Associations between size-fractionated particulate air pollution and blood pressure in a panel of type II diabetes mellitus patients

Impacts of household PM2.5 pollution on blood pressure of rural residents: Implication for clean energy transition

High blood pressure associated with PM_2.5 exposure is of great concern, especially for rural residents exposed to high PM_2.5 levels. However, the impact of short-term exposure to high PM_2.5 on blood pressure (BP) has not been well elucidated. Thus, this study aims to focus on the association between short-term PM_2.5 exposure with BP of rural residents and its variation between summer and winter. Our results showed that the summertime PM_2.5 exposure concentration was 49.3 ± 20.6 μg/m³, among which, mosquito coil users had 1.5-folds higher PM_2.5 exposure than non-mosquito coil users (63.6 ± 21.7 vs 43.0 ± 16.7 μg/m³, p < 0.05). The mean systolic and diastolic BP (SBP and DBP, respectively) of rural participants were 122 ± 18.2 and 76.2 ± 11.2 mmHg in summer, respectively. The PM_2.5 exposure, SBP, and DBP in summer were 70.7 μg/m³, 9.0 mmHg, and 2.8 mmHg lower than that in winter, respectively. Furthermore, the correlation between PM_2.5 exposure and SBP was stronger in winter than that in summer, possibly due to higher PM_2.5 exposure levels in winter. The transition of household energy from solid fuels in winter to clean fuels in summer would be benefit to the decline of PM_2.5 exposure as well as BP. Results from this study suggested that the reduction of PM_2.5 exposure would have positive effect on human health.

Short-term Air Pollution Levels and Blood Pressure in Older Women

BACKGROUND

Evidence of associations between daily variation in air pollution and blood pressure (BP) is varied and few prior longitudinal studies adjusted for calendar time.

METHODS

We studied 143,658 postmenopausal women 50 to 79 years of age from the Women's Health Initiative (1993-2005). We estimated daily atmospheric particulate matter (PM) (in three size fractions: PM2.5, PM2.5-10, and PM10) and nitrogen dioxide (NO2) concentrations at participants' residential addresses using validated lognormal kriging models. We used linear mixed-effects models to estimate the association between air pollution concentrations and repeated measures of systolic and diastolic BP (SBP, DBP) adjusting for confounders and calendar time.

RESULTS

Short-term PM2.5 and NO2 were each positively associated with DBP {0.10 mmHg [95% confidence interval (CI): 0.04, 0.15]; 0.13 mmHg (95% CI: 0.09, 0.18), respectively} for interquartile range changes in lag 3-5 day PM2.5 and NO2. Short-term NO2 was negatively associated with SBP [-0.21 mmHg (95%CI: -0.30, -0.13)]. In two-pollutant models, the NO2-DBP association was slightly stronger, but for PM2.5 was attenuated to null, compared with single-pollutant models. Associations between short-term NO2 and DBP were more pronounced among those with higher body mass index, lower neighborhood socioeconomic position, and diabetes. When long-term (annual) and lag 3-5 day PM2.5 were in the same model, associations with long-term PM2.5 were stronger than for lag 3-5 day.

CONCLUSIONS

We observed that short-term PM2.5 and NO2 levels were associated with increased DBP, although two-pollutant model results suggest NO2 was more likely responsible for observed associations. Long-term PM2.5 effects were larger than short-term.

Association of Short-Term Exposure to PM2.5 with Blood Lipids and the Modification Effects of Insulin Resistance: A Panel Study in Wuhan

Results of previous studies about the acute effects of fine particulate matter (PM2.5) on blood lipids were inconsistent. This study aimed to quantify the short-term effects of PM2.5 on blood lipids and estimate the modifying role of insulin resistance, reflected by the homeostasis model assessment of insulin resistance (HOMA-IR). From September 2019 to January 2020, the study recruited 70 healthy adults from Wuhan University for a total of eight repeated data collections. At each visit, three consecutive days were monitored for personal exposure to PM2.5, and then a physical examination was carried out on the fourth day. The linear mixed-effect models were operated to investigate the impact of PM2.5 over diverse exposure windows on blood lipids. With the median of the HOMA-IR 1.820 as the cut-off point, participants were assigned to two groups for the interaction analyses. We found the overall mean level (standard deviation, SD) of PM2.5 was 38.34 (18.33) μg/m3. Additionally, with a 10 μg/m3 rise in PM2.5, the corresponding largest responses in triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), as well as high-density lipoprotein cholesterol (HDL-C), were −0.91% (95% confidence interval (CI): −1.63%, −0.18%), −0.33% (95% CI: −0.64%, −0.01%,), −0.94% (95% CI: −1.53%, −0.35%), and 0.67% (95% CI: 0.32%, 1.02%), respectively. The interaction analyses revealed that a significantly greater reduction in the four lipids corresponded to PM2.5 exposure when in the group with the lower HOMA-IR (<1.820). In conclusion, short-term PM2.5 exposure over specific time windows among healthy adults was associated with reduced TG, TC, as well as LDL-C levels, and elevated HDL-C. Additionally, the association of PM2.5−lipids may be modulated by insulin resistance.

