposure

Background: Indoor air pollution has globally known as the risk factor of acute respiratory infection in young children. The exposure to indoor particulate matter 2.5 (PM2.5) and nitrogen dioxide (NO2) at house or school can be a potential risk to children’s health. This study aimed to examine the association between indoor PM2.5 and NO2 with oxidative stress markers in junior high school students.Design and Method: This study was conducted using a cross sectional study with 75 students collected randomly from four junior high schools in Jakarta. PM2.5 and NO2 were measured in classrooms and school yards. The schools were categorized based on the exposure level of PM2.5 and NO2 in classrooms. Superoxide dismutase (SOD) and reduced glutathione (GSH) were examined from the blood sample. All students were interviewed with questionnaires to determine upper respiratory tract infection, smoking family members, mosquito repellent usage, and dietary supplement consumption.Results: Mean concentration of indoor PM2.5 and NO2 were 0.125±0.036 mg m-3 and 36.37±22.33 µg m-3, respectively. The schools which located near to highway showed lower PM2.5 and higher NO2 level indicated the emission of traffic activity. Mean activity of SOD was 96.36±50.94 U mL-1 and mean concentration of GSH was of 0.62±0.09 µg mL-1. Most of the students reported upper respiratory tract infection history, smoking family member, use mosquito repellent at home, and do not consume dietary supplement.Conclusion: The level of oxidative stress markers and the exposure categories of classroom PM2.5 and NO2 was not significantly different, however there were significant correlation with cigarette smoke and mosquito repellent at home. Nevertheless, the exposure of indoor PM2.5 and NO2 increased the risk of the exposure to cigarette smoke and mosquito repellent at home. Further study on the air pollution at school and home is needed to affirm association towards student’s health and to design strategic control efforts.