Saharan dust and associations between particulate matter and daily mortality in Rome, Italy

Background: Outbreaks of Saharan-Sahel dust over Euro-Mediterranean areas frequently induce exceedances of the Europen Union''s 24-hr standard of 50 μg/m³ for particulate matter (PM) with aerodynamic diameter ≤ than 10 μm (PM₁₀).Objectives: We evaluated the effect of Saharan dust on the association between different PM fractions and daily mortality in Rome, Italy.Methods: In a study of 80,423 adult residents who died in Rome between 2001 and 2004, we performed a time-series analysis to explore the effects of PM_2.5, PM_2.5–10, and PM₁₀ on natural, cardiac, cerebrovascular, and respiratory mortality. We defined Saharan dust days by combining light detection and ranging (LIDAR) observations and analyses from operational models. We tested a Saharan dust–PM interaction term to evaluate the hypothesis that the effects of PM, especially coarse PM (PM_2.5–10), on mortality would be enhanced on dust days.Results: Interquartile range increases in PM_2.5–10 (10.8 μg/m³) and PM₁₀ (19.8 μg/m³) were associated with increased mortality due to natural, cardiac, cerebrovascular, and respiratory causes, with estimated effects ranging from 2.64% to 12.65% [95% confidence interval (CI), 1.18–25.42%] for the association between PM_2.5–10 and respiratory mortality (0- to 5-day lag). Associations of PM_2.5–10 with cardiac mortality were stronger on Saharan dust days (9.73%; 95% CI, 4.25–15.49%) than on dust-free days (0.86%; 95% CI, –2.47% to 4.31%; p = 0.005). Saharan dust days also modified associations between PM₁₀ and cardiac mortality (9.55% increase; 95% CI, 3.81–15.61%; vs. dust-free days: 2.09%; 95% CI, –0.76% to 5.02%; p = 0.02).Conclusions: We found evidence of effects of PM_2.5–10 and PM₁₀ on natural and cause-specific mortality, with stronger estimated effects on cardiac mortality during Saharan dust outbreaks. Toxicological and biological effects of particles from desert sources need to be further investigated and taken into account in air quality standards.     

Seasonal effects of PM10 concentrations on mortality in Tianjin, China: a time-series analysis

Aim

There are uncertainties regarding the modification effects of season and temperature on the relationship between air pollution and mortality. This study aims to examine the effects of season and temperature on mortality associated with particulate matter less than 10 μm in diameter (PM₁₀) in Tianjin, China.

Methods

Time-series analysis was used to explore the modification effects of season and temperature on the association between PM₁₀ and cause-specific mortality in Tianjin between 2006 and 2009. The causes studied were overall non-accidental mortality and subcategories of cardiovascular, respiratory, cardiopulmonary, stroke, and ischemic heart diseases (IHD).

Results

The association between PM₁₀ and mortality showed a strong seasonal pattern and the effects of PM₁₀ on cause-specific mortalities were strongest for high temperature days. Generally, the adverse effects were stronger in summer than for other seasons, except for respiratory mortality. In the summer period, a 10 μg/m³ increase in PM₁₀ at 0–1 days was associated with an increase in mortality for non-accidental (0.95 %, 95 % confidence interval [CI]: 0.45, 1.45), cardiovascular (1.40 %, 95 %CI: 0.77, 2.03), cardiopulmonary (1.37 %, 95 %CI: 0.77, 1.98), IHD (1.55 %, 95 %CI: 0.73, 2.37), and stroke (1.27 %, 95 % CI: 0.37, 2.12) causes. The overall increase in mortality per 10 μg/m³ increase in PM₁₀ was 0.42 % (95 %CI: 0.26, 0.58) for non-accidental, 0.41 % (95 %CI: 0.21, 0.62) for cardiovascular, 0.46 % (95 %CI: 0.26,0.65) for cardiopulmonary, 0.57 % (95 %CI: 0.30, 0.84) for IHD, and 0.32 % (95 %CI: 0.03,0.61) for stroke. At high temperatures (≥23.8 °C), a 10 μg/m³ increase in PM₁₀ at 0–1 days was associated with an increase in mortality of 0.90 % (95 %CI: 0.61,1.19) for non-accidental, 1.01 % for cardiovascular, 1.40 % (95 %CI: 0.55, 2.27) for respiratory, 1.06 % (95 %CI: 0.71, 1.41) for cardiopulmonary, 1.47 % (95 %CI: 1.00, 1.94) for IHD, and 0.75 % (95 %CI: 0.24, 1.28) for stroke. In addition, the PM₁₀ effects of high temperature days were stronger for those aged 65 years and over.

