Ambient PM2.5 exposure and hospital cost and length of hospital stay for respiratory diseases in 11 cities in Shanxi Province, China

Short-term associations between ambient PM1, PM2.5, and PM10 and hospital admissions, length of hospital stays, and hospital expenses for patients with cardiovascular diseases in rural areas of Fuyang, East China

Evidence on the impacts of PM1, PM2.5, and PM10 on the hospital admissions, length of hospital stays (LOS), and hospital expenses among patients with cardiovascular disease (CVD) is still limited in China, especially in rural areas. This study was performed in eight counties of Fuyang from 1 January 2015 to 30 June 2017. We use a three-stage time-series analysis to explore the effects of short-term exposure to PM1, PM2.5, and PM10 on hospital admissions, LOS, and hospital expenses for CVDs. An increment of 10 ug/m3 in PM1, PM2.5, and PM10 corresponded to an increment of 1.82% (95% CI: 1.34, 2.30), 0.96% (95% CI: 0.44, 1.48), and 0.79% (95% CI: 0.63%, 0.95%) in CVD hospital admissions, respectively. We observed that daily concentrations of PMs were associated with an increase in hospital admissions, LOS, and expenses for CVDs. Sustained endeavors are required to reduce air pollution so as to attenuate disease burdens from CVDs.

Temperature modification of air pollutants and their synergistic effects on respiratory diseases in a semi-arid city in Northwest China

Air pollutants and temperature are significant threats to public health, and the complex linkages between the environmental factors and their interactions harm respiratory diseases. This study is aimed to analyze the impact of air pollutants and meteorological factors on respiratory diseases and their synergistic effects in Dingxi, a city in northwestern China, from 2018 to 2020 using a generalized additive model (GAM). Relative risk (RR) was employed to quantitatively evaluate the temperature modification on the short-term effects of PM2.5 and O3 and the synergistic effects of air pollutants (PM2.5 and O3) and meteorological elements (temperature and relative humidity) on respiratory diseases. The results indicated that the RRs per inter-quatile range (IQR) rise in PM2.5 and O3 concentrations were (1.066, 95% CI: 1.009-1.127, lag2) and (1.037, 95% CI: 0.975-1.102, lag4) for respiratory diseases, respectively. Temperature stratification suggests that the influence of PM2.5 on respiratory diseases was significantly enhanced at low and moderate temperatures, and the risk of respiratory diseases caused by O3 was significantly increased at high temperatures. The synergy analysis demonstrated significant a synergistic effect of PM2.5 with low temperature and high relative humidity and an antagonistic effect of high relative humidity and O3 on respiratory diseases. The findings would provide a scientific basis for the impact of pollutants on respiratory diseases in Northwest China.

Short-term exposure to ambient nitrogen dioxide and increased hospitalization burden for depression in China: a multicity analysis

Evidence for the increased hospitalization burden, including admissions, expenditures and length of hospital stay (LOS) for depression attributable to ambient nitrogen dioxide (NO2) is lacking. We investigated the associations between short-term exposure to ambient NO2 and attributable admissions, hospitalization expenditures and LOS for depression in 57 Chinese cities during 2013-2017 using a well-established two-stage time-series study approach. Short-term exposure to ambient NO2 was associated with significantly increased admissions, hospitalization expenditures and LOS for depression, and the attributable fractions were 6.87% (95% CI: 2.90%, 10.65%), 7.12% (3.01%, 11.04%) and 6.12% (2.59%, 9.50%) at lag02, respectively. The projected total attributable admissions, hospitalization expenditures and LOS for depression related to ambient NO2 at the national level were 23,335 (9,863, 36,181) admissions, 318.70 (134.43, 492.21) million CNY and 539.55 (227.99, 836.99) thousand days during the study period, respectively. Short-term exposure to ambient NO2 is associated with increased hospitalization burden for depression.

