The need for a focus on air pollution research in the elderly

Study on the impact of central environmental protection inspection on the health of the older adult population-A quasi-natural experiment in China

In 2015, the central government of China established the Central Environmental Protection Inspection (CEPI) system for oversight of local governments. It enhanced local government enforcement of environmental regulations, which had a considerable influence on the health of the local older adult population. This study quantifies the effects of local government regulation brought about by CEPI on the health of the older adult. It examines the impact mechanism using the DID model and panel data from the China Health and Retirement Longitudinal Study (CHARLS). The results show that (1) local governments' environmental protection regulations implemented by CEPI have a positive impact on the general health of the older adult. The results of the study passed the parallel trend test, PSM test, replacement variable test, and placebo test and remained significant; (2) in terms of the impact mechanism, CEPI has promoted local governments' environmental governance initiatives, which has reduced industrial wastewater emissions, industrial sulfur dioxide emissions, and industrial fumes emissions. This has improved air quality, thereby creating a good living environment for the older adult and improving their overall health; (3) according to heterogeneity research, the health of older adult living in the Yangtze River Basin, urban older adult, and older adult without chronic diseases is more significantly affected by the environmental protection regulations of the local governments brought about by CEPI.

Ambient PM2.5 and cardiopulmonary mortality in the oldest-old people in China: A national time-stratified case-crossover study

BACKGROUND

Evidence on the associations of fine particulate matter (PM2.5) with cardiopulmonary mortality in the oldest-old (aged 80+ years) people remains limited.

METHODS

We conducted a time-stratified case-crossover study of 1,475,459 deaths from cardiopulmonary diseases in China to estimate the associations between short-term exposure to ambient PM2.5 and cardiopulmonary mortality among the oldest-old people.

FINDINGS

Each 10 μg/m3 increase in PM2.5 concentration (6-day moving average [lag05]) was associated with higher mortality from cardiopulmonary diseases (excess risks [ERs] = 1.69%, 95% confidence interval [CI]: 1.54%, 1.84%), cardiovascular diseases (ER = 1.72%, 95% CI: 1.54%, 1.90%), and respiratory diseases (ER = 1.62%, 95% CI: 1.33%, 1.91%). Compared to the other groups, females (ER = 1.94%, 95% CI: 1.73%, 2.15%) (p for difference test = 0.043) and those aged 95-99 years (ER = 2.31%, 95% CI: 1.61%, 3.02%) (aged 80-85 years old was the reference, p for difference test = 0.770) presented greater mortality risks. We found 14 specific cardiopulmonary causes associated with PM2.5, out of which emphysema (ER = 3.20%, 95% CI: 1.57%, 4.86%) had the largest association. Out of the total deaths, 6.27% (attributable fraction [AF], 95% CI: 5.72%, 6.82%) were ascribed to short-term PM2.5 exposure.

CONCLUSIONS

This study provides evidence of PM2.5-induced cardiopulmonary mortality and calls for targeted prevention actions for the oldest-old people.

FUNDING

This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Foreign Expert Program of the Ministry of Science and Technology, the Natural Science Foundation of Guangdong, China, and the Science and Technology Program of Guangzhou.

Effect of a single one-hour teaching session about environmental pollutants and climate change on the understanding and behavioral choices of adolescents: The BREATHE pilot randomized controlled trial

BACKGROUND

Despite the wealth of scientific information on the health effects of air pollution, the adult public's lifestyle continues to be largely detrimental towards the environment.

OBJECTIVE

The purpose of the study was to determine whether a short interactive teaching session on air pollution could shift reported behavioral choices of adolescents towards environmentally friendlier options.

METHODS

We performed a pilot randomized control trial in which eighth-grade students were randomized to receive a one-hour script-based teaching on either the effects of air pollution on lung health (intervention group) or the role of vaccination in public health (active control group). The enrolled students completed a survey (15 multiple-choice questions; five targeting understanding (score range 5 to 20); ten targeting behavioral choices (score range 10 to 38) newly designed for this study to evaluate their understanding and predict their future behavior towards air pollution immediately before, immediately after, and one month after the teaching sessions.

RESULTS

Seventy-seven students (age = 13.5±0.6 years; 50.4% female; median annual family income = $25K-$50K with 70.1% <$50K; 39 assigned to intervention group) were enrolled in the study. The teaching sessions did not result in any significant change in the participants' understanding domain scores in either the intervention or the control groups. However, the intervention (air pollution) teaching session resulted in a statistically significant increase in behavior domain score from baseline to immediately post-teaching, which continued to be present at one-month follow-up (mean ± standard deviation of score change immediately after = 1.7±3.3; score change 1-month after = 2.5±3.2; P<0.001; minimally important difference = 1.0).

DISCUSSION

This pilot study highlights the potential of a short one-time teaching session in promoting environmentally friendly behavior choices among adolescents.

Air quality health index (AQHI) based on multiple air pollutants and mortality risks in Taiwan: Construction and validation

The currently used air quality index (AQI) is not able to capture the additive effects of air pollution on health risks and reflect non-threshold concentration-response relationships, which has been criticized. We proposed the air quality health index (AQHI) based on daily air pollution-mortality associations, and compared its validity in predicting daily mortality and morbidity risks with the existing AQI. We examined the excess risk (ER) of daily elderly (≥65-year-old) mortality associated with 6 air pollutants (PM2.5, PM10, SO2, CO, NO2, and O3) in 72 townships across Taiwan from 2006 to 2014 by performing a time-series analysis using a Poisson regression model. Random effect meta-analysis was used to pool the township-specified ER for each air pollutant in the overall and seasonal scenarios. The integrated ERs for mortality were calculated and used to construct the AQHI. The association of the AQHI with daily mortality and morbidity were compared by calculating the percentage change per interquartile range (IQR) increase in the indices. The magnitude of the ER on the concentration-response curve was used to evaluate the performance of the AQHI and AQI, regarding specific health outcomes. Sensitivity analysis was conducted using coefficients from the single- and two-pollutant models. The coefficients of PM2.5, NO2, SO2, and O3 associated with mortality were included to form the overall and season-specific AQHI. An IQR increase in the overall AQHI at lag 0 was associated with 1.90%, 2.96%, and 2.68% increases in mortality, asthma, and respiratory outpatient visits, respectively. The AQHI had higher ERs for mortality and morbidity on the validity examinations than the current AQI. The AQHI, which captures the combined effects of air pollution, can serve as a health risk communication tool to the public.

The health impact of freight transport-related air pollution on vulnerable population groups

Every year, over 364,200 people in Europe die prematurely due to the effects of air pollution, in which the transportation sector plays an important role. In Brussels, freight transport generates €61,604 of air pollution health costs daily. Research has shown that dynamic spatiotemporal modeling of both emission sources and exposed people (using mobile phone data) renders more accurate impact results when analyzed in microenvironments. However, mobile data underrepresent population segments that are more sensitive to the effects of air pollution, such as toddlers, children and elderly individuals. This paper examined the link between vulnerable people aged 0-3, 3-18 and >65 years and freight transport-related air pollution concentrations in the Brussels-Capital Region (BCR). To this end, dynamic tailpipe emissions and their spatiotemporal dispersion were calculated using output from the Transport Agent-Based Model (TRABAM) on a daily basis. Population densities were calculated as a function of the residences' occupancy rate and school/class size and opening hours. The effects of exposure were then evaluated using age- and sex-differentiated exposure-response functions and monetized using local hospital cost factors. Data were compiled for 2021. A strong overlap between people's presence at the institutions' locations was noticed with a peak in (freight) transportation movements in the city. The results showed that €37,000 [€34,517.47-€40,047.13] of freight transport-related air pollution health costs were incurred daily by vulnerable population segments. While these vulnerable groups made up 25.34% of the total BCR population, they incurred 60% [56.03%-65.01%] of the engendered transportation air pollution costs. The results were then geographically analyzed to identify 465 traffic-related air pollution hotspots across the territory, which accounted for €36,000 [€33,677.85-€39,101.31] of total costs. The latter can be used in future studies to assess sector-specific freight transportation policies, which should take into consideration spatiotemporal population densities on the local level.

