Long-term air pollution exposure and incident physical disability in older US adults: a cohort study

BACKGROUND

Disability is a key marker of overall physical health in older adults and is often preceded by chronic disease. Although air pollution is a well recognised risk factor for multiple chronic diseases, its association with physical disability has not been well characterised. We investigated the associations of air pollutants with physical disability in a large cohort representative of older adults in the USA.

METHODS

We used biennial data on incident activities of daily living (ADL) disability collected from respondents of the Health and Retirement Survey between 2000 and 2016. As part of the Environmental Predictors of Cognitive Health and Aging study, we estimated 10-year average PM2·5, PM10-2·5, nitrogen dioxide (NO2), and ozone (O3) concentrations at participant residences before each survey using spatiotemporal prediction models. We used a time-varying, weighted Cox model to estimate hazard ratios (HRs) for incident physical disability per interquartile increase of air pollution with detailed adjustments for confounders.

FINDINGS

Among 15 411 respondents aged 65 years and older (mean age 70·2 [SD 6·5] years; 55% female, 45% male), 48% of respondents reported newly having ADL disability during a mean follow-up of 7·9 years (SD 4·7). In fully adjusted models, we found greater risks of ADL disability associated with higher concentrations of PM2·5 (HR 1·03 per 3·7 μg/m³ [95% CI 0·99-1·08], p=0·16), PM10-2·5 (1·05 per 4·9 μg/m³ [1·00-1·11], p=0·022), and NO2 (1·03 per 7·5 ppb [0·99-1·08]. p=0·064), although not all these associations were statistically significant. In contrast, O3 was associated with a lower risk of ADL disability (0·95 per 3·7 ppb [0·91-1·00], p=0·030). In a multi-pollutant model, associations were similar to the single-pollutant models for PM10-2·5 (1·05 per 4·9 μg/m³ [1·00-1·11], p=0·041) and O3 (0·94 per 3·7 ppb [0·88-1·01], p=0·083).

INTERPRETATION

Our findings suggest that air pollution might be an underappreciated risk factor for physical disability in later life, although additional research is needed.

FUNDING

National Institutes of Environmental Health Sciences and National Institute on Aging.

Air pollution and the burden of long-term care: Evidence from China

We examine the causal effects of PM2.5 exposure on the burden of long-term care (LTC) by matching a satellite-based PM2.5 (particulate matter smaller than 2.5 micrometers (μm) in diameter) dataset with a nationally representative longitudinal study in China from 2011 to 2018. We find significant adverse effects of PM2.5 exposure-instrumented by thermal inversions-on the LTC burden. A 10 μg/m3 increase in annual PM2.5 exposure increases average monthly hours of LTC and the associated financial costs by 28 h and CNY 452, respectively. The effects are greater for those who had never smoked nor experienced severe PM2.5 pollution (annual average PM2.5 > 35 μg/m3) in the previous 5 years. We also find that as PM2.5 increases, chronic diseases, particularly cardiovascular diseases, could lead to a higher likelihood of LTC dependency but reduce the total hours and costs of LTC provision. Finally, we find that PM2.5 reduces the total years of LTC need, suggesting that PM2.5 increases LTC costs by increasing the severity of LTC dependency, rather than the duration of LTC need. Our findings can assist policymakers in planning for LTC provisions and clean air policies.

Impact of comprehensive air pollution control policies on six criteria air pollutants and acute myocardial infarction morbidity, Weifang, China: A quasi-experimental study

Comprehensive air pollution control policies may reduce pollutant emissions. However, the impact on disease morbidity of the change for the concentration of air pollutants following the policies has been insufficiently studied. We aim to assess the impact of comprehensive air pollution control policies on the levels of six criteria air pollutants and acute myocardial infarction (AMI) morbidity in Weifang, China. This study performed an interrupted time series analysis. The linear model with spline terms and generalized additive quasi-Poisson model were used to estimate the immediate change from 2016 to 2019 in the daily concentration of six air pollutants (PM2.5, PM10, SO2, NO2, O3, and, CO) and AMI incident cases (Age ≥35) associated with the implementation of air pollution control policies in Weifang, respectively. After the implementation of air pollution control policies, air quality in Weifang had been improved. Specifically, the daily concentrations of PM2.5, PM10, SO2, and, CO immediately decreased by 27.9 % (95 % CI: 6.6 % to 44.3 %), 32.9 % (95 % CI: 17.5 % to 45.5 %), 14.6 % (95 % CI: 0.4 % to 26.8 %), and 33.9 % (95 % CI: 22.0 % to 44.0 %), respectively. In addition, the policies implementation was also associate with the immediate decline in the AMI morbidity (-6.5 %, 95 % CI: -10.4 % to -2.3 %). And subgroup analyses indicate that the health effects of the policy intervention were only observed in female (-9.4 %, 95 % CI: -14.4 % to -4.2 %) and those aged ≥65 years (-10.5 %, 95 % CI: -14.6 % to -6.2 %). During the final 20 months of the study period, the policy intervention was estimated to prevent 1603 (95 % CI: 574 to 2587) cases of incident AMI in Weifang. Our results provide strong rationale that the policy intervention significantly reduced ambient pollutant concentrations and AMI morbidity, which highlighted the importance for a comprehensive and rigorous air pollution control policy in regions with severe air pollution.

Mendelian randomization study supports the causal effects of air pollution on longevity via multiple age-related diseases

Growing evidence suggests that exposure to fine particulate matter (PM2.5) may reduce life expectancy; however, the causal pathways of PM2.5 exposure affecting life expectancy remain unknown. Here, we assess the causal effects of genetically predicted PM2.5 concentration on common chronic diseases and longevity using a Mendelian randomization (MR) statistical framework based on large-scale genome-wide association studies (GWAS) (>400,000 participants). After adjusting for other types of air pollution and smoking, we find significant causal relationships between PM2.5 concentration and angina pectoris, hypercholesterolaemia and hypothyroidism, but no causal relationship with longevity. Mediation analysis shows that although the association between PM2.5 concentration and longevity is not significant, PM2.5 exposure indirectly affects longevity via diastolic blood pressure (DBP), hypertension, angina pectoris, hypercholesterolaemia and Alzheimer's disease, with a mediated proportion of 31.5, 70.9, 2.5, 100, and 24.7%, respectively. Our findings indicate that public health policies to control air pollution may help improve life expectancy.

Chronic kidney disease and functional impairment in a longitudinal study of older adults in China

OBJECTIVES

To examine the associations of chronic kidney disease (CKD) with dynamic functional impairment among older Chinese adults.

DESIGN

This was a prospective longitudinal study.

SETTING

Data were derived from the Chinese Longitudinal Healthy Longevity Study.

PARTICIPANTS

All adults aged ≥60 years were potentially eligible. This study included 2970 participants.

