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Lu W, Tian Q, Xu R, Zhong C, Qiu L, Zhang H, Shi C, Liu Y, Zhou Y. Short-term exposure to ambient air pollution and pneumonia hospital admission among patients with COPD: a time-stratified case-crossover study. Respir Res 2022; 23:71. [PMID: 35346202 PMCID: PMC8962484 DOI: 10.1186/s12931-022-01989-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/13/2022] [Indexed: 11/13/2022] Open
Abstract
Background Pneumonia is a major contributor to hospital admission for patients with chronic obstructive pulmonary disease (COPD). However, evidence for acute effects of ambient air pollution exposure on pneumonia hospital admission among patients with COPD is scarce. We aimed to examine the association between short-term exposure to ambient air pollution and pneumonia hospital admission among patients with COPD. Methods We enrolled COPD cases aged ≥ 60 years old and further filtered those who were admitted into hospitals from pneumonia during 2016–2019 in Guangdong province, China for main analysis. A time-stratified case-crossover design was applied to investigate the association and conditional logistic regression model was used for data analysis. We performed inverse distance weighting method to estimate daily individual-level exposure on particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5), particulate matter with an aerodynamic diameter ≤ 10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) based on personal residential addresses. Results We included 6473 pneumonia hospital admissions during the study period. Each interquartile range (IQR) increase in PM2.5 (lag 2; IQR, 22.1 μg/m3), SO2 (lag 03; IQR, 4.2 μg/m3), NO2 (lag 03; IQR, 21.4 μg/m3), and O3 (lag 04; IQR, 57.9 μg/m3) was associated with an odds ratio in pneumonia hospital admission of 1.043 (95% CI: 1.004–1.083), 1.081 (95% CI: 1.026–1.140), 1.045 (95% CI: 1.005–1.088), and 1.080 (95% CI: 1.018–1.147), respectively. Non-linear trends for PM2.5, PM10, and SO2 were observed in the study. Sex, age at hospital admission, and season at hospital admission did not modify the associations. Conclusions We found significantly positive associations of short-term exposure to PM2.5, SO2, NO2, and O3 with pneumonia hospital admission among COPD patients. It provides new insight for comprehensive pneumonia prevention and treatment among COPD patients. Supplementary Information The online version contains supplementary material available at 10.1186/s12931-022-01989-9.
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Affiliation(s)
- Wenfeng Lu
- State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China.,School of Public Health, Guangzhou Medical University, Guangzhou, 511436, Guangdong, China
| | - Qi Tian
- Guangzhou Health Technology Identification and Human Resources Assessment Center, Guangzhou, 510080, Guangdong, China
| | - Ruijun Xu
- Department of Epidemiology, School of Public Health, Sun Yat-Sen University, Guangzhou, 510080, Guangdong, China
| | - Chenghui Zhong
- School of Public Health, Guangzhou Medical University, Guangzhou, 511436, Guangdong, China
| | - Lan Qiu
- School of Public Health, Guangzhou Medical University, Guangzhou, 511436, Guangdong, China
| | - Han Zhang
- School of Public Health, Guangzhou Medical University, Guangzhou, 511436, Guangdong, China
| | - Chunxiang Shi
- National Meteorological Information Center, China Meteorological Administration, Beijing, 100081, China
| | - Yuewei Liu
- Department of Epidemiology, School of Public Health, Sun Yat-Sen University, Guangzhou, 510080, Guangdong, China.
| | - Yun Zhou
- State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, Guangdong, China. .,School of Public Health, Guangzhou Medical University, Guangzhou, 511436, Guangdong, China.