Association of biomass fuel use with the risk of vision impairment among Chinese older adults: a cohort study

Cooking with biomass fuels has been reported to have adverse effects on health. This study aims to explore the association between cooking with biomass fuels and vision impairment among Chinese older adults aged 65 years and above. This cohort study drew on data from the 2011/2012 wave and the 2014 follow-up wave of the Chinese Longitudinal Healthy Longevity Survey. Participants' visual function was examined through a vision screening test. Exposure to indoor biomass fuels was self-reported. Cox proportional hazards models were applied to explore the relationship between biomass fuel use and vision impairment. Additionally, we compared the risk of vision impairment between participants who switched cooking fuel types and those who did not. Subgroup and interaction analyses were conducted to explore the potential effect modifiers. A total of 4711 participants were included in this study. During the follow-up, 1053 (22.35%) participants developed vision impairment. Cooking with biomass fuels increased the risk of vision impairment by 40% (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 1.21-1.61). Participants who switched from clean fuels to biomass fuels had a greater risk of vision impairment than persistent clean fuel users (HR: 1.44, 95% CI: 1.03-2.00). Greater effect estimates were found in participants who lived in eastern and central China and urban residents. Cooking with biomass fuels resulted in a greater risk of vision impairment among Chinese older adults. This risk also existed in those who changed their cooking fuels from clean fuels to biomass fuels. Further studies with an objective assessment of biomass fuel combustion are required to confirm our findings.

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.

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.

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 between ambient air pollution, meteorology, and daily hospital admissions for ischemic stroke: a time-stratified case-crossover study in Beijing

Air pollution and ischemic stroke (IS) are both vital factors affecting the health of Beijing citizens. This study aims at exploring the associations between air pollution, meteorology, and the hospital admission of IS (IS HA). Information on 476,659 IS inpatients in secondary and higher hospitals in Beijing from 2013 to 2018 were collected. A time-stratified case-crossover design with the generalized additive model and the distributed lag nonlinear model were used. In the single-pollutant models, an inter-quartile range increase in O_3, SO₂, CO, and NO₂ resulted in a significant highest increase in IS HA by 2.23% (95% CI: 1.56%, 2.90%), 1.53% (95% CI: 1.12%, 1.95%), 1.05% (95% CI: 0.70%, 1.40%), and 0.51% (95% CI: 0.24%, 0.79%) on the day of pollution, so did PM_2.5 and PM₁₀ by 1.13% (95% CI: 0.68%, 1.59%) and 1.19% (95% CI: 0.74%, 1.64%) at a lag of 0-5 days. There was a nonlinear relationship between meteorology and IS HA. In the multivariate model, the cumulative relative risks with a maximum lag time of 21 days of PM_2.5 and NO₂ were 1.11 (95% CI: 1.04, 1.19) and 0.88 (95% CI: 0.82, 0.94), while the effects of SO₂, O₃, and meteorology were insignificant. The findings suggested that particulate pollutants could increase the risk of IS, and the elderly were more sensitive to it, while the results of gaseous pollutants are still discordant. The control of air pollution and the protection of susceptible populations should receive higher attention from policymakers.

Short-term exposure to nitrogen dioxide and ischemic stroke incidence in Shenzhen, China: Modification effects by season and temperature

BACKGROUND AND OBJECTIVES

China has experienced a serious public health burden because of the increased incidence of ischemic stroke. Evidence describing the association between short-term exposure to nitrogen dioxide (NO₂) and ischemic stroke morbidity is limited, and few studies have focused on the effects of season and temperature. This study aimed to evaluate the acute effects of NO₂ on ischemic stroke incidence in Shenzhen, a southeastern city of China, considering the modified effects of season and temperature.

METHODS

A time-stratified case-crossover study was conducted between 2003 and 2014 among 98,482 ischemic stroke hospitalizations. Conditional quasi-Poisson regression was used to estimate the percentage changes in ischemic stroke admissions in relation to each 10 μg/m³ increment in NO₂.

RESULTS

NO₂ was positively associated with ischemic stroke onset over the full year, as well as in the cold season (November through April) and on cold days (ambient temperature≤median temperature), with significant single-day effects within 3 days after the exposure, and significant cumulative effects within the delayed five days. The maximum percentage changes were obtained at lag0-5, with 1.81% (95% confidence interval (CI) was 0.86-2.76%) over the full year, 2.75% (1.48-4.03%) in the cold season, and 3.04% (1.74-4.35%) on cold days. Additionally, the effects of exposure were found to be greater in males and people with higher education, and were lasting longer in subgroups of older individuals.

CONCLUSIONS

Our findings provide evidence that reductions in NO₂ levels might decrease ischemic stroke morbidity, and enhance the understanding of ischemic stroke occurrence associated with NO₂ modified by season and temperature.

The impact of environmental pollution on the physical health of middle-aged and older adults in China

While several studies have demonstrated the negative impacts of environmental pollution on population health, in general, few studies have examined the potential differential effects on the physical health of middle-aged and older populations, i.e., 45 years and older. Given the twin concerns of environmental pollution and population aging in China, this article employed a fixed effects model to infer the impact of environmental pollution on public health with a particular focus on middle-aged and older adults. The analyses were based on data from the 2011 to 2018 waves of the CHARLS and pollutant data from prefecture-level cities. The results showed that both the level and intensity of environmental pollution significantly increased the risk of chronic diseases and negatively impacted the physical health of middle-aged and older adults. Environmental pollution had its greatest negative effect on the physical health of the elderly, urban residents, residents of the Eastern region, and those with lower incomes than their counterparts. We further found that the potential channels of health effect were through reduced physical exercise and sleep duration and an increase in depressive symptoms, and the pollution prevention actions alleviated the health deterioration of environmental pollution for the middle-aged and the elderly. It is imperative for the government to urgently reinforce policy enforcement to decrease air and water pollution and enhance the ability to circumvent pollution for the lower socioeconomic groups.

Cooking with biomass fuels increased the risk for cognitive impairment and cognitive decline among the oldest-old Chinese adults (2011-2018): A prospective cohort study

BACKGROUNDS

While the pernicious effects of outdoor air pollution on cognitive ability have been previously examined, evidence regarding household air pollution is scarce.

METHODS

Using data from the Chinese Longitudinal Healthy Longevity Survey, we explored the relationship between cooking with biomass fuel and cognitive impairment and cognitive decline using a Cox proportional hazards model. We further assessed the correlation of biomass fuels and cognitive score using a generalized estimating equation. Cognitive ability was measured based on the Chinese version of the Mini-Mental State Examination (MMSE) and cognitive impairment was defined as MMSE < 24 points and cognitive decline was defined as a reduction of MMSE ≥ 3 points. On follow-up, we investigated the effect of switch-cooking combustibles on cognitive ability.