PRIMARY OUTCOME MEASURES

CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. Functional performances included instrumental activities of daily living (IADL) and basic activities of daily living (BADL), which were measured using six daily activities, including eating, dressing, transferring, using the toilet, bathing and continence, and eight daily activities, including visiting neighbours, shopping, cooking, washing clothes, walking 1 km, lifting 5 kg, crouching and standing up three times and taking public transportation, respectively.

RESULTS

This study included 2970 participants, including 988 (33.60%) participants with CKD. Participants with CKD had higher IADL scores than those without CKD (β=0.895, 95% CI: 0.761 to 1.029). Furthermore, there was a significant linear trend in the association of CKD severity with the IADL score (p<0.001). Similarly, CKD was significantly associated with higher BADL scores (β=0.067, 95% CI: 0.017 to 0.118). However, only participants with moderate and advanced CKD had a higher BADL score (β=0.088 and 0.152, 95% CI: 0.006 to 0.171 and 0.019 to 0.286, respectively).

CONCLUSIONS

CKD was associated with worse functional impairment. Furthermore, there was a significant linear trend in the association of the severity of CKD with the IADL score. However, only participants with moderate and advanced CKD had higher BADL scores.

Environmental pollution and life expectancy in Somalia: do renewable energy, urbanization, and economic growth matter?

Ensuring good quality of health and longevity became a topical for policymakers and academicians. Various determinants, including socio-economic factors, have been discussed in the literature. Nevertheless, the empirical studies on this issue are scanty in least-developed countries like Somalia where the health indicators are poor. In this regard, this undertaking examines the impacts of renewable energy, urbanization, environmental pollution, and economic growth on life expectancy in Somalia for the period straddling 1990-2016. The study uses a novelty machine learning method - Kernel regularized least square (KRLS) method. The empirical results indicated that renewable energy, economic growth, and urbanization are statistically significant; whereas, environmental pollution is statistically insignificant. Renewable energy, economic growth, and urbanization exert positive effects on life expectancy in Somalia and have increasing marginal effects. Besides, bidirectional causality between renewable energy and life expectancy, life expectancy and economic growth, and environmental pollution and life expectancy are established. Moreover, unidirectional causality from urbanization to life expectancy is also observed. The study suggests that a budgetary revision be made to sort out health-related concerns resulting from a lack of healthcare services and poor sanitation for improving the longevity of the people. Additionally, investments in clean energy are necessary as will improve health outcomes without compromising economic growth and life expectancy.

Correlation between air pollution and cognitive impairment among older individuals: empirical evidence from China

BACKGROUND

Little information is available regarding the impact of air pollution on cognitive impairment in older individuals in developing countries. This study empirically tested the impacts of the air quality index (AQI), air pollution intensity (quantified by the number of days of extreme air pollution in a year), and different pollutants on the cognitive abilities of older Chinese individuals.

METHODS

A panel of 28,395 participants spanning 122 cities in 2015 and 2018 was used, based on 3-year follow-up survey data from the China Health and Retirement Longitudinal Study (CHARLS) database. Data from the two phases of the CHARLS microsurvey were combined with relevant statistical data on air pollution in each region in the current year. These two surveys were used to investigate changes in basic health and macro-environmental indicators in older individuals in China, and a mean difference test was conducted. We then reduced the sample selection error by controlling for environmental migration and used two-way fixed and instrumental variable methods for endogenous treatment to avoid the estimation error caused by missing variables.

RESULTS

Air pollution had a significantly negative effect on the cognitive abilities of older individuals (odds ratio [OR]: 1.4633; 95% confidence interval [95% CI]: 1.20899-1.77116). Different pollution intensities(only AQI value is greater than 200 or more) had apparent effects on cognitive impairment, with an OR of approximately 1.0. Sulfur dioxide had significantly negative effects on cognitive ability, with OR of 1.3802 (95% CI: 1.25779-1.51451). Furthermore, air pollution impact analysis showed heterogeneous results in terms of age, sex, education, and regional economic development level. In addition, social adaptability (calculated using social participation, learning, adaptability, and social support) not only had a significant positive effect on the cognitive abilities of older individuals, but also regulated the cognitive decline caused by air pollution.

CONCLUSIONS

Air pollution affects cognitive impairment in older individuals, especially in those with lower education levels, and living in economically underdeveloped areas. This effect is synchronous and has a peak at an AQI of > 200.

Spatiotemporal evolution and characteristics of worldwide life expectancy

Exploring global differences in life expectancy can facilitate the development of strategies to narrow regional disparities. However, few researchers have systematically examined patterns in the evolution of worldwide life expectancy over a long time period. Spatial differences among 181 countries in 4 types of worldwide life expectancy patterns from 1990 to 2019 were investigated via geographic information system (GIS) analysis. The aggregation characteristics of the spatiotemporal evolution of life expectancy were revealed by local indicators of spatial association. The analysis employed spatiotemporal sequence-based kernel density estimation and explored the differences in life expectancy among regions with the Theil index. We found that the global life expectancy progress rate shows upward then downward patterns over the last 30 years. Female have higher rates of spatiotemporal progression in life expectancy than male, with less internal variation and a wider spatial aggregation. The global spatial and temporal autocorrelation of life expectancy shows a weakening trend. The difference in life expectancy between male and female is reflected in both intrinsic causes of biological differences and extrinsic causes such as environment and lifestyle habits. Investment in education pulls apart differences in life expectancy over long time series. These results provide scientific guidelines for obtaining the highest possible level of health in countries around the world.

Does physical activity attenuate the association between ambient PM2.5 and physical function?

BACKGROUND

Physical function (PF), such as muscle strength, performing daily activities, has gradually declined with the increase of age, causing the occurrence of disability and diseases burden. Air pollution exposure and physical activity (PA) were both linked to PF. We aimed to explore the individual and joint effects of particulate matter <2.5 μm (PM_2.5) and PA on PF.

METHODS

A total of 4537 participants and 12,011 observations aged ≥45 years old from the China Health and Retirement Longitudinal Study (CHARLS) cohort from 2011 to 2015 were included into the study. PF was assessed by a combined score of four tests, including grip strength, walking speed, sense of balance, and chair standing tests. Air pollution exposure data was from The ChinaHighAirPollutants (CHAP) dataset. The annual PM_2.5 exposure for each individual was estimated based on county-level resident addresses. We estimated the volume of moderate-to-vigorous physical activity (MVPA) by quoting metabolic equivalent (MET). Multivariate linear model was conducted for baseline analysis, and linear mixed model with random participant intercepts was constructed for cohort longitudinal analysis.

RESULTS

PM_2.5 was negatively associated with PF, while PA was positively associated with PF in baseline analysis. In cohort longitudinal analysis, a 10 μg/m³ increase in PM_2.5 was associated to a 0.025 point (95 % CI: -0.047, -0.003) decrease in PF score, and a 10-MET-h/week increase in PA was related to a 0.004 point (95 % CI: 0.001, 0.008) increase in PF score. The association between PM_2.5 and PF decreased by increased PA intensity, and PA reversed the detrimental effects between PM_2.5 and PF.