Short-Term Associations between Size-Fractioned Particles and Cardiopulmonary Function in COPD Patients: A Panel Study in Shanghai, China, during 2014-2021

It remains unknown which size fractions dominate the adverse cardiopulmonary effects of particulate matter (PM). Therefore, this study aimed to explore the differential associations between size-fractioned particle number concentrations (PNCs) and cardiopulmonary function measures, including the forced expiratory volume in one second (FEV₁), the forced vital capacity (FVC), and the left ventricular ejection fraction (LVEF). We conducted a panel study among 211 patients with chronic obstructive pulmonary disease (COPD) in Shanghai, China, between January 2014 and December 2021. We applied linear mixed-effect models to determine the associations between cardiopulmonary function measures and PNCs ranging from 0.01 to 10 μm in diameter. Generally, only particles <1 μm showed significant associations, i.e., ultrafine particles (UFPs, <0.1 μm) for FVC and particles ranging from 0.1 to 1 µm for FEV₁ and LVEF. An interquartile range (IQR) increment in UFP was associated with decreases of 78.4 mL in FVC. PNC_0.1-0.3 and PNC_0.3-1 corresponded to the strongest effects on FEV₁ (119.5 mL) and LVEF (1.5%) per IQR increment. Particles <1 µm might dominate the cardiopulmonary toxicity of PM, but UFPs might not always have the strongest effect. Tailored regulations towards particles <1 µm should be intensified to reduce PM pollution and protect vulnerable populations.

Short-Term Effects of Particle Size and Constituents on Blood Pressure in Healthy Young Adults in Guangzhou, China

Background Although several studies have focused on the associations between particle size and constituents and blood pressure, results have been inconsistent. Methods and Results We conducted a panel study, between December 2017 and January 2018, in 88 healthy university students in Guangzhou, China. Weekly systolic blood pressure and diastolic blood pressure were measured for each participant for 5 consecutive weeks, resulting in a total of 440 visits. Mass concentrations of particles with an aerodynamic diameter of ≤2.5 µm (PM2.5), ≤1.0 µm (PM1.0), ≤0.5 µm (PM0.5), ≤0.2 µm (PM0.2), and number concentrations of airborne particulates of diameter ≤0.1 μm were measured. Linear mixed-effect models were used to estimate the associations between blood pressure and particles and PM2.5 constituents 0 to 48 hours before blood pressure measurement. PM of all the fractions in the 0.2- to 2.5-μm range were positively associated with systolic blood pressure in the first 24 hours, with the percent changes of effect estimates ranging from 3.5% to 8.8% for an interquartile range increment of PM. PM0.2 was also positively associated with diastolic blood pressure, with an increase of 5.9% (95% CI, 1.0%-11.0%) for an interquartile range increment (5.8 μg/m3) at lag 0 to 24 hours. For PM2.5 constituents, we found positive associations between chloride and diastolic blood pressure (1.7% [95% CI, 0.1%-3.3%]), and negative associations between vanadium and diastolic blood pressure (-1.6% [95% CI, -3.0% to -0.1%]). Conclusions Both particle size and constituent exposure are significantly associated with blood pressure in the first 24 hours following exposure in healthy Chinese adults.

Effects of domestic solid fuel combustion emissions on the biomarkers of homemakers in rural areas of the Fenwei Plain, China

BACKGROUND

The health effects of heavy solid fuel use in winter in rural China are of concern. The effects of air pollution resulting from domestic solid fuel combustion in rural households on rural homemakers' biomarkers were revealed in this study.

METHODS

In total, 75 female homemakers from rural areas of Guanzhong Basin, the Fenwei Plain, People's Republic of China, were randomly selected and divided into three groups (biomass users, coal users, and nonusers of solid fuel user [control group]). The differences in biological indicators, including 8-hydrox-2'-deoxyguanosine (8-OHdG), interlukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in urine samples as well as blood pressure (BP, including systolic BP [SBP] and diastolic BP [DBP]) and heart rate (HR) among the groups in winter and summer were investigated using statistical analysis.

RESULTS

IL-6, 8-OHdG, HR, SBP, and DBP were significantly higher in winter than in summer (P < 0.05) owing to the poor air quality resulted from the excessive use of solid fuels in winter. Significant seasonal differences in 8-OHdG were observed for both coal and biomass users. After the influence of confounders was removed, only IL-6 levels in the urine of solid fuel users were significantly higher than that of the control group.