RESULTS

The mean (SD) age of 4161 participants was 81.7 (10.0) years old. The reported cooking with biomass fuels was correlated with an elevated risk of cognitive impairment (hazard ratio (HR): 1.19, 95% confidence interval (CI): 1.04, 1.37) and cognitive decline (HR: 1.18, 95% CI: 1.04, 1.33). Besides, cooking with biomass fuels was related to a decrease in cognitive score (β: -0.43, 95% CI: -0.73, -0.14). In comparison to persistent biomass fuel users, participants who reported changing their primary cooking fuels from biomass to clean fuels exhibited a reduced risk of cognitive impairment (HR: 0.68, 95% CI: 0.57, 0.82) and cognitive decline (HR: 0.66, 95% CI: 0.56, 0.76) and a higher cognitive score (β: 0.72, 95% CI: 0.17, 1.26). Cooking without ventilated cookstoves was associated with a higher risk of cognitive impairment (HR: 1.31, 95% CI: 1.10, 1.58) and cognitive decline (HR: 1.18, 95% CI: 1.02, 1.38), regardless of types of cooking fuels. Interaction and stratified analyses showed relatively poor cognitive ability in participants who engaged in irregular exercise or were not living with family members.

CONCLUSIONS

Cooking with biomass fuels was correlated with a higher risk of cognitive impairment and cognitive decline. Among the oldest-old population, this risk may, however, be lower for those changing their primary cooking fuels from biomass to clean fuels.

Short-term effect of fine particulate matter and ozone on non-accidental mortality and respiratory mortality in Lishui district, China

Background

In recent years, air pollution has become an imminent problem in China. Few studies have investigated the impact of air pollution on the mortality of the middle-aged and elderly people. Therefore, this study aims to evaluate the impact of PM_2.5 (fine particulate matter) and O₃ (ozone) on non-accidental mortality and respiratory mortality of the middle-aged and elderly people in Lishui District of Nanjing and provide the evidence for potential prevention and control measures of air pollution.

Method

Using daily mortality and atmospheric monitoring data from 2015 to 2019, we applied a generalized additive model with time-series analysis to evaluate the association of PM_2.5 and O₃ exposure with daily non-accidental mortality and respiratory mortality in Lishui District. Using the population attributable fractions to estimate the death burden caused by short-term exposure to O₃ and PM_2.5。.

Result

For every 10 μg/m³ increase in PM_2.5, non-accidental mortality increased 0.94% with 95% confidence interval (CI) between 0.05 and 1.83%, and PM_2.5 had a more profound impact on females than males. For every 10 μg/m³ increase in O₃, respiratory mortality increased 1.35% (95% CI: 0.05, 2.66%) and O₃ had a more profound impact on males than females. Compared with the single pollutant model, impact of the two-pollutant model on non-accidental mortality and respiratory mortality slightly decreased. In summer and winter as opposed to the other seasons, O₃ had a more obvious impact on non-accidental mortality. The population attributable fractions of non-accidental mortality were 0.84% (95% CI:0.00, 1.63%) for PM_2.5 and respiratory mortality were 0.14% (95% CI:0.01, 0.26%) for O₃. For every 10 μg/m³ decrease in PM_2.5, 122 (95% CI: 6, 237) non-accidental deaths could be avoided. For every 10 μg/m³ decrease in O₃, 10 (95% CI: 1, 38) respiratory deaths could be avoided.

Conclusion

PM_2.5 and O₃ could significantly increase the risk of non-accidental and respiratory mortality in the middle-aged and elderly people in Lishui District of Nanjing. Exposed to air pollutants, men were more susceptible to O₃ damage, and women were more susceptible to PM_2.5 damage. Reduction of PM_2.5 and O₃ concentration in the air may have the potential to avoid considerable loss of lives.

Ambient air pollution and the risk of ischaemic and haemorrhagic stroke

Stroke is a leading cause of disability and the second most common cause of death worldwide. Increasing evidence suggests that air pollution is an emerging risk factor for stroke. Over the past decades, air pollution levels have continuously increased and are now estimated to be responsible for 14% of all stroke-associated deaths. Interpretation of previous literature is difficult because stroke was usually not distinguished as ischaemic or haemorrhagic, nor by cause. This Review summarises the evidence on the association between air pollution and the different causes of ischaemic stroke and haemorrhagic stroke, to clarify which people are most at risk. The risk for ischaemic stroke is increased after short-term or long-term exposure to air pollution. This effect is most pronounced in people with cardiovascular burden and stroke due to large artery disease or small vessel disease. Short-term exposure to air pollution increases the risk of intracerebral haemorrhage, a subtype of haemorrhagic stroke, whereas the effects of long-term exposure are less clear. Limitations of the current evidence are that studies are prone to misclassification of exposure, often rely on administrative data, and have insufficient clinical detail. In this Review, we provide an outlook on new research opportunities, such as those provided by the decreased levels of air pollution due to the current COVID-19 pandemic.

Adequate indoor air quality in nursing homes: An unmet medical need

A small but growing body of literature indicates that concentrations of indoor particulate and gaseous pollutants in long-term care facilities (i.e., skilled nursing facilities) for older adults, hereafter referred to nursing homes, often exceed those recorded in nearby, comparable outdoor environments. Unlike the outdoors, indoor air quality (IAQ) in nursing homes is not regulated by legislation and is seldom monitored. To that end, residents of nursing homes commonly spend the vast majority of their time indoors where they are exposed to indoor air pollutants for long periods of time. Given that many nursing home residents, especially those of advanced age, are more susceptible to the effects of air pollutants, even at low concentrations, this prolonged exposure may adversely affect their health, well-being, quality of life and increase medical expenditures due to frequent, unscheduled acute care visits and hospitalizations. We propose an action plan for assessing IAQ in nursing homes, understanding the impacts of IAQ on adverse health outcomes of nursing home residents, and addressing vulnerabilities in these facilities to safeguard health, well-being, and quality of life of nursing home residents and minimizing unscheduled acute care visits and hospitalizations. We propose that IAQ should be regularly monitored in nursing homes to proactively identify and address vulnerabilities in these facilities and that resources should be provided for remedial interventions to improve IAQ in nursing homes, including but not limited to source control, improving ventilation and filtration, and deploying air cleaners where appropriate. This proactive approach may pave the way for establishing enforceable standards for indoor air quality in nursing homes that will promote health, well-being, and quality of life of nursing home residents and reduce medical expenditures.

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.

Evaluation of the Sex-and-Age-Specific Effects of PM2.5 on Hospital Readmission in the Presence of the Competing Risk of Mortality in the Medicare Population of Utah 1999-2009

Acute ambient air pollution exposure increases risk of cardiac events. We evaluated sex-and-age-specific effects of PM_2.5 on hospital readmission and death among 19,602 Medicare beneficiaries (N_events = 30,510) who survived cardiovascular events including myocardial infarction (MI), heart failure (HF), ischemic heart disease (IHD), and cardiac arrhythmias in Utah from 1999–2009. Fine and Gray regression jointly modeled the effect of PM_2.5 on readmission hazard rates while allowing for the competing risk of death. Models were stratified by age and sex and adjusted for Charlson Comorbidity Index, dual enrollment in Medicare Parts A and B, temperature, and household income. There were 2032 cardiac readmissions and 1420 deaths after discharge. Among males age 65–74 years admitted for HF, a 10 μm/m³ increase in PM_2.5 was associated with a 30% increase in risk of readmission (p = 0.01). Among females age 75–84 admitted for HF, PM_2.5 was associated with a 22% increase in risk of readmission (p = 0.01). Among females age 75–84 years admitted for IHD, PM_2.5 was associated with a 25% decrease in readmission (p = 0.01), however this was explained by a 36% increase in risk of death (p = 0.01). Exposure to PM_2.5 was associated with increased risk of readmission and death. Associations were dependent upon age, sex, and index condition.