CONCLUSION

PA attenuated the association of air pollution with PF at both high and low levels of air pollution, implying that PA may be an effective behavior to reduce the adverse effects of poor air quality on PF.

The effect of PM2.5 levels on continuum functional capability among older adults: Potential cause-effect or statistical associations

BACKGROUND

Since there is limited knowledge about health effects of the clean air policy (CAP, i.e., a series of emission-control actions) on continuum functional capacity (CFC) among the older adults on a large representative data, our research was to fill this gap.

METHODS

We used a continuous variable of airborne fine particulate matter (PM_2.5) particles as a proxy for the CAP to evaluate the linear and non-linear effect of PM_2.5 exposure on CFC of older adults, under the quasi-experimental framework of the temporal contrast between 2011 (before the CAP) and 2015 (after the CAP). Multiple environmental factors were considered and spline function was utilized to fit the spatial autocorrelations. A competing risk model was constructed to qualify the impact of PM_2.5 on multidimensional disability.

RESULTS

After adjusting for potential confounders, a J-shaped association was found between PM_2.5 concentration increase on CFC, with a threshold 2μg/m³. We also demonstrated that a 10-µg/m³ increase in PM_2.5 concentration was related to a 14.0% (95% CI:0.00, 19.00%) increment risk in the functional decline. Similarly, the competing risk model presented a hazard ratio of multidimensional disability ranging from 1.707(0.928-4.141) at 40μg/m³ concentration of PM_2.5 to 4.384 (1.970-9.755) over 80μg/m³. Stratified analyses showed that married men less than 80 years old in rural areas are more likely to be affected by PM_2.5 exposure, where the influencing mechanism of air pollutant to outdoor and indoor activities might be the potential cause.

CONCLUSION

Implementing CAP might improve CFC, prevent the occurrence of disability, and update the air policy.

Exploring the relationship between air quality and health shocks to the elderly: A retrospective cross-sectional study in China

Methods

We selected 5,172 microdata on individuals from the China Health and Retirement Longitudinal Study (CHARLS) 2018. The binary logit model, the ordered logit model, and the stepwise regression were employed to compare the effects of air pollution on self-rated health (SRH) and activities of daily living (ADL) in an elderly population. The effects on health shocks were explored in different age groups, different gender groups, different regions and different sources of pollutants, respectively.

Results

We found that air pollution significantly increased the risk of health shocks in the elderly population, especially in the 60–69 year age group, and the eastern/central region, where NO2 and O3 were important pollutant sources.

Conclusion

Targeted management of the environment is necessary to improve the health status of China's elderly population. In addition, paying attention to the health status of vulnerable populations is needed to achieve social equity.

Air pollution, governance quality, and health outcomes: evidence from developing countries

While studies have demonstrated that air pollution can be catastrophic to the population's health, few empirical studies are found in the economic literature because a considerable proportion of the evidence comes from epidemiological studies. Because of the crucial role of governance in the health community, good governance has been a contentious issue in public sector management in recent years. Therefore, the aim of this study is to examine the effects of air pollution and the role of governance on health outcomes. This study employed the generalized method of moment (GMM) estimation techniques to analyse panel data for 72 developing countries from 2010 to 2017. The empirical results confirm that higher PM_2.5 and CO₂ levels have a detrimental influence on life expectancy and healthy life expectancy, whereas the role of governance has a positive impact on life expectancy and healthy life expectancy. Furthermore, the findings show governance quality plays a role in moderating the negative effect of PM_2.5 on health outcomes. The ongoing rise in air pollution has had a significant impact on the health of developing countries. It appears that governance quality has improved health outcomes. The findings have important policy implications, such that strengthening governance can reduce air pollution emissions in developing countries. However, to reduce the health effects of air pollution, developing countries must implement effective environmental development policies and track the implementation and enforcement of such policies.

Spatial Effects of Digital Transformation, PM2.5 Exposure, Economic Growth and Technological Innovation Nexus: PM2.5 Concentrations in China during 2010-2020

Digital transformation can increase lending by commercial banks, which may have an impact on economic development and technological progress, thus affecting air pollution. However, a limited amount of literature has discussed the impact of the digital transformation of commercial banks (DTCB) on air pollution. Based on city-level data from 2010 to 2020, this study used a spatial Durbin model to explore the spatial effects of DTCB on air pollution. This study shows that DTCB significantly increases air pollution in local and surrounding cities. Heterogeneity analysis shows that DTCB increases local and surrounding city air pollution in non-innovative cities and cities with low digital economy development. However, in innovative cities and cities with high digital economy development, DTCB reduces PM2.5 emissions in local and surrounding cities. Mechanism analysis shows that DTCB has no significant impact on technological innovation, but significantly promotes economic development, thus increasing air pollution. From the perspective of DTCB, this paper deepens the research on digital finance and air pollution. Against the background of DTCB, the government should guide commercial banks to apply digital technology to increase lending for technology innovation and promote DTCB to achieve the dual goals of economic development and improvement in air quality.

The impact of air pollution on physical disability in a middle-aged and older Chinese population using regression discontinuity design

Emerging evidence has shown the association between ambient air pollution exposure and comorbid chronic diseases, which can subsequently impair physical function. However, less is known about the causal and contextual effect of air pollution on physical disability. Using data from the China Health and Retirement Longitudinal Study (CHARLS), this study employs a geographical regression discontinuity design based on the Huai River Policy to estimate the impact of ambient air pollution on physical disability in activities of daily living (ADL) in China. We find that a 10 μg/m³ increase in particulate matter [particulate matter smaller than 10 μm (PM₁₀)] leads to a 5.4% increase in the incidence of physical disability among middle-aged and older adults. This result is robust to using alternative measurement of key variables, different bandwidths and polynomial functions, and adjustment for a set of sociodemographic covariates. Stroke might be one of the potential pathological pathways linking air pollution and physical disability, with a 10 μg/m³ increase in PM₁₀ leading to a 4.7% increase in the incidence of stroke. In heterogeneity analyses, we find that older adults, males, urban residents, and people with lower socioeconomic status are more vulnerable to air pollution. These results contribute to the limited evidence on the causal and contextual effect of air pollution on physical health, and further provide policy implications for air quality control and health protection for vulnerable populations.

Associations between household solid fuel use and activities of daily living trajectories: A nationwide longitudinal study of middle and older adults in China

BACKGROUND

More studies focus on reporting the effects of ambient air pollution on physical activity while ignoring the hazards of indoor air pollution caused by household solid fuel use. Moreover, the impact of individual cognitive and depressive status on the health effects of air pollution is often overlooked.

OBJECTIVE

We examined the association between household solid fuel and activities of daily living (ADL) trajectories, and further examined this association in homogeneous subgroups of cognitive or depressive trajectories.

