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1.
Environ Sci Technol ; 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33621071

RESUMO

Concerns on nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in the environment have mainly arisen from their mutagenic and carcinogenic effects. The objective of this study is to investigate whether nitro-PAH exposures are associated with biomarkers of cardiovascular pathophysiology. In a panel study design, urines and blood samples were collected up to four times with a 2-week interval from 89 healthy adults. We measured 1-naphthylamine, 2-naphthylamine, 9-aminophenanthrene, 2-aminofluorene, and 1-aminopyrene as biomarkers of nitro-PAH exposures. We measured three urinary metabolites of arachidonic acid (AA) including 20-hydroxyeicosatetraenoic acid (20-HETE) from the cytochrome P450 (CYP) pathway, 8-isoprostane from the nonenzymatic pathway, and 11-dehydro-thromboxane B2 (11-dhTXB2) from the cyclooxygenase (COX) pathway. Urinary malondialdehyde, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 6-sulfatoxymelatonin (aMT6s) were measured to reflect systemic oxidative stress. Plasma concentrations of the soluble P-selectin and von Willebrand factor (vWF) were measured as biomarkers of platelet activation and endothelial dysfunction. We found that increased urinary concentrations of amino-PAHs were significantly associated with increased 20-HETE, 11-dhTXB2, and 8-OHdG and with decreased 8-isoprostane and aMT6s. Increased amino-PAHs were positively associated with P-selectin and vWF, respectively. These results suggest that exposure to nitro-PAHs increases systemic oxidative stress and alters AA metabolism toward CYP and COX pathways, leading to an increased cardiovascular disease risk.

2.
Environ Sci Technol ; 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33544581

RESUMO

The Mobile ObserVations of Ultrafine Particles study was a two-year project to analyze potential air quality impacts of ultrafine particles (UFPs) from aircraft traffic for communities near an international airport. The study assessed UFP concentrations within 10 miles of the airport in the directions of aircraft flight. Over the course of four seasons, this study conducted a mobile sampling scheme to collect time-resolved measures of UFP, CO2, and black carbon (BC) concentrations, as well as UFP size distributions. Primary findings were that UFPs were associated with both roadway traffic and aircraft sources, with the highest UFP counts found on the major roadway (I-5). Total concentrations of UFPs alone (10-1000 nm) did not distinguish roadway and aircraft features. However, key differences existed in the particle size distribution and the black carbon concentration for roadway and aircraft features. These differences can help distinguish between the spatial impact of roadway traffic and aircraft UFP emissions using a combination of mobile monitoring and standard statistical methods.

3.
Sci Total Environ ; 773: 145642, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33592483

RESUMO

Wildfires have frequently occurred in the western United States (US) during the summer and fall seasons in recent years. This study measures the PM2.5 infiltration factor in seven residences recruited from five dense communities in Seattle, Washington, during a 2020 wildfire episode and evaluates the impacts of HEPA-based portable air cleaner (PAC) use on reducing indoor PM2.5 levels. All residences with windows closed went through an 18-to-24-h no filtration session, with five of seven following that period with an 18-to-24-h filtration session. Auto-mode PACs, which automatically adjust the fan speed based on the surrounding PM2.5 levels, were used for the filtration session. 10-s resolved indoor PM2.5 levels were measured in each residence's living room, while hourly outdoor levels were collected from the nearest governmental air quality monitoring station to each residence. Additionally, a time-activity diary in minute resolution was collected from each household. With the impacts of indoor sources excluded, indoor PM2.5 mass balance models were developed to estimate the PM2.5 indoor/outdoor (I/O) ratios, PAC effectiveness, and decay-related parameters. Among the seven residences, the mean infiltration factor ranged from 0.33 (standard deviation [SD]: 0.06) to 0.76 (SD: 0.05). The use of auto-mode PAC led to a 48%-78% decrease of indoor PM2.5 levels after adjusting for outdoor PM2.5 levels and indoor sources. The mean (SD) air exchange rates ranged from 0.30 (0.13) h-1 to 1.41 (3.18) h-1 while the PM2.5 deposition rate ranged from 0.10 (0.54) h-1 to 0.49 (0.47) h-1. These findings suggest that staying indoors, a common protective measure during wildfire episodes, is insufficient to prevent people's excess exposure to wildfire smoke, and provides quantitative evidence to support the utilization of auto-mode PACs during wildfire events in the US.