CONCLUSIONS

IL-6 is a sensitive biomarker representing inflammatory responses to particulate matter emitted through household solid fuel combustion. Locally, excessive use of solid fuels in winter posed serious PM_2.5 pollution in this area and adverse effects on inflammatory biomarkers in these rural homemakers and induced DNA damage related to oxidative stress.

The association between short-term exposure to extremely high level of ambient fine particulate matter and blood pressure: a panel study in Beijing, China

High blood pressure (BP) is known as the main determinant of high cerebrovascular disease levels in China. Many studies discovered the associations between short-term exposure to PM_2.5 and BP, while most of those focused on low or medium PM_2.5 concentration. The aim of this study was to reveal the association between extremely high level ambient PM_2.5 exposure and BP. We conducted a repeated-measures panel study in Beijing, China, during December 1, 2016 to December 28, 2016. BP was monitored daily for all 133 participants. Daily concentration of PM_2.5 was obtained from local monitoring sites. A linear mixed-effect model combined with the distributed lag non-linear model was used to evaluate the associations between PM_2.5 and daily variations in BP. This study showed short-term exposure to PM_2.5 that was significantly associated with increased DBP (on lags of 0-8 days, Beta = 0.12, 95% confidence interval 0.04, 0.20). The single day effect of PM_2.5 on DBP had a 2-day lag, and the cumulative effect lags 5 days. The effects of PM_2.5 on SBP and DBP on hypertensive adults were significant. The cumulative effect of PM_2.5 on SBP and DBP had 2 rapidly increasing periods in hypertensive adults: lags of 0-2 days and lags of 0-7 days to lags of 0-11 days. Our study revealed that short-term exposure in the extreme high level of ambient PM_2.5 may increase BP among adults. Hypertensive adults may more sensitive than normotensive adults. The periodic high concentration of ambient PM_2.5 might magnify the effect of PM_2.5 on BP increase.

Geographic variations in the blood pressure responses to short-term fine particulate matter exposure in China

Results from recent studies on associations between blood pressure (BP) and short-term exposure to fine particulate matter (PM_2.5) have been inconsistent. Most studies have been evaluations of small geographic areas, with no national study in China. This study aimed to examine the acute BP responses to ambient PM_2.5 among the general population of Chinese adults. During 2012-2015, systolic and diastolic BP levels were obtained from a large national representative sample, the China Hypertension Survey database (n = 479,842). Daily PM_2.5 average exposures with a spatial resolution of 0.1° were estimated using a data assimilation that combines satellite measurements, air model simulations, and monitoring values. Overall, a 10-μg/m³ increase in daily PM_2.5 was associated with a 0.035 (95% confidence interval: 0.020, 0.049) mmHg change in systolic BP and 0.001 (-0.008, 0.011) mmHg in diastolic BP after adjustments. Stratified by geographic regions, the systolic and diastolic BP levels varied from -0.050 (-0.109, 0.010) to 0.242 (0.176, 0.307) mmHg, and from -0.026 (-0.053, 0.001) to 0.051 (0.020, 0.082) mmHg, respectively. Statistically significant positive BP-PM_2.5 associations were only found in South and North China for systolic levels and in Southwest China for diastolic levels. We further explored the regional study population characteristics and exposure-response curves, and found that the geographic variations in BP-PM_2.5 associations were probably due to different population compositions or different PM_2.5 exposure levels. Our study provided national-level evidence on the associations between ambient PM_2.5 exposure and elevated BP levels. The magnitude of the estimated associations varied substantially by geographic location in China. CLINICAL TRIAL REGISTRATION: The Clinical trial registration name was Survey on prevalence of hypertension in China; the registration number was ChiCTR-ECS-14004641. http://www.chictr.org.cn/showproj.aspx?proj=4932.

Short-term effects of real-time personal PM2.5 exposure on ambulatory blood pressure: A panel study in young adults

BACKGROUND

Short-term exposure to PM_2.5 has been shown to be associated with changes in blood pressure. However, most of the evidence is based on PM_2.5 measurements from fixed stations and resting blood pressure measured at a regular time.

OBJECTIVES

To evaluate the short-term daily and hourly effects of real-time personal PM_2.5 exposure on ambulatory blood pressure, and to compare the effects with those of PM_2.5 exposure from fixed stations.

METHODS

Between April 2017 and December 2017, 37 young adults were recruited in a panel study from a central urban area and a suburban area, to measure personal hourly PM_2.5 and ambulatory systolic blood pressure (SBP) as well as diastolic blood pressure (DBP) for three consecutive days. Hourly PM_2.5 concentrations were also obtained from the nearest monitoring station operated by Guangdong Environmental Monitoring Center. Generalized additive mixed model was employed to evaluate the effects of PM_2.5 on ambulatory blood pressure.

