nitrogen-dioxide and Respiratory-Tract-Infections

There is a growing understanding that chronic respiratory diseases in adults have their origins in early life. Adverse environmental exposures occurring in vulnerable periods during lung growth and development in the fetal period and in early childhood that alter lung structure and limit the growth in lung function may have lifelong consequences. Evidence is increasing that exposure to the ambient environment, including air pollutants, persistent toxic substances, water pollutants and respiratory viral infections, can inhibit lung function growth and predispose to chronic non-malignant lung diseases. These exposures generally interact with a genetic predisposition, and gene-environment interactions and epigenetic phenomena are attracting considerable study. An understanding of how ambient exposures impact on normal lung growth and development will aid in understanding of how chronic respiratory diseases of adults develop and may lead to new preventative strategies.

Topics: Adult; Air Pollutants; Arsenic; Child; Disease Susceptibility; Environmental Exposure; Female; Humans; Lung; Lung Diseases; Nitrogen Dioxide; Nutritional Status; Oxidative Stress; Ozone; Particulate Matter; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Tract Infections; Social Class; Sulfur Dioxide; Water Pollutants, Chemical

Topics: Acids; Air Pollutants; Air Pollution; Animals; Asthma; Ecosystem; Environmental Monitoring; Epidemiological Monitoring; Humans; Hypersensitivity; Lung Diseases, Obstructive; Lung Neoplasms; Nitrogen Dioxide; Ozone; Prognosis; Respiratory Tract Diseases; Respiratory Tract Infections; Rhinitis; Sulfur Dioxide; Vehicle Emissions

The main primary pollutants released into the atmosphere are sulfur dioxide (SO2), nitrogen monoxide and dioxide (NOx), particulate dust and in a less important part carbon monoxide (CO), hydrocarbons and heavy metals (Pb, Cd). Sulfur and nitrogen oxides are released from combustion of coals and fuels. Sulfates, nitrates and ozone are secondary pollutants resulting from chemical reactions within the atmosphere. While governmental directives limiting emissions have decreased SO2 and particulate matter levels, air quality in urban regions has improved in the last two decades. The role of air pollution as a risk factor for respiratory infections is difficult to address. Animal experiments demonstrate that air pollutants decrease the efficacy of lung defense mechanisms and increase the sensibility to respiratory infections. Nevertheless, because of difference in sensitivity between animal species and between exposure conditions, these effects are difficult to extrapolate to humans. Moreover, it is obvious that direct exposure studies of the sensibility of humans to respiratory infections are rare for ethical reasons. Epidemiological data addressing the role of air pollutants at usual levels can only suggest that some pollutants (SO2, suspended particulates) constitute a risk factor for respiratory infections. Since most of these studies do not include bacteriologic and virologic confirmation, it is unclear whether this respiratory morbidity is due to respiratory irritation or infection. In conclusion, we think that high concentrations of air pollutants are very likely to increase sensibility to respiratory infections in humans. There are however no sufficient data to clearly establish whether air pollution constitutes a risk factor for respiratory infections at usual ambient concentrations.

Topics: Air Pollutants; Animals; Carbon Monoxide; Dust; Epidemiologic Methods; Humans; Lung; Nitric Oxide; Nitrogen Dioxide; Respiratory Tract Infections; Risk Factors; Sulfur Dioxide

Most asthmatics have hyperresponsive airways. This makes them more sensitive than non-asthmatics to bronchoconstricting environmental exposures which, in their turn, may enhance responsiveness. Airway inflammation is considered to be a key determinant of airway hyperresponsiveness: the fact that chronic airway inflammation in cystic fibrosis does not lead to airway hyperresponsiveness of any importance indicates, however, that the role of airway inflammation is complex and incompletely elucidated. The main inducers of airway inflammation are viral infections, antigens, occupational stimuli and pollutants. Although exercise, airway cooling and hyper- or hypotonic aerosols are potent stimuli of bronchoconstriction, it is questionable if airway inflammation is involved in their mode of action. Each of the above-mentioned stimuli is discussed, with emphasis laid on the relation of symptoms to mechanisms.

Topics: Adult; Air Pollution; Antigens; Asthma; Child; Child, Preschool; Environmental Exposure; Humans; Inflammation; Nitrogen Dioxide; Respiratory Hypersensitivity; Respiratory Tract Infections; Smoking; Sulfur Dioxide

Topics: Adaptation, Physiological; Air Pollution; Animals; Cost-Benefit Analysis; Cricetinae; Disease Susceptibility; Dogs; Dose-Response Relationship, Drug; Guinea Pigs; Haplorhini; Humans; Lung; Mice; Microscopy, Electron; Nitrogen Dioxide; Oxidants, Photochemical; Ozone; Pulmonary Alveoli; Rabbits; Rats; Respiratory Tract Infections

Topics: Air Pollutants; Animals; Bronchi; Disease Models, Animal; Environmental Exposure; Humans; Lung Volume Measurements; Nitrogen Dioxide; Phagocytosis; Pulmonary Alveoli; Respiratory Tract Infections; Risk

Topics: Aerosols; Air Pollution; Animals; Chronic Disease; Cricetinae; Environmental Health; Guinea Pigs; Humans; Hydrocarbons; Lung; Mice; Nitrogen; Nitrogen Dioxide; Oxidation-Reduction; Oxides; Ozone; Rabbits; Rats; Respiratory Tract Infections; Vehicle Emissions

There is growing evidence that asthma symptoms can be aggravated or events triggered by exposure to indoor nitrogen dioxide (NO(2)) emitted from unflued gas heating. The impact of NO(2) on the respiratory health of children with asthma was explored as a secondary analysis of a randomised community trial, involving 409 households during the winter period in 2006 (June to September). Geometric mean indoor NO(2) levels were 11.4 μg · m(-3), while outdoor NO(2) levels were 7.4 μg · m(-3). Higher indoor NO(2) levels (per logged unit increase) were associated with greater daily reports of lower (mean ratio 14, 95% CI 1.12-1.16) and upper respiratory tract symptoms (mean ratio 1.03, 95% CI 1.00-1.05), more frequent cough and wheeze, and more frequent reliever use during the day, but had no effect on preventer use. Higher indoor NO(2) levels (per logged unit increase) were associated with a decrease in morning (-17.25 mL, 95% CI -27.63- -6.68) and evening (-13.21, 95% CI -26.03- -0.38) forced expiratory volume in 1 s readings. Outdoor NO(2) was not associated with respiratory tract symptoms, asthma symptoms, medication use or lung function measurements. These findings indicate that reducing NO(2) exposure indoors is important in improving the respiratory health of children with asthma.

