Beyond particulate matter: New evidence on the causal effects of air pollution on mortality.

The increasing demand for electricity worldwide has caused a corresponding rise in the consumption of coal, leading to an increase in sulfur dioxide (SO2) pollution levels. Despite the severity of the issue, there is a lack of conclusive evidence establishing a causal link between SO2 pollution and health, particularly in developing countries. We leverage a large national environmental regulation policy, implemented in China to reduce SO2 emissions, to estimate the impacts of SO2 pollution on mortality. We find that 1-µg/m3 reduction in SO2 concentrations leads to 18 fewer cardiovascular deaths per 100,000 people aged 60 years and above (0.9% decrease) and 2 fewer deaths per 100,000 children under the age of 5 (1.5% decrease) annually. A back-of-the-envelope calculation suggests that the total health benefits of the environmental policy outweigh its economic costs. The results are consistent across various robustness checks.

Command vs. market in China's energy intensity reduction strategies: Firm-level evidence.

China has significantly reduced the energy consumption for per unit of GDP by using both command-and-controls or market-based strategies. This paper examines empirically the relative effectiveness and efficiency of command-and-control strategy (energy reduction target) vs. market-based strategy (electricity price). We find that (1) electricity price was similarly effective in reducing electricity intensity across firms, but government targets were more effective for firms that were more technologically outdated and energy intensive; and (2) government targets led to expenditures that were not useful in reducing energy intensity, suggesting inefficiency associated with targets. Despite the Chinese governments' capacities and resources in directing and influencing enterprises, market-based approaches might still be more effective and efficient than command-and-control ones to reduce energy intensity.

How Vulnerable Are U.S. Crop Workers?: Evidence from Representative Worker Data and Implications for COVID-19.

Objectives This paper examines health profiles and work environments of hired U.S. farmworkers to understand the risk to essential workers and their employers, to the food supply, and to rural health systems such as what is possible with the COVID-19 pandemic. Methods Large-sample statistical methods and proprietary data from the National Agricultural Workers Survey from 2000 to 2018 were used to assess factors associated with exposure to COVID-19 and vulnerabilities associated with medical complications. Results An aging workforce and increased access to health care within the crop worker population has been associated with a higher reported incidence of diabetes, asthma, and heart disease among workers over time. These trends confirm a vulnerable, but essential, workforce with higher risks for COVID-19 complications than would have been true of U.S. farmworkers as a group in earlier years. Conclusions Increasing age and disease burden in the U.S. agricultural labor force puts workers at increased risk for developing COVID-19 complications. Limits to field sanitation and housing quality inflate the probability of the development of COVID-19 hotbeds in rural communities that could further compromise the physical health of workers, the economic health of farm establishments, the agricultural supply-chain, and rural health capacities. Additional and more targeted worker protections may minimize public health and economic costs in the long run.

The impact of PM2.5 on mortality in older adults: evidence from retirement of coal-fired power plants in the United States.

BACKGROUND: Evidence of causal relationship between mortality of older adults and low- concentration PM2.5 remains limited. OBJECTIVES: This study investigates the effects of low-concentration PM2.5 on the mortality of adults older than 65 using the closure of coal-fired power plants in the Eastern United States as a natural experiment. METHODS: We investigated power plants in the Eastern United States (US) that had production changes through unit shutdown or plant retirement between 1999 and 2013. We included only non-clustered power plants without scrubbers and with capacities greater than 50 MW. We used instrumental variable (IV) and difference-in-differences (DID) approaches to estimate the causal impact of PM2.5 concentrations on mortality among Medicare beneficiaries. We compared changes in monthly age-adjusted mortality before and after the retirement of coal-fired plants between the treated and control counties; we accounted for annual wind direction in our selection of treated and control counties. In the models, we initially included only county and monthly fixed effects, and then adjusted for covariates including: 1) only weather variables (temperature, dew point, pressure); and 2) weather variables and socio-economic variables (median household income and poverty rate). RESULTS: The monthly age-adjusted mortality rate averaged across all plants was approximately 423 per 100,000 (SD = 69) and was higher for males than females. Mean PM2.5 concentrations across all counties were 12 µg/m3 (SD = 3.78). Using the IV method, we found that reductions in PM2.5 concentrations significantly decreased monthly mortality among older adults. IV results show that a 1-µg/m3 reduction in PM2.5 concentrations leads to 7.17 fewer deaths per 100,000 per month, or a 1.7% lower monthly mortality rate among people older than 65 years. Using the DID approach, we found that power plant retirement significantly decreased: 1) monthly PM2.5 levels by 2.1 µg/m3, and 2) monthly age-adjusted mortality by approximately 15 people per 100,000 (or 3.6%) in treated counties relative to control counties. The mortality effects were higher among males than females and its impact was the greatest among people older than 75 years. CONCLUSION: These findings provide evidence of the effectiveness of local, plant-level control measures in reducing near-plant PM2.5 and mortality among U.S. Medicare beneficiaries.

