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Yu YQ, Zhu T. Concentration-dependent effects of reductive pulmonary inhalants on ultrafine particle-induced oxidative stress: Insights for health risk assessment. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 19:100339. [PMID: 38107555 PMCID: PMC10724529 DOI: 10.1016/j.ese.2023.100339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 12/19/2023]
Abstract
The impact of reductive pulmonary inhalants on ultrafine particles (UFPs)-induced pulmonary oxidative stress remains a crucial consideration, yet the concentration-dependent effects of these inhalants have remained unexplored. Here we synthesized composite UFPs simulating atmospheric UFPs, primarily composed of metals and quinones. We subjected these UFPs to varying concentrations (0-7000 μM) of two reductive pulmonary inhalants, N-acetylcysteine and salbutamol, to assess their influence on oxidative potential, measured through the dithiothreitol assay (OPDTT). Simultaneously, we analysed the soluble metal content of UFPs to uncover potential relationships between oxidative potential and metal solubility. Our results unveil a dual role played by these inhalants in shaping the OPDTT of composite UFPs. Specifically, OPDTT generally increased as inhalant concentrations rose from 0 to 300 μM. However, an intriguing reversal occurred when concentrations exceeded 500 μM, resulting in a decline in OPDTT. Relative to untreated UFPs, these inhalants induced promotion and inhibition effects within concentration ranges of 100-500 and >1000 μM, respectively. While no significant correlation emerged between OPDTT and soluble metal content as inhalant concentrations ranged from 0 to 7000 μM, noteworthy positive correlations emerged at lower inhalant concentrations (e.g., N-acetylcysteine at 0-300 μM). These findings provide insights into the potential influence of reductive pulmonary inhalants on health risks associated with UFP exposure, further underscoring the need for continued research in this critical area.
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Affiliation(s)
- Ya-qi Yu
- BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
- School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071, PR China
| | - Tong Zhu
- BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
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Guo J, Zhou J, Han R, Wang Y, Lian X, Tang Z, Ye J, He X, Yu H, Huang S, Li J. Association of Short-Term Co-Exposure to Particulate Matter and Ozone with Mortality Risk. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15825-15834. [PMID: 37779243 DOI: 10.1021/acs.est.3c04056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
A complex regional air pollution problem dominated by particulate matter (PM) and ozone (O3) needs drastic attention since the levels of O3 and PM are not decreasing in many parts of the world. Limited evidence is currently available regarding the association between co-exposure to PM and O3 and mortality. A multicounty time-series study was used to investigate the associations of short-term exposure to PM1, PM2.5, PM10, and O3 with daily mortality from different causes, which was based on data obtained from the Mortality Surveillance System managed by the Jiangsu Province Center for Disease Control and Prevention of China and analyzed via overdispersed generalized additive models with random-effects meta-analysis. We investigated the interactions of PM and O3 on daily mortality and calculated the mortality fractions attributable to PM and O3. Our results showed that PM1 is more strongly associated with daily mortality than PM2.5, PM10, and O3, and percent increases in daily all-cause nonaccidental, cardiovascular, and respiratory mortality were 1.37% (95% confidence interval (CI), 1.22-1.52%), 1.44% (95% CI, 1.25-1.63%), and 1.63% (95% CI, 1.25-2.01%), respectively, for a 10 μg/m3 increase in the 2 day average PM1 concentration. We found multiplicative and additive interactions of short-term co-exposure to PM and O3 on daily mortality. The risk of mortality was greatest among those with higher levels of exposure to both PM (especially PM1) and O3. Moreover, excess total and cardiovascular mortality due to PM1 exposure is highest in populations with higher O3 exposure levels. Our results highlight the importance of the collaborative governance of PM and O3, providing a scientific foundation for pertinent standards and regulatory interventions.