RESULTS

During the study period, the mean concentration of personal PM_2.5 exposure was 60.30 ± 52.14 μg/m³, while the value of PM_2.5 from fixed stations was 36.77 ± 21.52 μg/m³. Both personal PM_2.5 exposure and exposure from fixed stations averaged over the previous 1 to 3 days decreased blood pressure. During daytime, a 10 μg/m³ increase in 1-day moving average of personal PM_2.5 was associated with a 0.54 mmHg (95% CI: -1.03, -0.05) and 0.22 mmHg (95% CI: -0.59, 0.15) decrease in SBP and DBP, respectively. When using PM_2.5 exposures from fixed stations, the decrease in SBP and DBP were 0.95 mmHg (95% CI: -1.82, -0.07) and 0.74 mmHg (95% CI: -1.46, -0.03). Stratified analysis showed stronger effects in the central urban area and among males.

CONCLUSIONS

Both personal PM_2.5 exposure and exposure from fixed stations averaged over the previous 1 to 3 days decreased blood pressure. Stronger effects were found in a central urban area and among males.

Ambient Airborne Particulates of Diameter ≤1 μm, a Leading Contributor to the Association Between Ambient Airborne Particulates of Diameter ≤2.5 μm and Children's Blood Pressure

Evidence on the associations between airborne particulates of diameter ≤1 μm (PM₁) and airborne particulates of diameter ≤2.5 μm (PM_2.5) and childhood blood pressure (BP) is scarce. To help to address this literature gap, we conducted a study to explore the associations in Chinese children. Between 2012 and 2013, we recruited 9354 children, aged 5 to 17 years, from 62 schools in 7 northeastern Chinese cities. We measured their BP with a mercury sphygmomanometer. We used a spatiotemporal model to estimate daily ambient PM₁ and PM_2.5 exposures, which we assigned to participants' home addresses. Associations between particulate matter exposure and BP were evaluated with generalized linear mixed regression models. The findings indicated that exposure to each 10 mg/m³ greater PM₁ was significantly associated with 2.56 mm Hg (95% CI, 1.47-3.65) higher systolic BP and 61% greater odds for hypertension (odds ratio=1.61 [95% CI, 1.18-2.18]). PM₁ appears to play an important role in associations reported between PM_2.5 exposure and BP, and we found that the ambient PM₁/PM_2.5 ratio (range, 0.80-0.96) was associated with BP and with hypertension. Age and body weight modified associations between air pollutants and BP (P<0.01), with stronger associations among younger (aged ≤11 years) and overweight/obese children. This study provides the first evidence that long-term exposure to PM₁ is associated with hypertension in children, and that PM₁ might be a leading contributor to the hypertensive effect of PM_2.5. Researchers and policy makers should pay closer attention to the potential health impacts of PM₁.

Acute Effects of High-Level PM2.5 Exposure on Central Blood Pressure

Central aortic blood pressure (BP) has been increasingly recognized as having a closer relationship with cardiovascular risks than peripheral BP. However, the effects of particulate matter pollution on central aortic BP have not been clearly demonstrated. In this study, we assessed the association between short-term ambient fine particulate matter (with an aerodynamic diameter ≤2.5 μm; PM_2.5) exposure and central aortic BP in a Chinese community-based population. A total of 4715 visits were in our final analysis, including 2151 visits at the baseline and 2564 visits at the follow-up. Central aortic systolic BP (cSBP) was measured noninvasively using the method of radial artery tonometry with Omron HEM-9000AI machine. Data from air pollution monitoring stations were used to estimate daily PM_2.5 exposure. Generalized additive mixed models with clinical and meteorologic covariates adjusted were used to examine the association between PM_2.5 exposure and cSBP. The relationships between PM_2.5 exposure and cSBP were nonlinear, and significant increments of cSBP were observed when the PM_2.5 exposure concentration was above 100 μg/cm³. An interquartile range increase (80.25 μg/m³) in daily PM_2.5 on the day of cSBP measurement (lag 0 day) was associated with 2.54 mm Hg (95% CI, 0.92-4.16) elevation in cSBP. The associations of PM_2.5 with cSBP were not modified by age, sex, body mass index, medications, and comorbid diseases except for cardiovascular disease. Our findings demonstrated that short-term exposure to high concentration of ambient PM_2.5 above 100 μg/cm³ was associated with significant increases in central aortic BP in a Chinese community-based population.

