Μm In Aerodynamic Diameter Research Articles

Liver injury induced in Balb/c mice by PM2.5 exposure and its alleviation by compound essential oils.

Accumulating evidence has suggested a strong link between exposure to air pollution and public health. In particular, inhaled airborne particulate matter <2.5 μm in aerodynamic diameter (PM2.5) can rapidly diffuse from the lungs to the systemic blood circulation and accumulate in the liver. In this study, we used a Balb/c mouse model to investigate liver injury caused by PM2.5 inhalation and the anti-inflammatory and antioxidant effects of compound essential oils (CEOs) in alleviating the extent of this injury. The results of serum biochemical and histopathological analyses showed that PM2.5 exposure induced inflammatory liver injury, meantime CEOs pretreatment attenuated PM2.5-induced liver inflammatory injury. Western blot and qRT-PCR assays showed that PM2.5 increased secretion of cytokines, however CEOs suppressed the production of IL-6 and TNF-α. Furthermore, heme oxygenase-1(HO-1) and superoxide dismutase-1(SOD-1) expression levels showed that PM2.5 could trigger oxidative stress-mediated liver injury, whereas CEOs pretreatment might protect against PM2.5-induced liver injury through regulation of the antioxidant system. Molecular analysis showed that the expression of TLR4, a protein which plays a key role in liver health and injury. Results showed that TLR4 was promoted by PM2.5 but inhibited by CEOs pretreatment in PM2.5-induced inflammatory liver injury. In addition, PM2.5-promoted secretion of cytokines by activating TLR4/MyD88 pathway, whereas CEOs might alleviate this type of liver inflammation inhibiting the activation of TLR4/MyD88 signaling pathway.

Evaluation of the Danish AirGIS air pollution modeling system against measured concentrations of PM2.5, PM10, and black carbon

Background: Adverse health effects of air pollution have been reported in previous studies with varying methodological approaches to the exposure assessment. Measuring individual air pollution exposure for large-scale epidemiological studies is infeasible, calling for refined modeling tools. We evaluated the performance of the Geographical Information System–based air pollution and human exposure modeling system (AirGIS). Methods: Modeled concentrations were evaluated against measured concentrations of particulate matter (PM) less than 10 and 2.5 μm in aerodynamic diameter (PM10/PM2.5) from two fixed-site monitoring stations (background and street) and from two measurement campaigns in Copenhagen, Denmark. Modeled concentrations of black carbon (BC) were evaluated against measured PM2.5 absorbance and PM10 absorbance. Results: Mean concentrations measured in the four series were in the range of 10.4–15.3 μg/m3 for PM2.5 and 17.8–25.1 μg/m3 for PM10. The model underestimated by 7%–13% in comparison to the fixed-site monitoring stations. Correlation coefficients of 0.82 and 0.73 were observed for monthly and daily averages of measured and modeled PM2.5 at the background site and, correspondingly, 0.85 and 0.74 at the street site. The spatial variation, as evaluated from the two measurement campaigns, was also well reproduced. Correlation coefficients of 0.77 and 0.79 were observed for BC and PM2.5 absorbance and 0.76 for PM10 absorbance. Conclusion: The AirGIS framework showed an overall high degree of accuracy and will be applicable to future epidemiological studies on health effects of PM and BC.

Aggregated particles caused by instrument artifact

Abstract. Previous studies have indicated that superaggregates, clusters of aggregates of soot primary particles, can be formed in large-scale turbulent fires. Due to lower effective densities, higher porosity, and lower aerodynamic diameters, superaggregates may pass through inlets designed to remove particles &lt; 2.5 µm in aerodynamic diameter (PM2.5). Ambient particulate matter samples were collected at Peavine Peak, NV, USA (2515 m) northwest of Reno, NV, USA from June to November 2014. The Teledyne Advanced Pollution Instrumentation (TAPI) 602 BetaPlus particulate monitor was used to collect PM2.5 on two filter types. During this time, aggregated particles &gt; 2.5 µm in aerodynamic diameter were collected on 36 out of 158 sample days. On preliminary analysis, it was thought that these aggregated particles were superaggregates, depositing past PM10 (particles &lt; 10 µm in aerodynamic diameter) pre-impactors and PM2.5 cyclones. However, further analysis revealed that these aggregated particles were dissimilar to superaggregates observed in previous studies, both in morphology and in elemental composition. To determine if the aggregated particles were superaggregates or an instrument artifact, samples were investigated for the presence of certain elements, the occurrence of fires, high relative humidity and wind speeds, as well as the use of generators on site. Samples with aggregated particles, referred to as aggregates, were analyzed using a scanning electron microscope for size and shape and energy dispersive X-ray spectroscopy was used for elemental analysis. It was determined, based on the high amounts of aluminum present in the aggregate samples, that a sampling artifact associated with the sample inlet and prolonged, high wind events was the probable reason for the observed aggregates.