Does passive smoking at home lead to depression among older people in China?

BACKGROUND

This paper was carried out based on two motivations: (a) prior studies achieved mixed results regarding the effect of passive smoking on depression; and (b) studies on the impacts of passive smoking usually neglect effects on older people. In our paper, we studied the causal effect of passive smoking at home on depression among older people aged 60 years and older in China with a longitudinal study.

METHODS

In assessing the causal relationship, we developed a fixed-effects instrumental variable method using an exogenous variable-health consciousness and the smoking status of parents-as instruments of smoking status. We used data from the China Health and Retirement Longitudinal Study (CHARLS), which provides a national, high-quality, and longitudinal household survey of people aged 45 years and older.

RESULTS

Our empirical results reveal that passive smoking at home increased the depressive symptoms of older people, regardless of their smoking status. Moreover, the impact of passive smoking on depression is larger for nonsmokers than smokers. Additionally, the health consciousness and smoking status of parents are effective instrumental variables.

CONCLUSIONS

This paper calls for governments and medical institutions to pay more attention to the health of older people and their need for healthy living environments.

Cardiovascular and respiratory emergency dispatch due to short-term exposure to ambient PM10 in Dezful, Iran

Introduction: This study was conducted to determine the relation between exposure to particulate matter less than 10 microns (PM₁₀) caused by dust storms and the risk of cardiovascular, respiratory and traffic accident missions carried out by Emergency Medical Services (EMS).

Methods: This was a time-series study conducted in Dezful city, Iran. Daily information on the number of missions by the EMS due to cardiovascular, respiratory and crash problems and data on PM₁₀ were inquired from March 2013 until March 2016. A generalized linear model (GLM) with distributed lag models (DLMs) was used to evaluate the relation between the number of EMS missions and the average daily PM₁₀. The latent effects of PM₁₀ were estimated in single and cumulative lags, up to 14 days.

Results: In the adjusted model, for each IQR increase in the average daily PM₁₀ concentration, the risk of EMS missions in the total population in single lags of 2 to 7 days, and the cumulative lags of 0-7 and 0-14 days after exposure had a 0.8, 0.8, 0.8, 0.8, 0.7, 0.6, 6.7 and 1.4% significant increase. Also, for each IQR increase in the daily mean concentration of PM₁₀ in single 1 to 7, and cumulative lags of 0-2, 0-7, and 0-14 days after exposure, respectively, a 2.4, 2.7, 2.8, 2.9, 2.9, 2.7, 2.5, 7.4, 23.5 and 33. 3 % increase was observed in the risk of EMS cardiovascular missions.

Conclusion: Increase in daily PM₁₀ concentrations in Dezful is associated with an increase in the risk of EMS missions in lags up to two weeks after exposure.

Particulate Matter Exposure History Affects Antioxidant Defense Response of Mouse Lung to Haze Episodes

Few studies have focused on the association between previous particulate matter (PM) exposure and antioxidant defense response to a haze challenge. In this study, a combined exposure model was used to investigate whether and how PM exposure history affected the antioxidant defense response to haze episodes. At first, C57BL/6 male mice were randomly assigned to three groups and exposed for 5 weeks to whole ambient air, ambient air containing a low (≤75 μg/m³) PM concentration, and filtered air, which simulated different exposure history of high, relatively low, and almost zero PM concentrations. Thereafter, all mice underwent a 3-day haze exposure followed by a 7-day exposure to filtered air. The indexes involved in the primary and secondary antioxidant defense response were determined after pre-exposure and haze exposure, as well as 1 day, 3 days, and 7 days after haze exposure. Our research demonstrated repeated exposure to a high PM concentration compromised the antioxidant defense response and was accompanied by an increased susceptibility to a haze challenge. Conversely, mice with a lower PM exposure developed an oxidative stress adaption that protected them against haze challenge more efficiently and in a more timely manner than was the case in mice without PM exposure history.

The impact of indoor air quality on respiratory health of older people living in nursing homes: spirometric and exhaled breath condensate assessments

In the Portuguese Geriatric Study of the Health Effects of Indoor Air Quality in Senior Nursing Homes, we aimed to evaluate the impact of indoor air contaminants on the respiratory symptoms and biomarkers in a sample of elderly living in nursing homes. A total of 269 elderly answered a health questionnaire, performed a spirometry and 150 out of these collected an exhaled breath condensate sample for pH and nitrites analysis. The study included the evaluation of indoor chemical and microbiological contaminants. The median age of the participants was 84 (78-87) years and 70.6% were women. The spirometric data indicated the presence of airway obstruction in 14.5% of the sample. Median concentrations of air pollutants did not exceed the existing standards, although increased peak values were observed. In the multivariable analysis, each increment of 100 µg/m³ of total volatile organic compounds was associated with the odds of respiratory infection in the previous three months ( OR̂ =1.05; 95% CI: 1.00-1.09). PM_2.5 concentrations were inversely associated with pH values ( β̂ = -0.04, 95%: -0.06 to -0.01, for each increment of 10 µg/m³). Additionally, a direct and an inverse association were found between total bacteria and FEV₁/FVC and FVC, respectively.

Seasonal association between ambient ozone and hospital admission for respiratory diseases in Hanoi, Vietnam

BACKGROUND

Many studies have indicated the detrimental effect of ambient ozone to respiratory health in different countries. The levels of ozone in Hanoi, Vietnam are frequently above the WHO guideline but very few studies on the effects of ambient ozone on human health have been conducted in this location. This study aimed to examine the effects of ozone on hospital admission for respiratory diseases in Hanoi, by diseases, ages and seasons.

METHODS

Hospital admissions, air pollutants and meteorological data were collected from January 2010 to June 2014. We used generalized linear models and distributed lag linear model to assess the association. In addition to full year analysis, we conducted restricted analysis of the data for two summer (from June-August) and winter (from December-February) seasons and grouped hospital admissions by diseases and ages (all ages, children 0 to 5 years and elderly >65 years). The delayed effect of ozone was assessed using lags of up to 5 days.

RESULTS

Ozone has a stronger effect on the risk of hospital admission for respiratory diseases and wheeze-associated disorders in the winter. For respiratory diseases, children were affected by ozone more than other age groups in both winter and summer. Each increase of 10 μg/m3 of ozone is associated with an increase of 6.2% risk of admission for respiratory disease among children in the winter and 1.2% in the summer. For wheeze-associated disorders, the elderly group seemed to be more affected by ozone in full year and winter but no significant association was found between ozone and admission for wheeze-associated diseases in any age group.

CONCLUSIONS

Ozone is a risk factor for respiratory admission, especially amongst children under 5 years old in Hanoi, and ozone has a stronger effect in the winter than in the summer in this city.

