Effects Of Particulate Air Pollution Research Articles

Peas in a Pod? The Similarities between UFPs and Nanoparticles Yield Research Opportunities.

Vol. 125, No. 10 Science SelectionOpen AccessPeas in a Pod? The Similarities between UFPs and Nanoparticles Yield Research Opportunitiesis accompanied byNanomaterials Versus Ambient Ultrafine Particles: An Opportunity to Exchange Toxicology Knowledge Carrie Arnold Carrie Arnold Search for more papers by this author Published:20 October 2017CID: 104005https://doi.org/10.1289/EHP2097View Article in:中文版AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit From a size standpoint, engineered nanoparticles are identical to ultrafine particles (UFPs) in ambient air—both measure 100 nanometers100 nm or less in diameter—but differences in the origin and potential chemistry of the two groups of particles have sent investigators down separate paths of inquiry. In a new workshop report in EHP, researchers outline knowledge-sharing opportunities that may help bolster understanding of both types of particles.1“We realized that a lot of the work in ultrafine particles could be fed back into nanotoxicology, and vice versa,” says first author Vicki Stone, a toxicologist at Heriot Watt University in Edinburgh. “So we brought some of the field together to discuss these opportunities.”Initial studies on the negative health effects of particulate air pollution focused on coarse particles measuring 2.5 to 10 micrometers2.5–10μm in diameter (PM subscript 10PM2.5–10) and fine particles measuring less than or equal to 2.5 micrometers2.5μm or less in diameter (PM subscript 2.5PM2.5). It was not until the 1990s that animal studies revealed that even tinier particles can cause potentially harmful inflammatory responses.2 These UFPs can be inhaled deep into the lungs, where their large surface area gives them more opportunity to damage the alveoli.3“For negative health outcomes, they really give you more bang for your buck,” says Terry Gordon, an environmental health scientist at New York University. Gordon was not involved with the new report.Studies on ambient UFPs have largely relied on substances such as carbon black, titanium dioxide, and diesel soot. The problem, says Steffen Loft, an environmental health scientist at the University of Copenhagen, is that it is difficult to tell exactly what particles and particle combinations are causing problems. “There are lots of data on the effects of air pollution exposure, but these ultrafine particles are not as well characterized. It is hard to say this particle has this effect,” Loft says.UFPs (such as this sample, which came from wood smoke) can be inhaled deep into the lungs, where their large surface area gives them more opportunity to damage the alveoli. Unlike engineered nanoparticles, UFPs in any given sample can vary widely in their chemical makeup, making it difficult to tell exactly what particles and particle combinations may cause problems. Image: © Anette Kocbach Bølling.In the past decade, the field of nanotoxicology has taken off, and researchers have begun to develop new ways of characterizing nanomaterials and the ways in which they may exert their toxic effects. Used in everything from antimicrobial coatings on fabrics to sunscreens, engineered nanoparticles have raised a new set of health questions for exposed workers and consumers.Unlike ambient UFPs, which comprise a hodgepodge of chemicals created from combustion reactions, scientists know the exact makeup of engineered nanoparticles. Their use requires precise knowledge of their size and chemistry, which makes it easier to study any negative health outcomes.1The relatively recent emergence of these particles, however, means that scientists know less about the extent and potential health effects of exposures, Stone says. This is worrisome, she says, because the potential for exposure to engineered nanoparticles is significant—almost everyone uses at least one product containing some type of nanoparticle on a daily basis.Awareness of the knowledge gaps in the complementary areas of UFPs and engineered nanoparticles resulted in a 2015 meeting of top researchers in the field. The meeting was part of the European Union’s MODENA COST Initiative to coordinate interdisciplinary collaboration in nantoxicology. Out of that conference emerged the new report, which identified research priorities and key lessons that could be applied to this area. The lessons included broad overarching goals in applying research from UFPs to nanoparticles and vice versa. They also homed in on specific experimental strategies to elucidate the specific physiochemical effects of different particles and the ways in which toxicity is influenced by underlying chemistry.1There are no regulations that specifically address ambient UFPs, although their size lumps them into the range covered by PM subscript 2.5PM2.5 rules.4 The lack of targeted regulations, combined with shrinking research budgets, make it ever more challenging to study the health effects of UFPs and nanoparticles, Gordon says.As a result, knowledge-sharing efforts like those proposed in the report will be crucial to working to protect human health from the negative effects of air pollution. “These efforts are a good way to positively affect funding and get better data by promoting more efficient and better focused research,” Loft says.