Conclusion

Season and temperature could modify the adverse effects of PM₁₀. An increase in hot summer days caused by climate change may enhance the risks of air pollution on human health. More attention should be paid to older populations, especially in summer and days with high temperatures.     

A time-stratified case-crossover study of fine particulate matter air pollution and mortality in Guangzhou, China

Objectives

Few studies in China investigate health impact of fine particulate matter (PM_2.5) due to lack of monitoring data and the findings are controversial. The aim of this study is to examine the short-association between PM_2.5 and daily mortality in Guangzhou, the economic center of south China.

Methods

In Guangzhou, we measured daily PM_2.5 concentrations between 2007 and 2008 and conducted a time-stratified case-crossover analysis to explore the association between PM_2.5 and daily mortality, and examine potential effect modifiers including age, sex, and education.

Results

The averaged PM_2.5 concentration in 2007–2008 was 70.1?μg/m³ in Guangzhou, which was approximately seven times higher than the WHO Air Quality Guidelines for PM_2.5 (annual average: 10?μg/m³). Regression analysis showed that ambient PM_2.5 was associated with mortality from all causes and cardiorespiratory diseases. An increase of 10?μg/m³ in 2-day moving average (lag01) concentration of PM_2.5 corresponds to 0.90% [95% confidence interval (CI): 0.55, 1.26%] increase of total mortality, 1.22% (95% CI: 0.63, 1.68%) increase of cardiovascular mortality, and 0.97% (95% CI: 0.16, 1.79%) increase of respiratory mortality. The associations were stronger in the elderly (aged 65?years or more), in females, and in those with low education level, but the differences were statistically insignificant. After adjustment for nitrogen dioxide (NO₂), however, the effects of PM_2.5 decreased and became statistically insignificant.

Conclusions

Our findings provided new information for the adverse health effects of PM_2.5 in China, and may have some implications for environmental policy making and standard setting in Guangzhou.     

Acute effects of air pollution on pediatric asthma exacerbation: evidence of association and effect modification

We investigated the short-term effects of particulate matter with aerodynamic diameter <10 μg/m³ (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and ozone (O₃) on pediatric asthma emergency admissions in Athens, Greece over the period 2001–2004. We explored effect modification patterns by season, sex, age and by the presence of desert dust transported mainly from the Sahara area.We used daily time-series data provided by the children's hospitals and the fixed monitoring stations. The associations were investigated using Poisson regression models controlling for seasonality, weather, influenza episodes, day of the week and holiday effects.A 10 μg/m³ increase in PM₁₀ was associated with a 2.54% increase (95% confidence interval (CI): 0.06%, 5.08%) in the number of pediatric asthma hospital admissions, while the same increase in SO₂ was associated with a 5.98% (95% CI: 0.88%, 11.33%) increase. O₃ was associated with a statistically significant increase in asthma admissions among older children in the summer. Our findings provide limited evidence of an association between NO₂ exposure and asthma exacerbation. Statistically significant PM₁₀ effects were higher during winter and during desert dust days, while SO₂ effects occurred mainly during spring.Our study confirms previously reported PM₁₀ effects on emergency hospital admissions for pediatric asthma and further provides evidence of stronger effects during desert dust days. We additionally report severe effects of SO₂, even at today's low concentration levels.     

The Effect of Fine and Coarse Particulate Air Pollution on Mortality: A National Analysis

Background

Although many studies have examined the effects of air pollution on mortality, data limitations have resulted in fewer studies of both particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM_2.5; fine particles) and of coarse particles (particles with an aerodynamic diameter > 2.5 and < 10 μm; PM coarse). We conducted a national, multicity time-series study of the acute effect of PM_2.5 and PM coarse on the increased risk of death for all causes, cardiovascular disease (CVD), myocardial infarction (MI), stroke, and respiratory mortality for the years 1999–2005.

Method

We applied a city- and season-specific Poisson regression in 112 U.S. cities to examine the association of mean (day of death and previous day) PM_2.5 and PM coarse with daily deaths. We combined the city-specific estimates using a random effects approach, in total, by season and by region.