Topics: Adolescent; Air Pollution, Indoor; Asthma; Child; Cough; Female; Humans; Male; Nitrogen Dioxide; Respiratory Function Tests; Respiratory Tract Infections; Seasons; Sneezing

Short-term air pollution exposure is correlated with childhood acute upper respiratory infections (AURI) hospitalizations. We surveyed the relationship between AURI hospitalizations and air pollutant concentrations in children aged 0-14 years from 1 January 2014 to 31 December 2019 in Lanzhou City.. We collected both data on air pollutant concentrations and children's AURI hospitalizations during the study period. Distributional lagged nonlinear models were adopted to assess the short-term effects of air pollutants on children's AURI hospitalizations. We also performed subgroup analysis and sensitivity analysis.. A total of 15,881 children were hospitalized for AURI during the study period. The results showed that for each 10 µg/m. Short-term exposures to PM

Topics: Air Pollutants; Air Pollution; Child; China; Hospitalization; Humans; Nitrogen Dioxide; Particulate Matter; Respiratory Tract Infections; Time Factors

This study evaluated the association of the short-term exposure to environmental factors (relative humidity, temperature, NO. We performed a bidirectional case-crossover study in 30,445 children with ALRI under two years of age in the Spanish Minimum Basic Data Set (MBDS) from 2013 to 2015. Environmental data were obtained from Spain's State Meteorological Agency (AEMET). The association was assessed by conditional logistic regression.. Lower temperature one week before the day of the event (hospital admission) (q-value = 0.012) and higher relative humidity one week (q-value = 0.003) and two weeks (q-value<0.001) before the day of the event were related to a higher odds of hospital admissions. Higher NO. Short-term exposure to environmental factors (climatic conditions and ambient air contaminants) was linked to a higher likelihood of hospital admissions due to ALRI. Our findings emphasize the importance of monitoring environmental factors to assess the odds of ALRI hospital admissions and plan public health resources.

Topics: Air Pollutants; Air Pollution; Child; Child, Preschool; COVID-19; Cross-Over Studies; Hospitalization; Hospitals; Humans; Nitrogen Dioxide; Respiratory Tract Infections

The associations between viral etiology of acute respiratory infections (ARI) with meteorological factors and air pollutants among children is not fully understood. This study aimed to explore the viral etiology among children hospitalized for ARI and the association of meteorological factors and air pollutants with children hospitalization due to viral ARI.. Electronic health record data about children (aged between 1 month and 14 years) admitted for ARI at Kiang Wu Hospital in Macao between 2014 and 2017 was analyzed retrospectively. xMAP multiplex assays were used to detect viruses in the nasopharyngeal swab and distributed-lag nonlinear model (DLNM) was used to evaluate associations.. Among the 4880 cases of children hospitalization due to ARI, 3767 (77.2%) were tested positive for at least one virus and 676 (18%) exhibited multiple infections. Enterovirus (EV)/rhinovirus (HRV), adenovirus (ADV), respiratory syncytial virus (RSV) and influenza virus (IFV) were the most common viral pathogens associated with ARI and human bocavirus (hBOV) exhibited the highest multiple infection rates. Meteorological factors and air pollutants (PM. The effects of mean temperature, relative humidity and air pollutants should be taken into account when considering management of ARI among children.

Topics: Air Pollutants; Child; Hospitalization; Humans; Infant; Macau; Meteorological Concepts; Nitrogen Dioxide; Respiratory Syncytial Virus, Human; Respiratory Tract Infections; Retrospective Studies; Virus Diseases; Viruses

Lower respiratory tract viral infection (LRTI) is a significant cause of morbidity-mortality in older people worldwide. We analyzed the association between short-term exposure to environmental factors (climatic factors and outdoor air pollution) and hospital admissions with a viral LRTI diagnosis in older adults.. We conducted a bidirectional case-crossover study in 6367 patients over 65 years of age with viral LRTI and residential zip code in the Spanish Minimum Basic Data Set. Spain's State Meteorological Agency was the source of environmental data. Associations were assessed using conditional logistic regression. P-values were corrected for false discovery rate (q-values).. Almost all were hospital emergency admissions (98.13%), 18.64% were admitted to the intensive care unit (ICU), and 7.44% died. The most frequent clinical discharge diagnosis was influenza (90.25%). LRTI hospital admissions were more frequent when there were lower values of temperature and O. Unfavorable environmental factors (low temperatures, high relative humidity, and high concentrations of NO

Topics: Aged; Air Pollutants; Air Pollution; Cross-Over Studies; Hospitalization; Humans; Nitrogen Dioxide; Particulate Matter; Respiratory Tract Infections; Spain

Children's respiratory health are particularly vulnerable to outdoor air pollution, but evidence is lacking on the very acute effects of air pollution on the risk of acute upper respiratory infections (AURI) and acute lower respiratory infections (ALRI) in children. This study aimed to evaluate the risk of cause-specific AURI and ALRI, in children within 24 h of exposure to air pollution. We obtained data on emergency cases, including 11,091 AURI cases (acute pharyngitis, acute tonsillitis, acute obstructive laryngitis and epiglottitis, and unspecified acute upper respiratory infections) and 11,401 ALRI cases (pneumonia, acute bronchitis, acute bronchiolitis, unspecified acute lower respiratory infection) in Brisbane, Australia, 2013-2015. A time-stratified case-crossover analysis was used to examine the hourly association of AURI and ALRI with high concentration (95th percentile) of four air pollutants (particulate matters with aerodynamic diameter <10 μm (PM