Ambient air pollution associated with incident asthma, subsequent cardiovascular disease and death: A trajectory analysis of a national cohort

No previous study has examined the impact of air pollution on the cardiovascular disease (CVD) trajectory, especially among asthmatic subjects. Based on the UK Biobank cohort, we retrieved 292,227 adults free of asthma and CVD aged 37-73 years at recruitment (2006-2010). Annual mean concentrations of particulate matter (PM10 and PM2.5) and nitrogen oxides (NO2 and NOx) were assessed at each individual's addresses. We used multi-state models to estimate the associations of air pollution with the trajectory from healthy to incident asthma, subsequent CVD, and death. During a median follow-up of 11.7 years, a total of 6338 (2.2%) participants developed asthma, among which, 638 (10.1%) subsequently proceeded to CVD. We observed significant impacts of various air pollutants on the CVD dynamic transitions, with a more substantial effect of particulate matter pollutants than gaseous air pollutants. For example, the hazard ratios (95% confidence intervals) for per interquartile range increase in PM2.5 and PM10 were 1.28 (1.13, 1.44) and 1.27 (1.13, 1.43) for transitions from incident asthma to subsequent CVD. In conclusion, long-term air pollution exposure could affect the CVD trajectory. Distinguishing the effect of air pollutants on CVD transition stages has great significance for CVD health management and clinical prevention, especially among asthma patients.

The impact of ambient air pollution on hospital admissions, length of stay and hospital costs for patients with diabetes mellitus and comorbid respiratory diseases in Panzhihua, Southwest China

Background

There is limited evidence on association between air pollutants and hospital admissions, hospital cost and length of stay (LOS) among patients with diabetes mellitus (DM) and comorbid respiratory diseases (RD), especially in low- and middle-income countries (LMICs) with low levels of air pollution.

Methods

Daily data on RD-DM patients were collected in Panzhihua from 2016 to 2020. A generalised additive model (GAM) was used to explore the effect of air pollutants on daily hospital admissions, LOS and hospital cost. Attributable risk was employed to estimate RD-DM's burden due to exceeding air pollution exposure, using both 0 microgrammes per cubic metre (μg/m3) and WHO's 2021 air quality guidelines as reference.

Results

For each 10 ug/m3 increase of particles with an aerodynamic diameter <2.5 micron (μm) (PM2.5), particles with an aerodynamic diameter <10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3), the admissions of RD-DM patients increased by 7.25% (95% CI = 4.26 to 10.33), 5.59% (95% CI = 3.79 to 7.42), 10.10% (95% CI = 7.29 to 12.98), 12.33% (95% CI = 8.82 to 15.95) and -2.99% (95% CI = -4.08 to -1.90); per 1 milligramme per cubic metre (mg/m3) increase of carbon monoxide (CO) corresponded to a 25.77% (95% CI = 17.88 to 34.19) increment for admissions of RD-DM patients. For LOS and hospital cost, the six air pollutants showed similar effect. Given 0 μg/m3 as the reference, NO2 showed the maximum attributable fraction of 32.68% (95% CI = 25.12 to 39.42%), corresponding to an avoidable burden of 5661 (95% CI = 3611 to 5860) patients with RD-DM.

Conclusions

There is an association between PM2.5, PM10, SO2, NO2, and CO with increased hospital admissions, LOS and hospital cost in patients with RD-DM. Disease burden of RD-DM may be improved by formulating policies related to air pollutants exposure reduction, especially in LMICs with low levels of air pollution.

Cold spells linked with respiratory disease hospitalization, length of hospital stay, and hospital expenses: Exploring cumulative and harvesting effects

BACKGROUND

Previous studies have revealed the relationship between cold spells and morbidity and mortality due to respiratory diseases, while the detrimental effects of cold spells on the length of hospital stay and hospitalization expenses remain largely unknown.

METHODS

We collected hospitalization data for respiratory diseases in 11 cities of Shanxi, China during 2017-2019. In each case, exposure to meteorological variables and air pollution was estimated by the bilinear interpolation approach and inverse distance weighting method, respectively, and then averaged at the city level. Cold spells were defined as the daily mean temperature below the 10^th, 7.5^th, or 5^th percentiles for at least 2 to 5 consecutive days. We applied distributed lag non-linear models combined with generalized additive models to assess cumulative effects and harvesting effects.