Results

We found a 0.98% increase [95% confidence interval (CI), 0.75–1.22] in total mortality, a 0.85% increase (95% CI, 0.46–1.24) in CVD, a 1.18% increase (95% CI, 0.48–1.89) in MI, a 1.78% increase (95% CI, 0.96–2.62) in stroke, and a 1.68% increase (95% CI, 1.04–2.33) in respiratory deaths for a 10-μg/m³ increase in 2-day averaged PM_2.5. The effects were higher in spring. For PM coarse, we found significant but smaller increases for all causes analyzed.

Conclusions

We conclude that our analysis showed an increased risk of mortality for all and specific causes associated with PM_2.5, and the risks are higher than what was previously observed for PM₁₀. In addition, coarse particles are also associated with more deaths.     

Associations between Long-Term Air Pollutant Exposures and Blood Pressure in Elderly Residents of Taipei City: A Cross-Sectional Study

Background

Limited information is available regarding long-term effects of air pollution on blood pressure (BP) and hypertension.

Objective

We studied whether 1-year exposures to particulate matter (PM) and nitrogen oxides (NO_x) were correlated with BP and hypertension in the elderly.

Methods

We analyzed cross-sectional data from 27,752 Taipei City residents > 65 years of age who participated in a health examination program in 2009. Land-use regression models were used to estimate participants’ 1-year exposures to particulate matter with aerodynamic diameter ≤ 10 μm (PM₁₀), coarse particles (PM_2.5–10), fine particles (≤ 2.5 μm; PM_2.5), PM_2.5 absorbance, NO_x, and nitrogen dioxide (NO₂). Generalized linear regressions and logistic regressions were used to examine the association between air pollution and BP and hypertension, respectively.

Results

Diastolic BP was associated with 1-year exposures to air pollution, with estimates of 0.73 [95% confidence interval (CI): 0.44, 1.03], 0.46 (95% CI: 0.30, 0.63), 0.62 (95% CI: 0.24, 0.99), 0.34 (95% CI: 0.19, 0.50), and 0.65 (95% CI: 0.44, 0.85) mmHg for PM₁₀ (10 μg/m³), PM_2.5–10 (5 μg/m³), PM_2.5 absorbance (10^–5/m), NO_x (20 μg/m³), and NO₂ (10 μg/m³), respectively. PM_2.5 was not associated with diastolic BP, and none of the air pollutants was associated with systolic BP. Associations of diastolic BP with PM₁₀ and PM_2.5 absorbance were stronger among participants with hypertension, diabetes, or a body mass index ≥ 25 kg/m² than among participants without these conditions. One-year air pollution exposures were not associated with hypertension.

Conclusions

One-year exposures to PM₁₀, PM_2.5–10, PM_2.5 absorbance, and NO_x were associated with higher diastolic BP in elderly residents of Taipei.

Citation

Chen SY, Wu CF, Lee JH, Hoffmann B, Peters A, Brunekreef B, Chu DC, Chan CC. 2015. Associations between long-term air pollutant exposures and blood pressure in elderly residents of Taipei City: a cross-sectional study. Environ Health Perspect 123:779–784; http://dx.doi.org/10.1289/ehp.1408771     

Low-Concentration PM2.5 and Mortality: Estimating Acute and Chronic Effects in a Population-Based Study

Background

Both short- and long-term exposures to fine particulate matter (≤ 2.5 μm; PM_2.5) are associated with mortality. However, whether the associations exist at levels below the new U.S. Environmental Protection Agency (EPA) standards (12 μg/m³ of annual average PM_2.5, 35 μg/m³ daily) is unclear. In addition, it is not clear whether results from previous time series studies (fit in larger cities) and cohort studies (fit in convenience samples) are generalizable.

Objectives

We estimated the effects of low-concentration PM_2.5 on mortality.

Methods

High resolution (1 km × 1 km) daily PM_2.5 predictions, derived from satellite aerosol optical depth retrievals, were used. Poisson regressions were applied to a Medicare population (≥ 65 years of age) in New England to simultaneously estimate the acute and chronic effects of exposure to PM_2.5, with mutual adjustment for short- and long-term exposure, as well as for area-based confounders. Models were also restricted to annual concentrations < 10 μg/m³ or daily concentrations < 30 μg/m³.

Results

PM_2.5 was associated with increased mortality. In the study cohort, 2.14% (95% CI: 1.38, 2.89%) and 7.52% (95% CI: 1.95, 13.40%) increases were estimated for each 10-μg/m³ increase in short- (2 day) and long-term (1 year) exposure, respectively. The associations held for analyses restricted to low-concentration PM_2.5 exposure, and the corresponding estimates were 2.14% (95% CI: 1.34, 2.95%) and 9.28% (95% CI: 0.76, 18.52%). Penalized spline models of long-term exposure indicated a larger effect for mortality in association with exposures ≥ 6 μg/m³ versus those < 6 μg/m³. In contrast, the association between short-term exposure and mortality appeared to be linear across the entire exposure distribution.

