Short-term effects of air pollution on cardiovascular diseases: outcomes and mechanisms

Early biological effects in outdoor workers exposed to urban air pollution: A systematic review

Urban outdoor workers (OWs), identified as professionals spending most of their working shifts in an urban environment, are exposed for at least 8 h/day to traffic air pollution, leading to potential health risks. This paper reports the results of a systematic review aimed at identifying the potential health outcomes of exposure to air pollutants for OWs, focusing mainly on police officers, drivers and street vendors. Health outcomes were analysed in terms of early biological effects quantified with specific measured indicators. The main inclusion criterion was the assessment of at least one early biological effect (genetic and epigenetic damage/alterations, inflammation or oxidative stress indicators, or hormonal imbalance) in a population of OWs exposed to urban air pollution. By applying the PRISMA workflow, 82 papers were included in this study. The results showed that the measured pollutant concentrations were significantly below the current occupational limit values, while exceeds the indications of WHO for urban air pollution. This exposure led to significant alterations of biological markers in OWs with respect to non-exposed subjects. In particular, OWs presented an increased frequency of micronuclei and DNA adducts as the main DNA alterations, while police officers (a category of highly exposed OWs) showed hormonal alterations affecting mainly the hypothalamic-pituitary-gonadal axis. Concerning oxidative stress and inflammation, all the analysed matrices (i.e. blood, sputum, urine and lachrymal fluids) showed increased indices for OWs respect to non-exposed groups. Therefore, the evaluation of effect biomarkers to detect early alterations provides crucial information for supporting the occupational risk management of OWs and, at broader level, allows for an insight of the early-stage health outcomes due to urban air pollution.

China's progress in synergetic governance of climate change and multiple environmental issues

Advancing the synergetic control of climate change and environmental crisis is crucial for achieving global sustainable development goals. This study evaluates synergetic governance levels over climate change and four environmental issues at the provincial level in China from 2009 to 2020. Our findings reveal significant progress in China's coordinated efforts to mitigate carbon emissions, reduce air pollutants, and conserve water resources. However, there remains room for improvement in managing solid waste and protecting ecological systems and overall progress in synergetic governance has slowed since 2015. Employing a random forest model, we identify socio-economic factors with great influence on synergetic climate change and environmental governance, such as energy intensity, service sector development, electronic equipment manufacturing, and transportation. Additionally, we reveal nonlinear relationships between some factors and performance of environmental subsystems, including both plateau effects (e.g. output in the smelting of ferrous metals) and U-shaped patterns (e.g. output in the manufacturing of metal products), possibly attributed to constraints in end-of-pipe treatment capacities and complexities in supply chain networks. Furthermore, through hierarchical clustering analysis, we classify provinces into four groups and provide tailored recommendations for policymakers to enhance synergetic governance levels in their respective regions. The framework established in this study also serves as a valuable reference for countries seeking to develop practical and context-specific solutions to mitigate climate and environmental risks.

Estimates of global mortality burden associated with short-term exposure to fine particulate matter (PM2·5)

BACKGROUND

The acute health effects of short-term (hours to days) exposure to fine particulate matter (PM2·5) have been well documented; however, the global mortality burden attributable to this exposure has not been estimated. We aimed to estimate the global, regional, and urban mortality burden associated with short-term exposure to PM2·5 and the spatiotemporal variations in this burden from 2000 to 2019.

METHODS

We combined estimated global daily PM2·5 concentrations, annual population counts, country-level mortality rates, and epidemiologically derived exposure-response functions to estimate the mortality attributable to short-term PM2·5 exposure from 2000 to 2019, in the continental regions and in 13 189 urban centres worldwide at a spatial resolution of 0·1° × 0·1°. We tested the robustness of our mortality estimates with different theoretical minimum risk exposure levels, lag effects, and exposure-response functions.

FINDINGS

Approximately 1 million (95% CI 690 000-1·3 million) premature deaths per year from 2000 to 2019 were attributable to short-term PM2·5 exposure, representing 2·08% (1·41-2·75) of total global deaths or 17 (11-22) premature deaths per 100 000 population. Annually, 0·23 million (0·15 million-0·30 million) deaths attributable to short-term PM2·5 exposure were in urban areas, constituting 22·74% of the total global deaths attributable to this cause and accounting for 2·30% (1·56-3·05) of total global deaths in urban areas. The sensitivity analyses showed that our worldwide estimates of mortality attributed to short-term PM2·5 exposure were robust.

INTERPRETATION

Short-term exposure to PM2·5 contributes a substantial global mortality burden, particularly in Asia and Africa, as well as in global urban areas. Our results highlight the importance of mitigation strategies to reduce short-term exposure to air pollution and its adverse effects on human health.

FUNDING

Australian Research Council and the Australian National Health and Medical Research Council.

Disentangling impacts of multiple pollutants on acute cardiovascular events in New York city: A case-crossover analysis

BACKGROUND

Ambient air pollution contributes to an estimated 6.67 million deaths annually, and has been linked to cardiovascular disease (CVD), the leading cause of death. Short-term increases in air pollution have been associated with increased risk of CVD event, though relatively few studies have directly compared effects of multiple pollutants using fine-scale spatio-temporal data, thoroughly adjusting for co-pollutants and temperature, in an exhaustive citywide hospitals dataset, towards identifying key pollution sources within the urban environment to most reduce, and reduce disparities in, the leading cause of death worldwide.

OBJECTIVES

We aimed to examine multiple pollutants against multiple CVD diagnoses, across lag days, in models adjusted for co-pollutants and meteorology, and inherently adjusted by design for non-time-varying individual and aggregate-level covariates, using fine-scale space-time exposure estimates, in an exhaustive dataset of emergency department visits and hospitalizations across an entire city, thereby capturing the full population-at-risk.

METHODS

We used conditional logistic regression in a case-crossover design - inherently controlling for all confounders not varying within case month - to examine associations between spatio-temporal nitrogen dioxide (NO2), fine particulate matter (PM2.5), sulfur dioxide (SO2), and ozone (O3) in New York City, 2005-2011, on individual risk of acute CVD event (n = 837,523), by sub-diagnosis [ischemic heart disease (IHD), heart failure (HF), stroke, ischemic stroke, acute myocardial infarction].

RESULTS

We found significant same-day associations between NO2 and risk of overall CVD, IHD, and HF - and between PM2.5 and overall CVD or HF event risk - robust to all adjustments and multiple comparisons. Results were comparable by sex and race - though median age at CVD was 10 years younger for Black New Yorkers than White New Yorkers. Associations for NO2 were comparable for adults younger or older than 69 years, though PM2.5 associations were stronger among older adults.

DISCUSSION

Our results indicate immediate, robust effects of combustion-related pollution on CVD risk, by sub-diagnosis. Though acute impacts differed minimally by age, sex, or race, the much younger age-at-event for Black New Yorkers calls attention to cumulative social susceptibility.

Longitudinal associations between metabolites and immediate, short- and medium-term exposure to ambient air pollution: Results from the KORA cohort study

BACKGROUND

Short-term exposure to air pollution has been reported to be associated with cardiopulmonary diseases, but the underlying mechanisms remain unclear. This study aimed to investigate changes in serum metabolites associated with immediate, short- and medium-term exposures to ambient air pollution.

METHODS

We used data from the German population-based Cooperative Health Research in the Region of Augsburg (KORA) S4 survey (1999-2001) and two follow-up examinations (F4: 2006-08 and FF4: 2013-14). Mass-spectrometry-based targeted metabolomics was used to quantify metabolites among serum samples. Only participants with repeated metabolites measurements were included in this analysis. We collected daily averages of fine particles (PM2.5), coarse particles (PMcoarse), nitrogen dioxide (NO2), and ozone (O3) at urban background monitors located in Augsburg, Germany. Covariate-adjusted generalized additive mixed-effects models were used to examine the associations between immediate (2-day average of same day and previous day as individual's blood withdrawal), short- (2-week moving average), and medium-term exposures (8-week moving average) to air pollution and metabolites. We further performed pathway analysis for the metabolites significantly associated with air pollutants in each exposure window.

RESULTS

Of 9,620 observations from 4,261 study participants, we included 5,772 (60.0%) observations from 2,583 (60.6%) participants in this analysis. Out of 108 metabolites that passed quality control, multiple significant associations between metabolites and air pollutants with several exposure windows were identified at a Bonferroni corrected p-value threshold (p < 3.9 × 10-5). We found the highest number of associations for NO2, particularly at the medium-term exposure windows. Among the identified metabolic pathways based on the metabolites significantly associated with air pollutants, the glycerophospholipid metabolism was the most robust pathway in different air pollutants exposures.