Effects of Particulate Air Pollution on Lung Function in Healthy Adults and Adults With Asthma: A Systematic Review and Meta-Analysis

Effects of Particulate Air Pollution on Lung Function in Healthy Adults and Adults With Asthma: A Systematic Review and Meta-Analysis

Assessment of indoor and outdoor particulate air pollution at an urban background site in Iran.

The relationship between indoor and outdoor particulate air pollution was investigated at an urban background site on the Payambar Azam Campus of Mazandaran University of Medical Sciences in Sari, Northern Iran. The concentration of particulate matter sized with a diameter less than 1μm (PM1.0), 2.5μm (PM2.5), and 10μm (PM10) was evaluated at 5 outdoor and 12 indoor locations. Indoor sites included classrooms, corridors, and office sites in four university buildings. Outdoor PM concentrations were characterized at five locations around the university campus. Indoor and outdoor PM measurements (1-min resolution) were conducted in parallel during weekday mornings and afternoons. No difference found between indoor PM10 (50.1±32.1μg/m3) and outdoor PM10 concentrations (46.5±26.0μg/m3), indoor PM2.5 (22.6±17.4μg/m3) and outdoor PM2.5 concentration (22.2±15.4μg/m3), or indoor PM1.0 (14.5±13.4μg/m3) and outdoor mean PM1.0 concentrations (14.2±12.3μg/m3). Despite these similar concentrations, no correlations were found between outdoor and indoor PM levels. The present findings are not only of importance for the potential health effects of particulate air pollution on people who spend their daytime over a period of several hours in closed and confined spaces located at a university campus but also can inform regulatory about the improvement of indoor air quality, especially in developing countries.

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

Objectives To estimate the short term effect of particulate air pollution (particle diameter <10 μm, or PM10) on mortality and explore the heterogeneity of particulate air pollution effects in major...

Effect of particulate air pollution on coronary heart disease in China: Evidence from threshold GAM and Bayesian hierarchical model

There are few multicity studies to address the effect of short-term effect of particulate matter air pollution on daily Coronary Heart Disease (CHD) mortality in developing countries, much fewer to further discuss its threshold and seasonal effect. This study investigates the season-varying association between particulate matter less than or equal to 10 μm in aerodynamic diameter (PM10) and daily CHD mortality in seven cities of China. Time series threshold Poisson regression model is specified to estimate the health effect for four cities with the threshold effect, and conventional linear Poisson model is used to analyze the effect for three cities without threshold. We apply the Bayesian hierarchical model to pool the city-specific estimates into overall level. On average, a 10 μg/m3 increase of the moving average concentrations of current-day and previous-day PM10 is associated with an increase of 0.81% (95% Posterior Interval, PI: −0.04%, 1.67%) in daily CHD mortality for all the cities as a whole. The associations are smaller than reported in developed countries or regions with lower polluted level, which is consistent to the findings in the literature. The hazardous effect are higher in hot summer and cold winter (1.15% and 0.89%) but lower in relative warm spring and fall (0.85% and 0.69%). In summary, we found significant associations between short-term exposure to PM10 and CHD mortality in China. The sensitivity analyses in the study support the robustness of our results.

Acute Effects of Particulate Air Pollution on Ischemic Heart Disease Hospitalizations in Shanghai, China.