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Affiliation(s)
- Jianhui Guo
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China
| | - Jinyi Zhou
- Non-Communicable Chronic Disease Control and Prevention Institute, Jiangsu Provincial Center for Disease Control and Prevention, Jiangsu 210009, China
| | - Renqiang Han
- Non-Communicable Chronic Disease Control and Prevention Institute, Jiangsu Provincial Center for Disease Control and Prevention, Jiangsu 210009, China
| | - Yaqi Wang
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China
| | - Xinyao Lian
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China
| | - Ziqi Tang
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China
| | - Jin Ye
- School of Energy and Power, Jiangsu University of Science and Technology, Jiangsu 212100, China
| | - Xueqiong He
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, China
| | - Hao Yu
- Non-Communicable Chronic Disease Control and Prevention Institute, Jiangsu Provincial Center for Disease Control and Prevention, Jiangsu 210009, China
| | - Shaodan Huang
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, China
- Key Laboratory of Epidemiology of Major Diseases (Peking University), Ministry of Education, Beijing 100191, China
| | - Jing Li
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China
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Su WY, Wu DW, Tu HP, Chen SC, Hung CH, Kuo CH. Association between ambient air pollutant interaction with kidney function in a large Taiwanese population study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-28042-6. [PMID: 37328721 DOI: 10.1007/s11356-023-28042-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/29/2023] [Indexed: 06/18/2023]
Abstract
The associations and interactions between kidney function and other air pollutants remain poorly defined. Therefore, the aim of this study was to evaluate associations among air pollutants, including particulate matter (PM) with a diameter ≤ 2.5 μm (PM2.5), PM10 (PM with a diameter ≤ 10 μm), carbon monoxide (CO), nitrogen oxide (NO), nitrogen oxides (NOx), sulfur dioxide (SO2), and ozone (O3) with kidney function, and explore interactions among these air pollutants on kidney function. We used the Taiwan Air Quality Monitoring and Taiwan Biobank databases to derive data on community-dwelling individuals in Taiwan and daily air pollution levels, respectively. We enrolled 26,032 participants. Multivariable analysis showed that high levels of PM2.5, PM10, O3 (all p < 0.001), and SO2 (p = 0.001) and low levels of CO, NO (both p < 0.001), and NOx (p = 0.047) were significantly correlated with low estimated glomerular filtration rate (eGFR). With regard to negative effects, the interactions between PM2.5 and PM10 (p < 0.001), PM2.5 and PM10 (p < 0.001), PM2.5 and SO2, PM10 and O3 (both p = 0.025), PM10 and SO2 (p = 0.001), and O3 and SO2 (p < 0.001) on eGFR were significantly negatively. High PM10, PM2.5, O3, and SO2 were associated with a low eGFR, whereas high CO, NO, and NOx were associated with a high eGFR. Furthermore, negative interactions between PM2.5 and PM10, O3 and SO2, PM10 and O3, PM2.5 and SO2, and PM10 and SO2 on eGFR were observed. The findings of this study have important implications for public health and environmental policy. Specifically, the results of this study may be useful in individuals and organizations to take action to reduce air pollution and promote public health.
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Affiliation(s)
- Wei-Yu Su
- Department of General Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Da-Wei Wu
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd, Hsiao-Kang Dist, 812, Kaohsiung, Taiwan, Republic of China
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Hung-Pin Tu
- Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Szu-Chia Chen
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd, Hsiao-Kang Dist, 812, Kaohsiung, Taiwan, Republic of China.
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
| | - Chih-Hsing Hung
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Department of Pediatrics, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung, 812, Taiwan
| | - Chao-Hung Kuo
- Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 482, Shan-Ming Rd, Hsiao-Kang Dist, 812, Kaohsiung, Taiwan, Republic of China
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
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Yu YQ, Zhu T. Effects of endogenous and exogenous reductants in lung fluid on the bioaccessible metal concentration and oxidative potential of ultrafine particles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 882:163652. [PMID: 37094683 DOI: 10.1016/j.scitotenv.2023.163652] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/14/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Health risk posed by ultrafine particles (UFPs) is potentially increased by reducing substances present in lung fluid, although knowledge of the underlying mechanisms is insufficient. Here, UFPs mainly consisting of metals and quinones were prepared. The reducing substances examined included lung endogenous and exogenous reductants. UFPs were extracted in simulated lung fluid containing reductants. Extracts were used to analyze metrics relevant to health effects, including the bioaccessible metal concentration (MeBA) and oxidative potential (OPDTT). The MeBA of Mn (974.5-9896.9 μg L-1) was higher than those of Cu (155.0-599.6 μg L-1) and Fe (79.9-500.9 μg L-1). Correspondingly, UFPs containing Mn had higher OPDTT (2.07-12.0 pmol min-1 μg-1) than those containing Cu (2.03-7.11 pmol min-1 μg-1) and Fe (1.63-5.34 pmol min-1 μg-1). Endogenous and exogenous reductants can increase MeBA and OPDTT, and the increments were generally higher for composite than pure UFPs. Positive correlations between OPDTT and MeBA of UFPs in the presence of most reductants emphasized the importance of the bioaccessible metal fraction in UFPs for inducing oxidative stress by reactive oxygen species (ROS)-generating reactions between quinones, metals, and lung reductants. Present findings provide novel insight into the toxicity and health risks of UFPs.