Association of size-fractionated indoor particulate matter and black carbon with heart rate variability in healthy elderly women in Beijing

Associations between size-fractionated indoor particulate matter (PM) and black carbon (BC) and heart rate variability (HRV) and heart rate (HR) in elderly women remain unclear. Twenty-nine healthy elderly women were measured for 24-hour HRV/HR indices. Real-time size-fractionated indoor PM and BC were monitored on the same day and on the preceding day. Mixed-effects models were applied to investigate the associations between pollutants and HRV/HR indices. Increases in size-fractionated indoor PM were significantly associated with declines in power in the high-frequency band (HF), power in the low-frequency band (LF), and standard deviation of all NN intervals (SDNN). The largest decline in HF was 19% at 5-minute moving average for an interquartile range (IQR) increase (24 μg/m³ ) in PM_0.5 . The results showed that smaller particles could lead to greater reductions in HRV indices. The reported associations were modified by body mass index (BMI): Declines in HF at 5-minute average for an IQR increase in PM_0.5 were 34.5% and 1.0% for overweight (BMI ≥25 kg/m² ) and normal-weight (BMI <25 kg/m² ) participants, respectively. Moreover, negative associations between BC and HRV indices were found to be significant in overweight participants. Increases in size-fractionated indoor PM and BC were associated with compromised cardiac autonomic function in healthy elderly women, especially overweight ones.

The association between ambient inhalable particulate matter and the disease burden of respiratory disease: An ecological study based on ten-year time series data in Tianjin, China

There is limited evidence available worldwide about the quantitative relationship between particulate matter with an aerodynamic diameter of less than 10µm (PM₁₀) and years of life lost (YLL) caused by respiratory diseases (RD), especially regarding long-term time series data. We investigated the quantitative exposure-response association between PM₁₀ and the disease burden of RD. We obtained the daily concentration of ambient pollutants (PM₁₀, nitrogen dioxide and sulphur dioxide), temperature and relative humidity data, as well as the death monitoring data from 2001 to 2010 in Tianjin. Then, a time series database was built after the daily YLL of RD was calculated. We applied a generalized additive model (GAM) to estimate the burden of PM₁₀ on daily YLL of RD and to determine the effect (the increase of daily YLL) of every 10μg/m³ increase in PM₁₀ on health. We found that every 10μg/m³ increase in PM₁₀ was associated with the greatest increase in YLL of 0.84 (95% CI: 0.45, 1.23) years at a 2-day (current day and previous day, lag01) moving average PM₁₀ concentration for RD. The association between PM₁₀ and YLL was stronger in females and the elderly (≥65 years of age). The association between PM₁₀ and YLL of RD differed according to district. These findings also provide new epidemiological evidence for respiratory disease prevention.

The short term burden of ambient particulate matters on non-accidental mortality and years of life lost: A ten-year multi-district study in Tianjin, China

Years of life lost (YLL) is a more informative and accurate indicator than daily death counts for assessing air pollution related premature death. However, there is limited evidence available about the relationship of air pollution with YLL, especially in China. We conducted a ten-year (from January 1st, 2001 to December 31st, 2010) multi-district time-series study to estimate the effects of ambient particulate matter with an aerodynamic diameter of less than 10 μm in size (PM₁₀) on daily non-accidental deaths and YLL in six districts of Tianjin, China. Meta-analysis was used to merge the results of the six districts. We found that the increase of PM₁₀ was significantly associated with daily death and YLL in the six districts, except with the YLL in Heping district. 10 μg/m³ increases in PM₁₀ were associated with the maximum increases in excess risk (ER) of death counts of 0.33% (95% confidence interval [CI]: 0.25%, 0.41%) at lag01 and in YLL of 0.80 (95%CI: 0.47, 1.13) person year at lag01 for the combined effects of six districts, respectively. Moreover, the associations of PM₁₀ on daily death counts and YLL were stronger in the elder people (≥65 years) than those in the younger ones (<65 years). These findings may help to shed light on the policy-making of PM-control in China and provide useful information for the protection of susceptible population.

Comparison of Health Impact of Air Pollution Between China and Other Countries

Air pollution is the world's largest single environmental risk according to the World Health Organization (WHO), which caused around seven million deaths in 2012. Extensive epidemiological studies have been carried out worldwide to examine the health impacts of ambient air pollution, consistently demonstrating significant health impacts of ambient air pollution. Air pollution problem in China is especially serious; it has become the fourth biggest threat to the health of the Chinese people. In this review, we summarized existing literature, compared health impact of air pollution between China and other countries, and found substantial heterogeneity in the risk estimates of air pollution. The effect heterogeneities may be due to the differences in the characteristics of populations (e.g., the proportion of the elder population and people with preexisting diseases), exposure profile (e.g., air pollution concentrations and composition), and regional climate. Although the magnitude of relative risk estimates of air pollution is generally similar with that in other parts of the world, air pollution is one of China's most serious environmental health problems given the huge number of people exposed to high concentration levels of air pollution in China.

Association Between Short-Term Exposure to PM2.5 and PM10 and Mortality in Susceptible Subgroups: A Multisite Case-Crossover Analysis of Individual Effect Modifiers

We performed a multisite study to evaluate demographic and clinical conditions as potential modifiers of the particulate matter (PM)-mortality association. We selected 228,619 natural deaths of elderly persons (ages ≥65 years) that occurred in 12 Italian cities during the period 2006-2010. Individual data on causes of death, age, sex, location of death, and preexisting chronic and acute conditions from the previous 5 years' hospitalizations were collected. City-specific conditional logistic regression models were applied within the case-crossover "time-stratified" framework, followed by random-effects meta-analysis. Particulate matter less than or equal to 2.5 µm in aerodynamic diameter (PM2.5) and particulate matter less than or equal to 10 µm in aerodynamic diameter (PM10) were positively associated with natural mortality (1.05% and 0.74% increases in mortality risk for increments of 10 µg/m3 and 14.4 µg/m3, respectively), with greater effects being seen among older people, those dying out-of-hospital or during the warm season, and those affected by 2 or more chronic diseases. Limited associations were found among persons with no previous hospital admissions. Diabetes (1.98%, 95% confidence interval (CI): 0.54, 3.44) and cardiac arrhythmia (1.65%, 95% CI: 0.37, 2.95) increased risk of PM2.5-related mortality, while heart conduction disorders increased risk of mortality related to both PM2.5 (4.22%, 95% CI: 0.15, 8.46) and PM10 (4.19%, 95% CI: 0.38, 8.14). Among acute conditions, recent hospital discharge for heart failure modified the PM10-mortality association. The study found increases in natural mortality from PM exposure among people with chronic morbidity; diabetes and cardiac disorders were the main susceptibility factors.

Air quality of nursing homes and its effect on the lung health of elderly residents

In industrialized countries the elderly spend most of their time indoors. The elderly may be at a higher risk of suffering from indoor air pollution-related diseases compared to the rest of the population, because of their increased exposure to potential indoor risk factors. This editorial aims to critically analyze the recent literature regarding this important topic. Results of studies performed on the elderly living in nursing homes clearly highlight that they are at risk of respiratory health impairment, even at moderate air pollutant concentrations, particularly if they are over 80 years of age and living in poorly ventilated nursing homes. The future epidemiological research on ageing and respiratory diseases should investigate the underlying biological and physiological mechanisms, in addition to the adverse health effects of potential indoor risk factors, in order to help defining effective strategies for healthy ageing.