Conclusions

Using a mutually adjusted model, we estimated significant acute and chronic effects of PM_2.5 exposure below the current U.S. EPA standards. These findings suggest that improving air quality with even lower PM_2.5 than currently allowed by U.S. EPA standards may benefit public health.

Citation

Shi L, Zanobetti A, Kloog I, Coull BA, Koutrakis P, Melly SJ, Schwartz JD. 2016. Low-concentration PM_2.5 and mortality: estimating acute and chronic effects in a population-based study. Environ Health Perspect 124:46–52; http://dx.doi.org/10.1289/ehp.1409111     

Estimated short-term effects of coarse particles on daily mortality in Stockholm, Sweden

Background: Although serious health effects associated with particulate matter (PM) with aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5; fine fraction) are documented in many studies, the effects of coarse PM (PM_2.5–10) are still under debate.Objective: In this study, we estimated the effects of short-term exposure of PM_2.5–10 on daily mortality in Stockholm, Sweden.Method: We collected data on daily mortality for the years 2000 through 2008. Concentrations of PM₁₀, PM_2.5, ozone, and carbon monoxide were measured simultaneously in central Stockholm. We used additive Poisson regression models to examine the association between daily mortality and PM_2.5–10 on the day of death and the day before. Effect estimates were adjusted for other pollutants (two-pollutant models) during different seasons.Results: We estimated a 1.68% increase [95% confidence interval (CI): 0.20%, 3.15%] in daily mortality per 10-μg/m³ increase in PM_2.5–10 (single-pollutant model). The association with PM_2.5–10 was stronger for November through May, when road dust is most important (1.69% increase; 95% CI: 0.21%, 3.17%), compared with the rest of the year (1.31% increase; 95% CI: –2.08%, 4.70%), although the difference was not statistically significant. When adjusted for other pollutants, particularly PM_2.5, the effect estimates per 10 μg/m³ for PM_2.5–10 decreased slightly but were still higher than corresponding effect estimates for PM_2.5.Conclusions: Our analysis shows an increase in daily mortality associated with elevated urban background levels of PM_2.5–10. Regulation of PM_2.5–10 should be considered, along with actions to specifically reduce PM_2.5–10 emissions, especially road dust suspension, in cities.     

Carotid Intima-Media Thickness and Long-Term Exposure to Traffic-Related Air Pollution in Middle-Aged Residents of Taiwan: A Cross-Sectional Study

Background

Associations between long-term exposure to air pollution and carotid intima-media thickness (CIMT) have inconsistent findings.

Objectives

In this study we aimed to evaluate association between 1-year average exposure to traffic-related air pollution and CIMT in middle-aged adults in Asia.

Methods

CIMT was measured in Taipei, Taiwan, between 2009 and 2011 in 689 volunteers 35–65 years of age who were recruited as the control subjects of an acute coronary heart disease cohort study. We applied land-use regression models developed by the European Study of Cohorts for Air Pollution Effects (ESCAPE) to estimate each subject’s 1-year average exposure to traffic-related air pollutants with particulate matter diameters ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) and the absorbance levels of PM_2.5 (PM_2.5abs), nitrogen dioxide (NO₂), and nitrogen oxides (NO_x) in the urban environment.

Results

One-year average air pollution exposures were 44.21 ± 4.19 μg/m³ for PM₁₀, 27.34 ± 5.12 μg/m³ for PM_2.5, and (1.97 ± 0.36) × 10^–5/m for PM_2.5abs. Multivariate regression analyses showed average percentage increases in maximum left CIMT of 4.23% (95% CI: 0.32, 8.13) per 1.0 × 10^–5/m increase in PM_2.5abs; 3.72% (95% CI: 0.32, 7.11) per 10-μg/m³ increase in PM₁₀; 2.81% (95% CI: 0.32, 5.31) per 20-μg/m³ increase in NO₂; and 0.74% (95% CI: 0.08, 1.41) per 10-μg/m³ increase in NO_x. The associations were not evident for right CIMT, and PM_2.5 mass concentration was not associated with the outcomes.