Topics: Air Pollutants; Air Pollution; Australia; Child; Environmental Exposure; Humans; Nitrogen Dioxide; Ozone; Particulate Matter; Respiratory Tract Infections

To investigate the association between particulate matter with an aerodynamic diameter of less than 2.5 μm (PM. This study included 1,180 mother-child pairs from the Cohort for Childhood Origin of Asthma and allergic diseases. The PM. Higher PM

Topics: Adult; Air Pollutants; Female; Glutathione Transferase; Humans; Infant; Male; Maternal Exposure; Nitrogen Dioxide; Ozone; Particulate Matter; Polymorphism, Genetic; Pregnancy; Pregnancy Trimester, Third; Prenatal Exposure Delayed Effects; Respiratory Tract Infections

In recent years, air pollution and the number of children with respiratory tract infections increased. This also increased the burden related to the treatment of disease, so the government and relevant departments need to strengthen their management.. The aim of the present study was to quantitatively analyze the relationship between respiratory infection and air quality in children and gain insight into the burden of related diseases.. Data regarding outpatient and emergency department visits in children of 14 years or younger in 16 public and private medical institutions were collected for four months. Routine air quality monitoring data in Shanghai from the same period were correlated with these medical data by descriptive statistics, Pearson's correlation analysis and multivariate linear regression analysis.. There was a positive correlation between respiratory tract infections in 73376 children and Air Quality Index (AQI), PM2.5, SO2 and NO2 levels. The total medical expense per patient was 80.22 yuan, and the average compensation ratio of medical insurance per patient was 18.95%. The increase in AQI and the concentration of major air pollutants will lead to increased medical treatment for children with respiratory diseases.. It is suggested that the intensity of air pollution control should be increased, so that the special period of childhood respiratory protection is strengthened. Moreover, child medical insurance coverage should also be moderately increased to safeguard the rights and interests of children's health.

Topics: Adolescent; Air Pollutants; Air Pollution; Child; Child, Preschool; China; Emergency Service, Hospital; Female; Health Expenditures; Humans; Infant; Insurance, Health; Linear Models; Male; Nitrogen Dioxide; Particulate Matter; Respiratory Tract Infections; Seasons; Sulfur Dioxide

We evaluated associations between air pollution (nitrogen dioxide [NO

Topics: Acute Disease; Air Pollutants; Air Pollution; Child, Preschool; Cross-Sectional Studies; Female; Humans; Indonesia; Infant; Infant Death; Infant, Low Birth Weight; Infant, Newborn; Logistic Models; Male; Nitrogen Dioxide; Odds Ratio; Perinatal Death; Respiratory Tract Infections; Sulfur Dioxide

Pollution and climate have an impact on pediatric respiratory diseases; few studies have assessed this in the Autonomous City of Buenos Aires.. To assess the impact of the interaction between air pollutants and climate on the Emergency Department visits for acute lower respiratory tract infection (ALRTI) in a children's hospital.. Ecological, time-series study with generalized additive models that included total visits and visits for ALRTI to the Emergency Department between 2012 and 2016. A series with 7-day moving averages for ALRTI visits was founded as a bias control measure. Predictors were daily levels of air pollutants (carbon monoxide, nitrous dioxide, particulate matter < 10 μ) and meteorological variables (temperature, humidity). Pollutants were measured at three monitoring stations. Temporal variables (day of the week, warm/cold semester) were controlled.. There were 455 256 total visits; 17 298 accounted for visits for ALRTI. A correlation was established only between total visits and day of the week (Mondays and Saturdays, more visits; Thursdays, less visits). Less visits for ALRTI were recorded in the warm semester compared to the cold semester (relative risk = 0.23; 95 % confidence interval: 0.29-0.18; p < 0.001). One monitoring station did not show any correlation; the other two stations showed a weak correlation between carbon monoxide and particulate matter < 10 μ and visits for ALRTI.. The season accurately accounts for the increased number of total visits and visits for ALRTI. Although there was a correlation between the level of certain pollutants and the number of visits, its impact was irrelevant.. Introducción: La contaminación y el clima tienen impacto en la patología respiratoria en niños; pocos estudios lo evaluaron en la Ciudad de Buenos Aires. Objetivo: Evaluar el impacto de la interacción entre contaminantes atmosféricos y clima en las consultas por infección respiratoria aguda baja (IRAB) en un hospital pediátrico. Métodos: Estudio ecológico, de series temporales con modelos aditivos generalizados, que incluyó todas las consultas y consultas por IRAB (urgencias) entre 2012 y 2016. Para controlar sesgos, se conformó una serie con promedios móviles de 7 días para consultas por IRAB. Los predictores fueron niveles diarios de contaminantes atmosféricos (monóxido de carbono, dióxido nitroso, material particulado < 10 μ) y variables meteorológicas (temperatura, humedad). Los contaminantes fueron medidos en 3 estaciones de monitoreo. Se controló por variables temporales (día de la semana, semestre cálido/frío). Resultados: Las consultas totales fueron 455 256 y por IRAB 17 298. Solo consultas totales correlacionaron con día de la semana (lunes y sábados, más consultas y jueves, menos). El semestre cálido registró menos consultas por IRAB que el frío (riesgo relativo = 0,23; intervalo de confianza 95 %: 0,29-0,18; p < 0,001). Una estación de monitoreo no presentó ninguna correlación; las otras mostraron correlación débil entre monóxido de carbono y material particulado < 10 μ y consultas por IRAB. Conclusión: La época del año explica con precisión el incremento del número de consultas totales y por IRAB. Aunque el nivel de algunos contaminantes muestra correlación con el número de consultas, su impacto es irrelevante.