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Yee J, Cho YA, Yoo HJ, Yun H, Gwak HS. Short-term exposure to air pollution and hospital admission for pneumonia: a systematic review and meta-analysis. Environ Health 2021; 20:6. [PMID: 33413431 PMCID: PMC7792212 DOI: 10.1186/s12940-020-00687-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/14/2020] [Indexed: 05/30/2023]
Abstract
BACKGROUND Air pollution is a major issue that poses a health threat worldwide. Although several studies investigated the adverse effects of air pollution on various diseases, few have directly demonstrated the effects on pneumonia. Therefore, we performed a systematic review and meta-analysis on the associations between short-term exposure of air pollutants and hospital admission or emergency room (ER) visit for pneumonia. METHODS A literature search was performed using PubMed, Embase, and Web of Science up to April 10, 2020. Pooled estimates were calculated as % increase with 95% confidence intervals using a random-effects model. A sensitivity analysis using the leave-one-out method and subgroup analysis by region were performed. RESULTS A total of 21 studies were included in the analysis. Every 10 μg/m3 increment in PM2.5 and PM10 resulted in a 1.0% (95% CI: 0.5-1.5) and 0.4% (95% CI: 0.2-0.6) increase in hospital admission or ER visit for pneumonia, respectively. Every 1 ppm increase of CO and 10 ppb increase of NO2, SO2, and O3 was associated with 4.2% (95% CI: 0.6-7.9), 3.2% (95% CI: 1.3-5.1), 2.4% (95% CI: - 2.0-7.1), and 0.4% (95% CI: 0-0.8) increase in pneumonia-specific hospital admission or ER visit, respectively. Except for CO, the sensitivity analyses yielded similar results, demonstrating the robustness of the results. In a subgroup analysis by region, PM2.5 increased hospital admission or ER visit for pneumonia in East Asia but not in North America. CONCLUSION By combining the inconsistent findings of several studies, this study revealed the associations between short-term exposure of air pollutants and pneumonia-specific hospital admission or ER visit, especially for PM and NO2. Based on the results, stricter intervention policies regarding air pollution and programs for protecting human respiratory health should be implemented.
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Affiliation(s)
- Jeong Yee
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Republic of Korea
| | - Young Ah Cho
- College of Pharmacy, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea
- Mokhwa Convalescent Hospital, Jinju, Gyeongnam, 52828, Republic of Korea
| | - Hee Jeong Yoo
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Republic of Korea
- Department of Pharmacy, National Medical Center, Seoul, 04564, Republic of Korea
| | - Hyunseo Yun
- Graduate School of Clinical Biohealth, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Hye Sun Gwak
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, Republic of Korea.
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Curbani F, de Oliveira Busato F, Marcarini do Nascimento M, Olivieri DN, Tadokoro CE. Inhale, exhale: Why particulate matter exposure in animal models are so acute? Data and facts behind the history. Data Brief 2019; 25:104237. [PMID: 31367664 PMCID: PMC6646918 DOI: 10.1016/j.dib.2019.104237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/31/2019] [Accepted: 07/01/2019] [Indexed: 12/27/2022] Open
Abstract
We present a dataset obtained by extracting information from an extensive literature search of toxicological experiments using mice and rat animal models to study the effects of exposure to airborne particulate matter (PM). Our dataset covers results reported from 75 research articles considering paper published in 2017 and seminal papers from previous years. The compiled data and normalization were processed with an equation based on a PM dosimetry model. This equation allows the comparison of different toxicological experiments using instillation and inhalation as PM exposure protocols with respect to inhalation rates, concentrations and PM exposure doses of the toxicological experiments performed by different protocols using instillation and inhalation PM as exposure methods. This data complements the discussions and interpretations presented in the research article “Inhale, exhale: why particulate matter exposure in animal models are so acute?” Curbani et al., 2019.