METHODS

Participants were from the China Health and Retirement Longitudinal Study, which conducted four waves of surveys from 2011 to 2018. We collected information on participants' household fuel use, then the ADL, cognitive and depressive performances were assessed in each wave. The latent growth mixture model (LGMM) was used to identify the optimal trajectory class for ADL, cognition, and depression. Then, the multinomial logistic regression was used to assess the association between solid fuel use and ADL trajectories in total population, as well as subgroups with different cognitive or depression trajectories. Furthermore, we examined the association between switching household fuel types and ADL trajectories across the four-wave survey.

RESULTS

The study sample included 7052 participants. We identified three ADL trajectory classes in total population: "Low-stable", "Moderate-anterior rise", and "Moderate-posterior rise". The multinomial logistic regression results showed that solid fuel use was associated with elevated odds for the adverse ADL trajectories, and this association was still shown in homogeneous subgroups of cognitive or depressive trajectories, while some effects were less significant. In addition, the risk of adverse ADL trajectories generally increases with the times of solid fuel use across the four-wave survey.

CONCLUSIONS

For middle and older adults in China, household solid fuel use was not conducive to physical activity development, which inspires that a further transformation to cleaner fuels is an important intervention.

Residential proximity to major roadway and progression in physical disability in older adults in China

Evidence of a connection between living near major roadway and adverse health outcome has come to light. However, little is known about the effect of residential traffic exposure on aging-related physical disability and whether this effect can be modified. We used data derived from Chinese Longitudinal Healthy Longevity Surveys in 2018, with a total of 15,771 participants aged ≥ 65. Residential proximity to major roadway was used as a surrogate for traffic-related air pollution and physical function was measured using basic and instrumental activities of daily living. Logistic regression models were adopted for the analyses. Compared with those living > 300 m from major road, participants living within 200 m had higher risk of poorer physical functioning. The peak odds ratio was observed in severe disability caused by 101-200 m distance (OR = 1.34, 95% CI: 1.08, 1.66). And this association got stronger with longer duration of living close to major road. In dichotomized analyses using 200 m as a cutoff point, the effect associated with living close to major road was greater in male and current smoker. Specially, poor physical function appears earlier in female, but less severe than that in male. The result emphasizes the adverse effect of residential proximity to major roadways to aging-related declines in health-especially for basic living ability. This association was more pronounced in male and current smokers, which cannot be reversed by lowering the indoor air pollution.

The Causal Nexus among Energy Consumption, Environmental Degradation, Financial Development and Health Outcome: Empirical Study for Pakistan

Pakistan is facing an energy crisis and is also severely affected by climate change. Moreover, Pakistan is not doing well as far as health outcome indicators are concerned. The causal nexus among energy, environment, and health outcomes is well-established in literature. Besides, financial development also grabs the attention of health outcome literature as financial development can play a significant role in improving health outcomes. Thus, this study was conducted to test the causal nexus among energy consumption, environmental degradation, financial development, and health outcomes in the case of Pakistan. This study proxies health outcomes with life expectancy and infant mortality. Time series data have been analyzed through different econometric techniques, such as unit root tests, cointegration techniques, causality techniques, and cointegration regressions. Moreover, this study not just discovers the causal direction among variables but also determines the strength of causality through variance decomposition. Results of the study confirm that all variables of the study are cointegrated in the long run. The causality analysis reveals that unidirectional causality is running from energy consumption and environmental degradation to health outcomes, whereas bidirectional causality is found between financial development and health outcomes in the long run. Besides, this study also determines the effect of energy, environmental degradation, and financial development in the health outcome model and finds that energy and financial development can help Pakistan to improve health outcomes. Policy implications are recommended for Pakistan.

Determinants of life expectancy in most polluted countries: Exploring the effect of environmental degradation

BACKGROUND

Better understanding of the determinants of national life expectancy is crucial for economic development, as a healthy nation is a prerequisite for a wealthy nation. Many socioeconomic, nutritional, lifestyle, genetic and environmental factors can influence a nation's health and longevity. Environmental degradation is one of the critical determinants of life expectancy, which is still under-researched, as the literature suggests.

OBJECTIVES

This study aims to investigate the determinants of life expectancy in 31 world's most polluted countries with particular attention on environmental degradation using the World Bank annual data and British Petroleum data over the period of 18 years (2000-2017).

METHODS

The empirical investigation is based on the model of Preston Curve, where panel corrected standard errors (PCSE) and feasible general least square (FGLS) estimates are employed to explore the long-run effects. Pairwise Granger causality test is also used to have short-run causality among the variables of interest, taking into account the cross-sectional dependence test and other essential diagnostic tests.

RESULTS

The results confirm the existence of the Preston Curve, implying the positive effect of economic growth on life expectancy. Environmental degradation is found as a threat while health expenditure, clean water and improved sanitation affect the life expectancy positively in the sample countries. The causality test results reveal one-way causality from carbon emissions to life expectancy and bidirectional causalities between drinking water and life expectancy and sanitation and life expectancy.

CONCLUSION

Our results reveal that environmental degradation is a threat to having improved life expectancy in our sample countries. Based on the results of this study, we recommend that: (1) policy marker of these countries should adopt policies that will reduce carbon emissions and thus will improve public health and productivity; (2) environment-friendly technologies and resources, such as renewable energy, should be used in the production process; (3) healthcare expenditure on a national budget should be increased; and (4) clean drinking water and basic sanitation facilities must be ensured for all people.

Impact of Air Pollution on Residents' Medical Expenses: A Study Based on the Survey Data of 122 Cities in China

Background: With the development of the social economy, air pollution has resulted in increased social costs. Medical costs and health issues due to air pollution are important aspects of environmental governance in various countries.

Methods: This study uses daily air pollution monitoring data from 122 cities in China to empirically investigate the impact of air pollution on residents' medical expenses using the Heckman two-stage and instrumental variable methods, matching data from the 2018 China Health and Retirement Longitudinal Study (CHARLS) survey.

Results: The study found that poor air quality, measured by the air quality index (AQI), significantly increased the probability of chronic lung disease, heart disease, and self-rated poor health. Additionally, the AQI (with an effect of 4.51%) significantly impacted health-seeking behavior and medical expenses. The medical expenditure effects of mild, moderate, severe, and serious pollution days were 3.27, 7.21, 8.62, and 42.66%, respectively.

Conclusion: In the long run, residents' health in areas with a higher air pollution index, indicating poor air quality, is negatively impacted. The more extreme the pollution, the higher the probability of residents' medical treatment and the subsequent increase in medical expenses. Group and regional heterogeneity also play a role in the impact of air pollution on medical expenses. Compared with the existing literature, this study is based on individuals aged 15 years and above and produces reliable research conclusions.