RESULTS

There were significant associations between cold spells and hospital admissions, length of hospital stay, and hospital expenses for respiratory diseases. Compared with the non-cold spell period, the overall (lag 0-21) cumulative risk of hospitalization for total respiratory diseases was 1.232 (95 % CI: 1.090, 1.394) on cold spell days, and the increased length of hospital stay and hospitalization expenses were 112.793 (95 % CI: 10.755, 214.830) days and 127.568 (95 % CI: 40.513, 214.624) thousand Chinese yuan. The overall cumulative risks of cold spells on total respiratory diseases and pneumonia were statistically significant. We further observed harvesting effects in the associations between cold spells and hospital admission, length of hospital stay, and hospitalization expenses for respiratory diseases.

CONCLUSIONS

Cumulative cold-spell exposure for up to three weeks is associated with hospitalization, length of hospital stay, and hospital expenses for respiratory diseases. The observed harmful effects of cold spells on respiratory diseases can be partly attributable to harvesting effects.

Association between ambient sulfur dioxide pollution and asthma mortality: Evidence from a nationwide analysis in China

There is a lack of research on the effects of acute exposure to ambient sulfur dioxide (SO2) on mortality caused by asthma, especially nationwide research in China. To explore the acute effect of exposure to ambient SO2 on asthma mortality using nationwide dataset in China from 2015 to 2020 and further evaluate the associations in subgroups with different geographical and demographic characteristics. We used data from China's Disease Surveillance Points system with 29,553 asthma deaths in China during 2015-2020. The exposure variable was the daily mean concentrations of SO2 from the ChinaHighSO2 10 km × 10 km daily grid dataset. Bilinear interpolation was used to estimate each individual's exposure to air pollutants and meteorological variables. We used a time-stratified case crossover design at the individual level to analyze the exposure response relationship between short-term exposure to SO2 and asthma mortality. Stratified analyses were carried out by sex, age group, marital status, warm season and cold season, urbanicity and region. Significant associations between short-term exposure to ambient SO2 and increased asthma mortality were found in this nationwide study. The excess risk (ER) for each 10 μg/m3 increase in SO2 concentrations at lag07 was 7.78 % (95 % CI, 4.16-11.52 %). Season appeared to significantly modify the association. The associations were stronger in cold season (ER 9.78 %, 95 % CI:5.82 -13.89 %). The association remained consistent using different lag periods, adjusting for other pollutants, and in the analysis during pre-Corona Virus Disease 2019 (COVID-19) period. Our study indicates increased risk of asthma mortality with acute exposures to SO2 in Chinese population. The current study lends support for greater awareness of the harmful effect of SO2 in China and other countries with high SO2 pollution.

Spatial effects of air pollution on the economic burden of disease: implications of health and environment crisis in a post-COVID-19 world

Background

Air pollution has been identified as related to the diseases of susceptible population, but the spatial heterogeneity of its economic burden and its determinants are rarely investigated. The issue is of great policy significance, especially after the epidemic of COVID-19, when human are facing the joint crisis of health and environment, and some areas is prone to falling into poverty.

Methods

The geographical detector was adopted to study the spatial distribution characteristics of the incidence of catastrophic health expenditure (ICHE) for older adults in 100 rural areas in China at the prefecture-city level. The health factors, sociological factors, policy factors and environmental factors and their interactions are identified.

Results

First, most health service factors had strong explanatory power for ICHE whether it interacts with air pollution. Second, 50 single-factor high-risk areas of ICHE were found in the study, but at the same time, there were 21 areas dominated by multiple factors.