4.
Environ Int ; 147: 106342, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33401175

RESUMO

Given a large fraction of people's exposure to urban PM2.5 occur indoors, reducing indoor PM2.5 levels may offer a more feasible and immediate way to save substantial lives and economic losses attributable to PM2.5 exposure. We aimed to estimate the premature mortality and economic loss reductions associated with achieving the newly established Chinese indoor air guideline and a few hypothetical indoor PM2.5 guideline values. We used outdoor PM2.5 concentrations from 1497 monitoring sites in 339 Chinese cities in 2015, coupled with a steady-state mass balance model, to estimate indoor concentrations of outdoor-infiltrated PM2.5. Using province-specific time-activity patterns for urban residents, we estimated outdoor and indoor exposures to PM2.5 of outdoor origin. We then proceeded to use localized census-based concentration-response models and the value of statistical life estimates to calculate premature deaths and economic losses attributable to PM2.5 exposure across urban China. Finally, we estimated potentially avoidable mortality and corresponding economic losses by meeting the current 24-hour based guideline and various hypothetical indoor limits for PM2.5. In 2015 in urban areas of mainland China, the city-specific annual mean outdoor and indoor PM2.5 concentrations ranged 9-108 µg/m3 and 5-56 µg/m3, respectively. Indoor exposures contributed 62%-91% daily and 68%-83% annually to the total time-weighted exposures. The potential reductions in total deaths and economic losses for the scenario in which daily indoor concentrations met the current guideline of 75 µg/m3, 37.5 µg/m3, and 25 µg/m3 were 16.9 (95% CI: 0.7-62.1) thousand, 87.7 (95% CI: 9.7-197.7) thousand, and 165.5 (95% CI: 30.8-304.0) thousand, respectively. The corresponding reductions in economic losses were 5.7 (95% CI: 0.2-34.8) billion, 29.4 (95% CI: 2.4-109.6) billion, and 55.2 (95% CI: 7.7-168.0) billion US Dollars, respectively. Deaths and economic losses would be reduced exponentially within the range of 0-75 µg/m3 for hypothetical indoor PM2.5 limits. The findings demonstrate the effectiveness of reducing indoor concentrations of outdoor-originated PM2.5 in saving substantial lives and economic losses in China. The analysis provides quantitative evidence to support the implementation of an indoor air quality guideline or standard for PM2.5.

5.
Environ Int ; 145: 106154, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33038623

RESUMO

BACKGROUND: Ozone (O3) exposure has been associated with biomarkers of platelet activation and oxidative stress. The metabolism of arachidonic acid (AA) plays an important role in platelet activation and oxidative stress. However, AA metabolic pathways have not been examined in relation to O3 and other air pollutants. METHODS: Early morning urine and fasting blood were longitudinally collected up to four times from 89 healthy adults (22-52 years old, 25 women) in Changsha City, China. We measured three urinary AA metabolites, namely 11-dehydro-Thromboxane B2 (11-dhTXB2) produced from the arachidonic cyclooxygenase pathway, 20-hydroxyeicosatetraenoic acid (20-HETE) from the CYPs pathway, and 8-isoprostane from the non-enzymatic pathway. Urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured as indicators of oxidative damage to lipids and DNA, respectively. We measured soluble P-selectin (sCD62p) concentrations in plasma as an indicator of platelet activation. Indoor and outdoor air pollutants were measured and combined with participants' time-activity pattern to calculate personal exposure to O3, PM2.5, NO2, and SO2 averaged over 12-hour, 24-hour, 1-week, and 2-week periods prior to biospecimen collection, respectively. Linear mixed-effects models were used to examine the relationships of AA metabolites with air pollutant exposures, plasma sCD62p, and urinary MDA & 8-OHdG. RESULTS: We found that a 10% increase in 12 h and 24 h O3 exposure were associated with increases in urinary11-dhTXB2 by 1.4% (95%, 0.1% to 2.6%) and 1.3% (0.05% to 2.5%), respectively. These associations remained robust after adjusting for co-pollutant exposures. No significant associations were observed between 11-dhTXB2 and other pollutants or between O3 exposures and other AA metabolites. All the three AA metabolites were significantly and positively associated with urinary MDA and 8-OHdG, whereas only urinary 11-dhTXB2 was significantly and positively associated with plasma sCD62p. CONCLUSIONS: A metabolite of AA from the cyclooxygenase pathway was positively associated with short-term O3 exposure, and with a plasma marker of platelet activation and two urinary markers of oxidative stress. The results suggest that O3 exposure may contribute to increased platelet activation and oxidative damages via altering the metabolism of AA.