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Affiliation(s)
- Ya-Qi Yu
- BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, P.R. China
| | - Tong Zhu
- BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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Belz DC, Woo H, Putcha N, Paulin LM, Koehler K, Fawzy A, Alexis NE, Barr RG, Comellas AP, Cooper CB, Couper D, Dransfield M, Gassett AJ, Han M, Hoffman EA, Kanner RE, Krishnan JA, Martinez FJ, Paine R, Peng RD, Peters S, Pirozzi CS, Woodruff PG, Kaufman JD, Hansel NN. Ambient ozone effects on respiratory outcomes among smokers modified by neighborhood poverty: An analysis of SPIROMICS AIR. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154694. [PMID: 35318050 PMCID: PMC9117415 DOI: 10.1016/j.scitotenv.2022.154694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Neighborhood poverty has been associated with poor health outcomes. Previous studies have also identified adverse respiratory effects of long-term ambient ozone. Factors associated with neighborhood poverty may accentuate the adverse impact of ozone on respiratory health. OBJECTIVES To evaluate whether neighborhood poverty modifies the association between ambient ozone exposure and respiratory morbidity including symptoms, exacerbation risk, and radiologic parameters, among participants of the SPIROMICS AIR cohort study. METHODS Spatiotemporal models incorporating cohort-specific monitoring estimated 10-year average outdoor ozone concentrations at participants' homes. Adjusted regression models were used to determine the association of ozone exposure with respiratory outcomes, accounting for demographic factors, education, individual income, body mass index (BMI), and study site. Neighborhood poverty rate was defined by percentage of families living below federal poverty level per census tract. Interaction terms for neighborhood poverty rate with ozone were included in covariate-adjusted models to evaluate for effect modification. RESULTS 1874 participants were included in the analysis, with mean (± SD) age 64 (± 8.8) years and FEV1 (forced expiratory volume in one second) 74.7% (±25.8) predicted. Participants resided in neighborhoods with mean poverty rate of 9.9% (±10.3) of families below the federal poverty level and mean 10-year ambient ozone concentration of 24.7 (±5.2) ppb. There was an interaction between neighborhood poverty rate and ozone concentration for numerous respiratory outcomes, including COPD Assessment Test score, modified Medical Research Council Dyspnea Scale, six-minute walk test, and odds of COPD exacerbation in the year prior to enrollment, such that adverse effects of ozone were greater among participants in higher poverty neighborhoods. CONCLUSION Individuals with COPD in high poverty neighborhoods have higher susceptibility to adverse respiratory effects of ambient ozone exposure, after adjusting for individual factors. These findings highlight the interaction between exposures associated with poverty and their effect on respiratory health.
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Affiliation(s)
- Daniel C Belz
- Department of Medicine, Johns Hopkins University, 1830 E. Monument, 5th Floor, Baltimore, MD 21205, USA.
| | - Han Woo
- Department of Medicine, Johns Hopkins University, 1830 E. Monument, 5th Floor, Baltimore, MD 21205, USA.
| | - Nirupama Putcha
- Department of Medicine, Johns Hopkins University, 1830 E. Monument, 5th Floor, Baltimore, MD 21205, USA.
| | - Laura M Paulin
- Dartmouth-Hitchcock Medical Center/Geisel School of Medicine at Dartmouth, 1 Medical Center Dr, Pulmonary 5C Ste, Lebanon, NH 03756, USA.
| | - Kirsten Koehler
- Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Ashraf Fawzy
- Department of Medicine, Johns Hopkins University, 1830 E. Monument, 5th Floor, Baltimore, MD 21205, USA.
| | - Neil E Alexis
- University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - R Graham Barr
- Columbia University Medical Center, 630 W. 168th St., New York, NY 10032, USA.
| | - Alejandro P Comellas
- University of Iowa Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| | - Christopher B Cooper
- University of California, Los Angeles, 10833 Le Conte Ave, Los Angeles, CA 90095, USA.
| | - David Couper
- University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Mark Dransfield
- University of Alabama, Birmingham, 1720 2nd Ave South, Birmingham, AL 35294, USA.
| | - Amanda J Gassett
- University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA.
| | - MeiLan Han
- University of Michigan, 1500 E Medical Center Dr, Ann Arbor, MI 48109, USA.
| | - Eric A Hoffman
- University of Iowa Department of Internal Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| | - Richard E Kanner
- University of Utah, 50 North Medical Drive, Salt Lake City, UT 84132, USA.
| | - Jerry A Krishnan
- University of Illinois at Chicago, 1853 West Polk Street, Chicago, IL 60612, USA.
| | | | - Robert Paine
- University of Utah, 50 North Medical Drive, Salt Lake City, UT 84132, USA.
| | - Roger D Peng
- Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Stephen Peters
- Wake Forest University, 475 Vine St, Winston-Salem, NC 27101, USA.
| | - Cheryl S Pirozzi
- University of Utah, 50 North Medical Drive, Salt Lake City, UT 84132, USA.
| | - Prescott G Woodruff
- University of California, San Francisco, 513 Parnassus Ave, HSE, San Francisco, CA 94143, USA.
| | - Joel D Kaufman
- University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA.
| | - Nadia N Hansel
- Department of Medicine, Johns Hopkins University, 1830 E. Monument, 5th Floor, Baltimore, MD 21205, USA.