Background: Air pollution has been demonstrated to be a major risk factor for the development of cardiovascular and respiratory diseases worldwide. This study examines the relationship between the exposure to fine particulate matter (PM) and patient hospitalizations as a result of ischemic heart disease (IHD) during 2013–2014 in Shanghai, China. Methods: Daily IHD hospitalization data were acquired from the Shanghai Health Insurance Bureau (SHIB) from 1 January 2013 to 21 December 2014. Daily average concentrations of air pollution as well as meteorological data were obtained from the database of Shanghai Environmental Monitoring Center (SEMC) during the same time period, and all data were analyzed using standard epidemiological methodology. Generalized linear model (GLM) adjusted for time trends, weather conditions, and medical insurance policy was used to estimate the immediate and delayed effects of PMs on IHD hospitalizations, and the effects of PMs were also examined based on gender, age group and seasonal variation. Results: A total of 188,198 IHD hospitalizations were recorded during 2013–2014 in Shanghai, China. During this period, the average concentrations of the fine particulate matter with aerodynamic diameter of <10 μm (PM10) and ≤2.5 (PM2.5) were 76 µg/m3 and 56.3 µg/m3, respectively. The effect of PMs was strongest on days when a 10 μg/m3 increment increase of PM2.5 and PM10, which coincided with an increase in IHD hospitalizations by 0.25% (95% CI: 0.10%, 0.39%) and 0.57% (95% CI: 0.46%, 0.68%), respectively. Furthermore, the effect of PMs was significantly greater in males and people between 41 and 65 years old. Conclusions: Hospitalizations of IHD was strongly associated with short-term exposure to high levels of PM10 and PM2.5 during 2013–2014 in Shanghai, China.

Particulate air pollutants, APOE alleles and their contributions to cognitive impairment in older women and to amyloidogenesis in experimental models

Exposure to particulate matter (PM) in the ambient air and its interactions with APOE alleles may contribute to the acceleration of brain aging and the pathogenesis of Alzheimer’s disease (AD). Neurodegenerative effects of particulate air pollutants were examined in a US-wide cohort of older women from the Women’s Health Initiative Memory Study (WHIMS) and in experimental mouse models. Residing in places with fine PM exceeding EPA standards increased the risks for global cognitive decline and all-cause dementia respectively by 81 and 92%, with stronger adverse effects in APOE ɛ4/4 carriers. Female EFAD transgenic mice (5xFAD+/−/human APOE ɛ3 or ɛ4+/+) with 225 h exposure to urban nanosized PM (nPM) over 15 weeks showed increased cerebral β-amyloid by thioflavin S for fibrillary amyloid and by immunocytochemistry for Aβ deposits, both exacerbated by APOE ɛ4. Moreover, nPM exposure increased Aβ oligomers, caused selective atrophy of hippocampal CA1 neurites, and decreased the glutamate GluR1 subunit. Wildtype C57BL/6 female mice also showed nPM-induced CA1 atrophy and GluR1 decrease. In vitro nPM exposure of neuroblastoma cells (N2a-APP/swe) increased the pro-amyloidogenic processing of the amyloid precursor protein (APP). We suggest that airborne PM exposure promotes pathological brain aging in older women, with potentially a greater impact in ɛ4 carriers. The underlying mechanisms may involve increased cerebral Aβ production and selective changes in hippocampal CA1 neurons and glutamate receptor subunits.

Seasonal analysis of the short-term effects of air pollution on daily mortality in Northeast Asia

The constituents and concentrations of pollutants, individual exposures, and biologic responses to air pollution may vary by season and meteorological conditions. However, evidence regarding seasonality of the acute effects of air pollution on mortality is limited and inconsistent. Herein, we examined seasonal patterns in the short-term associations of particulate matter (PM) smaller than 10μm (PM10) with daily mortality in 29 cities of three northeast Asian countries. Stratified time-series models were used to determine whether season altered the effect of PM10 on mortality. This effect was first quantified within each season and at each location using a time-series model, after which city-specific estimates were pooled using a hierarchical Bayesian model. In all data sets, 3,675,348 non-accidental deaths were registered from 1993 to 2009. In Japan, a 10μg/m3 increase in PM10 was significantly associated with increases in non-accidental mortality of 0.44% (95% confidence interval [CI]: 0.03%, 0.8%) in spring and 0.42% (0.02%, 0.82%) in fall. In South Korea, a 10μg/m3 increase in PM10 was significantly associated with increases in non-accidental mortality of 0.51% (0.01%, 1.01%) in summer and 0.45% (0.03%, 0.87%) in fall, in cardiovascular disease mortality of 0.96% (0.29%, 1.63%) in fall, and in respiratory disease mortality of 1.57% (0.40%, 2.75%) in fall. In China, a 10μg/m3 increase in PM10 was associated with increases in non-accidental mortality of 0.33% (0.01%, 0.66%) in summer and 0.41% (0.09%, 0.73%) in winter, in cardiovascular disease mortality of 0.41% (0.08%, 0.74%) in spring and 0.33% (0.02%, 0.64%) in winter, and in respiratory diseases mortality of 0.78% (0.27%, 1.30%) in winter. Our analyses suggest that the acute effect of particulate air pollution could vary seasonally and geographically.