Air pollution exposures and blood pressure variation in type-2 diabetes mellitus patients: A retrospective cohort study in China

Air pollution exposure has been associated with hypertension, but limited studies have examined the associations in diabetic patients. We aimed to examine the associations of exposure to air pollution with blood pressure in diabetic patients. We identified patients who were previously diagnosed as type-2 diabetes mellitus from hospital records from January 2013 to May 2017. We used generalized linear models to estimate adverse effects of air pollution on systolic/diastolic blood pressure in diabetic patients. A total of 40,125 patients were enrolled in this study. An IQR increase in PM_2.5, PM₁₀, NO₂, SO₂, and O₃ exposure was associated with an increased risk of higher systolic blood pressure level (β = 0.628 for PM_2.5, β = 0.758 for PM₁₀, β = 0.766 for NO₂, β = 0.516 for SO₂, β = 0.482 for O₃, all P value < 0.05). Significant associations were observed for some air pollutants and SBP among patients with fasting blood glucose (FBG) ≥ 7.0 mmol/L, normal weight, and younger age. Little evidence was available for the associations between particulate matter (PM) or O₃ exposure and diastolic blood pressure in present study. In our study, diabetic patients were at increased risk of higher blood pressure when exposed to higher residential PM, NO₂ and SO₂. Individuals with lower BMI, younger age, and FBG ≥ 7.0 mmol/L were more susceptible to the adverse effects of ambient air pollution.

Ambient Air Pollution and Biomarkers of Health Effect

Recently, the air pollution situation of our country is very serious along with the development of urbanization and industrialization. Studies indicate that the exposure of air pollution can cause a rise of incidence and mortality of many diseases, such as chronic obstructive pulmonary disease (COPD), asthma, myocardial infarction, and so on. However, there is now growing evidence showing that significant air pollution exposures are associated with early biomarkers in various systems of the body. In order to better prevent and control the damage effect of air pollution, this article summarizes comprehensively epidemiological studies about the bad effects on the biomarkers of respiratory system, cardiovascular system, and genetic and epigenetic system exposure to ambient air pollution.

Global association between ambient air pollution and blood pressure: A systematic review and meta-analysis

Although numerous studies have investigated the association of ambient air pollution with hypertension and blood pressure (BP), the results were inconsistent. We performed a comprehensive systematic review and meta-analysis of these studies. Seven international and Chinese databases were searched for studies examining the associations of particulate (diameter<2.5 μm (PM_2.5), 2.5-10 μm (PM_2.5-10) or >10 μm (PM₁₀)) and gaseous (sulfur dioxide (SO₂), nitrogen dioxide (NO₂), nitrogen oxides (NO_x), ozone (O₃), carbon monoxide (CO)) air pollutants with hypertension or BP. Odds ratios (OR), regression coefficients (β) and their 95% confidence intervals were calculated to evaluate the strength of the associations. Subgroup analysis, sensitivity analysis, and meta-regression analysis were also conducted. The overall meta-analysis showed significant associations of long-term exposures to PM_2.5 with hypertension (OR = 1.05), and of PM₁₀, PM_2.5, and NO₂ with DBP (β values: 0.47-0.86 mmHg). In addition, short-term exposures to four (PM₁₀, PM_2.5, SO₂, NO₂), two (PM_2.5 and SO₂), and four air pollutants (PM₁₀, PM_2.5, SO₂, and NO₂), were significantly associated with hypertension (ORs: 1.05-1.10), SBP (β values: 0.53-0.75 mmHg) and DBP (β values: 0.15-0.64 mmHg), respectively. Stratified analyses showed a generally stronger relationship among studies of men, Asians, North Americans, and areas with higher air pollutant levels. In conclusion, our study indicates a positive association between ambient air pollution and increased BP and hypertension. Geographical and socio-demographic factors may modify the pro-hypertensive effects of air pollutants.

Estimated effects of air pollution and space-time-activity on cardiopulmonary outcomes in healthy adults: A repeated measures study

BACKGROUND

Exposure to air pollution is known to affect both short and long-term outcomes of the cardiopulmonary system; however, findings on short-term outcomes have been inconsistent and often from isolated and long-term rather than coexisting and short-term exposures, and among susceptible/unhealthy rather than healthy populations.

AIMS

We aimed to investigate separately the annual, daily and daily space-time-activity-weighted effect of ambient air pollution, as well as confounding or modification by other environmental (including noise) or space-time-activity (including total daily physical activity) exposures, on cardiopulmonary outcomes in healthy adults.

METHODS

Participants (N=57: 54% female) had indicators of cardiopulmonary outcomes [blood pressure (BP), pulse (HR) and heart rate variability (HRV {SDNN}), and lung function (spirometry {FEV₁, FVC, SUM})] measured on four different mornings (at least five days apart) in a clinical setting between 2011 and 2014. Spatiotemporal ESCAPE-LUR models were used to estimate daily and annual air pollution exposures (including PM₁₀, PM_Coarse, but not Ozone {derived from closest station}) at participant residential and occupational addresses. Participants' time-activity diaries indicated time spent at either address to allow daily space-time-activity-weighted estimates, and capture total daily physical activity (total-PA {as metabolic-equivalents-of-task, METs}), in the three days preceding health measurements. Multivariate-adjusted linear mixed-effects models (using either annual or daily estimates) were adjusted for possible environmental confounders or mediators including levels of ambient noise and greenness. Causal mediation analysis was also performed separately considering these factors as well as total-PA. All presented models are controlled by age, height, sex and season.