Conclusion

The different contributions and synergy among the factors constitute the complex mechanism of factors and catastrophic health expenditure. Moreover, during this process, air pollution aggravates the contribution of health service factors toward ICHE. In addition, the leading factors of ICHE are different among regions. At the end, this paper also puts forward some policy suggestions from the perspective of health and environment crisis in the post-COVID-19 world: environmental protection policies should be combined with the prevention of infectious diseases; advanced health investment is the most cost-effective policy for the inverse health sequences of air pollution and infectious diseases such as coronavirus disease 2019 (COVID-19); integrating environmental protection policy into healthy development policy, different regions take targeted measures to cope with the intertwined crisis.

Associations of Ambient NO2 with Daily Hospitalization, Hospitalization Expenditure and Length of Hospital Stay of Cause-Specific Respiratory Diseases - Shanxi, China, 2017-2019

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?

Numerous epidemiological studies have documented the association between ambient nitrogen dioxide (NO₂) and mortality and morbidity of respiratory diseases, however, research on the effect of NO₂ on the length of hospital stay (LOS) and hospitalization expenditure is limited.

WHAT IS ADDED BY THIS REPORT?

This study collected the respiratory hospitalization, hospital expenditure, and LOS for respiratory diseases from 2017-2019 in Shanxi, China, and comprehensively evaluated the association between ambient NO₂ exposure and respiratory hospitalization, expenditure, and LOS.

WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?

This study provides evidence on the association between ambient NO₂ and respiratory burden, suggesting that continuously reducing the NO₂ concentrations could prevent respiratory disease-associated hospital admissions and decrease the relative burden in Shanxi Province and other similar regions.

Association between ambient air pollution and hospital admissions, length of hospital stay and hospital cost for patients with cardiovascular diseases and comorbid diabetes mellitus: Base on 1,969,755 cases in Beijing, China, 2014-2019

BACKGROUND

Evidence on the effects of the air pollutants on the hospital admissions, hospital cost and length of stay (LOS) among patients with comorbidities remains limited in China, particularly for patients with cardiovascular diseases and comorbid diabetes mellitus (CVD-DM).

METHODS

We collected daily data on CVD-DM patients from 242 hospitals in Beijing between 2014 and 2019. Generalized additive model was employed to quantify the associations between admissions, LOS, and hospital cost for CVD-DM patients and air pollutants. We further evaluated the attributable risk posed by air pollutants to CVD-DM patients, using both Chinese and WHO air quality guidelines as reference.

RESULTS

Per 10 ug/m³ increase of particles with an aerodynamic diameter < 2.5 μm (PM_2.5), particles with an aerodynamic diameter < 10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbonic oxide (CO) and ozone (O₃) corresponded to a 0.64% (95% CI: 0.57 to 0.71), 0.52% (95% CI: 0.46 to 0.57), 0.93% (95% CI: 0.67 to 1.20), 0.98% (95% CI: 0.81 to 1.16), 1.66% (95% CI: 1.18 to 2.14) and 0.53% (95% CI: 0.45 to 0.61) increment for CVD-DM patients' admissions. Among the six pollutants, particulate pollutants (PM_2.5 and PM₁₀) in most lag days exhibited adverse effects on LOS and hospital cost. For every 10 ug/m³ increase in PM_2.5 and PM₁₀, the absolute increase with LOS will increase 62.08 days (95% CI: 28.93 to 95.23) and 51.77 days (95% CI:22.88 to 80.66), respectively. The absolute increase with hospital cost will increase 105.04 Chinese Yuan (CNY) (95% CI: 49.27 to 160.81) and 81.76 CNY (95% CI: 42.01 to 121.51) in PM_2.5 and PM₁₀, respectively. Given WHO 2021 air quality guideline as the reference, PM_2.5 had the maximum attributable fraction of 3.34% (95% CI: 2.94% to 3.75%), corresponding to an avoidable of 65,845 (95% CI: 57,953 to 73,812) patients with CVD-DM.

CONCLUSION

PM_2.5 and PM₁₀ are positively associated with hospital admissions, hospital cost and LOS for patients with CVD-DM. Policy changes to reduce air pollutants exposure may reduce CVD-DM admissions and substantial savings in health care spending and LOS.