6.
medRxiv ; 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32995819

RESUMO

The historic wildfires of August and September 2020, up and down the west coast have made Western cities in the U.S. rank among the highest in the world for dirtiest air. Washington State was impacted by active wildfire smoke in the state as well as transported aged wood smoke from Oregon and California. Particulate matter smaller than 2.5 µm in aerodynamic diameter (PM 2.5 ) is the primary pollutant from wildfire smoke of health concern for the public. This study aims to assess the potential population health impact of increased PM 2.5 concentrations attributable to the wildfire smoke. Daily PM 2.5 concentrations for each county before and during the 2020 Washington state wildfire smoke episode was obtained from the WA Department of Ecology. Utilizing previously established associations of short-term mortality and PM 2.5 concentrations we estimated increases in all-cause, respiratory, and cardiovascular mortality for Washington state attributable to the increased PM 2.5 levels during the wildfire episode. During the episode, PM 2.5 concentrations increased 99.4 µg/m 3 on average in Washington. Each week of wildfire smoke exposures are estimated to cause 91.0 (95% CI: 73.8, 107.1) cases of increased all-cause mortality, 19.9 (95% CI: 10.4, 29.3) increased cardiovascular disease deaths, and 9.7 (95% CI: 5.4, 14.0) increased respiratory disease deaths. This is without considering the coincidence with the COVID-19 pandemic, since wildfire smoke exposure may exacerbate the effects of SARS-CoV-2 infection based on some early evidence. Because wildfire smoke episodes are likely to continue impacting the Pacific Northwest in years to come, continued preparedness and mitigations to reduce exposures to wildfire smoke are necessary to avoid this excess health burden.

7.
Sci Total Environ ; 747: 141325, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32771792

RESUMO

This study evaluates the COVID-19 impacts on traffic-related air pollution, including ultrafine particles (UFPs), PM2.5, black carbon (BC), NO, NO2, NOx, and CO in a Northwestern US city. Hourly traffic, air pollutants, and meteorological data on/near a major freeway in the downtown of Seattle, Washington, were collected for five weeks before and ten weeks after the Washington Stay Home Order (SHO) was enacted, respectively (February 17-May 31, 2020). The pollutants between pre- and post-SHO periods were compared, and their differences were statistically tested. Besides, first-order multivariate autoregressive (MAR(1)) models were developed to reveal the impacts specific to the change of traffic due to the COVID-19 responses while controlling for meteorological conditions. Results indicate that compared with those in the post-SHO period, the median traffic volume and road occupancy decreased by 37% and 52%, respectively. As for pollutants, the median BC and PM2.5 levels significantly decreased by 25% and 33%, relatively, while NO, NO2, NOx, and CO decreased by 33%, 29%, 30%, and 17%, respectively. In contrast, neither size-resolved UFPs nor total UFPs showed significant changes between the two periods, although larger particles (≥115.5 nm) decreased by 4-29%. Additionally, significant differences were found in meteorological conditions between the two periods. Based on the MAR(1) models, controlling for meteorological conditions, the COVID-19 responses were associated with significant decreases in median levels of traffic-related pollutants including 11.5-154.0 nm particles (ranging from -3% [95% confidence interval (CI): -1%, -4%] to -12% [95% CI: -10%, -14%]), total UFPs (-7% [95% CI: -5%, -8%]), BC (-6% [95% CI: -5%, -7%]), PM2.5 (-2% [95% CI: -1%, -3%]), NO, NO2, NOx (ranging from -3% [95% CI: -2%, -4%] to -10% [95% CI: -18%, -12%]), and CO (-4% [95% CI, -3%, -5%]). These findings illustrate that the conclusion of the COVID-19 impacts on urban traffic-related air pollutant levels could be completely different in scenarios whether meteorology was adjusted for or not. Fully adjusting for meteorology, this study shows that the COVID-19 responses were associated with much more reductions in traffic-related UFPs than PM2.5 in the Seattle region, in contrast to the reverse trend from the direct empirical data comparison.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Betacoronavirus , Cidades , Humanos , Material Particulado/análise , Emissões de Veículos/análise , Washington
8.
Sci Total Environ ; 749: 141301, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32829269