Topics: Air Pollutants; Argentina; Carbon Monoxide; Child; Cities; Climate; Emergency Service, Hospital; Environmental Exposure; Hospitals, Pediatric; Humans; Nitrogen Dioxide; Particulate Matter; Respiratory Tract Infections; Seasons; Time Factors

In recent years, ambient air has been severely contaminated by particulate matters (PMs) and some gas pollutants (nitrogen dioxide (NO

Topics: Air Pollutants; Air Pollution; Cerebrovascular Disorders; China; Environmental Exposure; Humans; Lung Neoplasms; Meteorological Concepts; Mortality; Myocardial Ischemia; Nitrogen Dioxide; Particulate Matter; Public Health; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Infections; Seasons; Sulfur Dioxide

AbstractOtitis media (OM) is a very common disease in children, which results in a significant economic burden to the healthcare system for hospital-based outpatient departments, emergency departments (EDs), unscheduled medical examinations, and antibiotic prescriptions. The aim of this retrospective observational study is to investigate the association between climate variables, air pollutants, and OM visits observed in the 2007-2010 period at the ED of Cuneo, Italy. Measures of meteorological parameters (temperature, humidity, atmospheric pressure, wind) and outdoor air pollutants (particulate matter, ozone, nitrous dioxide) were analyzed at two statistical stages and in several specific steps (crude and adjusted models) according to Poisson's regression. Response variables included daily examinations for age groups 0-3, 0-6, and 0-18. Control variables included upper respiratory infections (URI), flu (FLU), and several calendar factors. A statistical procedure was implemented to capture any delayed effects. Results show a moderate association for temperature (T), age 0-3, and 0-6 with P < 0.05, as well as nitrous dioxide (NO

Topics: Adolescent; Air Pollutants; Child; Child, Preschool; Emergency Service, Hospital; Female; Humans; Infant; Infant, Newborn; Italy; Male; Nitrogen Dioxide; Otitis Media; Ozone; Particulate Matter; Respiratory Tract Infections; Risk; Weather

The aim of the study was to investigate the unknown effect of air pollutants on the occurrence or deterioration of respiratory diseases in the area with a humid continental climate. This retrospective study included 5868 patients with respiratory symptomatology (upper respiratory tract infection (URTI), pneumonia, acute bronchitis, chronic obstructive pulmonary disease (COPD), and asthma) admitted to emergency department (ED). The number of patients, values of meteorological parameters (mean daily values of air temperature pressure and relative humidity) and concentrations of air pollution particles (≤10 μm (PM10), ozone (O3) and nitrogen dioxide (NO2)) were collected during a two-year ( July 2008 - June 2010) period. There were 1839 (31.3%), 1712 (29.2%), 1313 (22.4%), 614 (10.5%) and 390 (6.6%) patients with pneumonia, COPD, URTI, acute bronchitis and asthma, respectively. The mean daily concentrations of NO2 (25.9 (1.7-89.7) μg/m3), O3 (47.1 (4.7-135.4) μg/m3) and PM10 particles (25.7 (4.6-146.6) μg/m3) were below the legally defined thresholds. Among other results, the occurrence of respiratory diseases showed positive Spearman's correlation with the values of air humidity (days 0-3, r=0.15 to 0.19), PM10(days 0-3, r=0.10 to 0.13) and NO2 concentrations (day 0, r=0.11), and negative correlation with the values of air temperature (days 0-3, r=-0.36 to -0.34), pressure (day 0, r=-0.10) and O3 concentrations (days 0-3, r=-0.21 to -0.22) (p<0.05 all). In conclusion, the occurrence of respiratory diseases showed correlation with weather conditions and air pollutants despite the legally permitted values in the region with a humid continental climate.

Topics: Acute Disease; Adult; Aged; Air Pollutants; Air Pollution; Asthma; Bronchitis; Croatia; Emergency Service, Hospital; Hospitalization; Humans; Male; Maximum Allowable Concentration; Middle Aged; Nitrogen Dioxide; Ozone; Pulmonary Disease, Chronic Obstructive; Reference Standards; Respiratory Tract Diseases; Respiratory Tract Infections; Retrospective Studies

The air pollution in China is a severe problem. The aim of our study was to investigate the impact of air pollutants on acute respiratory outcomes in outpatients. Outpatient data from 2 December 2013 to 1 December 2014 were collected, as well as air pollutant data including ozone (O₃), nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and particulate matter (PM

Topics: Acute Disease; Air Pollutants; Air Pollution; Ambulatory Care; Asthma; Bronchitis; Carbon Monoxide; China; Cross-Over Studies; Female; Humans; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Pneumonia; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Diseases; Respiratory Tract Infections; Sulfur Dioxide

Influenza-like illness causes substantial morbidity and mortality. Air pollution has already been linked to many health issues, and increasing evidence in recent years supports an association between air pollution and respiratory infections. It is a pioneer study in China to quantify the effects of air pollution on influenza-like illness. This study used wavelet coherence analysis and generalized additive models to explore the potential association between air pollution (including particulate matter with aerodynamic diameter ≦2.5 μm (PM2.5), particulate matter with aerodynamic diameter ≦10 μm (PM10) and nitrogen dioxide (NO2)) and influenza-like illness (a total of 59860 cases) in Nanjing, China from January 1, 2013 to December 31, 2013. The average concentrations of PM2.5, PM10 and NO2 were 77.37 μg/m(3), 135.20 μg/m(3) and 55.80 μg/m(3). An interquartile range increase in PM2.5 concentration was associated with a 2.99% (95% confidence interval (CI): 1.64%, 4.36%) increase in daily influenza-like cases on the same day, while the corresponding increase in NO2 was associated with a 3.77% (95% CI: 2.01%, 5.56%) increase in daily cases. People aged 0-4 were proved to be significantly susceptible to PM10 and NO2; 5-14 ages were significantly susceptible to PM2.5 and PM10; and 15-24 ages were significantly susceptible to all the analyzed air pollutants. Air pollution effects tended to be null or negative for patients aged over 25, which might be due to the small number of influenza-like cases in this age group. This study can be useful for understanding the adverse health effects of air pollution and the cause of influenza-like illness.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Air Pollutants; Child; Child, Preschool; China; Cities; Environmental Exposure; Humans; Infant; Infant, Newborn; Influenza, Human; Middle Aged; Models, Theoretical; Nitrogen Dioxide; Particle Size; Particulate Matter; Respiratory Tract Infections; Young Adult