Short-term effects of main air pollutants exposure on LOS and costs of CVD hospital admissions from 30,959 cases among suburban farmers in Pingliang, Northwest China

BACKGROUND

Although cardiovascular disease (CVD) has been the major contributor to global mortality and disability especially in undeveloped and developing countries/areas with severer air pollutions, studies are quite limited and evidence is insufficient of short-term main air pollutants exposure on health burden of CVD hospital admissions in those regions particularly through direct costs.

METHOD

Based on an analysis of 30,959 CVD hospital admissions among suburban farmers from 2018 to 2019 through multiple linear regression (MLR), our study evaluated the impact of main air pollutants (PM_2.5, PM₁₀, SO₂, CO, NO₂ and O₃) exposure on number of cases, length of stay (LOS) and costs of CVD hospital admissions in Pingliang, China.

RESULTS

Concentration of SO₂ and O₃ rising from a low level was found to lower the costs, LOS and daily cases of CVD hospital admissions and PM_2.5, PM₁₀, CO and NO₂ were found to aggravate the burden. Besides, the NO₂ could put more economic stress on those CVD patients in Pingliang (China) which implies that some improvements could be done on public medical insurance policy and benefit local suburban farmers by strengthening the supports on specific drugs and therapies.

CONCLUSIONS

More efforts should be made to lower the concentration of air pollution by coordinated control managements even in a low-level scenario. Concentration levels and interactions between main air pollutants may play an important role in air pollution-induced CVD health burden. Future research is needed to explore more evidence in different areas, especially with low-level SO₂ effects.

Reduction in daily ambient PM2.5 pollution and potential life gain by attaining WHO air quality guidelines in Tehran

BACKGROUND

Fine particulate matter pollution (PM_2.5) is widely considered to be a top-ranked risk factor for premature mortality and years of life lost (YLL). However, evidence regarding the effect of daily air quality improvement on life expectancy is scarce, especially in the Middle East such as Iran. This study aimed to investigate the potential benefits in life expectancy at concentrations meeting the daily PM_2.5 standards during 2012-2016 in Tehran, Iran.

METHODS

We collected daily non-accidental mortality and data on air pollutants and weather conditions from Tehran, Iran, 2012-2016. A quasi-Poisson or Gaussian time-series regression was employed to fit the associations between ambient PM_2.5 and mortality or YLL. Potential gains in life expectancy (PGLE) and attributable fraction (AF) were estimated by assuming that daily PM_2.5 concentrations attained the World Health Organization air quality guidelines (WHO AQG) 2005 (25 μg/m³) and 2021 (15 μg/m³).

RESULTS

During the study period, a total of 221,231 non-accidental deaths were recorded in Tehran, resulting in 3.6 million YLL. The mean concentration of ambient PM_2.5 was 34.7 μg/m³ (standard deviation: 15.3 μg/m³). For a 10-μg/m³ rise in 4-day moving average (lag 03-day) in PM_2.5 concentration, non-accidental mortality and YLL increased by 1.12% (95% confidence interval: 0.60, 1.65) and 20.73 (7.08, 34.39) person years, respectively. A relatively higher effect was observed in males and young adults aged 18-64 years. We estimated that 39830 [AF = 1.1%] and 74284 [AF = 2.1%] YLL could potentially be avoided if daily PM_2.5 concentrations attained the WHO AQG 2005 and 2021, respectively, which corresponded to potential gains in life expectancy of 0.18 (0.06, 0.30) and 0.34 (0.11, 0.56) years for each deceased person. PM_2.5-associated PGLE estimates were largely robust when performing sensitivity analyses.

CONCLUSIONS

Our findings indicated that short-term exposure to PM_2.5 is associated with increased non-accidental YLL and mortality. Prolonged life expectancy could be achieved if the particulate matter air pollution level were kept under a stricter standard.