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Li XB, Fan G, Lou S, Yuan B, Wang X, Shao M. Transport and boundary layer interaction contribution to extremely high surface ozone levels in eastern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115804. [PMID: 33065362 DOI: 10.1016/j.envpol.2020.115804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/01/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
Vertical measurements of ozone (O3) within the 3000-m lower troposphere were obtained using an O3 lidar to investigate the contribution of the interactions between the transport and boundary layer processes to the surface O3 levels in urban Shanghai, China during July 23-28, 2017. An extremely severe pollution episode with a maximum hourly O3 mixing ratio of 160.4 ppb was observed. In addition to enhanced local photochemical production, both downward and advection transport in the lower troposphere may have played important roles in forming the pollution episode. The O3-rich air masses in the lower free troposphere primarily originated from central China and the northern Yangtze River Delta (YRD) region. The downward transport of O3 from the lower free troposphere may have an average contribution of up to 49.1% to the daytime (09:00-16:00 local time) surface O3 in urban Shanghai during the pollution episode (July 23-26, 2017). As for the advection transport, large amounts of O3 were transported outward from Shanghai in the planetary boundary layer under the influence of southeasterly winds during the field study. In this condition, the boundary-layer O3 that was transported downward from the free troposphere in Shanghai could be transported back to the northern YRD region and accumulated therein, leading to the occurrence of severe O3 pollution events over the whole YRD region. Our results indicate that effective regional emission control measures are urgently required to mitigate O3 pollution in the YRD region.
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Affiliation(s)
- Xiao-Bing Li
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou, 510632, China
| | - Guangqiang Fan
- Key Lab of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, China.
| | - Shengrong Lou
- State Environmental Protection Key Laboratory of the Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Bin Yuan
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou, 510632, China
| | - Xuemei Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou, 510632, China
| | - Min Shao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou, 510632, China
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Balram D, Lian KY, Sebastian N. A novel soft sensor based warning system for hazardous ground-level ozone using advanced damped least squares neural network. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 205:111168. [PMID: 32846299 DOI: 10.1016/j.ecoenv.2020.111168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 06/11/2023]
Abstract
Estimation of hazardous air pollutants in the urban environment for maintaining public safety is a significant concern to mankind. In this paper, we have developed an efficient air quality warning system based on a low-cost and robust ground-level ozone soft sensor. The soft sensor was developed based on a novel technique of damped least squares neural network (DLSNN) with greedy backward elimination (GBE) for the estimation of hazardous ground-level ozone. Only three meteorological factors were used as input variables in the estimation of ground-level ozone and we have used weighted k-nearest neighbors (WkNN) classifier with fast response for development of air quality warning system. We have chosen the urban areas of Taiwan for this study and have analyzed seasonal variations in the ground-level ozone concentration of various cities in Taiwan as part of this work. Moreover, descriptive statistics and linear dependence of ozone concentration based on Spearman correlation coefficient, Kendall's tau coefficient, and Pearson coefficient are calculated. The proposed DLSNN/GBE method exhibited excellent performance resulting in very low mean square error (MSE), mean absolute error (MAE), and high coefficient of determination (R2) compared to other traditional approaches in ozone concentration estimation. We have achieved a good fit in the determination of ozone concentration from meteorological features of atmosphere. Moreover, the excellent performance of proposed urban air quality warning system was evident from the good F1-score value of 0.952 achieved by the WkNN classifier.
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Affiliation(s)
- Deepak Balram
- Department of Electrical Engineering, National Taipei University of Technology, No. 1, Section 3, Zhongxiao East Road, Taipei, 106, Taiwan, ROC
| | - Kuang-Yow Lian
- Department of Electrical Engineering, National Taipei University of Technology, No. 1, Section 3, Zhongxiao East Road, Taipei, 106, Taiwan, ROC.