The spatial variation in the effects of air pollution on cardiovascular mortality in Beijing, China

Owing to lack of data from multiple air quality monitoring stations, studies about spatial association between concentrations of ambient pollutants and mortality in China are rare. To investigate the spatial variation of association between concentrations of particulate matter less than 10 μm in aerodynamic diameter (PM10), nitrogen dioxide (NO2) and carbon monoxide (CO) and cardiovascular mortality in Beijing, China, we collected data including daily deaths, concentrations of PM10, NO2 and CO, and meteorological factors from 1 January 2009 to 31 December 2010 in all 16 districts of Beijing. Generalized additive model (GAM) and generalized additive mixed model (GAMM) were used to examine the citywide and district-specific effects of PM10, NO2 and CO on cardiovascular mortality. The citywide effect derived from GAMM was lower than that derived from GAM, and the strongest effects were identified for 2-day moving average lag 0–1. The interquartile increases in concentrations of PM10, NO2 and CO were associated with 2.46 (95% confidence interval (CI), 1.22–3.72), 4.11 (95%CI, 2.82–5.42) and 2.23 (95%CI, 1.14–3.33) percentage increases in daily cardiovascular mortality by GAMM, respectively. The relative risk of each district compared with reference district was generally statistically significant. The death risk associated with air pollutants varies across different geographic districts in Beijing. The data indicate that the risk is high in suburban areas and rural counties. We found significant and spatially varied adverse effects of air pollution on cardiovascular deaths across the rural and urban areas in Beijing.

Wind tunnel experiments on dust emissions from different landform types

The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 (particulate matter ≤10 μm aerodynamic diameter) and to assess natural sources of dust; however, the methodology and technique for determining the dust still present significant research challenges. In the past, specialized field observation and field wind tunnel studies have been used to understand the dust emission. A series of wind tunnel tests were carried out to identify natural sources of dust and measure the magnitudes of dust emissions from different landforms. The method used in this study allowed the measurement of the PM10 emission rate using a laboratory based environmental boundary layer wind tunnel. Results indicated that PM10 emissions demonstrated strong temporal variation and were primarily driven by aerodynamic entrainment. Sand dunes, playa, and alluvial fans had the largest dust emission rates (0.8–5.4 mg/(m2•s)) while sandy gravel, Gobi desert and abandoned lands had the lowest emission rates (0.003–0.126 mg/(m2•s)). Dust emissions were heavily dependent on the surface conditions, especially the availability of loose surface dust. High dust emissions were a result of the availability of dustparticle materials for entrainment while low dust emissions were a result of surface crusts and gravel cover. Soil surface property (surface crusts and gravel cover) plays an important role in controlling the availability of dust-sized particles for entrainment. The dust emission rate depended not only on the surface conditions but also on the friction velocity. The emission rate of PM10 varies as a power function of the friction velocity. Although dynamic abrasion processes have a strong influence on the amount of dust entrainment, aerodynamic entrainment may provide an important mechanism for dust emissions. Large volumes of dust entrained by aerodynamic entrainment cannot only occur at low shear velocity without saltation, but may dominate the entrainment process in many arid and semi-arid environments. So it may also be responsible for large magnitude dust storms. Playa and alluvial fan landforms, prior to developing a surface crust, may be the main sources of dust storms in Qinghai Province.

Longitudinal associations of long-term exposure to ultrafine particles with blood pressure and systemic inflammation in Puerto Rican adults