Frailty Related to the Exposure to Particulate Matter and Ozone: The Korean Frailty and Aging Cohort Study

This study aims to identify the association between the concentration of particulate matter <2.5 μm (PM_2.5), <10 μm (PM₁₀), and ozone (O₃) and frailty. The Korean Frailty Scale (KFS, 0-6 points) assessing physical, psychological, and social frailty, was applied to 2912 community-dwelling older adults between April 2016 and December 2017. Daily average concentrations of PM_2.5, PM₁₀, and O₃ (2015-2017) were obtained and matched with the residential areas. The frailty risk associated with exposure to PM_2.5, PM₁₀, and O₃ was evaluated using multiple logistic regression after adjusting for age, sex, BMI, lifestyle, socioeconomic status, and comorbidity. Participants were categorized into robust (0 points, 28.7%), pre-frail (1-2 points, 50.1%), and frail (≥3 points, 21.2%) groups. Each 1 μg/m³ increase of PM_2.5 and PM₁₀ increased the odds ratios (ORs) and 95% confidence intervals (CIs) of the frail group compared to the robust group: 1.055 (1.002, 1.112) and 1.095 (1.060, 1.131), and the pre-frail group: 1.053 (1.017, 1.090) and 1.062 (1.037, 1.087), respectively. Each 1-ppb increase of O₃ increased the OR (95% CI) of the frail group: 1.041 (1.023, 1.059) and the pre-frail group: 1.005 (0.985, 1.025). PM_2.5, PM₁₀, and O₃ may be associated dose-dependently with the frailty.

Impacts from Economic Development and Environmental Factors on Life Expectancy: A Comparative Study Based on Data from Both Developed and Developing Countries from 2004 to 2016

Both economic development level and environmental factors have significant impacts on life expectancy at birth (LE). This paper takes LE as the research object and selects nine economic and environmental indicators with various impacts on LE. Based on a dataset of economic and environmental indicators of 20 countries from 2004 to 2016, our research uses the Pearson Correlation Coefficient to evaluate the correlation coefficients between the indicators, and we use multiple regression models to measure the impact of each indicator on LE. Based on the results from models and calculations, this study conducts a comparative analysis of the influencing mechanisms of different indicators on LE in both developed and developing countries, with conclusions as follow: (1) GDP per capita and the percentage of forest area to land area have a positive impact on LE in developed countries; however, they have a negative impact on LE in developing countries. Total public expenditure on education as a percentage of GDP and fertilizer consumption have a negative impact on LE in developed countries; however, they have a positive impact on LE in developing countries. Gini coefficient and average annual exposure to PM2.5 have no significant effect on LE in developed countries; however, they have a negative impact on LE in developing countries. Current healthcare expenditures per capita have a negative impact on LE in developed countries, and there is no significant impact on LE in developing countries. (2) The urbanization rate has a significant positive impact on LE in both developed countries and developing countries. Carbon dioxide emissions have a negative impact on LE in both developed and developing countries. (3) In developed countries, GDP per capita has the greatest positive impact on LE, while fertilizer consumption has the greatest negative impact on LE. In developing countries, the urbanization rate has the greatest positive impact on LE, while the Gini coefficient has the greatest negative impact on LE. To improve and prolong LE, it is suggested that countries should prioritize increasing GDP per capita and urbanization level. At the same time, countries should also work on reducing the Gini coefficient and formulating appropriate healthcare and education policies. On the other hand, countries should balance between economic development and environmental protection, putting the emphasis more on environmental protection, reducing environmental pollution, and improving the environment's ability of self-purification.

Investigating Factors of Active Aging among Chinese Older Adults: A Machine Learning Approach

BACKGROUND AND OBJECTIVES

With the extension of healthy life expectancy, promoting active aging has become a policy response to rapid population aging in China. Yet, it has been inconclusive about the relative importance of the determinants of active aging. By applying a machine learning approach, this study aims to identify the most important determinants of active aging in three domains, i.e., paid/unpaid work, caregiving, and social activities, among Chinese older adults.

RESEARCH DESIGN AND METHOD

Data were drawn from the first wave of the China Health and Retirement Longitudinal Study (CHARLS), which surveys a nationally representative sample of adults aged 60-year-old and above (N=7,503). We estimated Random Forest and the least absolute shrinkage and selection operator (LASSO) regression models to determine the most important factors related to active aging.

RESULTS

Health has a generic effect on all outcomes of active aging. Our findings also identified the domain-specific determinants of active aging. Urban/rural residency is among the most important factors determining the likelihood of engaging in paid/unpaid work. Living in a multi-generational household is especially important in predicting caregiving activities. Neighborhood infrastructure and facilities have the strongest influence on older adults' participation in social activities.

DISCUSSION AND IMPLICATIONS

The application of feature selection models provides a fruitful first step in identifying the most important determinants of active aging among Chinese older adults. These results provide evidence-based recommendations for policies and practices promoting active aging.

Multidimensional healthy life expectancy of the older population in China

Research on healthy life expectancy (HLE) that considers cognitive impairment has been inadequate, particularly in the context of less developed countries. Using data from the China Health and Retirement Longitudinal Study, our study fills this research gap by computing active life expectancy (ALE), cognitive-impairment-free life expectancy (CIFLE), and active and cognitive-impairment-free life expectancy (ACIFLE) for China's older population, using multistate life tables. Results show that at age 60, the three life expectancies were 19.4 years (ALE), 9.5 years (CIFLE), and 8.8 years (ACIFLE) during the period 2011-13. HLE exhibits significant differentials by sex, urban/rural residence, educational level, marital status, and health status at age 60. Among China's older people, males and those living in urban areas experience higher CIFLE, and those who live with a spouse, are more educated, and are healthy at age 60 expect more years in good health according to all three HLE measures.Supplementary material for this article is available at: https://doi.org/10.1080/00324728.2021.1914854.

A Systematic Review of Sociodemographic, Macroeconomic, and Health Resources Factors on Life Expectancy

This review was aimed at systematically synthesizing and appraising the existing literature of sociodemographic, macroeconomic, and health resources factors on life expectancy. A systematic literature search of English databases, that is, PubMed/MEDLINE were scrutinized for exploring sociodemographic, macroeconomic, and health resources factors on life expectancy. The literature search was conducted in January 2020, covering a total of 46 articles from 2004 to 2019 met the review criteria, which were fully discussed subsequently. Among sociodemographic factors, infant mortality rate, literacy rate, education level, socioeconomic status, population growth, and gender inequality have a significant impact on life expectancy. Gross domestic product, Gini, income level, unemployment rate, and inflation rate are the main macroeconomic factors that significantly correlated with life expectancy. Among various health care resources, health care facilities, the number of the health care profession, public health expenditure, death rates, smoking rate, pollution, and vaccinations had a significant correlation with life expectancy. The systematic review showed general conformity of different studies, with a significant association between life expectancy and factors comprising several sociodemographic, macroeconomic, and various health care variables. This review found that only one study examined factors affecting life expectancy in Arabic countries. More studies on this region to fill this research gap were highly recommended.