Global burden of chronic obstructive pulmonary disease attributable to ambient particulate matter pollution and household air pollution from solid fuels from 1990 to 2019

We aimed to estimate the spatiotemporal trends in the global burden of chronic obstructive pulmonary disease (COPD) attributable to both household air pollution from solid fuels (HAP) and ambient particulate matter (APM) from 1990 to 2019 and compared the possible differences between the burdens attributable to APM and HAP. The number of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLLs) of COPD attributable to HAP from solid fuels and APM during 1990-2019 were extracted from the Global Burden of Diseases Study 2019. The proportion of YLLs in DALYs and average YLLs per COPD death were also calculated. Subgroup analyses by sex, age, and socio-demographic index (SDI) were conducted. The estimated annual percentage change (EAPC) was used to assess the temporal trend of age-standardized rate of mortality (ASMR) and DALYs (ASDR). Over the past 30 years, we observed a clear downward trend in COPD deaths attributable to HAP and an upward trend by 97.61% in COPD deaths attributable to APM. The global COPD burden attributable to APM in 2019 was higher than those due to HAP, except in low-SDI regions. For both HAP and APM, YLLs continued to predominate in DALYs of COPD, with an average YLLs per death of more than 10 years in different regions. The ASMR was higher in males and lower in high-SDI regions. The ASMR and ASDR attributable to HAP decreased globally in all age groups during 1990-2019, while those attributable to APM increased among people older than 80 years and in regions with lower SDI. Our study reveals an increasing trend in APM-attributable COPD burden over the past three decades. Comparatively, the global burden due to HAP decreased markedly, but it was still pronounced in low-SDI regions. Continued efforts on PM mitigation are needed for COPD prevention.

Risk/benefit tradeoff of habitual physical activity and air pollution on chronic pulmonary obstructive disease: findings from a large prospective cohort study

BACKGROUND

The combined health impact of physical activity (PA) and air pollution on chronic obstructive pulmonary disease (COPD) remains unclear. We investigated the joint effects of habitual PA and long-term fine particulate matter (PM2.5) exposure on COPD incidence in a prospective population-based cohort.

METHODS

A prospective cohort study was conducted using data from the UK Biobank. Incidence of COPD was ascertained through linkage to the UK National Health Services register. Annual mean PM2.5 concentration was obtained using land use regression model. PA was measured by questionnaire and wrist-worn accelerometer. Cox proportional hazard models were applied to examine the associations between PM2.5, PA, and COPD. Additive and multiplicative interactions were examined.

RESULTS

A total of 266,280 participants free of COPD at baseline were included in data analysis with an average follow-up of 10.64 years, contributing to around 2.8 million person-years. Compared with participants with low level of PA, those with higher PA levels had lower risks of COPD incidence [hazard ratio (HR): 0.769, 95% CI: 0.720, 0.820 for moderate level; HR: 0.726, 95% CI: 0.679, 0.776 for high level]. By contrast, PM2.5 was associated with increased risk of COPD (HR per interquartile range increment: 1.065, 95% CI: 1.032, 1.099). Limited evidence of interaction between habitual PA and PM2.5 exposure was found. Similar results were found for accelerometer-measured PA.

CONCLUSIONS

Our study suggests that habitual PA could reduce risk of COPD incidence, and such protective effects were not affected by ambient PM2.5 pollution exposure.

Influence of PM1 exposure on total and cause-specific respiratory diseases: a systematic review and meta-analysis

An increasing number of studies examined the potential effects of PM1 (submicronic particulate matter with an aerodynamic diameter ≤ 1 μm) on the risk of respiratory diseases; however, the results have been inconclusive. This study aimed to determine the overall association between PM1 with total and cause-specific respiratory diseases. A systematic review and meta-analysis was conducted with 68 related articles retrieved, and six articles met the full inclusion criteria for the final analysis. For a 10 μg/m3 increase in PM1, the pooled odds ratio (OR) was 1.05 (95% CI 0.98-1.12) for total respiratory diseases, 1.25 (95% CI 1.00-1.56) for asthma, and 1.07 (95% CI 1.04-1.10) for pneumonia with the I2 value of 87%, 70%, and 0%, respectively. Subgroup analyses showed that long-term exposure to PM1 was associated with increased risk of asthma (OR 1.47, 95% CI 1.33-1.63) with an I2 value of 0%, while short-term exposure to PM1 was not associated with asthma (OR 1.07, 95% CI 0.89-1.27) with the I2 value of 0%. Egger's test showed that publication bias existed (P = 0.041); however, the funnel plot was symmetrical with the inclusion of the moderator. In conclusion, elevated levels of PM1 may increase morbidity in total and cause-specific respiratory diseases in the population.