The winter choke: Coal-Fired heating, air pollution, and mortality in China.

China's coal-fired winter heating systems generate large amounts of hazardous emissions that significantly deteriorate air quality. Exploiting regression discontinuity designs based on the exact starting dates of winter heating across different cities, we estimate the contemporaneous impact of winter heating on air pollution and health. We find that turning on the winter heating system increased the weekly Air Quality Index by 36% and caused 14% increase in mortality rate. This implies that a 10-point increase in the weekly Air Quality Index causes a 2.2% increase in overall mortality. People in poor and rural areas are particularly affected by the rapid deterioration in air quality; this implies that the health impact of air pollution may be mitigated by improved socio-economic conditions. Exploratory cost-benefit analysis suggests that replacing coal with natural gas for heating can improve social welfare.

Do minimum wage laws affect those who are not covered? Evidence from agricultural and non-agricultural workers.

Some employers are not obligated to pay at least minimum wages to all employees. U.S. farm employers comprise one of these groups. Employees of large farms and H-2A workers (lawfully admitted, nonimmigrant workers performing temporary or seasonal agricultural work) are protected by minimum wage legislation, while some migrant workers (often those paid piece rates) are exempt. U.S. agriculture also is characterized by a large percentage of unauthorized workers who may or may not earn above minimum wage. Following insights from dual labor market theory and from theories of the signaling capacity of the minimum wage, we compare labor market outcomes in the agricultural sector (where minimum wage coverage is limited) to low wage/skill non-agricultural sectors (where minimum wage coverage is more complete) nationally using data from the Current Population Survey. We then extend our analysis to a detailed state-level case study of agricultural workers in California using a representative survey of employed farm workers. Results suggest wage increases for covered workers that exceed those for uncovered workers, but insignificant differences in hours worked. This is the first study to our knowledge to examine the impacts of minimum wage coverage on agricultural workers relative to other workers for the U.S.

New evidence on the impact of sustained exposure to air pollution on life expectancy from China's Huai River Policy.

This paper finds that a 10-µg/m3 increase in airborne particulate matter [particulate matter smaller than 10 µm (PM10)] reduces life expectancy by 0.64 years (95% confidence interval = 0.21-1.07). This estimate is derived from quasiexperimental variation in PM10 generated by China's Huai River Policy, which provides free or heavily subsidized coal for indoor heating during the winter to cities north of the Huai River but not to those to the south. The findings are derived from a regression discontinuity design based on distance from the Huai River, and they are robust to using parametric and nonparametric estimation methods, different kernel types and bandwidth sizes, and adjustment for a rich set of demographic and behavioral covariates. Furthermore, the shorter lifespans are almost entirely caused by elevated rates of cardiorespiratory mortality, suggesting that PM10 is the causal factor. The estimates imply that bringing all of China into compliance with its Class I standards for PM10 would save 3.7 billion life-years.

Particulate air pollution and mortality in 38 of China's largest cities: time series analysis.