BackgroundFew longitudinal studies have examined the association between ultrafine particulate matter (UFP, particles < 0.1 μm aerodynamic diameter) exposure and cardiovascular disease (CVD) risk factors. We used data from 791 adults participating in the longitudinal Boston Puerto Rican Health Study (Massachusetts, USA) between 2004 and 2015 to assess whether UFP exposure was associated with blood pressure and high sensitivity C-reactive protein (hsCRP, a biomarker of systemic inflammation).MethodsResidential annual average UFP exposure (measured as particle number concentration, PNC) was assigned using a model accounting for spatial and temporal trends. We also adjusted PNC values for participants’ inhalation rate to obtain the particle inhalation rate (PIR) as a secondary exposure measure. Multilevel linear models with a random intercept for each participant were used to examine the association of UFP with blood pressure and hsCRP.ResultsOverall, in adjusted models, an inter-quartile range increase in PNC was associated with increased hsCRP (β = 6.8; 95% CI = − 0.3, 14.0%) but not with increased systolic blood pressure (β = 0.96; 95% CI = − 0.33, 2.25 mmHg), pulse pressure (β = 0.70; 95% CI = − 0.27, 1.67 mmHg), or diastolic blood pressure (β = 0.55; 95% CI = − 0.20, 1.30 mmHg). There were generally stronger positive associations among women and never smokers. Among men, there were inverse associations of PNC with systolic blood pressure and pulse pressure. In contrast to the primary findings, an inter-quartile range increase in the PIR was positively associated with systolic blood pressure (β = 1.03; 95% CI = 0.00, 2.06 mmHg) and diastolic blood pressure (β = 1.01; 95% CI = 0.36, 1.66 mmHg), but not with pulse pressure or hsCRP.ConclusionsWe observed that exposure to PNC was associated with increases in measures of CVD risk markers, especially among certain sub-populations. The exploratory PIR exposure metric should be further developed.

Personal exposure measurements of school-children to fine particulate matter (PM2.5) in winter of 2013, Shanghai, China.

ObjectiveThe aim of this study was to perform an exposure assessment of PM2.5 (particulate matter less than 2.5μm in aerodynamic diameter) among children and to explore the potential sources of exposure from both indoor and outdoor environments.MethodsIn terms of real-time exposure measurements of PM2.5, we collected data from 57 children aged 8–12 years (9.64 ± 0.93 years) in two schools in Shanghai, China. Simultaneously, questionnaire surveys and time-activity diaries were used to estimate the environment at home and daily time-activity patterns in order to estimate the exposure dose of PM2.5 in these children. Principle component regression analysis was used to explore the influence of potential sources of PM2.5 exposure.ResultsAll the median personal exposure and microenvironment PM2.5 concentrations greatly exceeded the daily 24-h PM2.5 Ambient Air Quality Standards of China, the USA, and the World Health Organization (WHO). The median Etotal (the sum of the PM2.5 exposure levels in different microenvironment and fractional time) of all students was 3014.13 (μg.h)/m3. The concentration of time-weighted average (TWA) exposure of all students was 137.01 μg/m3. The median TWA exposure level during the on-campus period (135.81 μg/m3) was significantly higher than the off-campus period (115.50 μg/m3, P = 0.013 < 0.05). Besides ambient air pollution and meteorological conditions, storey height of the classroom and mode of transportation to school were significantly correlated with children’s daily PM2.5 exposure.ConclusionsChildren in the two selected schools were exposed to high concentrations of PM2.5 in winter of 2013 in Shanghai. Their personal PM2.5 exposure was mainly associated with ambient air conditions, storey height of the classroom, and children’s transportation mode to school.

Air Pollution Exposure with Fine Dust. Responses in the Pulmonary Vasculature and the Right Heart

Detrimental effects of air pollution with fine dust (particulate matter ≤2.5 μm in aerodynamic diameter, or PM2.5) on the systemic circulation and the left heart have been studied intensely during ...

The effect of ventilation on air particulate matter in school classrooms

Health problems and respiratory diseases are associated with indoor air particulate matter (PM) mass. This is specially a concern in schools as children spend most of their time indoors. Understanding factors that affect PM mass such as occupant activities, ventilation and the infiltrating outdoor environment are important to safeguard occupant health. We investigated the air quality inside and outside two low decile primary school classrooms (children ages 7–9) over a three-week period during the southern hemisphere winter season in Palmerston North, New Zealand. Both classrooms were heated with wall mounted inverter heat pumps and in addition one classroom roof was fitted with a solar air heated ventilation unit (treatment). Particulate matter was continuously sampled and monitored to identify particles less than 10 µm in aerodynamic diameter (PM10) both outside and inside both classrooms to compare their indoor air quality. Significantly higher PM10 concentrations occurred within both classrooms during school hours (0845–1500), but the ventilated treatment classroom had PM10 concentrations on average 66% lower than those measured in the unventilated control classroom. Elemental composition and source apportionment of hourly samples showed that outdoor sources of PM10 infiltrated indoors, with similar contributions in both classrooms to those measured outdoors. However, the increased PM10 in the classrooms was predominantly from crustal sources, thought to be soil tracked in from outside on children's footwear and re-suspended during activities within the classrooms. Our results indicate that ventilation plays an important role in the quality of indoor air of classrooms and will contribute to the wellbeing of the students. In addition, there is a need to improve dust exposure mitigation strategies (carpet cleaning regime, dust reducing carpet) in classrooms fitted with carpets.