To analyze the relationship between levels of air pollution and number of children hospitalizations because of respiratory tract infection in Shenmu County, the data regarding meteorological factors, environmental pollutants, that is SO(2) and NO(2), Particulate Matter 10 (PM10), and hospitalizations of children less than 16 years of age was collected during the time duration of November 2009 to October 2012. Using SAS 9.3, descriptive data analysis for meteorological and environmental factors and hospital admissions were performed along with main air pollutants determination. Using the statistical software R 3.0.1, a generalized additive Poisson regression model was established, the linear fitting models of the air pollutant concentrations and meteorological factors were introduced considering the lag effect, and the relative risk of the main atmospheric pollutants on children hospitalization was evaluated. The results showed that the primary air pollutant in Shenmu County is PM10 and its Pearson correlation coefficient with Air Pollution Index (API) is 0.917. After control of long term climate trend, "week day effect," meteorological factors, and impact of other contaminants, it was found that, on the same day and during the lag of 1 to 10 days, PM10 concentrations had no significant effect on children hospitalization rate.

Topics: Adolescent; Air Pollutants; Child; Child, Preschool; China; Coal Mining; Environmental Exposure; Environmental Monitoring; Hospitalization; Humans; Infant; Infant, Newborn; Linear Models; Nitrogen Dioxide; Particulate Matter; Respiratory Tract Infections; Seasons; Sulfur Dioxide

Air pollution has many negative health effects on the general population, especially children, subjects with underlying chronic disease and the elderly. The aims of this study were to evaluate the effects of traffic-related pollution on the exacerbation of asthma and development of respiratory infections in Italian children suffering from asthma or wheezing compared with healthy subjects and to estimate the association between incremental increases in principal pollutants and the incidence of respiratory symptoms.. This prospective study enrolled 777 children aged 2 to 18 years (375 with recurrent wheezing or asthma and 402 healthy subjects). Over 12 months, parents filled out a daily clinical diary to report information about respiratory symptoms, type of medication used and healthcare utilization. Clinical data were combined with the results obtained using an air pollution monitoring system of the five most common pollutants.. Among the 329 children with recurrent wheezing or asthma and 364 healthy subjects who completed follow-up, children with recurrent wheezing or asthma reported significantly more days of fever (p=0.005) and cough (p<0.001), episodes of rhinitis (p=0.04) and tracheitis (p=0.01), asthma attacks (p<0.001), episodes of pneumonia (p<0.001) and hospitalizations (p=0.02). In the wheezing/asthma cohort, living close to the street with a high traffic density was a risk factor for asthma exacerbations (odds ratio [OR]=1.79; 95% confidence interval [CI], 1.13-2.84), whereas living near green areas was found to be protective (OR=0.50; 95% CI, 0.31 -0.80). An increase of 10 μg/m3 of particulates less than 10 microns in diameter (PM10) and nitrogen dioxide (NO2) increased the onset of pneumonia only in wheezing/asthmatic children (continuous rate ratio [RR]=1.08, 95% CI: 1.00-1.17 for PM10; continuous RR=1.08, 95% CI: 1.01-1.17 for NO2).. There is a significant association between traffic-related pollution and the development of asthma exacerbations and respiratory infections in children born to atopic parents and in those suffering from recurrent wheezing or asthma. These findings suggest that environmental control may be crucial for respiratory health in children with underlying respiratory disease.

Topics: Adolescent; Air Pollution; Asthma; Automobiles; Child; Child, Preschool; Cough; Disease Progression; Female; Fever; Hospitalization; Humans; Italy; Male; Nitrogen Dioxide; Particulate Matter; Pneumonia; Prospective Studies; Residence Characteristics; Respiratory Sounds; Respiratory Tract Infections; Rhinitis; Risk Factors; Tracheitis

Upper and lower respiratory infections are common in early childhood and may be exacerbated by air pollution. We investigated short-term changes in ambient air pollutant concentrations, including speciated particulate matter less than 2.5 μm in diameter (PM2.5), in relation to emergency department (ED) visits for respiratory infections in young children. Daily counts of ED visits for bronchitis and bronchiolitis (n = 80,399), pneumonia (n = 63,359), and upper respiratory infection (URI) (n = 359,246) among children 0-4 years of age were collected from hospitals in the Atlanta, Georgia, area for the period 1993-2010. Daily pollutant measurements were combined across monitoring stations using population weighting. In Poisson generalized linear models, 3-day moving average concentrations of ozone, nitrogen dioxide, and the organic carbon fraction of particulate matter less than 2.5 μm in diameter (PM2.5) were associated with ED visits for pneumonia and URI. Ozone associations were strongest and were observed at low (cold-season) concentrations; a 1-interquartile range increase predicted a 4% increase (95% confidence interval: 2%, 6%) in visits for URI and an 8% increase (95% confidence interval: 4%, 13%) in visits for pneumonia. Rate ratios tended to be higher in the 1- to 4-year age group compared with infants. Results suggest that primary traffic pollutants, ozone, and the organic carbon fraction of PM2.5 exacerbate upper and lower respiratory infections in early life, and that the carbon fraction of PM2.5 is a particularly harmful component of the ambient particulate matter mixture.