Air Pollution modifies the association between successful and pathological aging throughout the frailty condition

The rapid growth in the number of older adults has many implications for public health, including the need to better understand the risks posed by environmental exposures. Aging leads to a decline and deterioration of functional properties at the cellular, tissue and organ level. This loss of functional properties yields to a loss of homeostasis and decreased adaptability to internal and external stress. Frailty is a geriatric syndrome characterized by weakness, weight loss, and low activity that is associated with adverse health outcomes. Frailty manifests as an age-related, biological vulnerability to stressors and decreased physiological reserves. Ambient air pollution exposure affects human health, and elderly people appear to be particularly susceptible to its adverse effects. The aim of this paper is to discuss the role of air pollution in the modulation of several biological mechanisms involved in aging. Evidence is presented on how air pollution can modify the bidirectional association between successful and pathological aging throughout the frailty conditions.

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.

Temperature modifies the association between particulate air pollution and mortality: A multi-city study in South Korea

Substantial epidemiologic literature has demonstrated the effects of air pollution and temperature on mortality. However, there is inconsistent evidence regarding the temperature modification effect on acute mortality due to air pollution. Herein, we investigated the effects of temperature on the relationship between air pollution and mortality due to non-accidental, cardiovascular, and respiratory death in seven cities in South Korea. We applied stratified time-series models to the data sets in order to examine whether the effects of particulate matter <10 μm (PM10) on mortality were modified by temperature. The effect of PM10 on daily mortality was first quantified within different ranges of temperatures at each location using a time-series model, and then the estimates were pooled through a random-effects meta-analysis using the maximum likelihood method. From all the data sets, 828,787 non-accidental deaths were registered from 2000-2009. The highest overall risk between PM10 and non-accidental or cardiovascular mortality was observed on extremely hot days (daily mean temperature: >99th percentile) in individuals aged <65 years. In those aged ≥65 years, the highest overall risk between PM10 and non-accidental or cardiovascular mortality was observed on very hot days and not on extremely hot days (daily mean temperature: 95-99th percentile). There were strong harmful effects from PM10 on non-accidental mortality with the highest temperature range (>99th percentile) in men, with a very high temperature range (95-99th percentile) in women. Our findings showed that temperature can affect the relationship between the PM10 levels and cause-specific mortality. Moreover, the differences were apparent after considering the age and sex groups.

Long-term effects of traffic particles on lung function decline in the elderly

RATIONALE

Few studies have been performed on air pollution effects on lung function in the elderly, a vulnerable population with low reserve capacity, and even fewer have looked at changes in the rate of lung function decline.

OBJECTIVES

We evaluated the effect of long-term exposure to black carbon on levels and rates of decline in lung function in the elderly.

METHODS

FVC and FEV1 were measured one to six times during the period 1995-2011 in 858 men participating in the Normative Aging Study. Exposure to black carbon, a tracer of traffic emissions, was estimated by a spatiotemporal land use regression model. We investigated the effects of moving averages of black carbon of 1-5 years before the lung function measurement using linear mixed models.

MEASUREMENTS AND MAIN RESULTS

A 0.5 μg/m(3) increase in long-term exposure to black carbon was associated with an additional rate of decline in FVC and FEV1 of between 0.5% and 0.9% per year, respectively, depending on the averaging time. In addition, black carbon exposure before the baseline visit was associated with lower levels of both FVC and FEV1, with effect estimates increasing up to 6-7% with a 5-year average exposure.

CONCLUSIONS

Our results support adverse effects of long-term exposure to traffic particles on lung function level and rate of decline in the elderly and suggest that functionally significant differences in health and risk of disability occur below the annual Environmental Protection Agency National Air Quality Standards.

Epigenetic influences on associations between air pollutants and lung function in elderly men: the normative aging study

BACKGROUND

Few studies have been performed on pulmonary effects of air pollution in the elderly--a vulnerable population with low reserve capacity--and mechanisms and susceptibility factors for potential effects are unclear.

OBJECTIVES

We evaluated the lag structure of air pollutant associations with lung function and potential effect modification by DNA methylation (< or ≥ median) at 26 individual CpG sites in nine candidate genes in a well-characterized cohort of elderly men.

METHODS

We measured forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and blood DNA methylation one to four times between 1999 and 2009 in 776 men from the Normative Aging Study. Air pollution was measured at fixed monitors 4 hr to 28 days before lung function tests. We used linear mixed-effects models to estimate the main effects of air pollutants and effect modification by DNA methylation.

RESULTS

An interquartile range (IQR) increase in subchronic exposure (3 to 28 days cumulated), but not in acute exposure (during the previous 4 hr, or the current or previous day), to black carbon, total and nontraffic particles with aerodynamic diameter ≤ 2.5 μm (PM2.5), carbon monoxide, and nitrogen dioxide was associated with a 1-5% decrease in FVC and FEV1 (p < 0.05). Slope estimates were greater for FVC than FEV1, and increased with cumulative exposure. The estimates slopes for air pollutants (28 days cumulated) were higher in participants with low (< median) methylation in TLR2 at position 2 and position 5 and high (≥ median) methylation in GCR.

CONCLUSIONS

Subchronic exposure to traffic-related pollutants was associated with significantly reduced lung function in the elderly; nontraffic pollutants (particles, ozone) had weaker associations. Epigenetic mechanisms related to inflammation and immunity may influence these associations.

Modification of the association between ambient air pollution and lung function by frailty status among older adults in the Cardiovascular Health Study

The susceptibility of older adults to the health effects of air pollution is well-recognized. Advanced age may act as a partial surrogate for conditions associated with aging. The authors investigated whether gerontologic frailty (a clinical health status metric) modified the association between ambient level of ozone or particulate matter with an aerodynamic diameter less than 10 µm and lung function in 3,382 older adults using 7 years of follow-up data (1990-1997) from the Cardiovascular Health Study and its Environmental Factors Ancillary Study. Monthly average pollution and annual frailty assessments were related to up to 3 repeated measurements of lung function using cumulative summaries of pollution and frailty histories that accounted for duration as well as concentration. Frailty history was found to modify long-term associations of pollutants with forced vital capacity. For example, the decrease in forced vital capacity associated with a 70-ppb/month greater cumulative sum of monthly average ozone exposure was 12.3 mL (95% confidence interval: 10.4, 14.2) for a woman who had spent the prior 7 years prefrail or frail as compared with 4.7 mL (95% confidence interval: 3.8, 5.6) for a similar woman who was robust during all 7 years (interaction P < 0.001).

Meta-analysis of gene expression in the mouse liver reveals biomarkers associated with inflammation increased early during aging

Aging is associated with a loss of cellular homeostasis, a decline in physiological function and an increase in various pathologies. Employing a meta-analysis, hepatic gene expression profiles from four independent mouse aging studies were interrogated. There was little overlap in the number of genes or canonical pathways perturbed, suggesting that independent study-specific factors may play a significant role in determining age-dependent gene expression. However, 43 genes were consistently altered during aging in three or four of these studies, including those that (1) exhibited progressively increased expression starting from 12 months of age, (2) exhibited similar expression changes in models of progeria at young ages and dampened or no changes in old longevity mouse models, (3) were associated with inflammatory tertiary lymphoid neogenesis (TLN) associated with formation of ectopic lymphoid structures observed in chronically inflamed tissues, and (4) overlapped with genes perturbed by aging in brain, muscle, and lung. Surprisingly, around half of the genes altered by aging in wild-type mice exhibited similar expression changes in adult long-lived mice compared to wild-type controls, including those associated with intermediary metabolism and feminization of the male-dependent gene expression pattern. Genes unique to aging in wild-type mice included those linked to TLN.