RESUMO

BACKGROUND/AIM: Melatonin is a free radical scavenger and an anti-inflammatory biomolecule. Air pollution exposure has been associated with increased inflammatory responses. We hypothesize that endogenous melatonin plays a role in inflammatory responses to air pollution exposure. METHODS: We tested this hypothesis in a cohort of 53 healthy adults (22-52 years old, 16 women), none of whom were on melatonin supplementation. Early morning urine and fasting blood were collected from each participant longitudinally up to three times. We analyzed urinary 6-sulfatoxymelatonin (aMT6s), as a surrogate of circulating melatonin, and pro- and anti-inflammatory cytokines in the plasma samples. Indoor and outdoor air pollutants were measured and combined with participants' time-activity patterns to calculate personal exposure to O3, PM2.5, NO2, and SO2 averaged over 12-hour, 24-hour, 1-week, and 2-week periods prior to biospecimen collection, respectively. Linear mixed-effects models were used to examine the relationships among urinary aMT6s, personal pollutant exposure, and plasma cytokines. A mediation analysis was conducted to examine the role of aMT6s in the relationships between pollutant exposures and inflammatory cytokines. RESULTS: One interquartile range (4.2 ppb) increase in 2-week O3 exposure was associated with a -26.2% (95% CI: -43.9% to -2.8%) decrease in aMT6s. Within the range of endogenous aMT6s concentrations (0.5-53.0 ng/ng creatinine) across the participants, increased aMT6s was associated with decreased pro-inflammatory cytokines including IL-1ß, IL-8, IL-17A, IFN-γ, and TNF-α. These cytokines were significantly and positively associated with 2-week average O3 exposure. Furthermore, 7.4% to 17.4% of the O3-cytokine associations were mediated by aMT6s. We did not find similar effects for the other pollutants. CONCLUSIONS: Pro-inflammatory responses to O3 exposure in the preceding 2 weeks partly resulted from the depletion of endogenous melatonin by O3.

9.
Environ Pollut ; 263(Pt A): 114503, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32304951

RESUMO

Exposure to air pollutants has been associated with respiratory and cardiovascular mortality, but the underlying molecular mechanisms remain inadequately understood. We aimed to examine molecular-level inflammatory and oxidative stress responses to personal air pollutant exposure. Fifty-three healthy adults aged 22-52 were measured three times for their blood inflammatory cytokines and urinary malondialdehyde (MDA, an oxidative stress biomarker) within 2 consecutive months. Pollutant concentrations monitored indoors and outdoors were combined with the time-activity data to calculate personal O3, PM2.5, NO2, and SO2 exposures averaged over 12 h, 24 h, 1 week, and 2 weeks, respectively, prior to biospecimen collection. Inflammatory cytokines and MDA were associated with pollutant exposures using linear mixed-effects models controlling for various covariates. After adjusting for a co-pollutant, we found that concentrations of proinflammatory cytokines were significantly and negatively associated with 12-h O3 exposures and significantly but positively associated with 2-week O3 exposures. We also found significant and positive associations of proinflammatory cytokines with 12-h and 24-h NO2 exposures, respectively. However, we did not find clear associations of PM2.5 and SO2 exposure with proinflammatory cytokines and with MDA. The removal of an O3-generating electrostatic precipitator in the mechanical ventilation systems of the offices and residences of the subjects was associated with significant decreases in IL-1ß, IL-2, IL-6, IL-8, IL-17A, and TNF-α. These findings suggest that exposure to O3 for different time durations may affect systemic inflammatory responses in different ways.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Biomarcadores , Exposição Ambiental/análise , Malondialdeído , Estresse Oxidativo , Material Particulado/análise
10.
Environ Sci Technol ; 54(7): 4286-4294, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32150678