Characterizing exposure to household air pollution within the Prospective Urban Rural Epidemiology (PURE) study

BackgroundHousehold air pollution (HAP) from combustion of solid fuels is an important contributor to disease burden in low- and middle-income countries (LIC, and MIC). However, current HAP disease burden estimates are based on integrated exposure response curves that are not currently informed by quantitative HAP studies in LIC and MIC. While there is adequate evidence supporting causal relationships between HAP and respiratory disease, large cohort studies specifically examining relationships between quantitative measures of HAP exposure with cardiovascular disease are lacking. ObjectiveWe aim to improve upon exposure proxies based on fuel type, and to reduce exposure misclassification by quantitatively measuring exposure across varying cooking fuel types and conditions in diverse geographies and socioeconomic settings. We leverage technology advancements to estimate household and personal PM2.5 (particles below 2.5 μm in aerodynamic diameter) exposure within the large (N~250,000) multi-country (N~26) Prospective Urban and Rural Epidemiological (PURE) cohort study. Here, we detail the study protocol and the innovative methodologies being used to characterize HAP exposures, and their application in epidemiologic analyses. Methods/designThis study characterizes HAP PM2.5 exposures for participants in rural communities in ten PURE countries with >10% solid fuel use at baseline (Bangladesh, Brazil, Chile, China, Colombia, India, Pakistan, South Africa, Tanzania, and Zimbabwe). PM2.5 monitoring includes 48-h cooking area measurements in 4500 households and simultaneous personal monitoring of male and female pairs from 20% of the selected households. Repeat measurements occur in 20% of households to assess impacts of seasonality. Monitoring began in 2017, and will continue through 2019. The Ultrasonic Personal Aerosol Sampler (UPAS), a novel, robust, and inexpensive filter based monitor that is programmable through a dedicated mobile phone application is used for sampling. Pilot study field evaluation of cooking area measurements indicated high correlation between the UPAS and reference Harvard Impactors (r = 0.91; 95% CI: 0.84, 0.95; slope = 0.95). To facilitate tracking and to minimize contamination and analytical error, the samplers utilize barcoded filters and filter cartridges that are weighed pre- and post-sampling using a fully automated weighing system. Pump flow and pressure measurements, temperature and RH, GPS coordinates and semi-quantitative continuous particle mass concentrations based on filter differential pressure are uploaded to a central server automatically whenever the mobile phone is connected to the internet, with sampled data automatically screened for quality control parameters. A short survey is administered during the 48-h monitoring period. Post-weighed filters are further analyzed to estimate black carbon concentrations through a semi-automated, rapid, cost-effective image analysis approach. The measured PM2.5 data will then be combined with PURE survey information on household characteristics and behaviours collected at baseline and during follow-up to develop quantitative HAP models for PM2.5 exposures for all rural PURE participants (~50,000) and across different cooking fuel types within the 10 index countries. Both the measured (in the subset) and the modelled exposures will be used in separate longitudinal epidemiologic analyses to assess associations with cardiopulmonary mortality, and disease incidence. DiscussionThe collected data and resulting characterization of cooking area and personal PM2.5 exposures in multiple rural communities from 10 countries will better inform exposure assessment as well as future epidemiologic analyses assessing the relationships between quantitative estimates of chronic HAP exposure with adult mortality and incident cardiovascular and respiratory disease. This will provide refined and more accurate exposure estimates in global CVD related exposure-response analyses.