Conclusions

Long-term exposures to traffic-related air pollution of PM_2.5abs, PM₁₀, NO₂, and NO_x were positively associated with subclinical atherosclerosis in middle-aged adults.

Citation

Su TC, Hwang JJ, Shen YC, Chan CC. 2015. Carotid intima–media thickness and long-term exposure to traffic-related air pollution in middle-aged residents of Taiwan: a cross-sectional study. Environ Health Perspect 123:773–778; http://dx.doi.org/10.1289/ehp.1408553     

Estimation of lean body weight in older women with hip fracture

Objective

Lean body weight (LBW) decreases with age while total body fat increases, resulting in altered drug pharmacokinetics. A semi-mechanistic equation estimating LBW using height, weight and sex has been developed for potential use across a wide range of body compositions. The aim of this study was to determine the ability of the LBW equation to estimate dual energy x-ray absorptiometry-derived fat free mass (FFM_DXA) in a population of older women with recent hip fracture.

Methods

Baseline, four and 12 month data obtained from 23 women enrolled in the Sarcopenia and Hip Fracture study were pooled to give 58 measurements. LBW was estimated using the equation: $LBW(kg) = \frac{{9270 \times Wt}} {{8780 + (244 \times BMI)}} $ Body composition was classified as: ??normal?? (BMI <25kg/m² and not sarcopenic), ??overweight-obese?? (BMI >25kg/m² and not sarcopenic), ??sarcopenic?? (sarcopenic and BMI <25kg/m²), or ??sarcopenic-obese?? (sarcopenic and BMI >25kg/m²). The ability of the LBW equation to predict FFM_DXA was determined graphically using Bland-Altman plots and quantitatively using the method of Sheiner and Beal.

Results

The mean ± SD age of female participants women was 83±7 years (n=23). Sarcopenia was frequently observed (65.2%). Bland-Altman plots demonstrated an underestimation by the LBW equation compared to FFM_DXA. The bias (95% CI) and precision (95% CI) calculated using the method of Sheiner and Beal was 0.5kg (?0.7, 1.66kg) and 4.4kg (?3.7, 12.4kg) respectively for pooled data.

Conclusion

This equation can be used to easily calculate LBW. When compared to FFM_DXA, the LBW equation resulted in a small underestimation on average in this population of women with recent hip fracture. The degree of bias may not be clinically important although further studies of larger heterogeneous cohorts are needed to investigate and potentially improve the accuracy of this predictive equation in larger clinical cohorts.     

Short-term effects of particulate matter exposure on daily mortality in Thailand: a case-crossover study

Several studies have shown seasonal variations between particulate matter (PM) exposure and daily mortality. However, few studies have focused on age differences on the risk of mortality from PM₁₀, in addition to seasonal effects. Therefore, we attempted to estimate the association between PM₁₀ and daily mortality in Thailand, while accounting for seasonal variations and age differences. A time-stratified case-crossover design was used in this study. Environmental, meteorological, and mortality data of 12 provinces in Thailand between 2011 and 2014 were analyzed to estimate the association between PM₁₀ and daily mortality attributed to non-accidental, cardiovascular, respiratory causes and age differences. The conditional logistic regression was employed to determine whether the risk of mortality differed by seasons and age groups. We found an association between cumulative exposure to PM₁₀ and increased risk of mortality attributed to non-accidental causes, cardiovascular diseases, and respiratory diseases. During the study period, cold months (November to February) [1.75% (95% CI 1.20, 2.31)] had a stronger effect of increased 10 μg/m³ in PM₁₀ with 1 ppb in O₃ on non-accidental mortality than hot (March to June) [0.67% (95% CI 0.15, 1.20)] and wet (July to October) [??1.00% (95% CI ??1.99, ??0.01)] months. However, increasing of age did not modify any associations between PM₁₀ and mortality. An association between PM₁₀ exposure and daily mortality was observed. Age difference was not significantly associated with the risk of mortality.     