CONCLUSIONS

Our study suggested that short- and medium-term exposure to air pollution might induce alterations of serum metabolites, particularly in metabolites involved in metabolic pathways related to inflammatory response and oxidative stress.

Association of SO2/CO exposure and greenness with high blood pressure in children and adolescents: A longitudinal study in China

Introduction

We aimed to investigate the association between greenness around schools, long-term gaseous air pollution exposure (SO₂ and CO), and blood pressure in children and adolescents.

Methods

From 2006 to 2018, a total of 219,956 Chinese children and adolescents aged 7-17 years in Beijing and Zhongshan were included in this longitudinal study. Annual average concentrations of SO₂ and CO and the mean values of normalized difference vegetation index around schools were calculated. We used the generalized estimation equation model, restricted cubic spline model, and Cox model to analyze the health effects.

Results

Among all the subjects, 52,515 had the first onset of HBP. During the follow-up, HBP's cumulative incidence and incidence density were 23.88% and 7.72 per 100 person-year respectively. Exposures to SO₂ and CO were significantly associated with SBP [β = 1.30, 95% CI: (1.26, 1.34) and 0.78 (0.75, 0.81)], DBP [β = 0.81 (0.79, 0.84) and 0.46 (0.44, 0.48)] and HBP [HR = 1.58 (1.57, 1.60) and 1.42 (1.41, 1.43)]. The risks of HBP attributed to SO₂ and CO pollution would be higher in school-aged children in the low greenness group: the attributable fractions (AFs) were 26.31% and 20.04%, but only 13.90% and 17.81% in the higher greenness group. The AFs were also higher for normal-BMI children and adolescents in the low greenness group (AFs = 30.90% and 22.64%, but 14.41% and 18.65% in the high greenness group), while the AFs were not as high as expected for obese children in the low greenness group (AFs = 10.64% and 8.61%), nor was it significantly lower in the high greenness group (AFs = 9.60% and 10.72%).

Discussion

Greenness could alleviate the damage effects of SO₂/CO exposure on the risks of HBP among children and adolescents, and the benefit is BMI sensitivity. It might offer insights for policymakers in making effective official interventions to prevent and control the prevalence of childhood HBP and the future disease burden caused by air pollution.

Association between Outdoor Air Pollution and Fatal Acute Myocardial Infarction in Lithuania between 2006 and 2015: A Time Series Design

BACKGROUND

Air pollution has a significant effect on human health and there is a broad body of evidence showing that exposure to air pollution is associated with an increased risk of adverse health effects. The main objective of this study was to assess the association of traffic-related air pollutants with fatal AMI during the ten-year period.

METHODS

The study was conducted in Kaunas city, where the WHO MONICA register included a total of 2273 adult cases of fatal AMI cases during the 10-year study period. We focused on the period between 2006 and 2015. The associations between exposure to traffic-related air pollution and the risk of fatal AMI were evaluated by using a multivariate Poisson regression model, RR presented per an increase in IQR.

RESULTS

It was found that the risk of fatal AMI was significantly higher in all subjects (RR 1.06; 95% CI 1.00-1.12) and women (RR 1.12; 95% CI 1.02-1.22) when the concentration of PM₁₀ in the ambient air was increased 5-11 days before the onset of AMI, adjusting for NO₂ concentration. The effect was stronger during spring in all subjects (RR 1.12; 95% CI 1.03-1.22), in men (RR 1.13; 95% CI 1.01-1.26), in younger-aged (RR 1.15; 95% CI 1.03-1.28), and in winter in women (RR 1.24; 95% CI 1.03-1.50).

CONCLUSIONS

Our findings show that ambient air pollution increases the risk of fatal AMI, and this pertains to PM₁₀ specifically.

Anti-Pollutant Activity of Porphyra yezoensis Water Extract and Its Active Compound, Porphyra 334, against Urban Particulate Matter-Induced Keratinocyte Cell Damage

Urban particulate matter (UPM) causes skin aging and inflammatory reactions by influencing skin cells through the aryl hydrocarbon receptor (AhR) signaling pathway. Porphyra yezoensis (also known as Pyropia yezoensis), a red alga belonging to the Bangiaceae family, is an edible red seaweed. Here, we examined the anti-pollutant effect of P. yezoensis water extract. While UPM treatment induced xenobiotic response element (XRE) promoter luciferase activity, P. yezoensis water extract reduced UPM-induced XRE activity. Next, we isolated an active compound from P. yezoensis and identified it as porphyra 334. Similar to the P. yezoensis water extract, porphyra 334 attenuated UPM-induced XRE activity. Moreover, although UPM augmented AhR nuclear translocation, which led to an increase in cytochrome P450 1A1 (CYP1A1) mRNA levels, these effects were reduced by porphyra 334. Moreover, UPM induced the production of reactive oxygen species (ROS) and reduced cell proliferation. These effects were attenuated in response to porphyra 334 treatment. Furthermore, our results revealed that the increased ROS levels induced by UPM treatment induced transient receptor potential vanilloid 1 (TRPV1) activity, which is related to skin aging and inflammatory responses. However, porphyra 334 treatment reduced this reaction by inhibiting ROS production induced by CYP1A1 activation. This indicates that porphyra 334, an active compound of P. yezoensis, attenuates UP-induced cell damage by inhibiting AhR-induced ROS production, which results in a reduction in TRPV1 activation, leading to cell proliferation. This also suggests that porphyra 334 could protect the epidermis from harmful pollutants.

Ambient fine particulate pollution hysteresis triggers wake-up stroke and rapidly triggers non-wake-up stroke: a case-crossover study

Atmospheric pollutants increase the risk of acute ischemic stroke (AIS) which has been widely reported. However, little is known about the relationships between air pollution and specific subsets of AIS, such as wake-up stroke (WUS) and non-wake-up stroke (non-WUS). This study aimed to explore the relationship between WUS and non-WUS and atmospheric pollutants. A total of 1432 patients (331 WUS patients and 1101 non-WUS patients) were admitted to a tertiary hospital from 2016 to 2019. A time-stratified case-crossover design and a conditional logistic regression model to study the associations of change in pollutant concentration with WUS and non-WUS events were constructed. Data analysis revealed that WUS-related risks increased 48 to 72 h after the increase in the PM_2.5 concentration (each 10 μg/m³ increase, lag 0-72 h) [threshold OR (95% CI):18 μg/m³ 1.03 (0.94-1.11), 35 μg/m³ 1.01 (0.92-1.12), 50 μg/m³ 1.04 (0.91-1.19)]; the non-WUS-related risk increased 1 to 6 h after the increase in the PM_2.5 concentration (each 10 μg/m³ increase, lag 0-1 h) [threshold OR (95% CI):18 μg/m³ 1.01 (0.98-1.03), 35 μg/m³ 1.00 (0.97-1.04), 50 μg/m³ 1.01 (0.96-1.05)] (lag 0-6 h) [threshold OR (95% CI): 18 μg/m³ 1.00 (0.97-1.03), 35 μg/m³ 1.00 (0.97-1.04), 50 μg/m³ 1.01 (0.97-1.06)]; O₃ exposure was related to WUS events, and its impact on WUS events was stronger and longer-lasting (1-96 h) than its impact on non-WUS events (1-6 h). Greater than or equal to 65 years of age, overweight (BMI ≥ 25), and diabetes had a significantly greater risk of WUS associated with increased PM_2.5 concentration in the previous 12-96 h than patients without these conditions. Patients with hypertension and smoking had a significant risk of non-WUS associated with increased PM_2.5 concentration in the previous 1-6 h. The increase in PM_2.5 concentration in the cold season increased the risk of both WUS and non-WUS events. Ambient air pollution hysteresis triggers WUS and rapidly triggers non-WUS, even if the degree of pollutant is relatively low. Patients with elderly, overweight, and diabetes appeared particularly susceptible to WUS, and patients with hypertension and smoking history were susceptible to non-WUS. We need to expand the sample for further investigation into mechanisms by which environmental pollutants trigger WUS or non-WUS.