Topics: Acute Disease; Air Pollution; Antimetabolites; Bronchiolitis; Bronchitis; Carbon Monoxide; Child, Preschool; Emergency Service, Hospital; Female; Georgia; Humans; Infant; Infant, Newborn; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Pneumonia; Respiratory Tract Infections; Retrospective Studies; Socioeconomic Factors; Time Factors

This study investigated whether outpatient visits of acute upper respiratory infections for children aged less than 15 years are associated with temperature, air pollutants and circulating respiratory viruses in Taipei, Taiwan, from 2003 to 2007.. Outpatient records for acute upper respiratory infections (ICD9 CM codes: 460, 462, 463,464, 465.9 and 487) in a randomly selected sample (n=39,766 children in 2005) was used to estimate the cumulative relative risks (RR) associated with average temperature lasting for 8 days (lag 0-7 days), air pollutants (NO2, O3 and PM(2.5)) lasting for 6 days (lag 0-5 days), and virus-specific positive isolation rate lasting for 11 days (lag 0-10 days) using distributed lag non-linear models after controlling for relative humidity, wind speed, day of week, holiday effects and long-term trend.. Average temperature of 33 °C was associated with the lowest risk for outpatient visits of acute upper respiratory infections. Relative to 33 °C, cumulative 8-day RR was highest at 15 °C of ambient average temperature [RR=1.94; 95% confidence interval (CI): 1.78, 2.11]. With the first quartile as reference, cumulative 6-day RRs were 1.25 (95% CI: 1.21, 1.29) for NO2, 1.04 (95% CI: 1.01, 1.06) for O3, and 1.00 (95% CI: 0.98, 1.03) for PM(2.5) at the 95th percentile. Per-standard deviation (SD) increase of virus-specific isolation rate for influenza type A (SD=13.2%), type B (SD=8.76%), and adenoviruses (SD=5.25%) revealed statistical significance for overall 11-day RRs of 1.02 (95% CI: 1.01, 1.03), 1.05 (95% CI: 1.03, 1.06) and 1.04 (95% CI: 1.03, 1.05), respectively.. Current study suggested a positive association between outpatient visits for acute upper respiratory infections and ambient environment factors, including average temperature, air pollutants, and circulating respiratory viruses.

Topics: Air Pollution; Child; Humans; Nitrogen Dioxide; Respiratory Tract Infections; Risk Factors; Taiwan; Temperature; Virus Diseases; Viruses

The harmful effect of dust storm on lung health is controversial. This study aimed to assess any associations between dust storms and emergency hospital admissions due to respiratory disease in Hong Kong.. Data on daily emergency admissions for respiratory diseases to major hospitals in Hong Kong, and indices of air pollutants and meteorological variables from January 1998 to December 2002 were obtained from several government departments. We identified five dust storm days during the study period. Independent t-tests were used to compare the mean daily number of admissions on dust storm and non-dust storm days. Case-crossover analysis using the Poisson regression was used to examine the effects of PM(10) to emergency hospital admissions due to respiratory diseases.. Significant increases in emergency hospital admission due to COPD were found 2 days after dust storm episode. The relative risk of PM(10) for lag 2 days was 1.05 (95% CI: 1.01-1.09) per 10 µg/m(3) .. Dust storms have an adverse effect on emergency hospital admission for COPD in Hong Kong. This also suggests the adverse effect of coarse particles on lung health.

Topics: Air Pollutants; Air Pollution; Cardiovascular Diseases; Disasters; Dust; Female; Hong Kong; Hospitalization; Humans; Male; Meteorological Concepts; Nitrogen Dioxide; Ozone; Particle Size; Particulate Matter; Patient Admission; Poisson Distribution; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Infections; Sulfur Dioxide

Because their lungs and immune system are not completely developed, children are more susceptible to respiratory disease and more vulnerable to ambient pollution. We assessed the relation between prenatal and postnatal nitrogen dioxide (NO(2)) levels and the development of lower respiratory tract infections (LRTI), wheezing and persistent cough during the first year of life.. The study population consisted of 352 children from a birth cohort in Valencia, Spain. Prenatal exposure to NO(2), a marker of traffic related air pollution was measured at 93 sampling sites spread over the study area during four different sampling periods of 7 days each. It was modeled for each residential address through land use regression using the empirical measurements and data from geographic information systems. Postnatal exposure was measured once inside and outside each home using passive samplers for a period of 14 days. Outcomes studied were any episode of LRTI during the child's first year of life diagnosed by a doctor (bronchitis, bronchiolitis or pneumonia), wheezing (defined as whistling sounds coming from the chest), and persistent cough (more than three consecutive weeks). Outcomes and potential confounders were obtained from structured questionnaires. Multiple logistic regression was used to identify associations.. The cumulative incidence (CI) at first year of life was 30.4% for LRTI (23.0% bronchiolitis, 11.9% bronchitis and 1.4% pneumonia), 26.1% for wheezing and 6.3% for persistent cough. The adjusted odds ratio (95% confidence interval) per 10μg/m(3) increment in postnatal outdoor NO(2) concentration was 1.40 (1.02-1.92) for persistent cough. We also found some pattern of association with LRTI, bronchiolitis, bronchitis, wheezing and persistent cough in different prenatal periods, although it was not statistically significant.. Our results indicate that exposure to outdoor, but not indoor, NO(2) during the first year of life increases the risk of persistent cough.

Topics: Cough; Environmental Exposure; Female; Geographic Information Systems; Humans; Incidence; Infant; Logistic Models; Models, Theoretical; Nitrogen Dioxide; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Sounds; Respiratory Tract Infections; Spain; Surveys and Questionnaires; Vehicle Emissions