Exposure to particulate matter and adverse birth outcomes: a comprehensive review and meta-analysis

Increasing number of studies have investigated the impact of maternal exposure to air pollution during pregnancy and adverse birth outcomes, particularly low birth weight (LBW, <2,500?g at birth) and preterm birth (PTB, <37 completed weeks of gestation). We performed a comprehensive review of the peer-reviewed literature and a meta-analysis to quantify the association between maternal exposure to particulate matter with aerodynamic diameter 2.5 and 10???m (PM_2.5 and PM₁₀) during pregnancy and the risk of LBW and PTB. We identified 20 peer-reviewed articles providing quantitative estimate of exposure and outcome that met our selection criteria. There was significant heterogeneity between studies, particularly for findings related to PM₁₀ exposure (LBW, I-squared 54%, p?=?0.01; PTB, I-squared?=?73%, p?<?0.01). Results from random-effect meta-analysis suggested a 9% increase in risk of LBW associated with a 10-??g/m³ increase in PM_2.5 (combined odds ratios (OR), 1.09; 95% confidence interval (CI), 0.90?C1.32), but our 95% CI included the null value. We estimated a 15% increase in risk of PTB for each 10-??g/m³ increase in PM_2.5 (combined OR, 1.15; CI, 1.14?C1.16). The magnitude of risk associated with PM₁₀ exposure was smaller (2% per 10-??g/m³ increase) and similar in size for both LBW and PTB, neither reaching formal statistical significance. We observed no significant publication bias, with p?>?0.05 based on both Begg's and Egger's bias tests. Our results suggest that maternal exposure to PM, particularly PM_2.5 may have adverse effect on birth outcomes. Additional mechanistic studies are needed to understand the underlying mechanisms for this association.     

Seasonal effect of PM10 concentrations on mortality and morbidity in Seoul, Korea: A temperature-matched case-crossover analysis

Background

Explorations of interactions between air pollution and seasonal changes have represented one approach in examining the consequences of global warming. However, only a few studies have focused on evaluating the effects of seasonal air pollution using data on both morbidity and mortality in Asia.

Method

We examined the associations between PM₁₀ concentrations and mortality and hospital admissions in Seoul, Korea for the periods 2000-2006 and 2001-2006. We employed a temperature-matched case-crossover design, where reference periods matched case days in regard to temperature (same rounded to degrees celsius (°C)), month, and year.

Results

A total of 238,826 deaths were identified, along with 98,570 and 93,553 inpatient admissions for cardiovascular and respiratory diseases, respectively. We found that the association with PM₁₀ and mortality/morbidity increased during the summer. During the study period, 10μg/m³ increase in PM₁₀ was associated with the increase in mortality by 0.28% (95% confidence interval: 0.12, 0.44), 0.51% (0.19, 0.83), and 0.59% (-0.08, 1.26) for non-accidental, cardiovascular, and respiratory causes. 10μg/m³ increase in PM₁₀ was also associated with increase in hospitalization from cardiovascular and respiratory causes by 0.77% (0.53, 1.01) and 1.19% (0.94, 1.44). In the summer, the increase in mortality and hospitalization was 0.57% (0.20, 0.93), 0.64% (-0.10, 1.38), 0.50% (-1.02, 2.05), 1.52% (0.89, 2.16), and 1.55% (0.87, 2.22).

Conclusions

This study provides evidence that the effect of PM₁₀ on mortality and morbidity varies with season and increases during the summer season.     

Does Air Pollution Trigger Infant Mortality in Western Europe? A Case-Crossover Study

Background: Numerous studies show associations between fine particulate air pollutants [particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀)] and mortality in adults.Objectives: We investigated short-term effects of elevated PM₁₀ levels on infant mortality in Flanders, Belgium, and studied whether the European Union (EU) limit value protects infants from the air pollution trigger.Methods: In a case-crossover analysis, we estimated the risk of dying from nontraumatic causes before 1 year of age in relation to outdoor PM₁₀ concentrations on the day of death. We matched control days on temperature to exclude confounding by variations in daily temperature.Results: During the study period (1998–2006), PM₁₀ concentration averaged 31.9 ± 13.8 μg/m³. In the entire study population (n = 2,382), the risk of death increased by 4% [95% confidence interval (CI), 0–8%; p = 0.045] for a 10-μg/m³ increase in daily mean PM₁₀. However, this association was significant only for late neonates (2–4 weeks of age; n = 372), in whom the risk of death increased by 11% (95% CI, 1–22%; p = 0.028) per 10-μg/m³ increase in PM₁₀. In this age class, infants were 1.74 (95% CI, 1.18–2.58; p = 0.006) times more likely to die on days with a mean PM₁₀ above the EU limit value of 50 μg/m³ than on days below this cutoff.Conclusions: Even in an affluent region in Western Europe, where infant mortality is low, days with higher PM air pollution are associated with an increased risk of infant mortality. Assuming causality, the current EU limit value for PM₁₀, which may be exceeded on 35 days/year, does not prevent PM₁₀ from triggering mortality in late neonates.     