Ambient Air Quality and Emergency Hospital Admissions in Singapore: A Time-Series Analysis

Air pollution exposure may increase the demand for emergency healthcare services, particularly in South-East Asia, where the burden of air-pollution-related health impacts is high. This article aims to investigate the association between air quality and emergency hospital admissions in Singapore. Quasi-Poisson regression was applied with a distributed lag non-linear model (DLNM) to assess the short-term associations between air quality variations and all-cause, emergency admissions from a major hospital in Singapore, between 2009 and 2017. Higher concentrations of SO₂, PM_2.5, PM₁₀, NO₂, and CO were positively associated with an increased risk of (i) all-cause, (ii) cardiovascular-related, and (iii) respiratory-related emergency admissions over 7 days. O₃ concentration increases were associated with a non-linear decrease in emergency admissions. Females experienced a higher risk of emergency admissions associated with PM_2.5, PM₁₀, and CO exposure, and a lower risk of admissions with NO₂ exposure, compared to males. The older adults (≥65 years) experienced a higher risk of emergency admissions associated with SO₂ and O₃ exposure compared to the non-elderly group. We found significant positive associations between respiratory disease- and cardiovascular disease-related emergency hospital admissions and ambient SO₂, PM_2.5, PM₁₀, NO₂, and CO concentrations. Age and gender were identified as effect modifiers of all-cause admissions.

Environmental effects on trace elements in the fingernails of centenarians and their offspring

Bio-monitoring is commonly used to investigate trace elements, and the human nail provides an ideal medium for such testing. Toxic and essential trace metals (Cd, Pb, Fe, and Se) in the fingernails of participants from the Hainan Province were investigated. Samples included 136 centenarians and 197 offspring (101 older adult children and 96 middle-aged grandchildren) who were also sampled for comparison. As a hotspot for longevity, participants in the Hainan Province were found to have high essential nutrients of Fe and Se, and lacked the toxic element Pb. A similar trend was found for trace elements in soil and rice in the Hainan Province. The trace elements preserved in nails revealed dietary and environmental influences that varied among different generations. For the grandchildren's generation, the environment played an important role in elements in their nails, and a significant correlation and linear relationships were found, especially for Fe and Se. As the participants increased in age (from the grandchildren to the centenarians), the correlation between various elements decreased. For centenarians, the influence of beneficial or harmful properties of the elements became more important than their environment. The results also pointed to the important role of trace elements in human health, especially Fe and Se as essential elements. This study can provide information on the factors that influence the existence of trace elements in the human body and demonstrate the advantage of using the human fingernail in bio-monitoring.

Impact of COVID-19 lockdown on PM concentrations in an Italian Northern City: A year-by-year assessment

In the last century, the increase in traffic, human activities and industrial production have led to a diffuse presence of air pollution, which causes an increase of risk of several health conditions such as respiratory diseases. In Europe, air pollution is a serious concern that affects several areas, one of the worst ones being northern Italy, and in particular the Po Valley, an area characterized by low air quality due to a combination of high population density, industrial activity, geographical factors and weather conditions. Public health authorities and local administrations are aware of this problem, and periodically intervene with temporary traffic limitations and other regulations, often insufficient to solve the problem. In February 2020, this area was the first in Europe to be severely hit by the SARS-CoV-2 virus causing the COVID-19 disease, to which the Italian government reacted with the establishment of a drastic lockdown. This situation created the condition to study how significant is the impact of car traffic and industrial activity on the pollution in the area, as these factors were strongly reduced during the lockdown. Differently from some areas in the world, a drastic decrease in pollution measured in terms of particulate matter (PM) was not observed in the Po Valley during the lockdown, suggesting that several external factors can play a role in determining the severity of pollution. In this study, we report the case study of the city of Pavia, where data coming from 23 air quality sensors were analyzed to compare the levels measured during the lockdown with the ones coming from the same period in 2019. Our results show that, on a global scale, there was a statistically significant reduction in terms of PM levels taking into account meteorological variables that can influence pollution such as wind, temperature, humidity, rain and solar radiation. Differences can be noticed analyzing daily pollution trends too, as—compared to the study period in 2019—during the study period in 2020 pollution was higher in the morning and lower in the remaining hours.

Isa WYH. An Evaluation of the Role of Oxidative Stress in Non-Obstructive Coronary Artery Disease

Approximately half of all women presenting to the emergency department with angina chest pain do not have obstructive coronary artery disease (CAD) on coronary angiography. This condition is termed non-obstructive coronary artery disease (NOCAD), and includes ischemia with no obstructive coronary artery disease (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA). Oxidative stress has been reported to be involved in the development and progression of CAD. However, a scarcity of studies has assessed a correlation between oxidative stress and NOCAD. Thus, a literature review was performed of available reports on the role of oxidative stress in NOCAD. Possible mechanisms involved in oxidative stress that may contribute to NOCAD were identified and evaluated. A key finding of this literature review was that oxidative stress caused vasoconstriction and endothelial damage, and this results in coronary microvascular dysfunction and vasospasm, which, in turn, lead to the pathogenesis of NOCAD.

Effects of Short-Term Air Pollution Exposure on Venous Thromboembolism: A Case-Crossover Study

RATIONALE

Exposure to outdoor air pollution is associated with increased cardiovascular disease, respiratory illness, and mortality. The effect of air pollution on venous thromboembolism (VTE) is less certain.

OBJECTIVES

To test for associations between short-term exposure to air pollution and VTE.

METHODS

Retrospective case-crossover study of adult patients with an objectively confirmed VTE event. Exposure to mean and maximum PM2.5 and ozone were estimated with inverse distance squared weighting from multiple stationary air quality monitors. Conditional logistic regression with a 7-day individual lag model estimated the odds ratio of VTE occurrence during the case period relative to the referent period. Prespecified subgroup analysis was performed to further test associations in higher risk patients.

RESULTS

A total of 2,803 VTE events met inclusion criteria for analysis. Deep vein thrombosis was identified in 1,966 (70.1%) and pulmonary embolism in 915 (32.6%) subjects. Median age was 57 years. Small negative associations were observed for maximum PM2.5 exposure at 1 day (odds ratio [95% confidence interval]; OR=0.992 [0.986-0.997]) and mean PM2.5 exposure at 1 day (OR=0.982 [0.97-0.994]), 5 days (OR=0.987 [0.975-0.999]), 6 days (OR=0.984 [0.972-0.996]), 7 days (OR=0.982 [0.971-0.994]), prior to VTE diagnosis. Similar negative associations were observed for 8-hour mean (OR=0.989 [0.981-0.997]) and 8-hour maximum (OR=0.992 [0.985-0.999]) ozone exposure 4 days prior to VTE diagnosis. Positive relationships (ORs~1.02) between 8-hour mean and maximum ozone exposure 6-7 days preceding VTE diagnosis were observed in a recently hospitalized subgroup.

CONCLUSIONS

Short-term exposure to PM2.5 and ozone does not appear to be associated with an overall increased risk of VTE. Further well-designed studies are needed to test whether previously reported associations between VTE and air pollution exist.

Low emission zones and population health

Air pollution has a detrimental impact on population health, but the effectiveness of policy measures targeting pollution is underexplored. I exploit the natural experiment generated by the staggered implementation of low emission zones in large cities across Germany to assess their impact on health. Using register data on outpatient and inpatient health care, I find that low emission zones reduce the number of patients with cardiovascular disease by 2-3%. This effect is particularly pronounced for those over the age of 65. The findings suggest that low emission zones can be an effective way to reduce air pollution and improve health.

The short- and long-term associations of particulate matter with inflammation and blood coagulation markers: A meta-analysis

Inflammation and the coagulation cascade are considered to be the potential mechanisms of ambient particulate matter (PM) exposure-induced adverse cardiovascular events. Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and fibrinogen are arguably the four most commonly assayed markers to reflect the relationships of PM with inflammation and blood coagulation. This review summarized and quantitatively analyzed the existing studies reporting short- and long-term associations of PM2.5(PM with an aerodynamic diameter ≤2.5 μm)/PM10 (PM with an aerodynamic diameter≤10 μm) with important inflammation and blood coagulation markers (TNF-α, IL-6, IL-8, fibrinogen). We reviewed relevant studies published up to July 2020, using three English databases (PubMed, Web of Science, Embase) and two Chinese databases (Wang-Fang, China National Knowledge Infrastructure). The OHAT tool, with some modification, was applied to evaluate risk of bias. Meta-analyses were conducted with random-effects models for calculating the pooled estimate of markers. To assess the potential effect modifiers and the source of heterogeneity, we conducted subgroup analyses and meta-regression analyses where appropriate. The assessment and correction of publication bias were based on Begg's and Egger's test and "trim-and-fill" analysis. We identified 44 eligible studies. For short-term PM exposure, the percent change of a 10 μg/m3 PM2.5 increase on TNF-α and fibrinogen was 3.51% (95% confidence interval (CI): 1.21%, 5.81%) and 0.54% (95% confidence interval (CI): 0.21%, 0.86%) respectively. We also found a significant short-term association between PM10 and fibrinogen (percent change = 0.17%, 95% CI: 0.04%, 0.29%). Overall analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were not significant. Subgroup analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were significant only found in studies conducted in Asia. Our findings support significant short-term associations of PM with TNF-α and fibrinogen. Future epidemiological studies should address the role long-term PM exposure plays in inflammation and blood coagulation markers level change.