Outdoor air pollution and incidence of ischemic and hemorrhagic stroke: a small-area level ecological study

BACKGROUND AND PURPOSE

Evidence linking outdoor air pollution and incidence of stroke is limited. We examined effects of outdoor air pollution on the incidence of ischemic and hemorrhagic stroke at the population level focusing on middle-aged and older people.

METHODS

We used a small-area level ecological study design and a stroke register set up to capture all incident cases of first-ever stroke occurring in a defined geographical area in south London (948 census output areas) where road traffic contributes to spatial variation in air pollution. Population-weighted averages were calculated for output areas using outdoor nitrogen dioxide and PM(10) concentrations modeled at a 20-m resolution.

RESULTS

There were 1832 ischemic and 348 hemorrhagic strokes in 1995 to 2004 occurring among a resident population of 267 839. Mean (SD) concentration was 25.1 (1.2) μg/m(3) (range, 23.3-36.4 μg/m(3)) for PM(10) and 41.4 (3.0) μg/m(3) (range, 35.4-68.0 μg/m(3)) for nitrogen dioxide. For ischemic stroke, adjusted rate ratios per 10-μg/m(3) increase, for all ages, 40 to 64 and 65 to 79 years, respectively, were 1.22 (0.77-1.93), 1.12 (0.55-2.28), and 1.86 (1.10-3.13) for PM(10) and 1.11 (0.93-1.32), 1.13 (0.86-1.50), and 1.23 (0.99-1.53) for nitrogen dioxide. For hemorrhagic stroke, the corresponding rate ratios were 0.52 (0.20-1.37), 0.78 (0.17-3.51), and 0.51 (0.12-2.22) for PM(10) and 0.86 (0.60-1.24), 1.12 (0.66-1.90), and 0.78 (0.44-1.39) for nitrogen dioxide.

CONCLUSIONS

Although there was no significant association between outdoor air pollutants and ischemic stroke incidence for all ages combined, there was a suggestion of increased risk among people aged 65 to 79 years. There was no evidence of increased incidence in hemorrhagic stroke.

Understanding the cumulative impacts of inequalities in environmental health: implications for policy

Racial or ethnic minority groups and low-income communities have poorer health outcomes than others. They are more frequently exposed to multiple environmental hazards and social stressors, including poverty, poor housing quality, and social inequality. Researchers are grappling with how best to characterize the cumulative effects of these hazards and stressors in order to help regulators and decision makers craft more-effective policies to address health and environmental disparities. In this article we synthesize the existing scientific evidence regarding the cumulative health implications of higher rates of exposure to environmental hazards, along with individual biological susceptibility and social vulnerability. We conclude that current environmental policy, which is focused narrowly on pollutants and their sources, should be broadened to take into account the cumulative impact of exposures and vulnerabilities encountered by people who live in neighborhoods consisting largely of racial or ethnic minorities or people of low socioeconomic status.

The need for better public health decisions on chemicals released into our environment

Protecting the health of the public-particularly the most vulnerable groups, such as children-requires rethinking current approaches to reducing environmental risks. We review the evolving understanding of the relationship between exposure to chemicals in the environment and disease, as well as the current state of managing those chemicals. We present recommendations to improve current approaches, including changing the burden of proof so that chemicals are not presumed safe in the absence of scientific data. We also propose modernizing approaches to assessing health risks.

The effects of childhood, adult, and community socioeconomic conditions on health and mortality among older adults in China

Using a large, nationally representative longitudinal sample of Chinese aged 65 and older, this study examines the effects of childhood, adult, and community socioeconomic conditions on mortality and several major health outcomes. The role of social mobility is also tested. We find that childhood socioeconomic conditions exert long-term effects on functional limitations, cognitive impairment, self-rated health, and mortality independent of adult and community socioeconomic conditions. Achieved conditions matter for most outcomes as well, considering that adult and community socioeconomic conditions have additional impacts on health among Chinese elders. The majority of the effects of childhood conditions are not mediated by adult and community conditions. The results also show that social mobility and health in later life are linked in complex ways and that psychosocial factors have marginal explanatory power for the effects of socioeconomic conditions. Overall, this study provides new longitudinal evidence from China to support the notion that health and mortality at older ages are influenced by long-term and dynamic processes structured by the social stratification system. We discuss our findings in the context of the life course and ecological perspective, emphasizing that human development is influenced by a nexus of social experiences that impact individuals throughout life.

Health inputs and cumulative health deficits among the older Chinese

Using a health economics framework, we examined how both individual level investments at different life stages and current community-level environmental factors affect individual health stock and flows at old ages. We used a nationwide dataset from the 2002 and 2005 waves of the Chinese Longitudinal Healthy Longevity Survey, which included more than 15,000 adults aged 65 and older from 22 provinces in mainland China. We measured health stock with a cumulative health deficit index, a measure developed in geriatrics and gerontology that reflects deficits, illnesses, and functional impairment in numerous domains of health. The cumulative health deficit index has not been used in health economics before, but is a significant contribution because it captures the health stock concept very well and overcomes the problems of inconsistency resulting from the use of different measures of health stock in research. Our results show that several proxy measures for individual health investments in both childhood (nutritional status and parental survival status) and adulthood (family financial condition and access to healthcare) yielded positive returns to health stock measured by the cumulative health deficit index. Investments in social connections and healthy behaviors (religious involvement, alcohol use, and exercise) also produced positive returns in health stock. Current community-level factors such as air quality and labor force participation rate were significantly associated with levels of health deficits in old age as well. Yet, most of these individual investment and community environment variables did not significantly affect short-term health flows (improvement or deterioration in health status over three years). Our findings have important implications for developing preventive health programs in the context of population aging by focusing on policy-relevant predictors and a comprehensive indicator of health status in later life.

Associations of environmental factors with elderly health and mortality in China

OBJECTIVES

We examined the effects of community socioeconomic conditions, air pollution, and the physical environment on elderly health and survival in China.

METHODS

We analyzed data from a nationally representative sample of 15 973 elderly residents of 866 counties and cities with multilevel logistic regression models in which individuals were nested within each county or city.

RESULTS

After control for individual-level factors, communities' gross domestic product per capita, adult labor force participation rate, and illiteracy rate were significantly associated with physical, mental, and overall health and mortality among the elderly in China. We also found that air pollution increased the odds of disability in activities of daily living (ADLs), cognitive impairment, and health deficits; more rainfall was protective, reducing the odds of ADL disability and cognitive impairment; low seasonal temperatures increased the odds of ADL disability and mortality; high seasonal temperatures increased the odds of cognitive impairment and deficits; and living in hilly areas decreased the odds of ADL disability and health deficits.

CONCLUSIONS

Efforts to reduce pollution and improve socioeconomic conditions could significantly improve elderly health and survival.