Ambient air pollution the risk of stillbirth: A prospective birth cohort study in Wuhan,China

Background

Recent studies suggest that ambient air pollution exposure during pregnancy is associated with stillbirth occurrence. However, the results on the associations between ambient air pollutants and stillbirths are inconsistent and little is known about the gestational timing of sensitive periods for the effects of ambient air pollutants exposure on stillbirth.

Short-term Associations between Fine and Coarse Particulate Matter and Hospitalizations in Southern Europe: Results from the MED-PARTICLES Project

Background: Evidence on the short-term effects of fine and coarse particles on morbidity in Europe is scarce and inconsistent.Objectives: We aimed to estimate the association between daily concentrations of fine and coarse particles with hospitalizations for cardiovascular and respiratory conditions in eight Southern European cities, within the MED-PARTICLES project.Methods: City-specific Poisson models were fitted to estimate associations of daily concentrations of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5), ≤ 10 μm (PM₁₀), and their difference (PM_2.5–10) with daily counts of emergency hospitalizations for cardiovascular and respiratory diseases. We derived pooled estimates from random-effects meta-analysis and evaluated the robustness of results to co-pollutant exposure adjustment and model specification. Pooled concentration–response curves were estimated using a meta-smoothing approach.Results: We found significant associations between all PM fractions and cardiovascular admissions. Increases of 10 μg/m³ in PM_2.5, 6.3 μg/m³ in PM_2.5–10, and 14.4 μg/m³ in PM₁₀ (lag 0–1 days) were associated with increases in cardiovascular admissions of 0.51% (95% CI: 0.12, 0.90%), 0.46% (95% CI: 0.10, 0.82%), and 0.53% (95% CI: 0.06, 1.00%), respectively. Stronger associations were estimated for respiratory hospitalizations, ranging from 1.15% (95% CI: 0.21, 2.11%) for PM₁₀ to 1.36% (95% CI: 0.23, 2.49) for PM_2.5 (lag 0–5 days).Conclusions: PM_2.5 and PM_2.5–10 were positively associated with cardiovascular and respiratory admissions in eight Mediterranean cities. Information on the short-term effects of different PM fractions on morbidity in Southern Europe will be useful to inform European policies on air quality standards.Citation: Stafoggia M, Samoli E, Alessandrini E, Cadum E, Ostro B, Berti G, Faustini A, Jacquemin B, Linares C, Pascal M, Randi G, Ranzi A, Stivanello E, Forastiere F, the MED-PARTICLES Study Group. 2013. Short-term associations between fine and coarse particulate matter and hospitalizations in Southern Europe: results from the MED-PARTICLES project. Environ Health Perspect 121:1026–1033; http://dx.doi.org/10.1289/ehp.1206151     

Acute Effects of Outdoor Air Pollution on Emergency Department Visits Due to Five Clinical Subtypes of Coronary Heart Diseases in Shanghai,China

Background

Air pollution can be a contributing cause to the development and exacerbation of coronary heart disease (CHD), but there is little knowledge about the acute effects of air pollution on different clinical subtypes of CHD.

Methods

We conducted a time-series study to investigate the association of air pollution (particulate matter with an aerodynamic diameter < 10 µm [PM₁₀], sulfur dioxide [SO₂], and nitrogen dioxide [NO₂]) on emergency department (ED) visits due to five different subtypes of CHD in Shanghai, China, from 2010 to 2012. We applied an over-dispersed Poisson generalized addictive model to analyze the associations after controlling for the seasonality, day of the week, and weather conditions.

Results

We identified a total of 47 523 ED visits for CHD. A 10-µg/m³ increase in the present-day concentrations of PM₁₀, SO₂, and NO₂ was associated with respective increases of 1.10% (95% confidence interval [CI] 0.33%–1.87%), 0.90% (95% CI −0.14%–1.93%), and 1.44% (95% CI 0.63%–2.26%) for total ED visits for CHD. These associations varied greatly by clinical type, with strong effects on sudden cardiac death, moderate effects on acute myocardial infarction and angina, weak effects on ischemic cardiomyopathy, and no effect on occult CHD. The associations were stronger among people aged 65 years or more than in younger individuals and in the cool season versus the warm one.

Conclusions

Outdoor air pollution may have different effects of air pollution on 5 subtypes of CHD. Our results might be useful for the primary prevention of various subtypes of CHD exacerbated by air pollution.Key words: air pollution, coronary heart disease, clinical subtypes, emergency department visits     

PM10 Exposure and Non-accidental Mortality in Asian Populations: A Meta-analysis of Time-series and Case-crossover Studies

Objectives

We investigated the association between particulate matter less than 10 µm in aerodynamic diameter (PM₁₀) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis.