Liaison between exposure to sub-micrometric particulate matter and allergic response in children from a petrochemical industry city

The study examines the association between exposure to sub-micrometric Particulate Matter (PM₁) and allergic response in a group of sensitive young children (age: 2-10 years) from Ploiesti city, Romania. The city is the only urban agglomeration in Europe surrounded by four oil refineries. A panel study was conducted by collecting medical information from children with respiratory illnesses and atopy (n = 135). Hot Spot Analysis revealed the areas of the city that are susceptible to high levels of PM₁. We found a close interaction between exposure to PM₁ outdoor concentrations and various physiological changes and clinical symptoms in children including triggering of allergic reactions, rhinitis, alteration of lung function, upper and lower respiratory tract symptoms, and bronchial asthma. During the 2-year study period, the incidence of hospitalizations was 40.7%. Strong correlations (p < 0.001) were observed between the PM₁ exposure and hospitalizations, and exposure and Immunoglobulin E (IgE). PM₁ exposure was also correlated with eosinophils (p < 0.05). Another positive correlation was observed between hospitalizations and IgE levels (p < 0.05). The mean results of tested indicators were as follows: wheezing (5.3, 95% CI (1.4-1.8); Coeff. of var. (CV) = 30%), IgE (382, 95% CI (349-445); CV = 102%), and EO% (5.3, 95% CI (3.3-4.2); CV = 69.5%). We can conclude that exposure to PM₁ influenced the frequency of wheezing episodes, increased hospitalizations, and the levels of allergic blood indicators in children, especially in infants and pre-schoolers. CAPSULE: Exposure to sub-micrometric particles (PM₁) influences the frequency of wheezing episodes, hospitalizations, and the levels of allergic blood indicators in children, especially in infants and pre-schoolers.

Ambient particulate matter and biomass burning: an ecological time series study of respiratory and cardiovascular hospital visits in northern Thailand

BACKGROUND

Exposure to particulate matter (PM) emitted from biomass burning is an increasing concern, particularly in Southeast Asia. It is not yet clear how the source of PM influences the risk of an adverse health outcome. The objective of this study was to quantify and compare health risks of PM from biomass burning and non-biomass burning sources in northern Thailand.

METHODS

We collected ambient air pollutant data (PM with a diameter of < 10 μm [PM10], PM2.5, Carbon Monoxide [CO], Ozone [O3], and Nitrogen Dioxide [NO2]) from ground-based monitors and daily outpatient hospital visits in Thailand during 2014-2017. Outpatient data included chronic lower respiratory disease (CLRD), ischaemic heart disease (IHD), and cerebrovascular disease (CBVD). We performed an ecological time series analysis to evaluate the association between daily air pollutants and outpatient visits. We used the 90th and 95th percentiles of PM10 concentrations to determine days of exposure to PM predominantly from biomass burning.

RESULTS

There was significant intra annual variation in PM10 levels, with the highest concentrations occurring during March, coinciding with peak biomass burning. Incidence Rate Ratios (IRRs) between daily PM10 and outpatient visits were elevated most on the same day as exposure for CLRD = 1.020 (95% CI: 1.012 to 1.028) and CBVD = 1.020 (95% CI: 1.004 to 1.035), with no association with IHD = 0.994 (95% CI: 0.974 to 1.014). Adjusting for CO tended to increase effect estimates. We did not find evidence of an exposure response relationship with levels of PM10 on days of biomass burning.

CONCLUSIONS

We found same-day exposures of PM10 to be associated with certain respiratory and cardiovascular outpatient visits. We advise implementing measures to reduce population exposures to PM wherever possible, and to improve understanding of health effects associated with burning specific types of biomass in areas where such large-scale activities occur.

Identification of inhalable rutile and polycyclic aromatic hydrocarbons (PAHs) nanoparticles in the atmospheric dust

Addressing the presence of rutile nanoparticles (NPs) in the air is a work in progress, and the development of methodologies for the identification of NPs in atmospheric dust is essential for the assessment of its toxicological effects. To address this issue, we selected the fast growing desertic city of Hermosillo in northern Mexico. Road dust (n = 266) and soils (n = 10) were sampled and bulk Ti-contents were tested by portable X-ray fluorescence. NPs were extracted from atmospheric dust by PM_1.0-PTFE filters and further characterized by Confocal Raman Microscopy, Energy-dispersive X-ray spectroscopy (EDS) coupled to Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Results showed (i) the average concentration of Ti in road dust (3447 mg kg^-1) was similar to natural values and worldwide urban dusts; (ii) the bulk geochemistry was not satisfactory for Ti-NPs identification; (iii) 76% of the total extracted PM_1.0 sample corresponded to NPs; (iv) mono-microaggregates of rutile NPs were identified; (v) ubiquitous polycyclic aromatic hydrocarbons (PAHs) were linked to NPs. The genotoxicity of rutile and PAHs, in connection with NPs content, make us aware of a crucial emerging environmental issue of significant health concern, justifying further research in this field.

Changes in extrapulmonary organs and serum enzyme biomarkers after chronic exposure to Buenos Aires air pollution

Urban air pollution is a serious environmental problem in developing countries worldwide, and health is a pressing issue in the megacities in Latin America. Buenos Aires is a megacity with an estimated moderate Air Quality Index ranging from 42 to 74 μg/m³. Exposure to Urban Air Particles from Buenos Aires (UAP-BA) induces morphological and physiological respiratory alterations; nevertheless, no studies on extrapulmonary organs have been performed. The aim of the present study was to explore the health effects of chronic exposure to UAP-BA (1, 6, 9, and 12 months) on the liver, heart, and serum risk biomarkers. BALB/c mice were exposed to UAP-BA or filtered air (FA) in inhalation chambers, and liver and heart histopathology, oxidative metabolism (superoxide dismutase, SOD; catalase, CAT; lipoperoxidation, TBARS), amino transaminases (AST, ALT) as serum risk biomarkers, alkaline phosphatase (ALP), paraxonase-1 (PON-1), and lipoprotein-associated phospholipase A2 (Lp-PLA2) were evaluated. Chronic exposure to real levels of UAP in Buenos Aires led to alterations in extrapulmonary organs associated with inflammation and oxidative imbalance and to changes in liver and heart risk biomarkers. Our results may reflect the impact of the persistent air pollution in Buenos Aires on individuals living in this Latin American megacity.

Ischaemic heart disease and stroke mortality by specific coal type among non-smoking women with substantial indoor air pollution exposure in China

BACKGROUND

Lifetime use of bituminous ('smoky') coal is associated with nearly a 100-fold higher risk of lung cancer mortality compared with anthracite ('smokeless') coal use in rural Xuanwei, China, among women. Risk of mortality from ischaemic heart disease (IHD) and stroke for these coal types has not been evaluated.

METHODS

A cohort of 16 323 non-smoking women in Xuanwei, who were lifetime users of either smoky or smokeless coal, were followed up from 1976 to 2011. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) to evaluate lifetime use of coal types and stoves in the home in relation to risk of IHD and stroke mortality.

RESULTS

Among lifetime users of smokeless coal, higher average exposure intensity (≥4 tons/year vs <2.5 tons/year, HR = 7.9, 95% CI = 3.5-17.8; Ptrend =<0.0001) and cumulative exposure (>64 ton-years vs ≤28 ton-years, HR = 6.5, 95% CI = 1.5-28.3; Ptrend =0.003) during follow-up and over their lifetime was associated with increased IHD mortality, and ventilated stove use dramatically reduced this risk (HR = 0.2, 95% CI 0.1-0.5). Higher cumulative exposure to smoky coal during follow-up showed positive associations with IHD mortality, but the evidence for other metrics was less consistent compared with associations with smokeless coal use.

CONCLUSIONS

Higher use of smokeless coal, which is burned throughout China and is generally regarded to be a cleaner fuel type, is associated with IHD mortality. Use of cleaner fuels or stove interventions may be effective in reducing the increasing burden of IHD in developing regions that currently rely on smokeless coal for cooking and heating.

Effects of short-term exposure to particulate matters on heart rate variability: A systematic review and meta-analysis based on controlled animal studies

BACKGROUND

Exposure to particulate matters (PM) is recognized as an important risk factor for cardiovascular disease. A change in cardiac autonomic function is one postulated mechanism leading to PM related cardiovascular events. This study therefore evaluated the associations of short-term exposure to PM and heart rate variability (HRV) parameters, which can reflect the cardiac autonomic function.