RESULTS

An increase in 5μg/m³ of daily space-time-activity-weighted PM_Coarse exposure was statistically significantly associated with a 4.1% reduction in total heart rate variability (SDNN; p=0.01), and remained robust after adjusting for suspected confounders [except for occupational-address noise (β=-2.7, p=0.20)]. An increase in 10ppb of annual mean Ozone concentration at the residential address was statistically significantly associated with an increase in diastolic BP of 6.4mmHg (p<0.01), which lost statistical significance when substituted with daily space-time-activity-weighted estimates. As for pulmonary function, an increase in 10μg/m³ of annual mean PM₁₀ concentration at the residential address was significantly associated with a 0.3% reduction in FVC (p<0.01) and a 0.5% reduction in SUM (p<0.04), for which again significance was lost when substituted for daily space-time-activity-weighted estimates These associations with pulmonary function remained robust after adjusting for suspected confounders, including annual Ozone, as well as total-PA and bioaerosol (pollen and fungal spore) levels (but not residential-neighborhood greenness {β=-0.22, p=0.09; β=-0.34, p=0.15, respectively}). Multilevel mediation analysis indicated that the proportion mediated as a direct effect on cardiopulmonary outcomes by suspected confounders (including total-PA, residential-neighborhood greenness, and occupational-address noise level) from primary exposures (including PM₁₀, PM_Coarse, and O₃) was not statistically significant.

CONCLUSION

Our findings suggest that increased daily space-time-activity-weighted PM_Coarse exposure levels significantly adversely affect cardiac autonomic modulation (as reduced total HRV) among healthy adults. Additionally, increased annual levels at the residential address of Ozone and PM₁₀ significantly increase diastolic blood pressure and reduce lung function, respectively, among healthy adults. These associations typically remained robust when adjusting for suspected confounders. Occupational-address noise and residential-neighborhood greenness levels, however, were seen as mediators of cardiovascular and pulmonary outcomes, respectively. Total daily physical activity was not seen as a mediator of any of the studied outcomes, which supports the promotion of active mobility within cities.

Fine particulate matter constituents and blood pressure in patients with chronic obstructive pulmonary disease: A panel study in Shanghai, China

OBJECTIVE

The evidence is limited about the potentially different health effects of various chemical constituents of fine particulate matter (PM_2.5). We thus assessed the acute effects of various chemical constituents of PM_2.5 on blood pressure (BP).

METHODS

We performed a longitudinal panel study with six repeated visits in 28 urban residents with chronic obstructive pulmonary disease in Shanghai, China from May to July, 2014. Twelve (43%) of them took antihypertensive medications. We measured resting BP by using a mercury sphygmomanometer and monitored real-time concentrations of PM_2.5 constituents at a nearby site. Based on the linear mixed-effects model, we evaluated the effects of 10 major constituents in PM_2.5 on BP, using a single-constituent model and a constituent-residual model after accounting for the multicollinearity.

RESULTS

We obtained a total of 168 pairs of effective BP measurements during the study period. There are moderate or high correlations among various PM_2.5 constituents. An interquartile range increase of PM_2.5 (19.1μg/m³) was associated with increments of 1.90mmHg [95% confidence interval (CI): 0.66, 3.13] in systolic BP, 0.68mmHg (95%CI: -0.02, 1.37) in diastolic BP and 1.23mmHg (95%CI: 0.19, 2.29) in pulse pressure. Some constituents of PM_2.5, including organic carbon, elemental carbon, nitrate and ammonium, were robustly associated with elevated BP after controlling for total PM_2.5 mass and accounting for multi-collinearity. Two constituents (magnesium and calcium) were associated with decreased BP.

CONCLUSIONS

Organic carbon, elemental carbon, nitrate and ammonium may be mainly responsible for elevated BP from a short-term exposure to PM_2.5.