Effects of Short-Term Exposure to Particulate Air Pollutants on the Inflammatory Response and Respiratory Symptoms: A Panel Study in Schoolchildren from Rural Areas of Japan.

The relationship between particulate air pollutants and respiratory symptoms in children has not been consistent among studies, potentially owing to differences in the inflammatory response to different particulate air pollutants. This study aimed to investigate the effect of particulate air pollutants on respiratory symptoms and the inflammatory response in schoolchildren. Three hundred-and-sixty children were included in the study. The children recorded daily respiratory symptom scores for October 2015. In addition, the daily amount of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α production was assessed in THP1 cells stimulated with suspended particulate matter (SPM), which was collected every day during the study period. Generalized estimating equation logistic regression analyses were used to estimate the associations among respiratory symptoms and the daily levels of SPM, IL-6, IL-8, and TNF-α. Daily SPM levels were not associated with respiratory symptoms or the daily IL-6, IL-8, and TNF-α levels. Conversely, there was a significant association between respiratory symptoms and the daily IL-6, IL-8, and TNF-α levels. These results suggested that the effects of particulate air pollutants on respiratory symptoms in schoolchildren might depend more on the pro-inflammatory response to them than on their mass concentration.

Short-term health effects of particulate air pollution in Latin America: a systematic review of the research status in Latin America

Short-term health effects of particulate air pollution in Latin America: a systematic review of the research status in Latin America

Assessing individual susceptibility to short-term effects of particulate air pollution on mortality in Seoul, Korea

Introduction Health effects of particulate matter (PM) could differ by individual characteristics, however, the modifying effects are inconsistent across previous studies. Finding susceptible population is important for explaining regional and temporal variation in PM risk. The objective of the study is to investigate individual susceptibility factors to PM related mortality in Seoul, Korea, 1998-2012. Methods Using a generalized additive model adjusted time-trend, we evaluated the association between PM and daily mortality caused by all, cardiovascular and respiratory diseases. Stratified analyses by individual characteristics-sex, age, place of death, occupation, marital status, and education-were conducted to examine the modification effects. We calculated the 95% confidence interval of differences between effect estimates by strata. The strata with mean daily death count under 5 were excluded from the analysis. Results An increase of 10 µg/m3 in daily average concentration of PM10 and PM2.5 was significantly associated with increase in all-cause mortality by 0.18% and 0.17%, respectively. The effects of PM10 on all-cause, cardiovascular, respiratory mortality were higher in elderly and male. In-hospital death, unemployed, married, and highly educated people were more susceptible to PM10 for all-cause mortality than others. For cardiovascular mortality, PM10 risks were higher in out-of-hospital death, those with professional occupation, married, and those with lower education level. Susceptibility pattern of PM2.5 was similar to PM10. Conclusions Our results shown that, depending on the types of disease, risks in PM are different between subpopulations. These findings provide some information about individual susceptibility that may have implications for further health risk assessment of air pollution and local environmental health policies.

Associations of autophagy with lung diffusion capacity and oxygen saturation in severe COPD: effects of particulate air pollution.

Although traffic exposure has been associated with the development of COPD, the role of particulate matter <10 μm in aerodynamic diameter (PM10) in the pathogenesis of COPD is not yet fully understood. We assessed the 1-year effect of exposure to PM10 on the pathogenesis of COPD in a retrospective cohort study. We recruited 53 subjects with COPD stages III and IV and 15 healthy controls in a hospital in Taiwan. We estimated the 1-year annual mean levels of PM10 at all residential addresses of the cohort participants. Changes in PM10 for the 1-year averages in quintiles were related to diffusion capacity of the lung for carbon monoxide levels (r=−0.914, P=0.029), changes in the pulse oxygen saturation (ΔSaO2; r=−0.973, P=0.005), receptor for advanced glycation end-products (r=−0.881, P=0.048), interleukin-6 (r=0.986, P=0.002), ubiquitin (r=0.940, P=0.017), and beclin 1 (r=0.923, P=0.025) in COPD. Next, we observed that ubiquitin was correlated with ΔSaO2 (r=−0.374, P=0.019). Beclin 1 was associated with diffusion capacity of the lung for carbon monoxide (r=−0.362, P=0.028), ΔSaO2 (r=−0.354, P=0.032), and receptor for advanced glycation end-products (r=−0.471, P=0.004). Autophagy may be an important regulator of the PM10-related pathogenesis of COPD, which could cause deterioration in the lung diffusion capacity and oxygen saturation.