Database for physiologically based pharmacokinetic (PBPK) modeling: physiological data for healthy and health-impaired elderly

Physiologically based pharmacokinetic (PBPK) models have increasingly been employed in chemical health risk assessments. By incorporating individual variability conferred by genetic polymorphisms, health conditions, and physiological changes during development and aging, PBPK models are ideal for predicting chemical disposition in various subpopulations of interest. In order to improve the parameterization of PBPK models for healthy and health-impaired elderly (herein defined as those aged 65 yr and older), physiological parameter values were obtained from the peer-reviewed literature, evaluated, and entered into a Microsoft ACCESS database. Database records include values for key age-specific model inputs such as ventilation rates, organ volumes and blood flows, glomerular filtration rates, and other clearance-related processes. In total, 528 publications were screened for relevant data, resulting in the inclusion of 155 publications comprising 1051 data records for healthy elderly adults and 115 data records for elderly with conditions such as diabetes, chronic obstructive pulmonary disease (COPD), obesity, heart disease, and renal disease. There are no consistent trends across parameters or their associated variance with age; the gross variance in body weight decreased with advancing age, whereas there was no change in variance for brain weight. The database contains some information to inform ethnic and gender differences in parameters; however, the majority of the published data pertain to Asian (mostly Japanese) and Caucasian males. As expected, the number of records tends to decrease with advancing age. In addition to a general lack of data for parameters in the elderly with various health conditions, there is also a dearth of information on blood and tissue composition in all elderly groups. Importantly, there are relatively few records for alveolar ventilation rate; therefore, the relationship between this parameter and cardiac output (usually assumed to be 1:1) in the elderly is not well informed by the database. Despite these limitations, the database represents a potentially useful resource for parameterizing PBPK models for the elderly to facilitate the prediction of dose metrics in older populations for application in risk assessment.

Access to healthcare services makes a difference in healthy longevity among older Chinese adults

The positive impact of access to healthcare on health and survival among older adults is well-documented in Western societies. However, whether the pattern still holds in developing countries where healthcare coverage is more limited is largely unknown. China, a developing country with the largest population in the world, has been transforming its antiquated healthcare system during the past few decades in response to rapid population aging. Yet, in recent years the lack of access to healthcare has been identified as the top concern by most citizens in China. We used the Chinese Longitudinal Healthy Longevity Survey and the community-level data sources from the National Bureau of Statistics of China to examine the impact of current as well as childhood access to healthcare services on subsequent three-year survival and healthy survival at old ages from 2002 to 2005 under a multilevel context. Healthy survival was measured by a cumulative deficit index calculated from thirty-nine variables pertaining to various dimensions of health. Our analyses showed that access to healthcare at present and during childhood improved the odds of subsequent three-year survivorship by 13-19% and 10%, respectively, controlling for various confounders. But the effect of access to healthcare at present was no longer statistically significant once baseline health status in 2002 was controlled for. Access to healthcare at present increased odds of healthy survival by 22-68%, while access to healthcare in childhood increased odds of healthy survival by 18%. All patterns held true for both men and women, for urban and rural areas, across ages, as well as across socioeconomic statuses. Our findings suggested that positive inputs such as access to healthcare services over the life course make a substantial difference in healthy longevity, which has implications for the establishment of the universal healthcare system.

Age-related lung cell response to urban Buenos Aires air particle soluble fraction

Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance and host defense. Bioavailability of soluble PM compounds like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and transition metals has been shown to play a key role in lung injury. We have previously characterized the size, shape, and chemical components of urban air particles from Buenos Aires (UAP-BA) and their biological impact on lungs. Herein, we evaluate the possible toxic effect of UAP-BA-soluble fraction (UAP-BAsf) on pulmonary cells obtained from young (1-2 months old) and aged (9-12 months old) Wistar rats using phagocytosis, oxidant-antioxidant generation, and apoptosis as endpoints. UAP-BA were collected in downtown BA and residual oil fly ash (ROFA), employed as a positive control, was collected from Boston Edison Co., Mystic Power Plant, Mystic, CT, USA. Both particle-soluble fractions (sf) were employed at concentrations ranging from 0 to 100 microg/mL. UAP-BAsf and ROFAsf even at the lowest dose assayed (10 microg/mL) showed in both lung cell populations the ability to stimulate phagocytosis and increase superoxide anion (O(2)(-)) generation. Both types of air particles caused a marked intracellular oxidant stress in aged pulmonary cells that may contribute to subsequent cell activation and production of proinflammatory mediators, leading to cell dysfunction. These data suggest that the impact of UAP-BAsf on phagocytosis, oxidant radical generation, and apoptosis is clearly dependent on the maturational state of the animal and might have different mechanisms of action.

Outdoor air pollution and emergency department visits for asthma among children and adults: a case-crossover study in northern Alberta, Canada

BACKGROUND

Recent studies have observed positive associations between outdoor air pollution and emergency department (ED) visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children.

METHODS

A time stratified case-crossover design was used to examine 57,912 ED asthma visits among individuals two years of age and older in the census metropolitan area of Edmonton, Canada between April 1, 1992 and March 31, 2002. Daily air pollution levels for the entire region were estimated from three fixed-site monitoring stations. Similarly, daily levels of aeroallergens were estimated using rotational impaction sampling methods for the period between 1996 and 2002. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression with adjustment for temperature, relative humidity and seasonal epidemics of viral related respiratory disease.

RESULTS

Positive associations for asthma visits with outdoor air pollution levels were observed between April and September, but were absent during the remainder of the year. Effects were strongest among young children. Namely, an increase in the interquartile range of the 5-day average for NO2 and CO levels between April and September was associated with a 50% and 48% increase, respectively, in the number of ED visits among children 2 - 4 years of age (p < 0.05). Strong associations were also observed with these pollutants among those 75 years of age and older. Ozone and particulate matter were also associated with asthma visits. Air pollution risk estimates were largely unchanged after adjustment for aeroallergen levels.

CONCLUSION

Our findings, taken together, suggest that exposure to ambient levels of air pollution is an important determinant of ED visits for asthma, particularly among young children and the elderly.

Vulnerability to air pollution health effects

INTRODUCTION

Ambient air pollution can have adverse effects on the health of exposed populations, but individuals or groups are not equally vulnerable, and pollution reduction benefits are likely to be unevenly distributed within a population. While the use of total-population risks is a valid approach for public health protection, it is increasingly recognized that more attention on vulnerable groups is necessary. This paper describes population vulnerability to the health effects of air pollutants using risk analysis concepts and based on available evidence.

METHODS

Publications reporting air pollution health risks for specific sub-populations, or more conceptual discussions of vulnerability, were selected following a literature search of the PubMed database. Only studies in the context of developed countries were included. Information on population characteristics and factors that can influence risk was assessed from the perspective of the vulnerability framework, and was used to outline interactions with biological susceptibility, exposure, and social coping.

RESULTS

Population characteristics encompass several factors that interact and confer vulnerability. Age, for example, regarded as significant mostly in terms of physiology, also relates to exposure through behaviours and activities that can be more amenable to prevention. Children are recognized as a high-risk group but their vulnerability may differ by childhood stage, while pregnant women are not explicitly identified as a vulnerable group despite growing evidence for reproductive risks. Social-economic factors have received little attention, although they can affect coping capacity as well as interact with susceptibility and exposure to air pollution.

CONCLUSIONS

Evidence for vulnerability components often lies in different fields of study and has not been evaluated in an integrated manner. Better understanding of population vulnerability can improve the scientific basis to assess risks and develop policies or other health protection initiatives to reduce the impacts of air pollution.