Long-term associations of modeled and self-reported measures of exposure to air pollution and noise at residence on prevalent hypertension and blood pressure

Air pollution, traffic noise and noise annoyance are suggested to be associated with hypertension and blood pressure (BP); however, the evidence remains inconsistent. Our study examined the long-term associations of modeled and self-reported measures of air pollution and traffic noise on prevalent hypertension and BP. We analyzed cross-sectional data from 2552 participants aged 31-72years from the KORA F4 (2006-2008) study conducted in the region of Augsburg, Germany. Land-use regression models were used to estimate residential long-term exposure to particulate matter <2.5μm (PM_2.5), soot content of PM_2.5 (PM_2.5abs) and nitrogen dioxide (NO₂). Road traffic noise levels at the facade of the dwellings were estimated for the participants' residences. Participants filled-in a questionnaire on noise annoyance and heavy traffic passing their residence. Linear and logistic regression models adjusting for confounders were used to assess the association between exposure measures and hypertension and BP. An interquartile increase in annual mean PM_2.5 (1μg/m³) was significantly associated with 15% higher prevalence of hypertension, without (95% CI: 2.5; 28.0%) and with (95% CI: 0.7; 30.8%) adjustment for traffic noise. Diastolic blood pressure (DBP) was associated with air pollutants and traffic noise with percent increases in mean of 0.7 (95% CI: 0.2; 1.2), 0.6 (95% CI: 0.1; 1.1) and 0.3 (95% CI: 0.0; 0.7) for an interquartile increase in PM_2.5 (1μg/m³) and PM_2.5abs (0.2∗10^-5/m), and 5dB(A) increase in 24-hour road traffic noise, respectively. Associations of PM_2.5abs and NO₂ with hypertension or DBP were stronger in men and diabetic individuals. No clear associations were seen with systolic BP or noise annoyance. In conclusion, self-reported measures of air pollution or noise did not perform better than the objective measures. Our findings provide further evidence for a link between air pollution, noise and cardiovascular disease and indicate a stronger association for men and diabetic individuals.

Particulate Matter Exposure and Stress Hormone Levels

Background:

Exposure to ambient particulate matter (PM) is associated with a number of adverse health outcomes, but potential mechanisms are largely unknown. Metabolomics represents a powerful approach to study global metabolic changes in response to environmental exposures. We therefore conducted this study to investigate changes in serum metabolites in response to the reduction of PM exposure among healthy college students.

Methods:

We conducted a randomized, double-blind crossover trial in 55 healthy college students in Shanghai, China. Real and sham air purifiers were placed in participants’ dormitories in random order for 9 days with a 12-day washout period. Serum metabolites were quantified by using gas chromatography-mass spectrometry and ultrahigh performance liquid chromatography-mass spectrometry. Between-treatment differences in metabolites were examined using orthogonal partial least square-discriminant analysis and mixed-effect models. Secondary outcomes include blood pressure, corticotropin-releasing hormone, adrenocorticotropic hormone, insulin resistance, and biomarkers of oxidative stress and inflammation.

Results:

The average personal exposure to PMs with aerodynamic diameters ≤2.5 μm was 24.3 μg/m 3 during the real purification and 53.1 μg/m 3 during the sham purification. Metabolomics analysis showed that higher exposure to PMs with aerodynamic diameters ≤2.5 μm led to significant increases in cortisol, cortisone, epinephrine, and norepinephrine. Between-treatment differences were also observed for glucose, amino acids, fatty acids, and lipids. We found significantly higher blood pressure, hormones, insulin resistance, and biomarkers of oxidative stress and inflammation among individuals exposed to higher PMs with aerodynamic diameters ≤2.5 μm.

Conclusions:

This study suggests that higher PM may induce metabolic alterations that are consistent with activations of the hypothalamus-pituitary-adrenal and sympathetic-adrenal-medullary axes, adding potential mechanistic insights into the adverse health outcomes associated with PM. Furthermore, our study demonstrated short-term reductions in stress hormone following indoor air purification.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02712333.

Acute effects of ambient temperature and particulate air pollution on fractional exhaled nitric oxide: A panel study among diabetic patients in Shanghai, China

Background

Epidemiological studies have shown the associations of ambient temperature and particulate matter (PM) air pollution with respiratory morbidity and mortality. However, the underlying mechanisms have not been well characterized. The aim of this study is to investigate the associations of temperature and fine and coarse PM with fractional exhaled nitric oxide (FeNO), a well-established biomarker of respiratory inflammation.

Methods

We conducted a longitudinal panel study involving six repeated FeNO tests among 33 type 2 diabetes mellitus patients from April to June 2013 in Shanghai, China. Hourly temperature and PM concentrations were obtained from a nearby fixed-site monitoring station. We then explored the associations between temperature, PM, and FeNO using linear mixed-effect models incorporated with distributed lag nonlinear models for the lagged and nonlinear associations. The interactions between temperature and PM were evaluated using stratification analyses.

Results

We found that both low and high temperature, as well as increased fine and coarse PM, were significantly associated with FeNO. The cumulative relative risk of FeNO was 1.75% (95% confidence interval [CI], 1.04–2.94) comparing 15 °C to the referent temperature (24 °C) over lags 0–9 days. A 10 μg/m³ increase in fine and coarse PM concentrations were associated with 1.18% (95% CI, 0.18–2.20) and 1.85% (95% CI, 0.62–3.09) FeNO in lag 0–1 days, respectively. PM had stronger effects on cool days than on warm days.