METHODS

Four electronic databases were searched for controlled studies of rodents published prior to December 2018. A systematic review and meta-analysis was conducted. Effect sizes were calculated for five main HRV parameters, including standard deviation of normal-to-normal intervals (SDNN), square root of mean squared differences between successive normal-to-normal intervals (rMSSD), low frequency (LF), high frequency (HF), and the ratio of LF and HF (LF/HF).

RESULTS

The review included 23 studies with 401 animals. Short-term exposure to PM by instillation yielded statistically significant effects on SDNN (Standardized Mean Difference [SMD] = -1.11, 95% Confidence Intervals [CI] = -2.22 to -0.01, P = 0.05), LF (SMD = -1.19, 95% CI = -1.99 to -0.40, P = 0.003) and LF/HF (SMD = -1.05, 95% CI = -2.03 to -0.07, P = 0.04). Short-term exposure to PM by inhalation only yielded statistically significant effect on LF/HF (SMD = -0.83, 95% CI = -1.39 to -0.27, P = 0.004). There was no evidence that animal model and exposure frequency influenced the relationship of PM and HRV.

CONCLUSIONS

Short-term exposure to PM can decrease HRV of rodents, affecting cardiac autonomic function. Exposure methods can influence the relationships of PM and HRV parameters. Further studies should focus on the effects of long-term PM exposure, on human beings, and potential influential factors of PM-HRV associations.

Pediatric Thermoregulation: Considerations in the Face of Global Climate Change

Predicted global climate change, including rising average temperatures, increasing airborne pollution, and ultraviolet radiation exposure, presents multiple environmental stressors contributing to increased morbidity and mortality. Extreme temperatures and more frequent and severe heat events will increase the risk of heat-related illness and associated complications in vulnerable populations, including infants and children. Historically, children have been viewed to possess inferior thermoregulatory capabilities, owing to lower sweat rates and higher core temperature responses compared to adults. Accumulating evidence counters this notion, with limited child-adult differences in thermoregulation evident during mild and moderate heat exposure, with increased risk of heat illness only at environmental extremes. In the context of predicted global climate change, extreme environmental temperatures will be encountered more frequently, placing children at increased risk. Thermoregulatory and overall physiological strain in high temperatures may be further exacerbated by exposure to/presence of physiological and environmental stressors including pollution, ultraviolet radiation, obesity, diabetes, associated comorbidities, and polypharmacy that are more commonly occurring at younger ages. The aim of this review is to revisit fundamental differences in child-adult thermoregulation in the face of these multifaceted climate challenges, address emerging concerns, and emphasize risk reduction strategies for the health and performance of children in the heat.

Risk of concentrations of major air pollutants on the prevalence of cardiovascular and respiratory diseases in urbanized area of Kuala Lumpur, Malaysia

Rapid urbanisation in Malaysian cities poses risks to the health of residents. This study aims to estimate the relative risk (RR) of major air pollutants on cardiovascular and respiratory hospitalisations in Kuala Lumpur. Daily hospitalisations due to cardiovascular and respiratory diseases from 2010 to 2014 were obtained from the Hospital Canselor Tuanku Muhriz (HCTM). The trace gases, PM₁₀ and weather variables were obtained from the Department of Environment (DOE) Malaysia in consistent with the hospitalisation data. The RR was estimated using a Generalised Additive Model (GAM) based on Poisson regression. A "lag" concept was used where the analysis was segregated into risks of immediate exposure (lag 0) until exposure after 5 days (lag 5). The results showed that the gases could pose significant risks towards cardiovascular and respiratory hospitalisations. However, the RR value of PM₁₀ was not significant in this study. Immediate effects on cardiovascular hospitalisations were observed for NO₂ and O₃ but no immediate effect was found on respiratory hospitalisations. Delayed effects on cardiovascular and respiratory hospitalisations were found with SO₂ and NO₂. The highest RR value was observed at lag 4 for respiratory admissions with SO₂ (RR = 1.123, 95% CI = 1.045-1.207), followed by NO₂ at lag 5 for cardiovascular admissions (RR = 1.025, 95% CI = 1.005-1.046). For the multi-pollutant model, NO₂ at lag 5 showed the highest risks towards cardiovascular hospitalisations after controlling for O₃ 8 h mean lag 1 (RR = 1.026, 95% CI = 1.006-1.047), while SO₂ at lag 4 showed highest risks towards respiratory hospitalisations after controlling for NO₂ lag 3 (RR = 1.132, 95% CI = 1.053-1.216). This study indicated that exposure to trace gases in Kuala Lumpur could lead to both immediate and delayed effects on cardiovascular and respiratory hospitalisations.

Characteristics of centenarians' lifestyles and their contribution to life satisfaction: A case study conducted on Hainan Island

BACKGROUND

Centenarians represent an intriguing model for healthy aging. They appear to have adapted well to their lives and are likely to be influenced by previous lifestyle habits, and their life satisfaction is influenced by mental and psychological health.

OBJECTIVE

The aim of this study is to explore centenarians' lifestyles by sex and their potential contribution to life satisfaction.

METHOD

In order to examine the common characteristics of centenarians in Hainan and the potential differences between men and women, a cross-sectional survey was conducted with 223 cognitively-intact Chinese centenarians. We also explored the association between life satisfaction and other physical factors using binary logistic regression and principal component analysis.

RESULTS

The results provided supplementary evidence indicating that women tended to live longer than men. However, the difference in life satisfaction observed between the sexes was not obvious (p = 0.659). The proportion of physical factors between each sex showed a similar trend in distribution. Most centenarians' lifestyles were similar, in that they followed a light diet and did not smoke or drink alcohol. Centenarians in better physical condition and with higher self-assessment, as well as those with "alcohol and tobacco habits," were more satisfied with their life. Of the factors examined in the binary logistic regression, sleep satisfaction was the only factor significantly positively correlated with life satisfaction (p < .01).

CONCLUSION

The research findings elucidated physiological and psychological health in centenarians and provided a model of healthy aging strategies for reference purposes.

Case-crossover analysis of short-term particulate matter exposures and stroke in the health professionals follow-up study

BACKGROUND

Stroke is a leading cause of morbidity and mortality in the United States. Associations between short-term exposures to particulate matter (PM) air pollution and stroke are inconsistent. Many prior studies have used administrative and hospitalization databases where misclassification of the type and timing of the stroke event may be problematic.

METHODS

In this case-crossover study, we used a nationwide kriging model to examine short-term ambient exposure to PM10 and PM2.5 and risk of ischemic and hemorrhagic stroke among men enrolled in the Health Professionals Follow-up Study. Conditional logistic regression models were used to obtain estimates of odds ratios (OR) and 95% confidence intervals (CI) associated with an interquartile range (IQR) increase in PM2.5 or PM10. Lag periods up to 3 days prior to the stroke event were considered in addition to a 4-day average. Stratified models were used to examine effect modification by patient characteristics.

RESULTS

Of the 727 strokes that occurred between 1999 and 2010, 539 were ischemic and 122 were hemorrhagic. We observed positive statistically significant associations between PM10 and ischemic stroke (ORlag0-3 = 1.26; 95% CI: 1.03-1.55 per IQR increase [14.46 μg/m3]), and associations were elevated for nonsmokers, aspirin nonusers, and those without a history of high cholesterol. However, we observed no evidence of a positive association between short-term exposure to PM and hemorrhagic stroke or between PM2.5 and ischemic stroke in this cohort.

CONCLUSIONS

Our study provides evidence that ambient PM10 may be associated with higher risk of ischemic stroke and highlights that ischemic and hemorrhagic strokes are heterogeneous outcomes that should be treated as such in analyses related to air pollution.

The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real-world conditions

Electronic cigarette (e-cigarette) use has steadily increased since 2010. Indoor e-cigarette use exposes bystanders to a new source of particulate matter (PM) air pollution. Elevated short-term exposures to PM with a lower measuremented aerodynamic diameter (≤2.5 μm), PM_2.5 and ultrafine particles (UFPs) have been linked to increased risk of adverse respiratory and cardiac events. This exposure study estimated concentrations of PM_2.5 and UFPs from indoor e-cigarette use at 0.5 meters (m) and 1 m away from an e-cigarette user and investigated whether these indoor concentrations varied across three common e-cigarette models. One e-cigarette user tested three different e-cigarettes containing the same nicotine solution on three separate occasions and measured concentrations on PM_2.5 and UFPs at 0.5 and 1 m in a ∼38 m³ office. Continuous measures of PM_2.5 and UFPs were taken for 5.5 min before e-cigarette use, then the user puffed seven times for 6.5 min (exposure), and for 10 min after ceasing e-cigarette use. Following the initiation of e-cigarette use, levels of PM_2.5 increased 160-fold at a distance of 0.5 m, and 103-fold at 1 m. The corresponding increases in UFP counts were 5.2, and 3.0-fold higher, respectively. The PM_2.5 concentrations and UFP counts between e-cigarette models were statistically significantly different at 1 m, but not at 0.5 m. There was substantial variability between distances, e-cigarettes, and replicates. This study indicates that e-cigarette vapors influence PM_2.5 and UFPs concentrations/counts at close proximity distances indoors; additional research is needed to characterize the composition of those particles and evaluate the impacts of other e-cigarette solutions on indoor air quality.