Temperature modifies the acute effect of particulate air pollution on mortality in Jiang'an district of Wuhan

To analyze the temperature modification effect on acute mortality due to particulate air pollution. Daily non-accidental mortality, cardiovascular mortality, and respiratory mortality data were obtained from Jiang'an District Center for Disease Control and Prevention. Daily meteorological data on mean temperature and relative humidity were collected from China Meteorological Data Sharing Service System. The daily concentration of particulate matter was collected from Wuhan Environmental Monitoring center. By using the stratified time-series models, we analyzed effects of particulate air pollution on mortality under different temperature zone from 2002 to 2010, meanwhile comparing the difference of age, gender and educational level, in Wuhan city of China. High temperature (daily average temperature > 33.4 ℃) obviously enhanced the effect of PM10 on mortality. With 10 μg/m(3) increase in PM10 concentrations, non-accidental, cardiovascular, and respiratory mortality increased 2.95% (95%CI: 1.68%-4.24%), 3.58% (95%CI: 1.72%-5.49%), and 5.07% (95%CI: 2.03%-9.51%) respectively. However, low temperature (daily average temperature <-0.21 ℃) enhanced PM10 effect on respiratory mortality with 3.31% (95% CI: 0.07%-6.64%) increase. At high temperature, PM10 had significantly stronger effect on non-accidental mortality of female aged over 65 and people with high educational level groups. With an increase of 10 μg/m(3), daily non-accidental mortality increased 4.27% (95% CI:2.45%-6.12%), 3.38% (95% CI:1.93%-4.86%) and 3.47% (95% CI:1.79%-5.18%), respectively. Whereas people with low educational level were more susceptible to low temperature. A 10 μg/m(3) increase in PM10 was associated with 2.11% (95% CI: 0.20%-4.04%) for non-accidental mortality. Temperature factor can modify the association between the PM10 level and cause-specific mortality. Moreover, the differences were apparent after considering the age, gender and education groups.

Acute Effects of Particulate Air Pollution on the Incidence of Coronary Heart Disease in Shanghai, China.

IntroductionEvidence based on ecological studies in China suggests that short-term exposure to particulate matter (PM) is associated with cardiovascular mortality. However, there is less evidence of PM-related morbidity for coronary heart disease (CHD) in China. This study aims to investigate the relationship between acute PM exposure and CHD incidence in people aged above 40 in Shanghai.MethodsDaily CHD events during 2005–2012 were identified from outpatient and emergency department visits. Daily average concentrations for particulate matter with aerodynamic diameter less than 10 microns (PM10) were collected over the 8-year period. Particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5) were measured from 2009 to 2012. Analyses were performed using quasi-poisson regression models adjusting for confounders, including long-term trend, seasonality, day of the week, public holiday and meteorological factors. The effects were also examined by gender and age group (41–65 years, and >65 years).ResultsThere were 619928 CHD outpatient and emergency department visits. The average concentrations of PM10 and PM2.5 were 81.7μg/m3 and 38.6μg/m3, respectively. Elevated exposure to PM10 and PM2.5 was related with increased risk of CHD outpatients and emergency department visits in a short time course. A 10 μg/m3 increase in the 2-day PM10 and PM2.5 was associated with increase of 0.23% (95% CI: 0.12%, 0.34%) and 0.74% (95% CI: 0.44%, 1.04%) in CHD morbidity, respectively. The associations appeared to be more evident in the male and the elderly.ConclusionShort-term exposure to high levels of PM10 and PM2.5 was associated with increased risk of CHD outpatient and emergency department visits. Season, gender and age were effect modifiers of their association.