Conclusions

This study suggested low ambient temperature, fine PM, and coarse PM might elevate the levels of respiratory inflammation. Our findings may help understand the epidemiological evidence linking temperature, particulate air pollution, and respiratory health.

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Both low and high temperatures were significantly associated with FeNO.

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The increases of fine and coarse PM concentrations were associated with FeNO.

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Both fine and coarse PM had stronger effects in cool days.

Ambient Air Pollution and Morbidity in Chinese

The rapid economic growth in China is coupled with a severe ambient air pollution, which poses a huge threat to human health and the sustainable development of social economy. The rapid urbanization and industrialization over the last three decades have placed China as one of countries with the greatest disease burden in world. Notably, the prevalence rate of chronic noncommunicable diseases (CND), including respiratory diseases, CVD, and stroke, in 2010 reaches 16.9%. The continuous growth of the incidence of CND urgent needs for effective regulatory action for health protection. This study aims to evaluate the impact of rapid urbanization on status of ambient air pollution and associated adverse health effects on the incidence and the burden of CND and risk assessment. Our findings would be greatly significant in the prediction of the risk of ambient air pollution on CND and for evidence-based policy making and risk management in China.

Personal exposure to fine particulate matter and blood pressure: A role of angiotensin converting enzyme and its DNA methylation

BACKGROUND

The underlying intermediate mechanisms about the association between fine particulate matter (PM2.5) air pollution and blood pressure (BP) were unclear. Few epidemiological studies have explored the potential mediation effects of angiotensin-converting enzyme (ACE) and its DNA methylation.

METHODS

We designed a longitudinal panel study with 4 follow-ups among 36 healthy college students in Shanghai, China from December 17, 2014 to July 11, 2015. We measured personal real-time exposure to PM2.5, serum ACE level, and blood methylation of ACE gene and the repetitive elements. We applied linear mixed-effects models to examine the effects of PM2.5 on ACE protein, DNA methylation and BP markers. Furthermore, we conducted mediation analyses to evaluate the potential pathways.

RESULTS

An interquartile range increase (26.78μg/m(3)) in 24-h average exposure to PM2.5 was significantly associated with 1.12 decreases in ACE average methylation (%5mC), 13.27% increase in ACE protein, and increments of 1.13mmHg in systolic BP, 0.66mmHg in diastolic BP and 0.82mmHg in mean arterial pressure. ACE hypomethylation mediated 11.78% (P=0.03) of the elevated ACE protein by PM2.5. Increased ACE protein accounted for 3.90~13.44% (P=0.35~0.68) of the elevated BP by PM2.5. Repetitive-element methylation was also decreased but did not significantly mediate the association between PM2.5 and BP.

CONCLUSIONS

This investigation provided strong evidence that short-term exposure to PM2.5 was significantly associated with BP, ACE protein and ACE methylation. Our findings highlighted a possible involvement of ACE and ACE methylation in the effects of PM2.5 on elevating BP.

Assessment of the Possible Association of Air Pollutants PM10, O3, NO2 With an Increase in Cardiovascular, Respiratory, and Diabetes Mortality in Panama City: A 2003 to 2013 Data Analysis

In recent years, Panama has experienced a marked economic growth, and this, in turn, has been associated with rapid urban development and degradation of air quality. This study is the first evaluation done in Panama on the association between air pollution and mortality. Our objective was to assess the possible association between monthly levels of PM10, O3, and NO2, and cardiovascular, respiratory, and diabetes mortality, as well as the seasonal variation of mortality in Panama City, Panama.The study was conducted in Panama City, using air pollution data from January 2003 to December 2013. We utilized a Poisson regression model based on generalized linear models, to evaluate the association between PM10, NO2, and O3 exposure and mortality from diabetes, cardiovascular, and respiratory diseases. The sample size for PM10, NO2, and O2 was 132, 132, and 108 monthly averages, respectively.We found that levels of PM10, O3, and NO2 were associated with increases in cardiovascular, respiratory, and diabetes mortality. For PM10 levels ≥ 40 μg/m3, we found an increase in cardiovascular mortality of 9.7% (CI 5.8-13.6%), and an increase of 12.6% (CI 0.2-24.2%) in respiratory mortality. For O3 levels ≥ 20 μg/m3 we found an increase of 32.4% (IC 14.6-52.9) in respiratory mortality, after a 2-month lag period following exposure in the 65 to <74 year-old age group. For NO2 levels ≥20 μg/m3 we found an increase in respiratory mortality of 11.2% (IC 1.9-21.3), after a 2-month lag period following exposure among those aged between 65 and <74 years.There could be an association between the air pollution in Panama City and an increase in cardiovascular, respiratory, and diabetes mortality. This study confirms the urgent need to improve the measurement frequency of air pollutants in Panama.