Estimation of the contributions of the sources driving PM2.5 levels in a Central Mediterranean coastal town

Receptor modelling techniques are widely used in order to identify the main natural and anthropogenic processes driving aerosol levels at a receptor. In this work, Positive Matrix Factorization (PMF) was used to apportion PM_2.5 levels at a traffic site (Msida) located in a coastal town. 180 filters collected throughout a yearly sampling campaign conducted in 2016, were chemically characterized by light absorbance analysis, x-ray fluorescence and ion chromatography in order to determine the concentrations of black carbon, 17 elements and 5 ions, respectively. The resulting chemical data base was used in conjunction with PMF in order to identify the 7 components affecting the PM_2.5 levels at the receptor site. Six of these sources are considered to be typical of the atmospheric composition of coastal traffic sites: traffic (27.3%), ammonium sulfate (23.6%), Saharan dust (15%), aged sea salt (12.7%), shipping (5%) and fresh sea salt (4.6%). This is the first time that such a study was carried out in Malta and helps in understanding the aerosol pollution climate of the Central Mediterranean, which is still relatively understudied when compared to the Eastern and Western Mediterranean. Furthermore, we have isolated a factor exclusive to Malta: the fireworks component, which is responsible for 2.9% of the PM_2.5 and which has health implications due to its chemical composition. The results of this work should also serve to guide the policy makers in achieving the necessary emission reductions in order to achieve the WHO guideline for PM_2.5 by 2020.

Negative Cellular Effects of Urban Particulate Matter on Human Keratinocytes Are Mediated by P38 MAPK and NF-κB-dependent Expression of TRPV 1

Urban particulate matter (UPM) exerts negative effects on various human organs. Transient receptor potential vanilloid 1 (TRPV1) is a polymodal sensory transducer that can be activated by multiple noxious stimuli. This study aimed to explore the effects of the UPM 1648a on the expression of TRPV1, and its regulatory mechanisms in HaCaT cells. UPM enhanced TRPV 1 promoter-luciferase reporter activity. UPM also increased expression of the TRPV 1 gene as evidenced by increased mRNA and protein levels of TRPV 1. In addition, elucidation of the underlying mechanism behind the UPM-mediated effects on TRPV 1 expression revealed that UPM can upregulate expression of the TRPV1 gene by activating activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB). The UPM treatment also altered Ca²⁺ influx and cell proliferation, as well as production of interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). In addition, these UPM-induced effects were attenuated by SB203580 and ammonium pyrrolidinedithiocarbamate (PDTC). However, SP600125 and PD98059 did not alter the UPM-induced effects. Taken together, these findings indicate that UPM upregulates expression of the TRPV 1 gene, which is mediated by the p38 mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways and suggest that UPM is a potential irritant that can induce skin processes such as aging and inflammatory responses.

Mitigation of air pollution by greenness: A narrative review

Air pollution represents one of the world's most important environmental health risks, being associated with an increased rate of multiple diseases (mainly cardiopulmonary) and of premature deaths. A number of actions have been suggested and implemented to mitigate the deleterious health effects of air pollution. Accordingly, recent research has attempted to estimate the beneficial effect of exposure to greenness on human health. In this narrative review, we summarize and review the current literature on the favourable association between greenness and human health in both the outdoor and indoor environments. The potential mechanisms underlying this benefit will be also addressed.

Air quality and acute myocardial infarction in adults during the 2016 Hangzhou G20 summit

To fulfill its commitment to a successful Hangzhou G20 summit (4 to 5 September 2016), the Chinese government implemented a series of measures to improve the air quality in Hangzhou. We report findings on air quality and acute myocardial infarction (AMI) hospital admissions in adults during the Hangzhou G20 summit. Three study periods were defined. The first period was pre-G20 (28 July to 27 August: limited restrictions on industrial emissions). The second period was G20 (28 August to 6 September) when there were further restrictions on industrial emissions and increased transportation restrictions. The third period was post-G20 (7 September to 6 October) when restrictions were relaxed again. The mean number of AMI admissions per day was, respectively, 8.2 during G20, 13.3 during pre-G20, and 15.1 during post-G20. We used time-series Poisson regression models to estimate the relative risk (RR) for AMI associated with pollution levels. Our results suggest that the air quality improvement can reduce the number of hospital admissions for AMI.

The clinicopathological and prognostic features of Chinese and Japanese inpatients with lung cancer

Here, we retrospectively compared the differences in clinicopathological behaviors and prognosis of lung cancer from the First Affiliated Hospital (CMU1, n=513), Shengjing Hospital (CMUS, n=1021), Tumor Hospital (CMUT, n=5378) of China Medical University, the First Affiliated Hospital of Dalian (DMU, n=2251) and Jinzhou (JMU, n=630) Medical University, Takaoka Kouseiren Hospital (Takaoka, n=163) of Japan. Japanese lung cancer patients showed smaller tumor size, lower TNM staging, lower ratio of squamous cell carcinoma and higher ratio of small and large cell carcinomas than Chinese patients (p<0.05). Survival analysis showed that tumor size was employed as a prognostic factor for the Japanese and Chinese cancer patients (p<0.05). In DMU and CMUS, the ratios of female patients or adenocarcinoma were higher than other hospitals (p<0.05), while the patients from CMUT and CMU1 were younger than the others (p<0.05). The ratios of squamous cell carcinoma from CMUT, CMU1 and JMU were higher than the others, while it was the same for the ratio of large and small cell carcinoma in Takaoka and CMU1 (p<0.05). TNM staging was higher in CMUT than JMU and Takaoka (p<0.05). The female patients of lung cancer showed young prone, large tumor size, a high ratio of adenocarcinoma and advanced TNM staging in comparison to the counterpart (p<0.05). The younger patients of lung cancer displayed smaller tumor size, higher ratio of adenocarcinoma, lower TNM staging than the elder in Takaoka (p<0.05). There were more aggressive behaviors and shorter survival time for Chinese than Japanese lung cancer patients. The prevention of lung cancer should be strengthened by establishing a systematic and effective screening strategy, especially for the young and female patients.

Seasonal and monthly variability in the incidence of venous thromboembolism

Many studies showed that the occurrence of cardiovascular and cerebrovascular events exhibits a seasonal and monthly variation. Evidences of a seasonal and monthly variation in the incidence of venous thromboembolism (VTE) are more conflicting. We conducted a systematic review and a meta-analysis of the literature to assess the presence of an infradian rhythm of this disease. MEDLINE and EMBASE databases were searched up to January 2010. Monthly and seasonal variation in the incidence of VTE were analysed. We included studies analysing seasonal or monthly aggregation in the incidence of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with an objective diagnosis of VTE. Two authors independently reviewed and extracted data. Seventeen studies for a total of about 35,000 patients were included. Twelve studies analysed the seasonal variation and 10 studies the monthly variation of VTE. Our results showed a significantly increased incidence of VTE in winter (chi-square 146.04, p <0.001), with a relative risk (RR) of VTE of 1.143 (99% CI [1.141, 1.144]), and a significantly increased incidence of VTE in January (chi-square 232.57, p <0.001) with an RR of VTE of 1.194 (99% CI 1.186, 1.203). Subgroup analyses including only idiopathic venous thromboembolic events confirmed the results of principal analyses. In conclusion, our data support the presence of an infradian pattern in the incidence of venous thromboembolic events, with a significantly higher risk in Winter and in January. Future studies are needed to better clarify the mechanisms behind this pattern.