| | - Neethu Sebastian
- Institute of Organic and Polymeric Materials, National Taipei University of Technology, No. 1, Section 3, Zhongxiao East Road, Taipei, 106, Taiwan, ROC
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Oyana TJ, Lomnicki SM, Guo C, Cormier SA. A Scalable Field Study Protocol and Rationale for Passive Ambient Air Sampling: A Spatial Phytosampling for Leaf Data Collection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10663-10673. [PMID: 28805054 PMCID: PMC5792061 DOI: 10.1021/acs.est.7b03643] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Stable, bioreactive, radicals known as environmentally persistent free radicals (EPFRs) have been found to exist on the surface of airborne PM2.5. These EPFRs have been found to form during many combustion processes, are present in vehicular exhaust, and persist in the environment for weeks and biological systems for up to 12 h. To measure EPFRs in PM samples, high volume samplers are required and measurements are less representative of community exposure; therefore, we developed a novel spatial phytosampling methodology to study the spatial patterns of EPFR concentrations using plants. Leaf samples for laboratory PM analysis were collected from 188 randomly drawn sampling sites within a 500-m buffer zone of pollution sources across a sampling grid measuring 32.9 × 28.4 km in Memphis, Tennessee. PM was isolated from the intact leaves and size fractionated, and EPFRs on PM quantified by electron paramagnetic resonance spectroscopy. The radical concentration was found to positively correlate with the EPFR g-value, thus indicating cumulative content of oxygen centered radicals in PM with higher EPFR load. Our spatial phytosampling approach reveals spatial variations and potential "hotspots" risk due to EPFR exposure across Memphis and provides valuable insights for identifying exposure and demographic differences for health studies.
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Affiliation(s)
- Tonny J. Oyana
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
- Department of Preventive Medicine, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Slawomir M. Lomnicki
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Chuqi Guo
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Stephania A. Cormier
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
- Department of Preventive Medicine, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
- Le Bonheur Children’s Medical Center, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
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9
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Zhang X, Staimer N, Gillen DL, Tjoa T, Schauer JJ, Shafer MM, Hasheminassab S, Pakbin P, Vaziri ND, Sioutas C, Delfino RJ. Associations of oxidative stress and inflammatory biomarkers with chemically-characterized air pollutant exposures in an elderly cohort. ENVIRONMENTAL RESEARCH 2016; 150:306-319. [PMID: 27336235 PMCID: PMC5003670 DOI: 10.1016/j.envres.2016.06.019] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/18/2016] [Accepted: 06/10/2016] [Indexed: 05/12/2023]
Abstract
BACKGROUND Exposure to air pollution has been associated with cardiorespiratory morbidity and mortality. However, the chemical constituents and pollution sources underlying these associations remain unclear. METHOD We conducted a cohort panel study involving 97 elderly subjects living in the Los Angeles metropolitan area. Airway and circulating biomarkers of oxidative stress and inflammation were measured weekly over 12 weeks and included, exhaled breath condensate malondialdehyde (EBC MDA), fractional exhaled nitric oxide (FeNO), plasma oxidized low-density lipoprotein (oxLDL), and plasma interleukin-6 (IL-6). Exposures included 7-day personal nitrogen oxides (NOx), daily criteria-pollutant data, five-day average particulate matter (PM) measured in three size-fractions and characterized by chemical components including transition metals, and in vitro PM oxidative potential (dithiothreitol and macrophage reactive oxygen species). Associations between biomarkers and pollutants were assessed using linear mixed effects regression models. RESULTS We found significant positive associations of airway oxidative stress and inflammation with traffic-related air pollutants, ultrafine particles and transition metals. Positive but nonsignificant associations were observed with PM oxidative potential. The strongest associations were observed among PM variables in the ultrafine range (PM <0.18µm). It was estimated that an interquartile increase in 5-day average ultrafine polycyclic aromatic hydrocarbons was associated with a 6.3% (95% CI: 1.1%, 11.6%) increase in EBC MDA and 6.7% (95% CI: 3.4%, 10.2%) increase in FeNO. In addition, positive but nonsignificant associations were observed between oxLDL and traffic-related pollutants, ultrafine particles and transition metals while plasma IL-6 was positively associated with 1-day average traffic-related pollutants. CONCLUSION Our results suggest that exposure to pollutants with high oxidative potential (traffic-related pollutants, ultrafine particles, and transition metals) may lead to increased airway oxidative stress and inflammation in elderly adults. This observation was less clear with circulating biomarkers.
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Affiliation(s)
- Xian Zhang
- Department of Epidemiology, School of Medicine, University of California, Irvine, CA, USA
| | - Norbert Staimer
- Department of Epidemiology, School of Medicine, University of California, Irvine, CA, USA
| | - Daniel L Gillen
- Department of Statistics, School of Information and Computer Sciences, University of California, Irvine, CA, USA
| | - Tomas Tjoa
- Department of Epidemiology, School of Medicine, University of California, Irvine, CA, USA
| | - James J Schauer
- University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, WI, USA
| | - Martin M Shafer
- University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, WI, USA
| | - Sina Hasheminassab
- Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Payam Pakbin
- Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Nosratola D Vaziri
- Division of Nephrology and Hypertension, Department of Medicine, School of Medicine, University of California, Irvine, CA, USA
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Ralph J Delfino
- Department of Epidemiology, School of Medicine, University of California, Irvine, CA, USA.