Assessment of particulate matter and ammonia emission concentrations and respective plume profiles from a commercial poultry house

Poultry-emitted air pollutants, including particulate matter (PM) and ammonia, have raised concerns due to potential negative effects on human health and the environment. However, developing and optimizing remediation technologies requires a better understanding of air pollutant concentrations, the emission plumes, and the relationships between the pollutants. Therefore, we conducted ten field experiments to characterize PM (total suspended particulate [TSP], particulate matter less than 10 μm in aerodynamic diameter [PM10], and particulate matter less than 2.5 μm in aerodynamic diameter [PM2.5]) and ammonia emission-concentration profiles from a typical commercial poultry house. The emission factors of the poultry house, which were calculated using the concentrations and fan speed, were 0.66 (0.29–0.99) g NH3-N bird−1d−1 for ammonia, 52 (44–168) g d−1AU−1 (AU = animal unit = 500 kg) for TSP, 3.48 (1.16–9.03) g d−1AU−1 for PM10, and 0.07 (0.00–0.36) g d−1AU−1 for PM2.5. PM and ammonia emission concentrations decreased as distance from the fan increased. Although emission concentrations were similar in the daytime and nighttime, diurnal and nocturnal plume shapes were different due to the increased stability of the atmosphere at night. Particle size distribution analysis revealed that, at a given height, the percentage of PM10 and PM2.5 was consistent throughout the plume, indicating that the larger particles were not settling out of the airstream faster than the smaller particles. Overall, the direction of the measured air pollutant emission plumes was dominated by the tunnel fan ventilation airflow rate and direction instead of the ambient wind speed and direction. This is important because currently-available air dispersion models use ambient or modeled wind speed and direction as input parameters. Thus, results will be useful in evaluating dispersion models for ground-level, horizontally-released, point sources and in developing effective pollutant remediation strategies for emissions.

Air Pollution Exposure Is Associated With Lower Lung Function, but Not Changes in Lung Function, in Patients With Idiopathic Pulmonary Fibrosis

Air pollution exposure is associated with acute exacerbation, disease progression, and mortality in patients with idiopathic pulmonary fibrosis (IPF). The objective of this study was to describe the impact of air pollution exposures on disease severity, as well as changes in lung function, in patients with IPF. Using home spirometers and symptom diaries, 25 patients with IPF prospectively recorded FVC weekly for up to 40weeks. Residential addresses were geocoded to estimate weekly mean air pollution exposures for ground-level ozone (O3), nitrogen dioxide (NO2), and particulate matter< 2.5 or 10 μm in aerodynamic diameter (PM2.5 and PM10, respectively). The dependence of weekly clinical measurements on preceding levels of each pollutant was assessed with the use of linear mixed models, yielding beta-coefficients with 95%CIs, using varying lag times. Lower mean FVC %predicted was consistently associated with increased mean exposures to PM10 in the 2 to 5weeks preceding clinical measurements (range, -0.46 to -0.39 [95%CI, -0.73 to -0.13]; P< .005). Lower mean FVC %predicted over the study period was inversely related to mean levels of NO2 (-0.45 [95%CI, -0.85 to -0.05]; P= .03), PM2.5 (-0.45 [95%CI, -0.84 to -0.07]; P= .02), and PM10 (-0.57 [95%CI, -0.92 to -0.21]; P=.003), averaged over the study. Weekly changes in FVC and changes over 40weeks were independent of pollution exposures. Higher air pollution exposures were associated with lower lung function, but not changes in lung function, in patients with IPF. Further studies are needed to characterize the mechanisms underlying this relationship.

Field and laboratory comparison of PM10 instruments in high winds

Abstract Instruments capable of measuring PM10 (particulate matter ≤10 µm in aerodynamic diameter) concentrations may vary in performance as a result of different technologies utilized in measuring PM10. Therefore, the performance of five instruments capable of measuring PM10 concentrations above eroding soil surfaces was tested during high wind events at field sites in the Columbia Plateau and inside a wind tunnel. Comparisons among the Big Spring Number Eight (BSNE) sampler, DustTrak monitor, E-sampler, High-Volume sampler, and Tapered Element Oscillating Microbalance (TEOM) monitor were made at field sites during nine wind erosion events and inside a wind tunnel at two wind speeds (7 and 12 m s−1) and two ambient PM10 concentrations (2 and 50 mg m−3). PM10 concentrations were similar for the High-Volume sampler and TEOM monitor as well as for the BSNE samplers and DustTrak monitors but higher for the High-Volume sampler and TEOM monitor than the E-sampler during field erosion events. Based upon wind tunnel experiments, the TEOM monitor measured the highest PM10 concentration while the DustTrak monitor typically measured the lowest PM10 concentration as compared with other instruments. In addition, PM10 concentration appeared to lower for all instruments at a wind speed of 12 as compared with 7 m s−1 inside the wind tunnel. Differences in the performance of instruments in measuring PM10 concentration poses risks in comparing PM10 concentration among different instrument types or using multiple instrument types to jointly measure concentrations in the field or laboratory or even the same instrument type subject to different wind speeds.