RESUMO

This study examines the feasibility of the in situ calibration of instruments for fleet vehicle-based mobile monitoring of ultrafine particles (UFPs) and black carbon (BC) by comparing rendezvous vehicle measurements. Two vehicles with identical makes and models of UFP and BC monitors as well as GPS receivers were sampled within 140 m of each other for 2 h in total during winter in Seattle, Washington. To identify an optimal intervehicle distance for rendezvous calibration, 6 different buffers within 0-140 m for UFP monitors and 5 different buffers within 0-90 m for BC monitors were chosen, and the results of calibration were compared against a reference scenario, which consisted of mobile colocation measurements with both sets of the UFP and BC monitors deployed in one of the vehicles. Results indicate that the optimal distances for rendezvous calibration are 10-80 m for UFP monitors and 0-30 m for BC monitors. In comparison with the mobile colocation calibration, the rendezvous calibration shows a normalized root mean squared deviation of 6-14% and a normalized mean absolute deviation of 4-8% for these monitors. Criteria for applying a rendezvous calibration approach are presented, and an extension of this approach to an instrumented fleet of mobile monitoring vehicles is discussed.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Calibragem , Monitoramento Ambiental , Material Particulado , Emissões de Veículos , Washington
11.
Indoor Air ; 29(4): 604-615, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31077433

RESUMO

Reducing indoor ozone levels may be an effective strategy to reduce total exposure and associated mortality. Here we estimate (a) premature mortalities attributable to ozone for China's urban population ≥25 years of age; (b) the fraction of total exposure occurring indoors; and (c) mortalities that can be potentially avoided through meeting current and more stringent indoor ozone standards/guidelines based on 1-hour daily maxima. To estimate ozone-attributable premature mortalities, we used hourly outdoor ozone concentrations measured at 1497 monitoring stations located in 339 Chinese cities and a published concentration-response model. We proceeded to estimate province-specific infiltration factors and co-occurring hourly indoor ozone concentrations. For the year 2015, we estimated that indoor exposures accounted for 59% (95% confidence interval (CI): 26%-79%) of the total ozone exposure that resulted in 70800 (95% CI: 35 900-137 700) premature all-cause mortalities in urban China. If the current Chinese indoor ozone standards (80 ppbv (160 µg/m3 ); 56 ppbv (112 µg/m3 )) were met, the mean estimates of reduction in mortalities would be indistinguishable from zero. With stricter 1-hour indoor ozone guidelines, the expected mortality reductions increase exponentially per unit decrease in indoor ozone. The analysis in this paper should help facilitate formulating present and future indoor ozone guidelines.


Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Mortalidade Prematura , Ozônio/efeitos adversos , Adulto , Poluentes Atmosféricos/normas , Poluição do Ar em Ambientes Fechados/análise , China/epidemiologia , Monitoramento Ambiental , Feminino , Humanos , Masculino , Ozônio/análise , Ozônio/normas , População Urbana
12.
Environ Sci Technol ; 53(6): 3119-3127, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30794390

RESUMO

This study estimates adult mortalities attributed to PM2.5 across urban China in 2015 and the corresponding mortalities that might be avoided by meeting the yearly averaged indoor PM2.5 threshold in the newly established Assessment Standard for Healthy Building (ASHB) and seven other potential thresholds. We use outdoor PM2.5 concentrations from ∼1500 monitoring sites in 339 Chinese cities, coupled with a detailed exposure model, to estimate outdoor and indoor exposures to PM2.5 originating outdoors. We proceed to calculate premature mortality attributable to PM2.5 exposure using an integrated exposure-response model. Results indicate that indoor exposures accounted for 66%-87% of total exposure to PM2.5 of outdoor origin and 81% (95% confidence interval (CI), 71%-87%), i.e., 316 000 (95% CI, 176 000-435 000), of the 389 000 (95% CI, 245 000-501 000) mortalities attributable to "outdoor PM2.5" for the urban population ≥25 years of age in China in 2015. Potentially 14 000 (95% CI, 8000-20 000) deaths might be avoided if indoor PM2.5 of outdoor origin met the ASHB guideline of 35 µg/m3 for annual mean indoor PM2.5, and 162 000 (95% CI, 79 000-237 000) deaths might be avoided by meeting a 10 µg/m3 threshold. The analysis in this work should be helpful in formulating indoor air quality policies.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Adulto , China , Cidades , Monitoramento Ambiental , Humanos , Material Particulado
13.
J Thorac Dis ; 10(7): 4643-4652, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30174917