Methods

Among the 819 published studies searched from PubMed and EMBASE using key words related to PM₁₀ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per 10 µg/m³ increase of daily PM₁₀ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test.

Results

Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per 10 µg/m³ increase of daily PM₁₀ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias.

Conclusions

We found a significant positive association between PM₁₀ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.     

Differential Effects of Source-Specific Particulate Matter on Emergency Hospitalizations for Ischemic Heart Disease in Hong Kong

Background: Ischemic heart disease (IHD) is a major public health concern. Although many epidemiologic studies have reported evidence of adverse effects of particulate matter (PM) mass on IHD, significant knowledge gaps remain regarding the potential impacts of different PM sources. Much the same as PM size, PM sources may influence toxicological characteristics.Objectives: We identified contributing sources to PM₁₀ mass and estimated the acute effects of PM₁₀ sources on daily emergency IHD hospitalizations in Hong Kong.Methods: We analyzed the concentration data of 19 PM₁₀ chemical components measured between 2001 and 2007 by positive matrix factorization to apportion PM₁₀ mass, and used generalized additive models to estimate associations of interquartile range (IQR) increases in PM₁₀ exposures with IHD hospitalization for different lag periods (up to 5 days), adjusted for potential confounders.Results: We identified 8 PM₁₀ sources: vehicle exhaust, soil/road dust, regional combustion, residual oil, fresh sea salt, aged sea salt, secondary nitrate, and secondary sulfate. Vehicle exhaust, secondary nitrate, and secondary sulfate contributed more than half of the PM₁₀ mass. Although associations with IQR increases in 2-day moving averages (lag₀₁) were statistically significant for most sources based on single-source models, only PM₁₀ from vehicle exhaust [1.87% (95% CI: 0.66, 3.10); IQR = 4.9 μg/m³], secondary nitrate [2.28% (95% CI: 1.15, 3.42); IQR = 8.6 μg/m³], and aged sea salt [1.19% (95% CI: 0.04, 2.36); IQR = 5.9 μg/m³] were significantly associated with IHD hospitalizations in the multisource model. Analysis using chemical components provided similar findings.Conclusion: Emergency IHD hospitalization was significantly linked with PM₁₀ from vehicle exhaust, nitrate-rich secondary PM, and sea salt–related PM. Findings may help prioritize toxicological research and guide future monitoring and emission-control polices.Citation: Pun VC, Yu IT, Ho KF, Qiu H, Sun Z, Tian L. 2014. Differential effects of source-specific particulate matter on emergency hospitalizations for ischemic heart disease in Hong Kong. Environ Health Perspect 122:391–396; http://dx.doi.org/10.1289/ehp.1307213     

Ambient Air Pollution and Daily Outpatient Visits for Cardiac Arrhythmia in Shanghai,China

Background

Cardiac arrhythmias are cardiac rhythm disorders that comprise an important public health problem. Few prior studies have examined the association between ambient air pollution and arrhythmias in general populations in mainland China.

Methods

We performed a time-series analysis to investigate the short-term association between air pollution (particulate matter with an aerodynamic diameter less than 10 µm [PM₁₀], sulfur dioxide [SO₂], and nitrogen dioxide [NO₂]) and outpatient visits for arrhythmia in Shanghai, China. We applied the over-dispersed Poisson generalized additive model to analyze the associations after control for seasonality, day of the week, and weather conditions. We then stratified the analyses by age, gender, and season.

Results

We identified a total of 56 940 outpatient visits for cardiac arrhythmia. A 10-µg/m³ increase in the present-day concentrations of PM₁₀, SO₂, and NO₂ corresponded to increases of 0.56% (95% CI 0.42%, 0.70%), 2.07% (95% CI 1.49%, 2.64%), and 2.90% (95% CI 2.53%, 3.27%), respectively, in outpatient arrhythmia visits. The associations were stronger in older people (aged ≥65 years) and in females. This study provides the first evidence that ambient air pollution is significantly associated with increased risk of cardiac arrhythmia in mainland China.

Conclusions

Our analyses provide evidence that the current air pollution levels have an adverse effect on cardiovascular health and strengthened the rationale for further limiting air pollution levels in the city.Key words: air pollution, outpatient visits, cardiac arrhythmias, time-series