Populations in Asia are not only at risk of harm to their health through environmental degradation as a result of worsening pollution problems but also constantly threatened by recurring and emerging influenza epidemics and. pandemics. Situated in the area with the world's fastest growing economy and close to hypothetical epicenters of influenza transmission, Hong Kong offers a special opportunity for testing environmental management and public health surveillance in the region. In the Public Health and Air Pollution in Asia (PAPA*) project, the Hong Kong research team assessed the health effects of air pollution and influenza as well as the interaction between them. The team also assessed disparities in the health effects of air pollution between relatively deprived and more affluent areas in Hong Kong. The aim was to provide answers to outstanding research questions relating to the short-term effects of air pollution on mortality and hospital admissions; the health effects of influenza with a view to validating different measures of influenza activity according to virologic data; the confounding effects of influenza on estimates of the health effects of air pollution; the modifying effects of influenza on the health effects of air pollution; and the modifying effects of neighborhood social deprivation on the health effects of air pollution.. Data on mortality and hospital admissions for all natural causes, as well as the subcategories of cardiovascular diseases (CVD) and respiratory diseases (RD), were derived from the Hong Kong Census and Statistics Department and the Hospital Authority. Daily concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter with an aerodynamic diameter < or = 10 pm (PM10); and ozone (O3) were derived from eight monitoring stations with hourly data that were at least 75% complete during the study period. Three measures of influenza and respiratory syncytial virus (RSV) activity were derived from positive isolates of specimens in the virology laboratory of Queen Mary Hospital (QMH), the main clinical teaching center at The University of Hong Kong and part of the Hong Kong Hospital Authority network of teaching hospitals: influenza intensity (defined as the weekly proportion of positive isolates of influenza in the total number of specimens received for diagnostic tests); the presence of influenza epidemic (defined as a period when the weekly frequency of these positive isolates is > or = 4% of the annual total number of positive isolates [i.e., twice the expected mean value] in two or more consecutive weeks); and influenza predominance (defined as a period of influenza epidemic when the weekly frequency of RSV was less than 2% for two or more consecutive weeks). The weekly proportion of positive isolates of RSV in total specimens was determined in the same way as for influenza intensity. A social deprivation index (SDI) was defined by taking the average of the proportions of households or persons with the following six characteristics in each geographic area using the census statistics: unemployment; household income < U.S. $250 per month; no schooling at all; never-married status; one-person household; and subtenancy. A Poisson regression with quasi-likelihood to account for overdispersion was used to develop core models for daily health outcomes, with a natural spline smoothing function to filter out seasonal patterns and long-term trends in this time-series study of daily mortality and hospital admissions, and with adjustment for days of the week, temperature, and relative humidity (RH). Air pollutant concentration values were entered into the core model to assess the health effects of specific pollutants. The possible confounding effects of influenza were assessed by observing changes in magnitude of the effect estimate when each influenz

Topics: Adolescent; Adult; Age Factors; Aged; Air Pollutants; Air Pollution; Child; Child, Preschool; Female; Hong Kong; Humans; Infant; Infant, Newborn; Influenza, Human; Male; Middle Aged; Nitrogen Dioxide; Ozone; Particulate Matter; Patient Admission; Respiratory Syncytial Virus Infections; Respiratory Tract Infections; Seasons; Sex Factors; Sulfur Dioxide; Time Factors; Young Adult

Indoor air concentrations of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), and dust particles were measured for 49 biomass and 46 fossil fuel users in urban slums of Dhaka, Bangladesh. The health impacts of these pollutants were assessed on 65 and 51 children under five years old from families who use biomass and fossil fuel as main source of energy, respectively. Mean concentrations of CO were found to be significantly higher in biomass fuel users (P = 0.010), while geometric mean concentrations of benzene, xylene, toluene, hexane, total VOCs, and NO2 were significantly higher (P < 0.01) in the fossil fuel users. Symptoms such as redness of eyes, itching of skin, nasal discharge, cough, shortness of breath, chest tightness, wheezing, or whistling chest were found to be associated with the choice of biomass fuel, with the odds ratio ranging from 4.0 to 6.3. No significant association of use of biomass fuel with respiratory diseases, eczema, diarrhea, or viral fever was observed after adjustment for potential confounders. These results suggest a significant association between the biomass fuel-using population and respiratory symptoms. These symptoms may not be due to the pollutants only, as some other underlying causes may be present.. The health of children under five years old in Bangladesh, especially those living in poor socioeconomic conditions, is considered to be worsening because of indoor air pollution. It is commonly suggested that biomass fuel should be replaced by fossil fuel, as pollution levels are believed to be higher with biomass fuel. Our findings, however, suggest that pollution can be higher with fossil fuels, and indicate that a switch in fuel from biomass to fossil does not necessarily improve the children's health. Awareness programs should therefore be undertaken to avoid the unnecessary use of gas. Clean fuels and clean stoves should also be ensured to reduce emissions of indoor air pollutants.

Topics: Air Pollution, Indoor; Bangladesh; Biomass; Carbon Dioxide; Carbon Monoxide; Child, Preschool; Cooking; Dust; Environmental Monitoring; Epidemiological Monitoring; Fossil Fuels; Housing; Humans; Infant; Infant, Newborn; Nitrogen Dioxide; Organic Chemicals; Particulate Matter; Respiratory Tract Infections; Volatilization

Inuit infants have extremely high rates of lower respiratory tract infection (LRTI), but the causes for this are unclear. The aims of this study were to assess, in young Inuit children in Baffin Region, Nunavut, the feasibility of an epidemiologic study of the association between indoor air quality (IAQ) and respiratory health; to obtain data on IAQ in their housing; and to identify and classify risk factors for LRTI. Twenty houses in Cape Dorset, Nunavut with children below 2 years of age, were evaluated using a structured housing inspection and measurement of IAQ parameters, and a respiratory health questionnaire was administered. Twenty-five percent of the children had, at some time, been hospitalized for chest illness. Houses were very small, and had a median of six occupants per house. Forty-one percent of the houses had a calculated natural air change rate <0.35 air changes per hour. NO(2) concentrations were within the acceptable range. Smokers were present in at least 90% of the households, and nicotine concentrations exceeded 1.5 microg/m(3) in 25% of the dwellings. Particulates were found to be correlated closely with nicotine but not with NO(2) concentrations, suggesting that their main source was cigarette smoking rather than leakage from furnaces. Mattress fungal levels were markedly increased, although building fungal concentrations were low. Dust-mites were virtually non-existent. Potential risk factors related to IAQ for viral LRTI in Inuit infants were observed in this study, including reduced air exchange and environmental tobacco smoke exposure. Severe lower respiratory tract infection is common in Inuit infants. We found reduced air change rates and high occupancy levels in houses in Cape Dorset, which may increase the risk of respiratory infections. This suggests the measures to promote better ventilation or more housing may be beneficial. Further health benefits may be obtained by reducing bed sharing by infants and greater turnover of mattresses, which were found to have high levels of fungi.