RESUMO

Background: Studies have suggested that age increases susceptibility to ozone-associated mortality, but the underlying mechanisms are unclear. In a previous study, personal exposure to ozone was significantly associated with a platelet activation biomarker, plasma soluble P-selectin (sCD62P), and blood pressure in 89 healthy adults, aged 22-52 years. The present study examines whether age modifies these associations in the same adults and in additional adults. Methods: Interaction terms of age and exposure were analyzed using hierarchical Bayesian mixed effects ridge regressions. Data from a similar additional study involving 71 healthy participants, aged 19-26 years, were pooled with the data from the first study to evaluate age effect modification when more young adults were added to the analysis. Results: In the 89 adults, significant age interactions were observed for past 24-hour and 2-week ozone exposures and sCD62P. Based on the pooled data (89 plus 71 adults), a 10 ppb increase in 24-hour ozone exposure was associated with increases in sCD62P and systolic blood pressure (SBP) by 22.3% (95% CI: 14.3%, 31.2%) and 1.35 (-0.18, 2.84) mmHg, respectively, at age 25; these values increased to 48.6% (32.7%, 65.1%) and 4.98 (2.56, 7.35) mmHg, respectively, at age 40. Conclusions: These results mechanistically suggest that increasing age enhances cardiovascular effects of ozone.

14.
Environ Int ; 114: 27-36, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29475121

RESUMO

BACKGROUND: More than 90% of the world's population lives in areas where outdoor air pollution levels exceed health-based limits. In these areas, individuals may use indoor air filtration, often on a sporadic basis, in their residences to reduce exposure to respirable particles (PM2.5). Whether this intervention can lead to improvements in health outcomes has not been evaluated. METHODS: Seventy non-smoking healthy adults, aged 19 to 26 years, received both true and sham indoor air filtration in a double-blinded randomized crossover study. Each filtration session was approximately 13 h long. True and sham filtration sessions were separated by a two-week washout interval. The study was carried out in a suburb of Shanghai. RESULTS: During the study period, outdoor PM2.5 concentrations ranged from 18.6 to 106.9 µg/m3, which overlapped with levels measured in Western Europe and North America. Compared to sham filtration, true filtration on average decreased indoor PM2.5 concentration by 72.4% to 10.0 µg/m3 and particle number concentration by 59.2% to 2316/cm3. For lung function measured immediately after the end of filtration, true filtration significantly lowered airway impedance at 5 Hz (Z5) by 7.1% [95% CI: 2.4%, 11.9%], airway resistance at 5 Hz (R5) by 7.4% [95% CI: 2.4%, 12.5%], and small airway resistance (R5-R20) by 20.3% [95% CI: 0.1%, 40.5%], reflecting improved airway mechanics especially for the small airways. However, no significant improvements for spirometry indicators (FEV1, FVC) were observed. True filtration also significantly lowered von Willebrand factor (VWF) by 26.9% [95% CI: 7.3%, 46.4%] 24 h after the end of filtration, indicating reduced risk for thrombosis. Stratified analysis in male and female participants showed that true filtration significantly decreased pulse pressure by 3.3% [95% CI: 0.8%, 7.4%] in females, and significantly reduced VWF by 42.4% [95% CI: 17.4%, 67.4%] and interleukin-6 by 22.6% [95% CI: 0.4%, 44.9%] in males. Effect modification analyses indicated that filtration effects in male and female participants were not significantly different. CONCLUSION: A single overnight residential air filtration, capable of reducing indoor particle concentrations substantially, can lead to improved airway mechanics and reduced thrombosis risk.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Pressão Sanguínea , Exposição por Inalação/análise , Adulto , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Feminino , Filtração , Humanos , Masculino , Adulto Jovem
15.
JAMA Intern Med ; 177(9): 1344-1353, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28715576