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10
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Pongpiachan S. Assessment of Reliability when Using Diagnostic Binary Ratios of Polycyclic Aromatic Hydrocarbons in Ambient Air PM10. Asian Pac J Cancer Prev 2016; 16:8605-11. [PMID: 26745124 DOI: 10.7314/apjcp.2015.16.18.8605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The reliability of using diagnostic binary ratios of particulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) as chemical tracers for source characterisation was assessed by collecting PM10 samples from various air quality observatory sites in Thailand. The major objectives of this research were to evaluate the effects of day and night on the alterations of six different PAH diagnostic binary ratios: An/(An + Phe), Fluo/(Fluo + Pyr), B[a]A/(B[a]A + Chry), B[a]P/(B[a]P + B[e]P), Ind/(Ind + B[g,h,i]P), and B[k]F/Ind, and to investigate the impacts of site-specific conditions on the alterations of PAH diagnostic binary ratios by applying the concept of the coefficient of divergence (COD). No significant differences between day and night were found for any of the diagnostic binary ratios of PAHs, which indicates that the photodecomposition process is of minor importance in terms of PAH reduction. Interestingly, comparatively high values of COD for An/(An + Phe) in PM10 collected from sites with heavy traffic and in residential zones underline the influence of heterogeneous reactions triggered by oxidising gaseous species from vehicular exhausts. Therefore, special attention must be paid when interpreting the data of these diagnostic binary ratios, particularly for cases of low-molecular-weight PAHs.
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Affiliation(s)
- Siwatt Pongpiachan
- NIDA Center for Research and Development of Disaster Prevention and Management, School of Social and Environmental Development, National Institute of Development Administration (NIDA), Sereethai Road, Bangkapi, Bangkok, Thailand E-mail :
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Kurhanewicz N, McIntosh-Kastrinsky R, Tong H, Walsh L, Farraj AK, Hazari MS. Ozone co-exposure modifies cardiac responses to fine and ultrafine ambient particulate matter in mice: concordance of electrocardiogram and mechanical responses. Part Fibre Toxicol 2014; 11:54. [PMID: 25318591 PMCID: PMC4203862 DOI: 10.1186/s12989-014-0054-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/02/2014] [Indexed: 12/19/2022] Open
Abstract
Background Studies have shown a relationship between air pollution and increased risk of cardiovascular morbidity and mortality. Due to the complexity of ambient air pollution composition, recent studies have examined the effects of co-exposure, particularly particulate matter (PM) and gas, to determine whether pollutant interactions alter (e.g. synergistically, antagonistically) the health response. This study examines the independent effects of fine (FCAPs) and ultrafine (UFCAPs) concentrated ambient particles on cardiac function, and determine the impact of ozone (O3) co-exposure on the response. We hypothesized that UFCAPs would cause greater decrement in mechanical function and electrical dysfunction than FCAPs, and that O3 co-exposure would enhance the effects of both particle-types. Methods Conscious/unrestrained radiotelemetered mice were exposed once whole-body to either 190 μg/m3 FCAPs or 140 μg/m3 UFCAPs with/without 0.3 ppm O3; separate groups were exposed to either filtered air (FA) or O3 alone. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure, and cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 hrs post-exposure. Results FCAPs alone caused a significant decrease in baseline left ventricular developed pressure (LVDP) and contractility, whereas UFCAPs did not; neither FCAPs nor UFCAPs alone caused any ECG changes. O3 co-exposure with FCAPs caused a significant decrease in heart rate variability when compared to FA but also blocked the decrement in cardiac function. On the other hand, O3 co-exposure with UFCAPs significantly increased QRS-interval, QTc and non-conducted P-wave arrhythmias, and decreased LVDP, rate of contractility and relaxation when compared to controls. Conclusions These data suggest that particle size and gaseous interactions may play a role in cardiac function decrements one day after exposure. Although FCAPs + O3 only altered autonomic balance, UFCAPs + O3 appeared to be more serious by increasing cardiac arrhythmias and causing mechanical decrements. As such, O3 appears to interact differently with FCAPs and UFCAPs, resulting in varied cardiac changes, which suggests that the cardiovascular effects of particle-gas co-exposures are not simply additive or even generalizable. Additionally, the mode of toxicity underlying this effect may be subtle given none of the exposures described here impaired post-ischemia recovery. Electronic supplementary material The online version of this article (doi:10.1186/s12989-014-0054-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicole Kurhanewicz
- Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Rachel McIntosh-Kastrinsky
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Haiyan Tong
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, Chapel Hill, NC, 27711, USA.
| | - Leon Walsh
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, Chapel Hill, NC, 27711, USA.
| | - Aimen K Farraj
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, Chapel Hill, NC, 27711, USA.
| | - Mehdi S Hazari
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, Chapel Hill, NC, 27711, USA.