Rural-urban differences in health outcomes, healthcare use, and expenditures among older adults under universal health insurance in China

Rural-urban inequalities in health status and access to care are a significant issue in China, especially among older adults. However, the rural-urban differences in health outcomes, healthcare use, and expenditures among insured elders following China's comprehensive healthcare reforms in 2009 remain unclear. Using the Chinese Longitudinal Healthy Longevity Surveys data containing a sample of 2,624 urban and 6,297 rural residents aged 65 and older, we performed multivariable regression analyses to determine rural-urban differences in physical and psychological functions, self-reported access to care, and healthcare expenditures, after adjusting for individual socio-demographic characteristics and health conditions. Nonparametric tests were used to evaluate the changes in rural-urban differences between 2011 and 2014. Compared to rural residents, urban residents were more dependent on activities of daily living (ADLs) and instrumental ADLs. Urban residents reported better adequate access to care, higher adjusted total expenditures for inpatient, outpatient, and total care, and higher adjusted out-of-pocket spending for outpatient and total care. However, rural residents had higher adjusted self-payment ratios for total care. Rural-urban differences in health outcomes, adequate access to care, and self-payment ratio significantly narrowed, but rural-urban differences in healthcare expenditures significantly increased from 2011 to 2014. Our findings revealed that although health and healthcare access improved for both rural and urban older adults in China between 2011 and 2014, rural-urban differences showed mixed trends. These findings provide empirical support for China's implementation of integrated rural and urban public health insurance systems, and further suggest that inequalities in healthcare resource distribution and economic development between rural and urban areas should be addressed to further reduce the rural-urban differences.

How longer can people live by achieving the daily ambient fine particulate pollution standards in the Pearl River Delta region, China?

BACKGROUND

Previous research has reported the effects of long-term fine particulate matter (PM_2.5) pollution on years of life lost (YLL), but these effects may not represent the full impact. This study aims to estimate potential benefits in life time from adhering to daily ambient PM_2.5 concentration standards/guidelines.

METHODS

This study evaluated the relationship between daily ambient PM_2.5 level and YLL using a two-stage approach with generalized additive models and meta-analysis. Potential life expectancy gains were then estimated by presuming that daily PM_2.5 levels were in compliance with the Chinese and WHO standards. In addition, the attributable fraction of YLL due to excess PM_2.5 exposure was also calculated.

RESULTS

During 2013-2016, 459,468 non-accidental deaths were recorded in the six cities of Pearl River Delta, China. Each 10 μg/m³ increment in four-day average (lag₀₃) level of PM_2.5 was related to an increment of 13.31 [95% confidence interval (CI): 5.74, 20.87] years of life lost. Implementation of the WHO guidelines might avoid 180,980.83 YLLs (95% CI: 78,116.07, 283,845.60), which corresponded to 0.39 (95% CI: 0.17, 0.62) years of increased life time per death. Additionally, an estimated 0.15% (95% CI: 0.06%, 0.23%) or 2.04% (95% CI: 0.88%, 3.20%) of YLLs could be attributed to PM_2.5 exposures higher than the Chinese or WHO guidelines, respectively.

CONCLUSIONS

This study suggests that people might live longer by controlling daily PM_2.5 concentration and highlights the need to adopt stricter standards in China.

Cumulative exposure to air pollution and subsequent mortality among older adults in China

BACKGROUND

Research on the health effects of exposure to air pollution is growing. However, relatively little attention has been paid to the effects of long-term and cumulative exposure to air pollutants. Individual-level studies on the health consequences of air pollution in China are especially scarce. The purpose of this study is to examine the effect of cumulative exposure to sulfur dioxide (SO2), an air pollutant of particular concern in China, on all-cause mortality in older Chinese adults.

METHODS

Using a nationally representative sample of older adults in China (N = 11 199), we tracked mortality over an 11-year period (2000-11). Air pollution data were linked to respondents using provincial identifiers. To examine the effect of cumulative SO2 exposure on mortality, we employed multilevel multinomial logistic regression models that account for within subject clustering of observations over time and clustering at the province level.

RESULTS

We found that every 10-μg/m3 increase in cumulative exposure to SO2 increased the odds of death by nearly 1% (OR = 1.008; 95% CI: 1.002-1.014), controlling for province- and individual-level social and economic characteristics.

CONCLUSIONS

Our analysis shows that air pollution is a risk factor for morality in older Chinese adults. Findings suggest that stronger SO2 regulations may enhance longevity.

Residential Greenness Alters Serum 25(OH)D Concentrations: A Longitudinal Cohort of Chinese Older Adults

Objectives

Vitamin D deficiency is prevalent among older adults. We aimed to study whether residential greenness could alter serum 25(OH)D concentrations as a possible mechanism of residential greenness's positive health effects.

Design

A longitudinal cohort study.

Setting and Participants

We included older adults aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) with follow-up between 2012 and 2014.

Methods

We measured residential greenness by calculating annual average Normalized Difference Vegetation Index (NDVI) in a 500 m radius by using satellite images around each participant's residential address. Serum 25-hydroxyvitamin D (25(OH)D) concentration was dichotomized into 2 categories: nondeficiency (≥50 nmol/L) and deficiency (<50 nmol/L). We used the generalized estimating equation to examine the relationship between annual average NDVI and serum 25(OH)D.

Results

We included 1336 participants in our analysis. The annual average NDVI was 0.49, and mean serum 25(OH)D was 43 nmol/L at baseline. Each 0.1-unit increase in annual average NDVI was associated with a 13% higher odds of vitamin D nondeficiency [95% confidence interval (CI): 1.01, 1.26]. The association was stronger among men [odds ratio (OR): 1.17, 95% CI: 1.02, 1.35] than women (OR: 1.08, 95% CI: 0.91, 1.29) and also stronger among those who were free of activities of daily living (ADL) disability at baseline (OR: 1.12, 95% CI: 1.00, 1.25). During the follow-up period, the participants who lived in greener areas were more likely to have an improved, rather than stable or deteriorated, vitamin D status (OR: 1.94, 95% CI: 1.51, 2.51).

Conclusions and Implications

Our study suggests that higher levels of residential greenness are associated with higher serum 25(OH)D concentrations, which has implications for prevention of vitamin D deficiency among older adults.