Objectives To estimate the short term effect of particulate air pollution (particle diameter <10 µm, or PM10) on mortality and explore the heterogeneity of particulate air pollution effects in major cities in China.Design Generalised linear models with different lag structures using time series data.Setting 38 of the largest cities in 27 provinces of China (combined population >200 million).Participants 350 638 deaths (200 912 in males, 149 726 in females) recorded in 38 city districts by the Disease Surveillance Point System of the Chinese Center for Disease Control and Prevention from 1 January 2010 to 29 June 2013.Main outcome measure Daily numbers of deaths from all causes, cardiorespiratory diseases, and non-cardiorespiratory diseases and among different demographic groups were used to estimate the associations between particulate air pollution and mortality.Results A 10 µg/m3 change in concurrent day PM10 concentrations was associated with a 0.44% (95% confidence interval 0.30% to 0.58%) increase in daily number of deaths. Previous day and two day lagged PM10 levels decreased in magnitude by one third and two thirds but remained statistically significantly associated with increased mortality. The estimate for the effect of PM10 on deaths from cardiorespiratory diseases was 0.62% (0.43% to 0.81%) per 10 µg/m3 compared with 0.26% (0.09% to 0.42%) for other cause mortality. Exposure to PM10 had a greater impact on females than on males. Adults aged 60 and over were more vulnerable to particulate air pollution at high levels than those aged less than 60. The PM10 effect varied across different cities and marginally decreased in cities with higher PM10 concentrations.Conclusion Particulate air pollution has a greater impact on deaths from cardiorespiratory diseases than it does on other cause mortality. People aged 60 or more have a higher risk of death from particulate air pollution than people aged less than 60. The estimates of the effect varied across cities and covered a wide range of domain.

Long-Term Effects of Famine on Chronic Diseases: Evidence from China's Great Leap Forward Famine.

We evaluate the long-term effects of famine on chronic diseases using China's Great Leap Forward Famine as a natural experiment. Using a unique health survey, we explore the heterogeneity of famine intensity across regions and find strong evidence supporting both the adverse effect and the selection effect. The two offsetting effects co-exist and their magnitudes vary in different age cohorts at the onset of famine. The selection effect is dominant among the prenatal/infant famine-exposed cohort, while the adverse effect appears dominant among the childhood/puberty famine-exposed cohort. The net famine effects are more salient in rural residents and non-migrants subsamples. Gender differences are also found, and are sensitive to smoking and drinking behaviors. Our conclusion is robust to various specifications. Copyright © 2016 John Wiley & Sons, Ltd.

The Effects of Weight Perception on Adolescents' Weight-Loss Intentions and Behaviors: Evidence from the Youth Risk Behavior Surveillance Survey.

The objective of this study was to examine the correlation between self-perception of being overweight and weight loss intentions, eating and exercise behaviors, as well as extreme weight-loss strategies for U.S. adolescents. This study uses 50,241 observations from the Youth Risk Behavior Surveillance Survey (YRBSS) 2001-2009, which were nationally representative sample of 9th- through 12th-grade students in both public and private schools in the US. This study finds that, irrespective of the weight status base on self-reported weight and height, adolescents who perceive themselves as overweight have a stronger intention to lose weight, but do not develop better eating and exercise habits, compared with their counterparts of same gender and reported weight status. Normal-weight adolescents, if they perceive themselves as overweight, are more likely to engage in health-compromising weight-loss methods. This study shows that it is critical to transform weight-loss intentions into actual behaviors among overweight/obese adolescents and improve the efficacy of behavioral interventions against childhood obesity. It also highlights the need of establishing a correct perception of body weight among normal weight adolescents to curb extreme weight-loss methods.

The associations between ambient air pollution and adult respiratory mortality in 32 major Chinese cities, 2006-2010.

BACKGROUND: China has experienced increasingly severe levels of air pollution in the past decades, yet studies on the health effects of air pollution in China at a national study level, remain limited. This study assess the sub-chronic effect of ambient air pollution on respiratory mortality in the 32 largest Chinese cities. METHODS: We employ two-way fixed effects panel data analysis and monthly air pollution and mortality panel data. We estimate associations between monthly respiratory mortality and air pollution; pollution is defined as particulate matter with aerodynamic diameter <10µm. We adjust for city characteristics, seasonality (monthly effects), and weather conditions (precipitation and temperature). We examine the associations between monthly injury mortality and air pollution to check for robustness. RESULTS: The results show positive and statistically significant associations of air pollution with respiratory mortality. During the study period (2006-2010) a 10µg/m(3) increase in monthly PM10 concentration is associated with a 1.05% (95% CI, 0.08-2.04%) increase in adult respiratory mortality rate. The air pollution effect is the most salient in northern cities (with central heating system) during the cold season (October-April); a 10µg/m(3) increase in monthly PM10 concentrations is associated with a 1.62% (95% CI, 0.22-3.46%) increase in the elderly respiratory mortality rate. There is no statistically significant association between the young adult respiratory mortality and air pollution. CONCLUSIONS: The elderly respiratory mortality rate in China is positively and statistically significantly associated with air pollution. The effect is largest in northern cities during cold months when coal is burned for heating.