Long-Term Residential Exposure to Ultrafine Particles and C-Reactive Protein (CRP)

Background/Aim: Long-term exposure to ambient air pollution contributes to the burden of disease and particularly affects cardiovascular (CV) causes of death. We investigated the association between particle number concentration (PNC), a marker for ultrafine particles (UFP), and other air pollutants and high sensitivity C-reactive protein (hs-CRP) as a potential link between air pollution and CV disease. Methods: A cross-sectional analysis was performed on data of the second follow-up of the KORA S4 survey in Augsburg, Germany (2013-2014). Residential long-term exposure to PNC, particulate matter &lt;10µm and &lt;2.5µm in aerodynamic diameter (PM10 and PM2.5, respectively), PMcoarse (2.5-10µm), absorbance of PM2.5 (PM2.5abs), nitrogen dioxide (NO2) and nitrogen oxides (NOx) was estimated by land-use regression models. Associations between annual air pollution concentration and hs-CRP were modelled in 2,252 participants using linear regression adjusting for confounders. Possible effect-modifiers were examined by interaction terms. Two-pollutant models were calculated for pollutants with Spearman inter-correlation &lt;0.70. Results: The results pointed to a positive association between PNC, PM10, PMcoarse, PM2.5abs, NO2 and NOx and hs-CRP. For PNC, an interquartile-range (IQR, 2,000 particles/cm3) increase was associated with a 3.63% [95% confidence interval (CI): -0.86%; 8.33%] increase in hs-CRP. Effect estimates were higher for women, non-obese and participants without history of CVD. Effect modification was also seen for participants without diabetes with the highest effect estimate of 14.71% [95% CI: 5.47%; 24.77%] for an IQR increase of 2.1 µg/m³ in PM10. In two-pollutant models, adjustment for PM2.5 strengthened the effect estimates for PNC and PM10 (increase per IQR 6.31% [95% CI: 0.42%; 12.53%] and 7.34% [95%CI: 0.40%; 14.77%], respectively). Conclusions: Our results highlight the role of UFP within the complex mixture of ambient air pollution and their inflammatory potential and help fill a research gap since studies on chronic exposure to ultrafine particles are still scarce.

C-reactive protein (CRP) and long-term air pollution with a focus on ultrafine particles.

Long-term exposure to ambient air pollution contributes to the global burden of disease by particularly affecting cardiovascular (CV) causes of death. We investigated the association between particle number concentration (PNC), a marker for ultrafine particles, and other air pollutants and high sensitivity C-reactive protein (hs-CRP) as a potential link between air pollution and CV disease. We cross-sectionally analysed data from the second follow up (2013 and 2014) of the German KORA baseline survey which was conducted in 1999-2001. Residential long-term exposure to PNC and various other size fractions of particulate matter (PM10 with size of <10 μm in aerodynamic diameter, PMcoarse 2.5-10 μm or PM2.5 < 2.5 μm, respectively), soot (PM2.5abs: absorbance of PM2.5), nitrogen oxides (nitrogen dioxide NO2 or oxides NOx, respectively) and ozone (O3) were estimated by land-use regression models. Associations between annual air pollution concentrations and hs-CRP were modeled in 2252 participants using linear regression models adjusted for several confounders. Potential effect-modifiers were examined by interaction terms and two-pollutant models were calculated for pollutants with Spearman inter-correlation <0.70. Single pollutant models for PNC, PM10, PMcoarse, PM2.5abs, NO2 and NOx showed positive but non-significant associations with hs-CRP. For PNC, an interquartile range (2000 particles/cm3) increase was associated with a 3.6% (95% CI: -0.9%, 8.3%) increase in hs-CRP. A null association was found for PM2.5. Effect estimates were higher for women, non-obese participants, for participants without diabetes and without a history of cardiovascular disease whereas ex-smokers showed lower estimates compared to smokers or non-smokers. For O3, the dose-response function suggested a non-linear relationship. In two-pollutant models, adjustment for PM2.5 strengthened the effect estimates for PNC and PM10 (6.3% increase per 2000 particles/cm3 [95% CI: 0.4%; 12.5%] and 7.3% per 16.5 μg/m3 [95% CI: 0.4%; 14.8%], respectively). This study adds to a scarce but growing body of literature showing associations between long-term exposure to ultrafine particles and hs-CRP, one of the most intensely studied blood biomarkers for cardiovascular health. Our results highlight the role of ultrafine particles within the complex mixture of ambient air pollution and their inflammatory potential.