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Affiliation(s)
- Flávio Curbani
- Programa de Pós-Graduação em Ecologia de Ecossistemas, Universidade Vila Velha, Rua Comissário José Dantas de Melo, 21, Boa Vista, CEP 29102-920, Vila Velha, ES, Brazil.,Departamento de Tecnologia Industrial, Centro Tecnológico, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP 29060-970, Vitória, ES, Brazil
| | - Fernanda de Oliveira Busato
- Laboratory of Immunobiology, Universidade Vila Velha, Rua Comissário José Dantas de Melo, 21, Boa Vista, CEP 29102-920, Vila Velha, ES, Brazil
| | - Maynara Marcarini do Nascimento
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Vila Velha, Rua Comissário José Dantas de Melo, 21, Boa Vista, CEP 29102-920, Vila Velha, ES, Brazil
| | | | - Carlos Eduardo Tadokoro
- Programa de Pós-Graduação em Ecologia de Ecossistemas, Universidade Vila Velha, Rua Comissário José Dantas de Melo, 21, Boa Vista, CEP 29102-920, Vila Velha, ES, Brazil.,Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Vila Velha, Rua Comissário José Dantas de Melo, 21, Boa Vista, CEP 29102-920, Vila Velha, ES, Brazil
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Herbert JA, Valentine MS, Saravanan N, Schneck MB, Pidaparti R, Fowler AA, Reynolds AM, Heise RL. Conservative fluid management prevents age-associated ventilator induced mortality. Exp Gerontol 2016; 81:101-9. [PMID: 27188767 DOI: 10.1016/j.exger.2016.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 05/09/2016] [Accepted: 05/13/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Approximately 800 thousand patients require mechanical ventilation in the United States annually with an in-hospital mortality rate of over 30%. The majority of patients requiring mechanical ventilation are over the age of 65 and advanced age is known to increase the severity of ventilator-induced lung injury (VILI) and in-hospital mortality rates. However, the mechanisms which predispose aging ventilator patients to increased mortality rates are not fully understood. Ventilation with conservative fluid management decreases mortality rates in acute respiratory distress patients, but to date there has been no investigation of the effect of conservative fluid management on VILI and ventilator associated mortality rates. We hypothesized that age-associated increases in susceptibility and incidence of pulmonary edema strongly promote age-related increases in ventilator associated mortality. METHODS 2month old and 20month old male C57BL6 mice were mechanically ventilated with either high tidal volume (HVT) or low tidal volume (LVT) for up to 4h with either liberal or conservative fluid support. During ventilation, lung compliance, total lung capacity, and hysteresis curves were quantified. Following ventilation, bronchoalveolar lavage fluid was analyzed for total protein content and inflammatory cell infiltration. Wet to dry ratios were used to directly measure edema in excised lungs. Lung histology was performed to quantify alveolar barrier damage/destruction. Age matched non-ventilated mice were used as controls. RESULTS At 4h, both advanced age and HVT ventilation significantly increased markers of inflammation and injury, degraded pulmonary mechanics, and decreased survival rates. Conservative fluid support significantly diminished pulmonary edema and improved pulmonary mechanics by 1h in advanced age HVT subjects. In 4h ventilations, conservative fluid support significantly diminished pulmonary edema, improved lung mechanics, and resulted in significantly lower mortality rates in older subjects. CONCLUSION Our study demonstrates that conservative fluid alone can attenuate the age associated increase in ventilator associated mortality.
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Affiliation(s)
- Joseph A Herbert
- Department of Biomedical Engineering, Virginia Commonwealth University, 401 W Main St, PO Box 843067, Richmond, VA 23284, United States
| | - Michael S Valentine
- Department of Biomedical Engineering, Virginia Commonwealth University, 401 W Main St, PO Box 843067, Richmond, VA 23284, United States
| | - Nivi Saravanan
- Department of Biomedical Engineering, Virginia Commonwealth University, 401 W Main St, PO Box 843067, Richmond, VA 23284, United States
| | - Matthew B Schneck
- Department of Biomedical Engineering, Virginia Commonwealth University, 401 W Main St, PO Box 843067, Richmond, VA 23284, United States
| | | | - Alpha A Fowler
- Division of Pulmonary Disease and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, United States
| | - Angela M Reynolds
- Department of Mathematics and Applies Mathematics 1015 Floyd Avenue P.O. Box 842014 Richmond, VA 23284-2014, United States
| | - Rebecca L Heise
- Department of Biomedical Engineering, Virginia Commonwealth University, 401 W Main St, PO Box 843067, Richmond, VA 23284, United States; Department of Physiology and Biophysics VCU School of Medicine 1101 East Marshall Street P.O. Box 980551 Richmond, VA 23298-0551, United States.
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Sameenoi Y, Koehler K, Shapiro J, Boonsong K, Sun Y, Collett J, Volckens J, Henry CS. Microfluidic electrochemical sensor for on-line monitoring of aerosol oxidative activity. J Am Chem Soc 2012; 134:10562-8. [PMID: 22651886 PMCID: PMC3397383 DOI: 10.1021/ja3031104] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Particulate matter (PM) air pollution has a significant impact on human morbidity and mortality; however, the mechanisms of PM-induced toxicity are poorly defined. A leading hypothesis states that airborne PM induces harm by generating reactive oxygen species in and around human tissues, leading to oxidative stress. We report here a system employing a microfluidic electrochemical sensor coupled directly to a particle-into-liquid sampler (PILS) system to measure aerosol oxidative activity in an on-line format. The oxidative activity measurement is based on the dithiothreitol (DTT) assay, where, after being oxidized by PM, the remaining reduced DTT is analyzed by the microfluidic sensor. The sensor consists of an array of working, reference, and auxiliary electrodes fabricated in a poly(dimethylsiloxane)-based microfluidic device. Cobalt(II) phthalocyanine-modified carbon paste was used as the working electrode material, allowing selective detection of reduced DTT. The electrochemical sensor was validated off-line against the traditional DTT assay using filter samples taken from urban environments and biomass burning events. After off-line characterization, the sensor was coupled to a PILS to enable on-line sampling/analysis of aerosol oxidative activity. Urban dust and industrial incinerator ash samples were aerosolized in an aerosol chamber and analyzed for their oxidative activity. The on-line sensor reported DTT consumption rates (oxidative activity) in good correlation with aerosol concentration (R(2) from 0.86 to 0.97) with a time resolution of approximately 3 min.