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12
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Li P, Gu Y, Yu S, Li Y, Yang J, Jia G. Assessing the suitability of 8-OHdG and micronuclei as genotoxic biomarkers in chromate-exposed workers: a cross-sectional study. BMJ Open 2014; 4:e005979. [PMID: 25300459 PMCID: PMC4194798 DOI: 10.1136/bmjopen-2014-005979] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/27/2014] [Accepted: 08/28/2014] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES We aimed to investigate suitable conditions of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and micronucleus (MN) as genotoxic biomarkers at different levels of occupational chromate exposure. DESIGN A cross-sectional study was used. PARTICIPANTS 84 workers who were exposed to chromate for at least 1 year were chosen as the chromate exposed group, while 30 non-exposed individuals were used as controls. MAIN OUTCOME MEASURES Environmental and biological exposure to chromate was respectively assessed by measuring the concentration of chromate in the air (CrA) and blood (CrB) by inductively coupled plasma mass spectrometer (ICP-MS) in all participants. MN indicators, including micronucleus cell count (MNCC), micro-nucleus count (MNC), nuclear bridge (NPB) and nuclear bud (NBUD) were calculated by the cytokinesis-block micronucleus test (CBMN), while the urinary 8-OHdG was measured by the ELISA method and normalised by the concentration of Cre. RESULTS Compared with the control group, the levels of CrA, CrB, MNCC, MNC and 8-OHdG in the chromate-exposed group were all significantly higher (p<0.05). There were positive correlations between log(8-OHdG) and LnMNCC or LnMNC (r=0.377 and 0.362). The levels of LnMNCC, LnMNC and log (8-OHdG) all have parabola correlations with the concentration of CrB. However, there was a significantly positive correlation between log (8-OHdG) and CrB when the CrB level was below 10.50 µg/L (r=0.355), while a positive correlation was also found between LnMNCC or LnMNC and CrB when the CrB level was lower than 9.10 µg/L (r=0.365 and 0.269, respectively). CONCLUSIONS MN and 8-OHdG can be used as genotoxic biomarkers in the chromate-exposed group, but it is only when CrB levels are lower than 9.10 and 10.50 µg/L, respectively, that they can accurately reflect the degree of genetic damage.
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Affiliation(s)
- Ping Li
- Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, People's Republic of China
| | - Yongen Gu
- Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, People's Republic of China
| | - Shanfa Yu
- Department of Occupational Health Science, Institute of Occupational Medicine, Zhengzhou, Henan, People's Republic of China
| | - Yang Li
- Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, People's Republic of China
| | - Jinglin Yang
- Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, People's Republic of China
| | - Guang Jia
- Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, People's Republic of China
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13
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Valavanidis A, Vlachogianni T, Fiotakis K, Loridas S. Pulmonary oxidative stress, inflammation and cancer: respirable particulate matter, fibrous dusts and ozone as major causes of lung carcinogenesis through reactive oxygen species mechanisms. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:3886-907. [PMID: 23985773 PMCID: PMC3799517 DOI: 10.3390/ijerph10093886] [Citation(s) in RCA: 455] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/24/2013] [Accepted: 08/15/2013] [Indexed: 02/07/2023]
Abstract
Reactive oxygen or nitrogen species (ROS, RNS) and oxidative stress in the respiratory system increase the production of mediators of pulmonary inflammation and initiate or promote mechanisms of carcinogenesis. The lungs are exposed daily to oxidants generated either endogenously or exogenously (air pollutants, cigarette smoke, etc.). Cells in aerobic organisms are protected against oxidative damage by enzymatic and non-enzymatic antioxidant systems. Recent epidemiologic investigations have shown associations between increased incidence of respiratory diseases and lung cancer from exposure to low levels of various forms of respirable fibers and particulate matter (PM), at occupational or urban air polluting environments. Lung cancer increases substantially for tobacco smokers due to the synergistic effects in the generation of ROS, leading to oxidative stress and inflammation with high DNA damage potential. Physical and chemical characteristics of particles (size, transition metal content, speciation, stable free radicals, etc.) play an important role in oxidative stress. In turn, oxidative stress initiates the synthesis of mediators of pulmonary inflammation in lung epithelial cells and initiation of carcinogenic mechanisms. Inhalable quartz, metal powders, mineral asbestos fibers, ozone, soot from gasoline and diesel engines, tobacco smoke and PM from ambient air pollution (PM₁₀ and PM₂.₅) are involved in various oxidative stress mechanisms. Pulmonary cancer initiation and promotion has been linked to a series of biochemical pathways of oxidative stress, DNA oxidative damage, macrophage stimulation, telomere shortening, modulation of gene expression and activation of transcription factors with important role in carcinogenesis. In this review we are presenting the role of ROS and oxidative stress in the production of mediators of pulmonary inflammation and mechanisms of carcinogenesis.