Role of oxidative stress in cardiovascular disease outcomes following exposure to ambient air pollution

Exposure to ambient air pollution is associated with adverse cardiovascular outcomes. These are manifested through several, likely overlapping, pathways including at the functional level, endothelial dysfunction, atherosclerosis, pro-coagulation and alterations in autonomic nervous system balance and blood pressure. At numerous points within each of these pathways, there is potential for cellular oxidative imbalances to occur. The current review examines epidemiological, occupational and controlled exposure studies and research employing healthy and diseased animal models, isolated organs and cell cultures in assessing the importance of the pro-oxidant potential of air pollution in the development of cardiovascular disease outcomes. The collective body of data provides evidence that oxidative stress (OS) is not only central to eliciting specific cardiac endpoints, but is also implicated in modulating the risk of succumbing to cardiovascular disease, sensitivity to ischemia/reperfusion injury and the onset and progression of metabolic disease following ambient pollution exposure. To add to this large research effort conducted to date, further work is required to provide greater insight into areas such as (a) whether an oxidative imbalance triggers and/or worsens the effect and/or is representative of the consequence of disease progression, (b) OS pathways and cardiac outcomes caused by individual pollutants within air pollution mixtures, or as a consequence of inter-pollutant interactions and (c) potential protection provided by nutritional supplements and/or pharmacological agents with antioxidant properties, in susceptible populations residing in polluted urban cities.

Health Effects of Ambient Air Pollution in Developing Countries

The deleterious effects of ambient air pollution on human health have been consistently documented by many epidemiologic studies worldwide, and it has been calculated that globally at least seven million deaths are annually attributable to the effects of air pollution. The major air pollutants emitted into the atmosphere by a number of natural processes and human activities include nitrogen oxides, volatile organic compounds, and particulate matter. In addition to the poor ambient air quality, there is increasing evidence that indoor air pollution also poses a serious threat to human health, especially in low-income countries that still use biomass fuels as an energy resource. This review summarizes the current knowledge on ambient air pollution in financially deprived populations.

Associations Between Air Quality Changes and Biomarkers of Systemic Inflammation During the 2014 Nanjing Youth Olympics: A Quasi-Experimental Study

There is increasing interest in quasi-experimental research to evaluate whether actions taken to improve air quality will benefit public health. We conducted a quasi-experimental study to evaluate inflammatory response to changes in air quality during the 2014 Nanjing Youth Olympics in China. We repeatedly measured 8 biomarkers of systemic inflammation in 31 healthy adults and obtained hourly air pollutant concentrations from a nearby fixed-site monitoring station. We used linear mixed-effect models to examine the associations between air quality changes and blood biomarkers. Air pollutant concentrations decreased apparently during the Youth Olympics. Concomitantly, we observed significant decreases in levels of soluble cluster of differentiation 40 (CD40) ligand and interleukin 1β (geometric means ratios were 0.45 and 0.24, respectively) from the pre-Olympic period to the intra-Olympic period. Afterwards, levels of C-reactive protein and vascular cell adhesion molecule 1 increased significantly (geometric means ratios were 2.22 and 1.29, respectively) in the post-Olympic period. Fine particulate matter and ozone were significantly associated with soluble CD40 ligand, P-selectin, interleukin 1β, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1. Other pollutants showed positive but nonsignificant associations. Our study indicated that reduced air pollution, especially fine particulate matter and ozone, during the 2014 Nanjing Youth Olympics was associated with alleviated systemic inflammation in healthy adults.

Ambient Air Pollution and the Risk of Central Retinal Artery Occlusion

PURPOSE

To investigate whether daily changes in ambient air pollution were associated with an increased risk of central retinal artery occlusion (CRAO).

DESIGN

Retrospective population-based cohort study.

PARTICIPANTS

We identified patients newly diagnosed with CRAO between 2001 and 2013 in a representative database of 1 000 000 patients that were randomly selected from all registered beneficiaries of the National Health Insurance program in Taiwan. We identified air pollutant monitoring stations located near these patients' residences in different administrative areas in Taiwan to determine the recorded concentrations of particulate matter ≤2.5 μm (PM_2.5), particulate matter ≤10 μm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃). Patients without corresponding monitoring stations were excluded.

METHODS

We used a time-stratified case-crossover study design and conditional logistic regression analysis to assess associations between the risk of CRAO and the air pollutant levels in the days preceding each event.

MAIN OUTCOME MEASURES

Odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We enrolled 96 patients with CRAO in this study. The mean age was 65.6 years (standard deviation, 12.7 years) and 67.7% of patients were male. The risk of CRAO onset was significantly increased (OR, 1.09; 95% CI, 1.01-1.17; P = 0.03) during a 5-day period following a 1 part per billion increase in NO₂ levels. After multipollutant adjustment, the increase in risk was most prominent after 4 days (OR, 1.40; 95% CI, 1.05-1.87; P = 0.02) to 5 days (OR, 2.16; 95% CI, 1.10-4.23; P = 0.03) of elevated NO₂ levels in diabetic patients. The risk of CRAO onset also significantly increased in patients with hypertension and in patients ≥65 years old, after 1 day of elevated SO₂ levels (OR, 1.88; 95% CI, 1.07-3.29; P = 0.03 and OR, 1.90; 95% CI, 1.13-3.21; P = 0.02, respectively). The transient concentration of the other air pollutants, including PM_2.5, PM₁₀, and O₃, did not significantly affect the occurrence of CRAO in this study.

CONCLUSIONS

These results demonstrated a positive association between air pollution and CRAO onset, particularly in patients with diabetes or hypertension and those older than 65 years.

Characteristics of Ambient Black Carbon Mass and Size-Resolved Particle Number Concentrations during Corn Straw Open-Field Burning Episode Observations at a Rural Site in Southern Taiwan

Information on the effect of open-field burning of agricultural residues on ambient black carbon (BC) mass and size-resolved particle number concentrations is scarce. In this study, to understand the effect of such open-field burning on short-term air quality, real-time variations of the BC mass and size-resolved particle number concentrations were monitored before and during a corn straw open-field burning episode at a rural site. Correlations between the BC mass and size-resolved particle number concentrations during the episode were investigated. Moreover, the particle number size distribution and absorption Ångström exponent were determined for obtaining the characteristics of aerosol emissions from the corn straw open-field burning. The results can be used to address public health concerns and as a reference for managing similar episodes of open-field burning of agricultural residues.

A structured review of panel studies used to investigate associations between ambient air pollution and heart rate variability

INTRODUCTION

Dysfunction of the autonomic nervous system is one of the postulated pathways linking short-term exposure to air pollution to adverse cardiovascular outcomes. A hypothesis is that exposure to air pollution decreases heart rate variability, a recognized independent predictor of poorer cardiovascular prognosis.

METHODS

We conducted a structured review of panel studies published between 1946 and July 2015 of the association between ambient air pollution and parameters of heart rate variability reflecting autonomic nervous function. We focused on exposure to mass concentrations of fine particles (PM2.5), nitrogen dioxide (NO2), and ozone (O3), and four commonly used indices of heart rate variability (HRV): standard deviation of all normal-to-normal intervals (SDNN); root mean square of successive differences in adjacent normal-to-normal intervals (RMSSD); high frequency power (HF); and low frequency power (LF). We searched bibliographic databases and references of identified articles and abstracted characteristics of their design and conduct, and synthesized the quantitative findings in graphic form according to health condition of the study population and the functional form of the HRV indices used in the regression analyses.

RESULTS

A total of 33 panel studies were included: 31, 12, and 13 studies were used to investigate ambient exposure to PM2.5, NO2 and O3, respectively. We found substantial variation across studies in terms of design characteristics and statistical methodologies, and we identified some studies that may have had methodological and statistical issues. Because many panel studies were not comparable to each other, meta-analyses were not generally possible, although we were able to pool the results obtained amongst older adults who had cardiovascular disease for the 24-h average concentrations of PM2.5 prior to the heart rate variability measurements. In studies of PM2.5 among older adults with cardiovascular disease, logarithmic transformations of the HRV indices were used in ten studies. Negative associations across all HRV indices were found in 60-86% of these studies for periods of exposures ranging from 5-min to 5-days. The pooled percent changes for an increase of 10μg/m(3) in the 24-h prior to the measurements of HRV were: -2.11% for SDNN (95% confidence interval (95%CI): -4.00, -0.23%), -3.29% for RMSSD (95%CI: -6.32, -0.25%), -4.76% for LF (95%CI: -12.10, 2.58%), and -1.74% for HF (95%CI: -7.79, 4.31%). No transformations were used in seven studies of PM2.5 among older adults with cardiovascular disease, and we found for absolute differences pooled changes in the HRV indices, for an increase of 10μg/m(3), of -0.31ms for SDNN (95%CI: -1.02, 0.41ms) and -1.22ms for RMSSD (95%CI: -2.37; -0.07ms). For gaseous pollutants, negative associations over periods of exposure ranging from 5-min or to 5-days prior to the heart rate variability measurements were reported in 71-83% of studies of NO2 and 57-100% of studies of O3, depending of the indices of heart rate variability. However, many of these studies had statistical or methodological issues, and in the few studies without these issues the confidence intervals were relatively wide and mostly included the null.