RESUMO

Importance: Exposure to ozone has been associated with cardiovascular mortality, but the underlying biological mechanisms are not yet understood. Objective: To examine the association between ozone exposure and cardiopulmonary pathophysiologic mechanisms. Design, Setting, and Participants: A longitudinal study involving 89 healthy adult participants living on a work campus in Changsha City, China, was conducted from December 1, 2014, to January 31, 2015. This unique quasiexperimental setting allowed for better characterization of air pollutant exposure effects because the participants spent most of their time in controlled indoor environments. Concentrations of indoor and outdoor ozone, along with the copollutants particulate matter, nitrogen dioxide, and sulfur dioxide, were monitored throughout the study period and then combined with time-activity information and filtration conditions of each residence and office to estimate 24-hour and 2-week combined indoor and outdoor mean exposure concentrations. Associations between each exposure measure and outcome measure were analyzed using single-pollutant and 2-pollutant linear mixed models controlling for ambient temperature, secondhand smoke exposure, and personal-level time-varying covariates. Main Outcomes and Measures: Biomarkers indicative of inflammation and oxidative stress, arterial stiffness, blood pressure, thrombotic factors, and spirometry were measured at 4 sessions. Results: Of the 89 participants, 25 (28%) were women and the mean (SD) age was 31.5 (7.6) years. The 24-hour ozone exposure concentrations ranged from 1.4 to 19.4 parts per billion (ppb), corresponding to outdoor concentrations ranging from 4.3 to 47.9 ppb. Within this range, in models controlling for a second copollutant and other potential confounders, a 10-ppb increase in 24-hour ozone was associated with mean increases of 36.3% (95% CI, 29.9%-43.0%) in the level of platelet activation marker soluble P-selectin, 2.8% (95% CI, 0.6%-5.1%) in diastolic blood pressure, 18.1% (95% CI, 4.5%-33.5%) in pulmonary inflammation markers fractional exhaled nitric oxide, and 31.0% (95% CI, 0.2%-71.1%) in exhaled breath condensate nitrite and nitrate as well as a -9.5% (95% CI, -17.7% to -1.4%) decrease in arterial stiffness marker augmentation index. A 10-ppb increase in 2-week ozone was associated with increases of 61.1% (95% CI, 37.8%-88.2%) in soluble P-selectin level and 126.2% (95% CI, 12.1%-356.2%) in exhaled breath condensate nitrite and nitrate level. Other measured biomarkers, including spirometry, showed no significant associations with either 24-hour ozone or 2-week ozone exposures. Conclusions and Relevance: Short-term ozone exposure at levels not associated with lung function changes was associated with platelet activation and blood pressure increases, suggesting a possible mechanism by which ozone may affect cardiovascular health.


Assuntos
Doenças Cardiovasculares , Exposição Ambiental , Nitratos/análise , Nitritos/análise , Ozônio , Pneumonia , Adulto , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Testes Respiratórios/métodos , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , China/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Exposição Ambiental/prevenção & controle , Feminino , Humanos , Masculino , Dióxido de Nitrogênio , Estresse Oxidativo , Ozônio/efeitos adversos , Ozônio/análise , Pneumonia/diagnóstico , Pneumonia/epidemiologia , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Tempo de Protrombina/métodos , Espirometria/métodos , Rigidez Vascular
16.
Environ Sci Technol ; 50(18): 10236-44, 2016 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-27571436

RESUMO

This study investigates the impacts of outdoor and indoor ozone concentrations, ESP operation and occupancy on particle number concentrations within a modern office in Changsha, China. The office's one-pass air handling system contains a mini-bag filter (MERV 12) followed by an electrostatic precipitator (ESP) and high efficiency particulate air (HEPA) filter. Over a five-week period the system was operated either without the ESP (Stage 1, first-third week) or with the ESP (Stage 2, fourth and fifth week). Ozone and particle number concentrations were measured on working days. During both stages, indoor ozone and particle number concentrations tracked the outdoor ozone concentration. When operating, the ESP produced approximately 29 mg h(-1) of ozone, increasing supply air ozone by 15 ppb and steady-state indoor ozone by about 3 ppb. Occupancy tended to decrease indoor ozone and increase particle levels. During occupancy, indoor particle levels were low (∼2600 particle/cm(3)) when the supply air ozone level was less than 18 ppb. Above this threshold, the supply air ozone concentration and indoor particle number concentration were linearly related, and ESP operation increased the average indoor particle level by about 22 000 particles/cm(3). The implications for worker exposure to both ozone and particles are discussed.


Assuntos
Poluição do Ar em Ambientes Fechados , Ozônio , Poluentes Atmosféricos , China , Tamanho da Partícula , Eletricidade Estática
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