Extreme weather and air pollution effects on cardiovascular and respiratory hospital admissions in Cyprus

In many regions of the world, climatic change is associated with increased extreme temperatures, which can have severe effects on mortality and morbidity. In this study, we examine the effect of extreme weather on hospital admissions in Cyprus, for inland and coastal areas, through the use of synoptic weather classifications (air mass types). In addition, the effect of particulate air pollution (PM10) on morbidity is examined. Our results show that two air mass types, namely (a) warm, rainy days with increased levels of water vapour in the atmosphere and (b) cold, cloudy days with increased levels of precipitation, were associated with increased morbidity in the form of hospital admissions. This was true both for cardiovascular and respiratory conditions, for all age groups, but particularly for the elderly, aged over 65. Particulate air pollution was also associated with increased morbidity in Cyprus, where the effect was more pronounced for cardiovascular diseases.

Can Low Carbon Development Strategies Reduce The Health Effects Of Particulate Air Pollution? Findings From A Mixed Industrial Area In Malaysia

Low carbon development, a strategy proposed to slow climate change by reducing greenhouse gas emission, is often associated with the improvement of public health. Yet very few studies have examined...

Assessing responses of cardiovascular mortality to particulate matter air pollution for pre-, during- and post-2008 Olympics periods

BackgroundThe link between particulate air pollution and cardiovascular (CVD) mortality has been investigated. However, there is little direct evidence that reduction measures which decrease particulate air pollution would lead to a reduction in CVD mortality. ObjectivesIn Beijing, China, air quality improvement strategies were developed and actions were taken before and during the 2008 Olympic and Paralympic Games. Taking advantage of this opportunity, the aim of the study was to assess the effects of changes in particulate air pollution before (May 20–July 20, 2008), during (August 1–September 20, 2008) and after (October 1–December 1, 2008) the Olympics period. MethodsConcentrations of air pollution, meteorology and CVD death counts were obtained from official networks and monitoring sites located on the Peking University campus. Air pollution effects with lags of 0–4 days as well as of the 5-day average on cause-specific CVD mortality were investigated for the complete study period (May 20–December 1, 2008) using Quasi-Poisson regression models. Different gender and age subgroups were taken into account. Additionally, effect modification by air mass origin was investigated. In a second step, air pollution effects were estimated for the three specific periods by including an interaction term in the models. ResultsWe observed large concentration decreases in all measured air pollutants during the unique pollution intervention for the Beijing 2008 Olympics. For the whole period, adverse effects of particulate air pollution were observed on CVD mortality with a 1-day delay as well as for the 5-day average exposure, e.g. an 8.8% (95%CI: 2.7–15.2%) increase in CVD mortality with an interquartile range increase in ultrafine particles. The effects were more pronounced in females, the elderly and for cerebrovascular deaths, but not modified by air mass origin. The specific sub-period analysis results suggested that the risks of CVD mortality were lowest during the Olympic Games where strongest reduction measures have been applied. ConclusionsThe results indicated that the reduction of air pollution due to air quality control measures led to a decreased risk of CVD mortality in Beijing. Our findings provide new insight into efforts to reduce ambient air pollution.

Acute toxicity of silver and carbon nanoaerosols to normal and cystic fibrosis human bronchial epithelial cells

Inhalation of engineered nanoparticles (NP) poses a still unknown risk. Individuals with chronic lung diseases are expected to be more vulnerable to adverse effects of NP than normal subjects, due to altered respiratory structures and functions. Realistic and dose-controlled aerosol exposures were performed using the deposition chamber NACIVT. Well-differentiated normal and cystic fibrosis (CF) human bronchial epithelia (HBE) with established air–liquid interface and the human bronchial epithelial cell line BEAS-2B were exposed to spark-generated silver and carbon nanoaerosols (20 nm diameter) at three different doses. Necrotic and apoptotic cell death, pro-inflammatory response, epithelial function and morphology were assessed within 24 h after aerosol exposure. NP exposure resulted in significantly higher necrosis in CF than normal HBE and BEAS-2B cells. Before and after NP treatment, CF HBE had higher caspase-3 activity and secreted more IL-6 and MCP-1 than normal HBE. Differentiated HBE had higher baseline secretion of IL-8 and less caspase-3 activity and MCP-1 secretion compared to BEAS-2B cells. These biomarkers increased moderately in response to NP exposure, except for MCP-1, which was reduced in HBE after AgNP treatment. No functional and structural alterations of the epithelia were observed in response to NP exposure. Significant differences between cell models suggest that more than one and fully differentiated HBE should be used in future toxicity studies of NP in vitro.Our findings support epidemiologic evidence that subjects with chronic airway diseases are more vulnerable to adverse effects of particulate air pollution. Thus, this sub-population needs to be included in nano-toxicity studies.