Long-term exposure to PM2.5 and incidence of disability in activities of daily living among oldest old

Currently the Chinese government has adopted World Health Organization interim target-1 values as the national ambient air quality standards values. However, the population-based evidence was insufficient, especially for the oldest old (aged 80+). We evaluated the association of fine particulate matters (PM_2.5) exposure and incidence of disability in activities of daily living (ADL) in 15 453 oldest old in 886 counties/cities in China from 2002 to 2014 using Cox model with penalized splines and competing risk models to evaluate the linear or non-linear association. After adjusting for potential confounders, a J-shaped association existed between PM_2.5 exposure with a threshold concentration of 33 μg/m³, and incident disability in ADL. Above this threshold, the risk magnitude significantly increased with increase of PM_2.5 concentrations; compared to 33 μg/m³, the hazard ratio ranged from 1.03 (1.00-1.06) at 40 μg/m³ to 2.25 (1.54-3.29) at 110 μg/m³. The risk magnitude was not significantly changed below this threshold. Each 10 μg/m³ increase in PM_2.5 exposure corresponded to a 7.7% increase in the risk of disability in ADL (hazard ratio 1.077, 95% CI 1.051-1.104). Men, smokers, and participants with cognitive impairment might be more vulnerable to PM_2.5 exposure. The study provided limited population-based evidence for the oldest old and detected a threshold of 33 μg/m³, and supported that reduction to current World Health Organization interim target-1value (35 μg/m³) and Chinese national ambient air quality standards (35 μg/m³) or lower may be associated with lower risk of disability in ADL.

Residential greenness, activities of daily living, and instrumental activities of daily living: A longitudinal cohort study of older adults in China

Supplemental Digital Content is available in the text.

Background:

We aimed to explore whether higher levels of residential greenness were related to lower odds of disabilities in activities of daily living (ADL) and instrumental activities of daily living (IADL).

Methods:

We included older adults 65 years of age or older from the Chinese Longitudinal Healthy Longevity Survey. Our exposure was Normalized Difference Vegetation Index in 500 m radius around residence. Our outcome was ADL and IADL. We used binary logistic regression and mixed-effects logistic regression to estimate the odds of ADL and IADL disabilities.

Results:

A total of 36,803 and 32,316 participants were included for the analysis of ADL and IADL, with 71.6% free of ADL disability and 47.3% free of IADL disability. In the logistic regression model, compared with the participants living in the lowest quartile of residential greenness, those in the highest quartile had a 28% (odds ratio [OR] = 0.72; 95% confidence interval [CI] = 0.65, 0.79) lower odds of ADL disability and a 14% (OR = 0.86; 95% CI = 0.77, 0.95) lower odds of IADL disability. A similar association was found in the mixed-effects logistic regression models. During the follow-up period, 5,004 and 4,880 healthy participants developed ADL and IADL disabilities. Per 0.1-unit increase in baseline annual average Normalized Difference Vegetation Index (NDVI) was related to an OR of 0.95 of developing ADL disability (95% CI = 0.93, 0.98) and IADL disability (95% CI = 0.91, 0.98).

Conclusions:

Our study suggests that increasing green space is associated with lower odds of ADL and IADL disabilities, which may reduce caregiver burden of long-term care for Chinese older adults.

Relationship between Air Pollution and Regional Longevity in Guangxi, China

Air pollution has become a global environmental challenge and poses major threats to human health, particularly for the aging population. However, few studies have investigated the effects of air pollutants on human longevity, especially based on the total regional quantities and sources. Based on investigation of the spatiotemporal variations of three air pollutants (PM₁₀, SO₂, and NOx) and three longevity indicators (centenarian ratio, centenarity index, and aging tendency), this study aims to identify the relationship between air pollution and regional longevity in Guangxi Province. Air pollutant and population data from 109 counties and areas of Guangxi were collected from environmental research reports and statistical yearbooks. Cluster and outlier analysis was used to detect the regions with high and low clusters of the longevity indicators and air pollutants. Geographically weighted regression analyses were performed to determine the relationship between longevity and air pollutants. A negative relationship between the air pollutants PM₁₀, SO₂, and NOx on the aged population was observed. From a provincial level, industrial sources from the urban areas of cities located in the central province, including Liuzhou, Nanning, Laibing, Guigang and Yulin, were important contributors to the air pollutants PM₁₀, SO₂, and NOx, and thus could contribute to negative impacts on regional longevity. The key findings from this study will provide a case for management of air pollutants based on public health policies in China as well as other developing communities.

Neighborhood environments and self-rated health in Mainland China, Japan and South Korea

Neighborhood environments are considered crucial determinants of self-rated health. Previous research has documented a positive association between the quality of neighborhood environments and health status. However, the relationship between neighborhood environments and health status in East Asian countries has received far less attention. This study examined the relationship between the three main types of neighborhood environments (built, natural, and social) and self-rated health in Mainland China, Japan, and South Korea. It also compared the neighborhood effects on self-rated health across the three countries. Our analytical sample included 3,675, 2,390, and 1,500 respondents in China, Japan, and South Korea respectively from the 2010 East Asian Social Survey. Ordinal Logistic Regression models were estimated for each country and the country differences were tested. This study found that neighborhood built, natural and social environments are positively associated with self-rated health in China, Japan and South Korea. These effects vary somewhat by country, and neighborhood social environment has the strongest association with self-rated health in Japan, followed by South Korea and then China. The similar relationship between perceived neighborhood environments and self-rated health across the three countries underscores the prevalent impact of perceived neighborhood environments on health. The greater association between social environment and self-rated health in Japan suggests the greater need of community based support system in an aging society not only for the older people, but also for the general population, especially those who are living in poor neighborhood social environment.

Air Pollution and Performance-Based Physical Functioning in Dutch Older Adults

BACKGROUND

Functional limitations are a major cause for needing care and institutionalization among older adults. Exposure to air pollution has been suggested to be associated with increased functional limitations in older people.

OBJECTIVE

Our objective was to assess the association between air pollution and physical functioning in Dutch older adults.

METHODS

We analyzed data on performance-based (walking speed, ability to rise from a chair, putting on and taking off a cardigan, balance test) and self-reported physical functioning for 1,762 participants of the Longitudinal Aging Study Amsterdam, who participated in measurement cycles performed in 2005/2006, 2008/2009, and 2011/2012. Annual average outdoor air pollution concentrations [nitrogen dioxide (NO₂), nitrogen oxides (NO_x), particulate matter with diameters ≤2.5μm (PM_2.5), ≤10μm (PM₁₀), and 2.5-10μm (PM_coarse), and PM_2.5 absorbance] at the home address at the start of the first measurement cycle were estimated using land-use regression models. Analyses were performed using mixed models with random participant intercepts adjusting for potential confounders.

RESULTS

Exposure to most air pollutants was associated with reduced performance-based physical functioning; for example, an interquartile range increase in NO₂ exposure was associated with a 0.22 (95% confidence interval: 0.03, 0.42) lower performance test score in fully adjusted models, equivalent to the difference in performance score between participants who differed by 9 mo in age. Exposure to air pollution was generally not statistically significantly associated with self-reported functional limitations, and not associated with a faster decline in performance-based physical functioning over the study period.

CONCLUSION

This study suggests that exposure to air pollution may adversely affect physical performance of older adults in the Netherlands. https://doi.org/10.1289/EHP2239.