The effect of ambient PM(10) on sperm quality in Wuhan

Objective: To investigate the effect of exposure to particulate matter ≤10 μm in aerodynamic diameter (PM(10)) on sperm quality in different stages of sperm development. Methods: This cross-sectional study included 1 827 patients attending the reproductive medicine center in Renmin Hospital of Wuhan University during April 2013 to January 2015. Air pollution data from January 2013 to January 2015 was obtained from the database of Wuhan Municipal Environmental Protection Bureau. The generalized linear model was employed to assess the association between each exposure variables and sperm parameters for several exposure windows (0-9, 10-14, 15-69, 70-90, 0-90 days before sampling) . Results: The average levels of PM(10) was (116.2±71.6) μg/m(3) during the research period. Sperm volume was (75.4±49.1) ×10(6)/ml in sample population, (29.4±16.2) % in progressive motility and (51.8±21.6) % in total motility. Exposure to PM(10) was inversely associated with sperm concentration (β:-0.319; 95%CI:-0.529,-0.046) during 70-90 lag days. PM(10) exposure during the 0-90 lag days was significantly associated with progressive motility (β:-0.312; 95%CI:-0.527,-0.097) and total motility (β:-0.347; 95%CI:-0.636,-0.059) after adjusted for age, education level, BMI, smoking, abstinence time, temperature, humidity and season. Conclusion: Exposure to PM(10) was associated with statistically significant decrements in sperm concentration and motility, and the adverse impact on sperm concentration was significantly in early phases of spermatogenesis.

Short-term Effects of Ambient PM2.5 and PM2.5-10 on Mortality in Major Cities of Korea

ABSTRACT While many epidemiological studies have examined the health effects of different sizes of ambient particulate matter (PM), the findings have been mixed. PM is a heterogeneous mixture, and its chemical components differ by size, with more combustion related materials in the fine mode and more crustal materials in the coarse mode. This study estimates the risk of mortality associated with exposure to PM2.5 (particulate matter less than 2.5 µm in aerodynamic diameter) and PM2.5-10 (particulate matter less than 10 µm and greater than 2.5 µm in aerodynamic diameter). Long-term measurements of PM2.5 and PM2.5-10 were compared with the all-cause, cardiovascular, and respiratory mortality observed from January 2006 till December 2012 in three large cities in Korea (viz., Seoul, Busan, and Incheon). A time-series analysis based on a quasi-Poisson distribution was used to evaluate the associations of PM2.5 and PM2.5-10 with mortality. A 10 µg m−3 increase in PM2.5 (lag01) was associated with an increase of 1.18% (95% CI: 0.64, 1.72), 0.34% (95% CI: 0.03, 0.64), and 0.43% (90% CI: 0.02, 0.95) in the all-cause mortality in Busan, Seoul, and Incheon, respectively, during the study period. An increase in respiratory mortality of 0.52% (95% CI: 0.09, 0.96) and 2.25% (95% CI: 0.38, 4.15) was associated with a 10 µg m–3 increase in PM2.5 (lag01) in Seoul and Busan, respectively. Overall, the strongest associations were observed in Busan as well as among the elderly population. Statistically significant associations between ambient PM2.5 and PM2.5-10, and mortality were observed in this study. Exposure to fine particles, which mostly originate in combustion and mobile emissions, showed stronger effects on human health than coarse particles, which mostly originate in natural sources such as soil and mechanical processes.

Regions of pollution with particulate matter in Poland

The study presents the temporal and spatial variability of particulate matter concentration in Poland in the calendar winter season (December-February). The basis for the study were the hourly and daily values of particulate matter PM10 concentration from the period 2005/06 – 2014/15, obtained from 33 air pollution monitoring stations. In Poland, the obligation to monitor the concentration of the finer fraction of particles smaller than 2.5µm in aerodynamic diameter was introduced only in 2010. Consequently, data on PM2.5 concentration refer to a shorter period, i.e. 2009/10 – 2014/15, and were obtained from 23 stations. Using the cluster analysis (k-means method), three regions of comparable variability of particulate matter concentration were delineated. The largest region, i.e. Region I, comprises the northern and eastern central area of Poland, and its southern boundary is along the line Gorzów Wlkp-Bydgoszcz-Konin-Łódź-Kielce-Lublin. Markedly smaller Region II is located to the south of Region I. By far the smallest area was designated to Region III which covers the south west area of Poland. The delineated regions show a marked variability in terms of mean concentration of both PM fractions in winter (PM10: region I - 33 µg·m-3, region II - 55 µg·m-3, region III - 83 µg·m-3; PM2,5: region I - 35 µg·m-3, region II - 50 µg·m-3, region III - 60 µg·m-3) and, in the case of PM10, the frequency of excessive daily limit value.