Ambient sulfur dioxide and hospital expenditures and length of hospital stay for respiratory diseases: A multicity study in China

BACKGROUND

Ambient sulfur dioxide (SO2) has been associated with morbidity and mortality of respiratory diseases, however, its effect on length of hospital stays (LOS) and cost for these diagnoses remain unclear.

METHODS

We collected hospital admission information for respiratory diseases from all 11 cities in the Shanxi Province of China during 2017-2019. We assessed individual-level exposure by using an inverse distance weighting approach based on geocoded residential addresses. A generalized additive model was built to delineate city-specific effects of SO2 on hospitalization, hospital expenditure, and length of hospital stay for respiratory diseases. The overall effects were obtained by random-effects meta-analysis. We further estimated the respiratory burden attributable to SO2 by comparing different reference concentrations.

RESULTS

We observed significant effects of SO2 exposure on respiratory diseases. At the provincial level, each 10 μg/m3 increase in SO2 on lag03 was associated with a 0.63% (95% CI: 0.14-0.11) increase in hospital admission, an increase of 4.56 days (95% CI: 1.16-7.95) of hospital stay, and 3647.97 renminbi (RMB, Chinese money) (95% CI: 1091.05-6204.90) in hospital cost. We estimated about 6.13 (95% CI: 1.33-11.10) thousand hospital admissions, 65.77 million RMB (95% CI: 19.67-111.87) in hospital expenditure, and 82.13 (95% CI: 20.87-143.40) thousand days of hospital stay could have potentially been avoided had the daily SO2 concentrations been reduced to WHO's reference concentration (40 µg/m3). Variable values in correspondence with this reference concentration could reduce the hospital cost and LOS of each case by 52.67 RMB (95% CI: 15.75-89.59) and 0.07 days (95% CI: 0.02-0.117).

CONCLUSION

This study provides evidence that short-term ambient SO2 exposure is an important risk factor of respiratory diseases, indicating that continually tightening policies to reduce SO2 levels could effectively reduce respiratory disease burden in Shanxi Province.

Long-term impacts of ambient fine particulate matter exposure on overweight or obesity in Chinese adults: The China-PAR project

Although emerging researches have linked ambient fine particulate matter (PM_2.5) to obesity, evidence from high-polluted regions is still lacking. We thus assessed the long-term impacts of PM_2.5 on body mass index (BMI) and the risk of the prevalence of overweight/obesity (BMI≥25 kg/m²), by incorporating the well-established Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project comprising 77,609 participants with satellite-based PM_2.5 estimates at 1-km spatial resolution. The average of long-term PM_2.5 level was 70.4 μg/m³, with the range of 32.1-94.2 μg/m³. Each 10 μg/m³ increment of PM_2.5 was associated with 0.421 kg/m² (95% confidence interval [CI]: 0.402, 0.439) and 13.5% (95% CI: 12.8%, 14.3%) increased BMI and overweight/obesity risk, respectively. Moreover, compared with the lowest quartile of PM_2.5 (≤57.5 μg/m³), the relative risk of the prevalence of overweight/obesity from the highest quartile (>85.9 μg/m³) was 1.611 (95% CI: 1.566, 1.657). The exposure-response curve suggested a non-linear relationship between PM_2.5 exposure and overweight/obesity. Besides, the association was modified by age, diabetes mellitus, hypertension and dyslipidemia status. Our study provides the evidence for the adverse impacts of long-term PM_2.5 on BMI and overweight/obesity in China, and the findings are important for policy development on air quality, especially in severely polluted areas.