Two Mechanisms: The Role of Social Capital and Industrial Pollution Exposure in Explaining Racial Disparities in Self-Rated Health

This study provides an empirical test of two mechanisms (social capital and exposure to air pollution) that are theorized to mediate the effect of neighborhood on health and contribute to racial disparities in health outcomes. To this end, we utilize the Social Capital Benchmark Study, a national survey of individuals nested within communities in the United States, to estimate how multiple dimensions of social capital and exposure to air pollution, explain racial disparities in self-rated health. Our main findings show that when controlling for individual-confounders, and nesting within communities, our indicator of cognitive bridging, generalized trust, decreases the gap in self-rated health between African Americans and Whites by 84%, and the gap between Hispanics and Whites by 54%. Our other indicator of cognitive social capital, cognitive linking as represented by engagement in politics, decreases the gap in health between Hispanics and Whites by 32%, but has little impact on African Americans. We also assessed whether the gap in health was explained by respondents' estimated exposure to toxicity-weighted air pollutants from large industrial facilities over the previous year. Our results show that accounting for exposure to these toxins has no effect on the racial gap in self-rated health in these data. This paper contributes to the neighborhood effects literature by examining the impact that estimated annual industrial air pollution, and multiple measures of social capital, have on explaining the racial gap in health in a sample of individuals nested within communities across the United States.

Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research

BACKGROUND

Dementia is a devastating condition typically preceded by a long prodromal phase characterized by accumulation of neuropathology and accelerated cognitive decline. A growing number of epidemiologic studies have explored the relation between air pollution exposure and dementia-related outcomes.

METHODS

We undertook a systematic review, including quality assessment, to interpret the collective findings and describe methodological challenges that may limit study validity. Articles, which were identified according to a registered protocol, had to quantify the association of an air pollution exposure with cognitive function, cognitive decline, a dementia-related neuroimaging feature, or dementia.

RESULTS

We identified 18 eligible published articles. The quality of most studies was adequate to exemplary. Almost all reported an adverse association between at least one pollutant and one dementia-related outcome. However, relatively few studies considered outcomes that provide the strongest evidence for a causal effect, such as within-person cognitive or pathologic changes. Reassuringly, differential selection would likely bias toward a protective association in most studies, making it unlikely to account for observed adverse associations. Likewise, using a formal sensitivity analysis, we found that unmeasured confounding is also unlikely to explain reported adverse associations.

DISCUSSION

We also identified several common challenges. First, most studies of incident dementia identified cases from health system records. As dementia in the community is underdiagnosed, this could generate either non-differential or differential misclassification bias. Second, almost all studies used recent air pollution exposures as surrogate measures of long-term exposure. Although this approach may be reasonable if the measured and etiologic exposure windows are separated by a few years, its validity is unknown over longer intervals. Third, comparing the magnitude of associations may not clearly pinpoint which, if any, pollutants are the probable causal agents, because the degree of exposure misclassification differs across pollutants. The epidemiologic evidence, alongside evidence from other lines of research, provides support for a relation of air pollution exposure to dementia. Future studies with improved design, analysis and reporting would fill key evidentiary gaps and provide a solid foundation for recommendations and possible interventions.

Intelligence, democracy, and international environmental commitment

This paper investigates the determinants of nations' commitment to environmental protection at the international level by focusing on the role of national intelligence and the level of democracy. The national intelligence is measured by nation's IQ scores. The findings based on a sample of 152 nations provide strong evidence that intelligence has statistically significant impact on ratification of international environmental agreements, and the countries with IQ 10-points above global average are 23% more likely to sign multilateral environmental agreements than others. The findings also demonstrate that it is the combination of high-level of intelligence of nations and democracy, that likely result in international environmental commitments.

Successful aging: Advancing the science of physical independence in older adults

The concept of 'successful aging' has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. A consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults.

Health Expectancies in Adults Aged 50 Years or Older in China

OBJECTIVE

The purpose of this study is to understand the functional health of older adults in China and to assess the potential for advancing healthy and active aging.

METHOD

Data of 13,739 older adults aged 50 years and older from the China Health and Retirement Longitudinal Study in 2011 were analyzed. Life expectancy in good perceived health, chronic-disease-free life expectancy, active life expectancy, and severe impairment-free life expectancy were calculated using Sullivan's method.

RESULTS

At age 50 years, older adults had a life expectancy in good perceived health of 7.0 and 6.7 years in men and women, respectively. They would remain chronic-disease-free for 8.4 and 8.6 years, without activity limitation for 23.6 and 26.0 years, and severe impairment-free for 21.4 and 24.2 years.

DISCUSSION

The world's largest aging population was spending a substantial proportion of remaining life years in suboptimal health and well-being, while remaining largely independent in basic self-care without severe impairments.

A study of air pollutants influencing life expectancy and longevity from spatial perspective in China

Life expectancy and longevity are influenced by air pollutants and socioeconomic status, but the extend and significance are still unclear. Better understanding how the spatial differences of life expectancy and longevity are affected by air pollutants is needed for generating public health and environmental strategies since the whole of China is now threatened by deteriorated air quality. 85 major city regions were chosen as research areas. Geographically Weighted Regression (GWR) and Stepwise Regression (SR) were used to find the spatial correlations between health indicators and air pollutants, adjusted by per capita GDP(1). The results were, regions with higher life expectancy were mainly located in the east area and areas with good air quality, a regional difference of 10 μg/m(3) in ambient air SO2(2) could cause adjusted 0.28 year's difference in life expectancy, a regional difference of 10 μg/m(3) in ambient air PM10(3) could lead to a longevity ratio difference of 2.23, and per capita GDP was positively associating with life expectancy but not longevity ratio, with a regional difference of 10,000 RMB(4) associating with adjusted 0.49 year's difference in life expectancy. This research also showed the evidences that there exist spatially differences for ambient air PM10 and SO2 influencing life expectancy and longevity in China, and this influences were clearer in south China.

The association between air pollution and mortality in Thailand

Bayesian statistical inference with a case-crossover design was used to examine the effects of air pollutants {Particulate matter <10 μm in aerodynamic diameter (PM₁₀), sulphur dioxide (SO₂), and ozone (O₃)} on mortality. We found that all air pollutants had significant short-term impacts on non-accidental mortality. An increase of 10 μg/m³ in PM₁₀, 10 ppb in O₃, 1 ppb in SO₂ were associated with a 0.40% (95% posterior interval (PI): 0.22, 0.59%), 0.78% (95% PI: 0.20, 1.35%) and 0.34% (95% PI: 0.17, 0.50%) increase of non-accidental mortality, respectively. O₃ air pollution is significantly associated with cardiovascular mortality, while PM₁₀ is significantly related to respiratory mortality. In general, the effects of all pollutants on all mortality types were higher in summer and winter than those in the rainy season. This study highlights the effects of exposure to air pollution on mortality risks in Thailand. Our findings support the Thailand government in aiming to reduce high levels of air pollution.