Smog episodes, fine particulate pollution and mortality in China.

BACKGROUND: Starting from early January 2013, northern China was hit by multiple prolonged and severe smog events which were characterized by extremely high-level concentrations of ambient fine particulate matter (PM2.5) with hourly peaks of PM2.5 over 800 µg/m(3). However, the consequences of this severe air pollution are largely unknown. This study investigates the acute effect of the smog episodes and PM2.5 on mortality for both urban and rural areas in northern China. DATA AND METHODS: We collected PM2.5, mortality, and meteorological data for 5 urban city districts and 2 rural counties in Beijing, Tianjin and Hebei Province of China from January 1, 2013 through December 31, 2013. We employed the generalized additive models to estimate the associations between smog episodes or PM2.5 and daily mortality for each district/county. RESULTS: Without any meteorological control, the smog episodes are positively and statistically significantly associated with mortality in 5 out of 7 districts/counties. However, the findings are sensitive to the meteorological factors. After controlling for temperature, humidity, dew point and wind, the statistical significance disappears in all urban districts. In contrast, the smog episodes are consistently and statistically significantly associated with higher total mortality and mortality from cardiovascular/respiratory diseases in the two rural counties. In Ji County, a smog episode is associated with 6.94% (95% Confidence Interval, -0.20 to 14.58) increase in overall mortality, and in Ci County it is associated with a 19.26% (95% CI, 6.66-33.34) increase in overall mortality. The smog episodes kill people primarily through its impact on cardiovascular and respiratory diseases. On average, a smog episode is associated with 11.66% (95% CI, 3.12-20.90) increase in cardiovascular and respiratory mortality in Ji County, and it is associated with a 22.23% (95% CI, 8.11-38.20) increase in cardiovascular and respiratory mortality in Ci County. A 10 µg/m(3) increase in PM2.5 concentration is associated with 0.88% (95% CI, 0.3-1.46) increase in overall mortality and 1.2% (95% CI, 0.55-1.85) in Ji County. A 10 µg/m(3) increase in PM2.5 concentration is associated with 0.55% (95% CI, -0.02 to 1.13) increase in overall mortality in Ci County. The findings suggest that the smog episodes and fine particulate have bigger and more detrimental impacts on rural residents, especially for those living close to big and polluted cities. CONCLUSIONS: The smog episodes and PM2.5 are statistically associated with mortality in rural areas of China. The associations for urban areas are not statistically significant.

Overweight Misperception among Adolescents in the United States.

The purpose of this study was to examine the discrepancies between perceived and reported overweight status among U.S. adolescents (n>70,000), and to identify factors contributing to such discrepancies. We used the YRBSS data (years 2001-2009) and found statistically significant, gender and race specific discrepancies between perceived and reported overweight status. Factors such as BMI, school performance, and being sexually active are additional predictors of overweight misperception. The findings suggest that evidence based strategies should be employed to help adolescents establish correct weight perception. These strategies should also be tailored based on gender, race, and weight perception of target audience.

Health care reform: understanding individuals' attitudes and information sources.

Since passage of the Affordable Care Act (ACA) was signed into law by President Barrack Obama, little is known about state-level perceptions of residents on the ACA. Perceptions about the act could potentially affect implementation of the law to the fullest extent. This 3-year survey study explored attitudes about the ACA, the types of information sources that individuals rely on when creating those attitudes, and the predictors of these attitudes among state of Indiana residents. The respondents were split between favorable and unfavorable views of the ACA, yet the majority of respondents strongly supported individual components of the act. National TV news, websites, family members, and individuals' own reading of the ACA legislation were identified as the most influential information sources. After controlling for potential confounders, the respondent's political affiliation, age, sex, and obtaining ACA information from watching national television news were the most important predictors of attitudes about the ACA and its components. These results mirror national-level findings. Implications for implementing health care reform at the state-level are discussed.