Blood Pressure and Same-Day Exposure to Air Pollution at School: Associations with Nano-Sized to Coarse PM in Children.

BackgroundUltrafine particles (UFP) may contribute to the cardiovascular effects of particulate air pollution, partly because of their relatively efficient alveolar deposition.ObjectiveIn this study, we assessed associations between blood pressure and short-term exposure to air pollution in a population of schoolchildren.MethodsIn 130 children (6–12 years of age), blood pressure was determined during two periods (spring and fall 2011). We used mixed models to study the association between blood pressure and ambient concentrations of particulate matter and ultrafine particles measured in the schools’ playground.ResultsIndependent of sex, age, height, and weight of the child, parental education, neighborhood socioeconomic status, fish consumption, heart rate, school, day of the week, season, wind speed, relative humidity, and temperature on the morning of examination, an interquartile range (860 particles/cm3) increase in nano-sized UFP fraction (20–30 nm) was associated with a 6.35 mmHg (95% CI: 1.56, 11.14; p = 0.01) increase in systolic blood pressure. For the total UFP fraction, systolic blood pressure was 0.79 mmHg (95% CI: 0.07, 1.51; p = 0.03) higher, but no effects on systolic blood pressure were found for the nano-sized fractions with a diameter > 100 nm, nor PM2.5, PMcoarse, and PM10. Diastolic blood pressure was not associated with any of the studied particulate mass fractions.ConclusionChildren attending school on days with higher UFP concentrations (diameter < 100 nm) had higher systolic blood pressure. The association was dependent on UFP size, and there was no association with the PM2.5 mass concentration.CitationPieters N, Koppen G, Van Poppel M, De Prins S, Cox B, Dons E, Nelen V, Int Panis L, Plusquin M, Schoeters G, Nawrot TS. 2015. Blood pressure and same-day exposure to air pollution at school: associations with nano-sized to coarse PM in children. Environ Health Perspect 123:737–742; http://dx.doi.org/10.1289/ehp.1408121

Cardiac autonomic dysfunction: particulate air pollution effects are modulated by epigenetic immunoregulation of Toll-like receptor 2 and dietary flavonoid intake.

BackgroundShort‐term fine particles (PM2.5) exposure is associated with reduced heart rate variability, a strong predictor of cardiac mortality among older people. Identifying modifiable factors that confer susceptibility is essential for intervention. We evaluated whether Toll‐like receptor 2 (TLR2) methylation, a reversible immune‐epigenetic process, and its dietary modulation by flavonoids and methyl nutrients, modify susceptibility to heart rate variability effects following PM2.5 exposure.Methods and ResultsWe measured heart rate variability and PM2.5 repeatedly over 11 years (1275 total observations) among 573 elderly men from the Normative Aging Study. Blood TLR2 methylation was analyzed using pyrosequencing. Daily flavonoid and methyl nutrients intakes were assessed through the Food Frequency Questionnaire (FFQ). Every 10 μg/m3 increase in 48‐hour PM2.5 moving average was associated with 7.74% (95% CI: −1.21% to 15.90%; P=0.09), 7.46% (95% CI: 0.99% to 13.50%; P=0.02), 14.18% (95% CI: 1.14% to 25.49%; P=0.03), and 12.94% (95% CI: −2.36% to 25.96%; P=0.09) reductions in root mean square of successive differences, standard deviation of normal‐to‐normal intervals, low‐frequency power, and high‐frequency power, respectively. Higher TLR2 methylation exacerbated the root mean square of successive differences, standard deviation of normal‐to‐normal intervals, low‐frequency, and high‐frequency reductions associated with heightened PM2.5 (Pinteraction=0.006, 0.03, 0.05, 0.04, respectively). Every interquartile‐range increase in flavonoid intake was associated with 5.09% reduction in mean TLR2 methylation (95% CI: 0.12% to 10.06%; P=0.05) and counteracted the effects of PM2.5 on low frequency (Pinteraction=0.05). No significant effect of methyl nutrients on TLR2 methylation was observed.ConclusionsHigher TLR2 methylation may confer susceptibility to adverse cardiac autonomic effects of PM2.5 exposure in older individuals. Higher flavonoid intake may attenuate these effects, possibly by decreasing TLR2 methylation.