Short-Term Air Pollution and Incident Pneumonia. A Case-Crossover Study.

The relationship between air pollution and pneumonia is poorly understood. To examine relationships between short-term air pollution exposure and number and severity of pneumonia cases along the Wasatch Front in Utah, a region with periodic high levels of outdoor air pollution. We applied time-stratified case-crossover analyses with distributed lag to patients presenting to seven emergency departments with pneumonia over a 2-year period. We compared levels of particulate matter less than or equal to 2.5 μm in aerodynamic diameter, nitrogen dioxide, and ozone at patient residences with emergency department cases, hospitalizations, objectively defined severe pneumonia, and mortality. We calculated direct cost impacts of particulate matter less than or equal to 2.5 μm in aerodynamic diameter reduction. We evaluated 4,336 pneumonia cases in seven hospitals. Among adults aged 65 years and older, we found consistently positive associations between particulate matter less than or equal to 2.5 μm in aerodynamic diameter within 6 days of presentation and instances of pneumonia (Lag Day 1 adjusted odds ratio, 1.35 per 10 μg/m3 over 12 μg/m3; 95% confidence interval, 1.16-1.57), severe pneumonia (Lag Day 1 adjusted odds ratio, 1.38; 95% confidence interval, 1.06-1.80), and inpatient mortality (Lag Day 5 adjusted odds ratio, 1.50; 95% confidence interval, 1.03-2.16). Smaller associations were found between nitrogen dioxide exposure and pneumonia occurrence, severity, and inpatient and 30-day mortality. Ozone exposure was modestly associated with increased instance and severity of pneumonia in younger adults. Particulate matter less than or equal to 2.5 μm in aerodynamic diameter and nitrogen dioxide effects were greatest in colder months, and ozone effects were greatest in warmer months. Reduction of particulate matter less than or equal to 2.5 μm in aerodynamic diameter levels to less than 12.0 mg/m3 could prevent 76-112 cases of pneumonia per year in these hospitals serving approximately half of the Wasatch Front's population, reducing direct medical facility costs by $807,000 annually. Among older adults, short-term ambient particulate matter less than or equal to 2.5 μm in aerodynamic diameter exposure is associated with more emergency department visits and hospitalizations for pneumonia, severe pneumonia, increased mortality, and increased healthcare costs. Nitrogen dioxide and ozone modestly increase pneumonia risk and illness severity.

Exposures to fine particulate matter (PM2.5) and birthweight in a rural-urban, mother-child cohort in Tamil Nadu, India

BackgroundExposure to PM2.5 (fine particulate matter <less than 2.5µm in aerodynamic diameter) related to ambient and household air pollution has been associated with low birthweight. Few of these studies, however, have been conducted in high exposure settings that are commonly encountered in low and middle income countries (LMICs). ObjectivesWe examined whether PM2.5 exposures during pregnancy were associated with birthweight in an integrated rural-urban, mother-child cohort in the state of Tamil Nadu, India. MethodsWe recruited 1285 pregnant women in the first trimester of pregnancy from primary health care centers and urban health posts and followed them until birth to collect antenatal care data and birthweight. We estimated pregnancy period PM 2.5 exposures through direct serial measurements of 24-h household PM2.5 concentrations, performed across each trimester. Mothers also completed detailed questionnaires to provide data on covariates related to household, socio-economic, demographic and maternal health characteristics. The association between PM2.5 exposures and birth weight was assessed using linear and logistic regression models that controlled for potential confounders. ResultsA 10-μg/m3 increase in pregnancy period PM2.5 exposures was associated with a 4g (95% CI: 1.08g, 6.76g) decrease in birthweight and 2% increase in prevalence of low birthweight [odds ratio(OR) = 1.02; 95%CI:1.005,1.041] after adjusting for gestational age, infant sex, maternal BMI, maternal age, history of a previous low birth weight child, birth order and season of conception. ConclusionsThe study provides some of the first quantitative effects estimates for linking rural-urban PM2.5 exposures and birthweight in India, adding important evidence for this association from high exposure settings in LMICs, that also experience dual health burdens from ambient and household air pollution. Study results also point to the need for considering maternal PM2.5 exposures alongside other risk factors for low birthweight in India