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Affiliation(s)
- Yupaporn Sameenoi
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Kirsten Koehler
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Jeff Shapiro
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Kanokporn Boonsong
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Yele Sun
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Jeffrey Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, USA
| | - John Volckens
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Charles S. Henry
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA
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Godleski JJ, Diaz EA, Lemos M, Long M, Ruiz P, Gupta T, Kang CM, Coull B. Toxicological evaluation of realistic emission source aerosols (TERESA)-power plant studies: assessment of cellular responses. Inhal Toxicol 2011; 23 Suppl 2:60-74. [PMID: 21466245 PMCID: PMC3697151 DOI: 10.3109/08958378.2010.563804] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The Toxicological Evaluation of Realistic Emission Source Aerosols (TERESA) project assessed primary and secondary particulate by simulating the chemical reactions that a plume from a source might undergo during atmospheric transport and added other atmospheric constituents that might interact with it. Three coal-fired power plants with different coal and different emission controls were used. Male Sprague-Dawley rats were exposed for 6 h to either filtered air or aged aerosol from the power plant. Four exposure scenarios were studied: primary particles (P); primary + secondary (oxidized) particles (PO); primary + secondary (oxidized) particles + SOA (POS); and primary + secondary (oxidized) particles neutralized + SOA (PONS). Exposure concentrations varied by scenario to a maximum concentration of 257.1 ± 10.0 μg/m(3). Twenty-four hours after exposure, pulmonary cellular responses were assessed by bronchoalveolar lavage (BAL), complete blood count (CBC), and histopathology. Exposure to the PONS and POS scenarios produced significant increases in BAL total cells and macrophage numbers at two plants. The PONS and P scenarios were associated with significant increases in BAL neutrophils and the presence of occasional neutrophils and increased macrophages in the airways and alveoli of exposed animals. Univariate analyses and random forest analyses showed that increases in total cell count and macrophage cell count were significantly associated with neutralized sulfate and several correlated measurements. Increases in neutrophils in BAL were associated with zinc. There were no significant differences in CBC parameters or blood vessel wall thickness by histopathology. The association between neutrophils increases and zinc raises the possibility that metals play a role in this response.
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Affiliation(s)
- John J Godleski
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA.
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Pereira CEL, Heck TG, Saldiva PHN, Rhoden CR. Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung. Braz J Med Biol Res 2007; 40:1353-9. [PMID: 17713644 DOI: 10.1590/s0100-879x2006005000164] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Accepted: 06/25/2007] [Indexed: 11/21/2022] Open
Abstract
Oxidative stress plays a major role in the pathogenesis of particle-dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a) determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs, and b) determine if intermittent short-term exposures (every 4 days) induce some degree of tolerance. Three-month-old male Wistar rats were exposed to ambient particulate matter (PM) from vehicles (N = 30) for 6 or 20 continuous hours, or for intermittent (5 h) periods during 20 h for 4 consecutive days or to filtered air (PM <10 microm; N = 30). Rats continuously breathing polluted air for 20 h (P-20) showed a significant increase in the total number of leukocytes in bronchoalveolar lavage compared to control (C-20: 2.61 x 105 +/- 0.51;P-20: 5.01 x 105 +/- 0.81; P < 0.05) and in lipid peroxidation ([MDA] nmol/mg protein: C-20: 0.148 +/- 0.01; P-20: 0.226 +/- 0.02; P < 0.05). Shorter exposure (6 h) and intermittent 5-h exposures over a period of 4 days did not cause significant changes in leukocytes. Lipid damage resulting from 20-h exposure to particulate air pollution did not cause a significant increase in lung water content. These data suggest oxidative stress as one of the mechanisms responsible for the acute adverse respiratory effects of particles, and suggest that short-term inhalation of ambient particulate air pollution from street with high automobile traffic represents a biological hazard.