CONCLUSIONS AND DISCUSSION

We were not persuaded by the results that there was an association between PM2.5 and any of the four indices of heart rate variability. For NO2 and O3 the number of high-quality studies was insufficient to draw any definite conclusions. Further panel studies with improved design and methodologies are needed to help establish or refute an association between ambient exposure to air pollution and heart rate variability.

Hair elements and healthy aging: a cross-sectional study in Hainan Island, China

Healthy aging is considered as the core issue of aging population. Centenarians are a symbol of healthy aging. Concentration of elements in hair is an indicator of micronutrient status, which can affect the human health. In the present study, we investigated element concentrations in the scalp hair of 255 healthy centenarians from Hainan Island, China. The pattern of intergenerational transmission of elements and the effects of confounders such as sex, age, education level, smoking habits, alcohol intake, and frequency of hospitalization on hair element concentrations were assessed. For most elements, the load in hair increased significantly through intergenerational transmission (i.e., centenarians < children < grandchildren). Our results also demonstrated that female centenarians had significantly higher concentrations of Ca, Mg, Mn, Se, and Sr but lower levels of Cr and P. The Mn level was statistically significantly lower in the primary studies group. Alcohol intake was positively associated with Cd and Na levels, whereas smoking habits showed no significant effect on all the elements. Furthermore, the frequency of hospitalization was significantly positively associated with Cd, Cu, and Pb concentration. Moreover, our analysis suggested that adequate concentrations of Fe and Se might increase the life span of centenarians, whereas excessive concentrations of P and Pb were harmful to health and reduced life span. These results imply that element concentrations could be manipulated as a therapeutic modality in geriatric disease. They might also provide reference values for diseased subjects, allowing improved diagnoses and more effective therapies, which might support effective policies on health and aging.

COHgb levels predict the long-term development of acute myocardial infarction in CO poisoning

BACKGROUND

There are several studies evaluating the cardiac effects of carbon monoxide (CO) poisoning during the acute period; however, the number of studies evaluating the long-term cardiac effects is limited.

OBJECTIVE

The present study aimed to evaluate the effects of blood carboxyhemoglobin (COHb) levels, elevated due to CO poisoning on the long-term development of acute myocardial infarction (AMI).

METHODS

This cross-sectional cohort study included a total of 1013 consecutive patients who presented to the emergency department (ED) due to CO poisoning, between January 2005 and December 2007. The diagnosis of CO poisoning was made according to the medical history and a COHb level of greater than 5%. In terms of AMI development, the patients were followed up for an average of 56 months.

RESULTS

At the end of follow-up, 100 (10%) of 1013 patients experienced AMI. Carboxyhemoglobin levels at the time of poisoning were higher among those who were diagnosed with AMI compared to those who were not (55%±6% vs 30%±7%; P<.001). Using a multivariate Cox proportional hazards model with forward stepwise method, age, COHb level, CO exposure time, and smoking remained associated with an increased risk of AMI after adjustment for the variables found to be statistically significant in a univariate analysis. According to a receiver operating characteristic curve analysis, the optimal cutoff value of COHb used to predict the development of AMI was found to be greater than 45%, with 98% sensitivity and 94.1% specificity.

CONCLUSION

In patients presenting to the ED with CO poisoning, COHb levels can be helpful for risk stratification in the long-term development of AMI.

The relationship of exposure to air pollutants in pregnancy with surrogate markers of endothelial dysfunction in umbilical cord

BACKGROUND

This study aims to investigate the association of exposure to ambient air pollution during pregnancy with cord blood concentrations of surrogate markers of endothelial dysfunction.

METHODS

This population-based cohort was conducted from March 2014 to March 2015 among 250 mother-neonate pairs in urban areas of Isfahan, the second large and air-polluted city in Iran. We analyzed the association between the ambient carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), particular matter 10 (PM10), and air quality index (AQI) with cord blood levels of endothelin-1, vascular adhesion molecule (VCAM), and intercellular adhesion molecule (ICAM). Multiple regression analysis was conducted after adjustment for potential confounding factors and covariates. The regression coefficient (beta), standard error of the estimate (SE), and 95% confidence intervals for each regression coefficient (95% CI) are reported.

RESULTS

Data of 233 mother-neonate pairs were complete, and included in the analysis. Multiple regression analyses showed that AQI, CO and O3 had significant correlation with cord blood ICAM-1 [Beta (SE), 95%CI: 2.93 (0.72), 1.33,5.54; 2.28(1.44), 1.56,5.12; and 2.02(0.01), 1.03,2.04, respectively] as well as with VCAM-1 [2.78(0.91), 1.69,4.57; 2.47(1.47), 1.43,5.37; and 2.01(0.01),1.07,2.04, respectively]. AQI, PM10, and SO2 were significantly associated with Endothelin-1 concentrations [Beta (SE), 95%CI: 10.16(5.08),7.61,14.28; 9.70(3.46), 2.88,16.52; and 1.07(0.02), 1.03,2.11, respectively].

CONCLUSIONS

The significant associations of air pollutants with markers of endothelial dysfunction during fetal period may provide another evidence on the adverse health effects of air pollutants on early stages of atherosclerosis from fetal period. Our findings underscore the importance of considering environmental factors in primordial prevention of chronic diseases.

Short-term effects of atmospheric particulate matter on myocardial infarction: a cumulative meta-analysis

Atmospheric particulate matter (PM) is hypothesized to increase the risk of myocardial infarction (MI). However, the epidemiological evidence is inconsistent. We identified 33 studies with more than 4 million MI patients and applied meta-analysis and meta-regression to assess the available evidence. Twenty-five studies presented the effects of the PM level on hospitalization for MI patients, while eight studies showed the effects on mortality. An increase in PM10 was associated with hospitalization and mortality in myocardial infarction patients (RR per 10 μg/m(3) = 1.011, 95% CI 1.006-1.016; RR per 10 μg/m(3) = 1.008, 95 % CI 1.004-1.012, respectively); PM2.5 also increased the risk of hospitalization and mortality in MI patients (RR per 10 μg/m(3) = 1.024, 95% CI 1.007-1.041 for hospitalization and RR per 10 μg/m(3) = 1.012, 95% CI 1.010-1.015 for mortality). The results of the cumulative meta-analysis indicated that PM10 and PM2.5 were associated with myocardial infarction with the addition of new studies each year. In conclusion, short-term exposure to high PM10 and PM2.5 levels revealed to increase risk of hospitalization and mortality for myocardial infarction. Policy support of pollution control and individual protection was strongly recommended.

Association between particulate air pollution and venous thromboembolism: A systematic literature review

Air pollution is a leading global problem for public health. A number of ambient pollutants have been involved, including carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3) and particulate matter (PM). Although exposure to PM has been linked to a wide array of cardiovascular and respiratory disorders, its effect on venous thrombotic disorders is still uncertain. To elucidate this issue, we have performed a systematic review on the existing literature on the association between PM and venous thromboembolism (VTE), using MEDLINE, EMBASE and Cochrane electronic databases. Of the 158 reviewed studies, 11 of them (3 case-crossover studies, 2 time-series studies, 2 case-control studies, 2 prospective cohort studies, 2 retrospective studies) involving more than 500,000 events fulfilled the inclusion criteria and results are presented here. Because there was substantial heterogeneity in study design, duration of follow-up, statistical measure of effects, clinical outcomes and threshold, we refrained to perform a quantitative analysis of the available data and carried out only a systematic review. Overall, the literature data suggest a link between PM and VTE, but further trials on larger populations of patients with homogeneous study designs and outcomes are warranted.

Evaluation of atherosclerosis as a potential mode of action for cardiovascular effects of particulate matter

Epidemiology studies have consistently reported associations between PM2.5 exposure and cardiovascular (CV) morbidity and mortality, but the epidemiology evidence for associations between PM2.5 and subclinical measures of atherosclerosis is unclear. We critically reviewed the experimental studies of PM2.5 and effects associated with acceleration and exacerbation of atherosclerosis and evaluated whether they support a biologically plausible, human-relevant mode of action (MoA) for the associations between PM2.5 exposure and adverse CV outcomes reported in epidemiology studies. We focused on outcomes related to atherosclerotic plaque development, thrombosis, and coagulation, and we examined whether these outcomes were correlated with measures of oxidative stress and systemic or pulmonary inflammation, to evaluate whether these processes are likely to be key early events for atherogenic effects of PM. While the current experimental evidence indicates that the acceleration and exacerbation of atherosclerosis is a biologically plausible MoA in experimental animal models, we found that the human relevance of the key events in the proposed MoA is unclear and not well supported by the existing data. Further studies are needed to fill several important data gaps before the human relevance of this MoA can be established.