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Affiliation(s)
- Athanasios Valavanidis
- Department of Chemistry, University of Athens, University Campus Zografou, Athens 15784, Greece.
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14
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Shen H, Anastasio C. Formation of hydroxyl radical from San Joaquin Valley particles extracted in a cell-free surrogate lung fluid. ATMOSPHERIC CHEMISTRY AND PHYSICS 2011; 11:9671-9682. [PMID: 22121357 PMCID: PMC3223122 DOI: 10.5194/acp-11-9671-2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Previous studies have suggested that the adverse health effects from ambient particulate matter (PM) are linked to the formation of reactive oxygen species (ROS) by PM in cardiopulmonary tissues. While hydroxyl radical ((•)OH) is the most reactive of the ROS species, there are few quantitative studies of (•)OH generation from PM. Here we report on (•)OH formation from PM collected at an urban (Fresno) and rural (Westside) site in the San Joaquin Valley (SJV) of California. We quantified (•)OH in PM extracts using a cell-free, phosphate-buffered saline (PBS) solution with or without 50μM ascorbate (Asc). The results show that generally the urban Fresno PM generates much more (•)OH than the rural Westside PM. The presence of Asc at a physiologically relevant concentration in the extraction solution greatly enhances (•)OH formation from all the samples. Fine PM (PM(2.5)) generally makes more (•)OH than the corresponding coarse PM (PM(cf), i.e. with diameters of 2.5 to 10 μm) normalized by air volume collected, while the coarse PM typically generates more (•)OH normalized by PM mass. (•)OH production by SJV PM is reduced on average by (97±6)% when the transition metal chelator desferoxamine (DSF) is added to the extraction solution, indicating a dominant role of transition metals. By measuring calibration curves of (•)OH generation from copper and iron, and quantifying copper and iron concentrations in our particle extracts, we find that PBS-soluble copper is primarily responsible for (•)OH production by the SJV PM, while iron often makes a significant contribution. Extrapolating our results to expected burdens of PM-derived (•)OH in human lung lining fluid suggests that typical daily PM exposures in the San Joaquin Valley are unlikely to result in a high amount of pulmonary (•)OH, although high PM events could produce much higher levels of (•)OH, which might lead to cytotoxicity.
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Affiliation(s)
- H Shen
- Department of Land, Air and Water Resources, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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15
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Kim SH, Yoon HJ. Climate change and respiratory allergic diseases. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2011. [DOI: 10.5124/jkma.2011.54.2.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Sang-Heon Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Ho Joo Yoon
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
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16
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Farraj AK, Boykin E, Ledbetter A, Andrews D, Gavett SH. Increased lung resistance after diesel particulate and ozone co-exposure not associated with enhanced lung inflammation in allergic mice. Inhal Toxicol 2010; 22:33-41. [PMID: 20017592 DOI: 10.3109/08958370902862434] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Exposure to diesel exhaust particulate matter (DEP) exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (O(3)). Since levels of both pollutants in ambient air tend to be simultaneously elevated, we investigated the possible synergistic effect of these agents on the exacerbation of allergic airways disease in mice. Male BALB/c mice were sensitized ip with ovalbumin (Ova) or vehicle only, then exposed once per week for 4 wk via nose-only inhalation (4 h) to the PM(2.5) fraction of DEP (2 mg/m(3)), O(3) (0.5 ppm), DEP and O(3), or filtered air, and then challenged with aerosolized ovalbumin. Ova sensitization in air-exposed mice enhanced pulmonary inflammatory cell infiltration, several indicators of injury in the lung (lactate dehydrogenase, albumin and total protein), and lung resistance (R(L)) and elastance (E(L)) in response to methacholine (MCh) aerosol challenge. DEP exposure did not enhance the Ova-induced increase in pulmonary cell infiltration, indicators of injury, or R(L) and E(L). O(3) exposure enhanced the Ova-induced increase in inflammatory cell infiltration and N-acetylglucosaminidase (NAG) in the lung, but had no effect on R(L) or E(L). DEP co-exposure significantly attenuated the O(3)-induced increase in cell infiltration and indicators of injury; co-exposure had no effect on E(L) relative to air-exposed Ova-sensitized mice. However, only DEP-O(3) co-exposure significantly increased the Ova-induced increase in R(L). Thus, O(3) and DEP co-exposure exacerbated airways hyperresponsiveness, a response that was not associated with parallel increases in pulmonary inflammation and one that may be mediated by a unique mechanism.
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Affiliation(s)
- Aimen K Farraj
- Experimental Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
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