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Affiliation(s)
- C E L Pereira
- Curso de Pós-graduação em Ciências Médicas e Laboratório de Estresse Oxidativo e Poluição Atmosférica, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, RS, Brasil
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Kappos AD, Bruckmann P, Eikmann T, Englert N, Heinrich U, Höppe P, Koch E, Krause GHM, Kreyling WG, Rauchfuss K, Rombout P, Schulz-Klemp V, Thiel WR, Wichmann HE. Health effects of particles in ambient air. Int J Hyg Environ Health 2004; 207:399-407. [PMID: 15471105 DOI: 10.1078/1438-4639-00306] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED A summary of a critical review by a working group of the German commission on Air Pollution Prevention of VDI and DIN of the actual data on exposure and health effects (excluding cancer) of fine particulate air pollution is presented. EXPOSURE Typical ambient particle concentrations for PM10 (PM2.5) in Germany are in the range of 10-45 (10-30) microg/m3 as annual mean and 50-200 (40-150) microg/m3 as maximum daily mean. The ratio of PM2.5/PM10 generally amounts between 0.7 and 0.9. HEALTH EFFECTS During the past 10 years many new epidemiological and toxicological studies on health effects of particulate matter (PM) have been published. In summary, long-term exposure against PM for years or decades is associated with elevated total, cardiovascular, and infant mortality. With respect to morbidity, respiratory symptoms, lung growth, and function of the immune system are affected. Short-term studies show consistant associations of exposure to daily concentrations of PM with mortality and morbidity on the same day or the subsequent days. Patients with asthma, COPD, pneumonia, and other respiratory diseases as well as patients with cardio-vascular diseases and diabetes are especially affected. The strongest associations are found for PM2.5 followed by PM10, with no indication of a threshold value for the health effects. The data base for ultra fine particles is too small for final conclusions. The available toxicological data support the epidemiological findings and give hints as to the mechanisms of the effects. CONCLUSION The working group concludes that a further reduction of the limit values proposed for 2005 will substantially reduce health risks due to particulate air pollution. Because of the strong correlation of PM10 with PM2.5 at most German sites there is no specific need for limit values of PM2.5 for Germany in addition to those of PM10.
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Antonini JM, Roberts JR, Clarke RW, Yang HM, Barger MW, Ma JY, Weissman DN. Effect of age on respiratory defense mechanisms: pulmonary bacterial clearance in Fischer 344 rats after intratracheal instillation of Listeria monocytogenes. Chest 2001; 120:240-9. [PMID: 11451845 DOI: 10.1378/chest.120.1.240] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVES To examine the lung defense mechanisms of both young and aged rats before and after pulmonary challenge with a bacterial pathogen. DESIGN Male Fischer 344 rats, either 2.5 months or 20 months of age, were intratracheally inoculated with 5 x 10(3), 5 x 10(4), or 5 x 10(5) Listeria monocytogenes, and the effects on mortality, lung inflammation, pulmonary bacterial clearance, alveolar macrophage (AM) function, and T-lymphocyte characterization were determined. MEASUREMENTS AND RESULTS In noninfected control animals, the older rats had lower numbers of AMs on lavage and a lower percentage of total T, CD4+, and CD8+ cells. No difference was observed between noninfected young and old rats in AM function, assessing both chemiluminescence and nitric oxide (NO) production. After bacterial challenge, aged rats exhibited an increase in mortality, pulmonary infection, and edema, and lung lesions, which were more extensive than those observed in the younger rats. Interestingly, AM chemiluminescence was enhanced, while AM NO, a highly important antibacterial defense product, was abrogated in the aged rats as compared to the young rats. CONCLUSIONS This study demonstrated that advanced age is associated with alterations in lung defense mechanisms and increased susceptibility to pulmonary bacterial infection marked by elevated mortality, slowed pulmonary bacterial clearance, and altered AM function, specifically a decrease in NO production. These observations are indicative of reduced pulmonary defense function in an older population of rats.
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Affiliation(s)
- J M Antonini
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
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