Disease specific air quality health index (AQHI) for spatiotemporal health risk assessment of multi-air pollutants.

While significant reductions in certain air pollutant concentrations did not induce obvious mitigations of health risks, a shift from air quality management to health risk prevention and control might be necessary to protect public health. This study thus constructed an Air Quality Health Index (AQHI) for respiratory (Res-AQHI), cardiovascular (Car-AQHI), and allergic (Aller-AQHI) risk groups using mixed exposure under multi-air pollutants and portrayed their distribution and variation at multiple spatiotemporal scales using spatial analysis in GIS with the medical big data and air pollution remote sensing data by taking Hunan Province in China as a case. Results showed that the AQHIs constructed for specific health-risk groups could better express their risks than common AQHI and AQI. Moreover, based on the spatiotemporal association of health and environmental information, the allergic risk group in Hunan provided the highest health risk mainly affected by O3. The following cardiovascular and respiratory risk groups can be significantly attributed to NO2. Moreover, the spatiotemporal heterogeneity of AQHIs within regions was also evident. On the annual scale, the population in the air health risk hotspots for respiratory and cardiovascular risk decreased, while allergic risks increased. Meanwhile, on seasonal scale, the hotspots for respiratory and cardiovascular risks expanded significantly in winter while completely disappearing for allergic risk. These findings suggest that disease specific AQHIs effectively disclose the health effects of multi-air pollutants and their subsequently varied spatiotemporal distribution patterns.

Nitrogen dioxide and hospital length of stay and cost for systemic lupus erythematosus in Hunan, China.

BACKGROUND: Evidence of both epidemiological and clinical studies exploring the impact of nitrogen dioxide (NO2) on the systemic lupus erythematosus (SLE) disease activity have been contradictory. OBJECTIVES: To evaluate the association between short-term NO2 exposure and length of hospital stay (LOS) and hospital cost of SLE and estimate the burden of disease attributable to NO2 exposure. METHODS: We collected health data of SLE inpatients who were hospitalized at secondary and tertiary hospitals in Hunan province of China during 2017-2019. Daily ambient concentrations of air pollutants (O3, CO, NO2, SO2, PM2.5 and PM10) and other environmental factors were obtained from public repositories by linking to individual addresses and date of hospitalization. Mixed effect models were employed to assess the associations between LOS and hospital cost for SLE inpatients and NO2 exposures during the previous 1 to 21 days (lag1-lag21) before hospitalization. We further estimated excess LOS and hospital cost attributable to NO2 exposure according to China's and World Health Organization's air quality guideline (AQG) respectively. RESULTS: A total of 11,447 records from 221 hospitals were finally included in our study. After full adjustments, 1 µg/m3 increment of NO2 was significantly associated with 0.038 day increase in LOS (95%CI: 0.0159-0.0601, P = 0.0008) and 0.0384 thousand yuan increase in hospital cost (95%CI: 0.0017-0.0679, P = 0.0395) with a lagged effect of 7 days prior to admission. Based on the adjusted effects of lag7, controlling for short-term NO2 exposure according to AQG could avoid up to 1.47 thousand days of hospitalization and 1.35 million yuan of cost for SLE in Hunan province during 2017 to 2019. CONCLUSIONS: Excess LOS and substantial economic burden among SLE inpatients attributable to NO2 could be avoid if policies were implemented to reduce the exposure.