Topics: Air Pollutants; Air Pollution, Indoor; Antigens, Dermatophagoides; Arthropod Proteins; beta-Glucans; Carbon Dioxide; Cysteine Endopeptidases; Dust; Endotoxins; Female; Fungi; Housing; Humans; Humidity; Infant; Inuit; Male; Nicotine; Nitrogen Dioxide; Nunavut; Respiratory Tract Infections; Risk Factors; Temperature; Tobacco Smoke Pollution; Yeasts

The purpose of this study was to examine the association between ambient air pollution and hospitalization for respiratory infections among children who were younger than 15 years in Toronto during a 4-year period (1998-2001).. Exposures averaged during periods that varied from 1 to 7 days were used to assess the effects of air pollutants, including thoracic particulate matter (PM10), fine (PM2.5) and coarse (PM10-2.5) particulate matter, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3), on hospitalization for respiratory infections. A case-crossover design was used to calculate odds ratios for the hospitalization adjusted for daily weather conditions with an incremented exposure corresponding to the interquartile range in air pollution exposures.. When particulate matter and gaseous pollutants were mutually taken into account, the effect remained pronounced for PM10-2.5 in both boys and girls. The adjusted odds ratio for 6-day average exposure to PM10-2.5 with an increment of 6.5 microg/m3 was 1.15 (95% confidence interval: 1.02-1.30) for boys and 1.18 (95% confidence interval: 1.01-1.36) for girls. The effect also remained for PM10 in boys and for NO2 in girls. PM2.5, CO, SO2, and O3 showed no significant effects on hospitalization for respiratory infection in both genders when other pollutants were taken into consideration.. Our study suggested a detrimental effect of relatively low levels of ambient particulate matter and gaseous pollutants, especially coarse particulate matter and NO2, on hospitalization for respiratory infections in children.

Topics: Adolescent; Air Pollutants; Air Pollution; Carbon Monoxide; Child; Child, Preschool; Environmental Exposure; Female; Hospitalization; Humans; Infant; Male; Nitrogen Dioxide; Ontario; Ozone; Particle Size; Respiratory Tract Infections; Sulfur Dioxide; Urban Health; Weather

Nitrogen dioxide (NO(2)) has been related to respiratory infections in experimental studies but its role remains controversial in general population studies of children. We aim to assess the association between indoor NO(2) and lower respiratory tract infections (LRTI) during the first year of life in a multicentre prospective cohort study.. Children (n = 1611) were recruited prior to birth for the Asthma Multicentre Infants Cohort Study (AMICS). Three concurrent cohorts (Ashford, Kent [UK]; Barcelona city, and Menorca Island [Spain]) followed the same research protocol. NO(2) was measured with passive diffusion tubes placed in the living room for 2 weeks when infants were approximately 3 months old. Doctor-diagnosed LRTI during the first year of life (as well as antibiotic use) were measured by questionnaire, and in Ashford validated by the examination of clinical records. In Barcelona, direct measurements using nasopharyngeal lavage and cultures within a continuous surveillance system were done.. The cumulative rates of LRTI (39% in Ashford, 28% in Barcelona, and 45% in Menorca) were unrelated to NO(2) levels (corresponding medians 6, 46, and 12 ppb, respectively) in all three centres (all odds ratios being around 1). Similarly, the rates of LRTI in Barcelona measured with the continuous record showed no association with NO(2) (all rate ratios being below 1). In addition, there was no association between rate of antibiotics courses per year per child (2.4 in Ashford, 1.7 in Barcelona, 0.9 in Menorca) and NO(2) levels.. Indoor NO(2) at current levels does not seem to be involved in increasing respiratory infections by itself in infants, suggesting that the effects observed in studies on outdoor air are probably due to other copollutants.

Topics: Air Pollutants; Air Pollution, Indoor; England; Female; Fossil Fuels; Household Articles; Humans; Incidence; Infant; Male; Nitrogen Dioxide; Prospective Studies; Respiratory Tract Infections; Spain

Several studies have linked air pollution by nitrogen dioxide (NO(2)) with increased hospital admissions for asthma in children. Exacerbations of asthma in children are often precipitated by upper respiratory infections. It is therefore possible that NO(2) increases the risk of airways obstruction when asthmatic children develop upper respiratory infections.. To test this hypothesis a sample of 114 asthmatic children aged 7-12 years were followed for a total of up to 13 months. Probable upper respiratory infections were identified by consensus review of daily symptom diaries, and episodes of airways obstruction from serial records of peak expiratory flow (PEF). Personal exposures to NO(2) were measured with Palmes tubes that were changed weekly. Generalised estimating equations were used to assess the relative risk (RR) of an asthmatic exacerbation starting within seven days of an upper respiratory infection according to estimated NO(2) exposure during the one week period from two days before to four days after the onset of the infection.. The children were followed for an average of 34 weeks during which 318 upper respiratory infections and 224 episodes of reduced PEF were diagnosed. PEF episodes were much more likely to occur in the seven days following the onset of an upper respiratory infection than at other times. Estimated exposures to NO(2) at the time of infections were generally low (geometric mean 10.6 microg/m(3)). Compared with exposures of < or = 8 microg/m(3), exposures of >28 microg/m(3) were associated with a RR of 1.9 (95% confidence interval 1.1 to 3.4) for the development of an asthmatic episode within seven days of an infection.. The findings give some support to the hypothesis that NO(2) increases the risk of asthmatic exacerbations following respiratory infections, even at relatively low levels of exposure. Further studies in populations with higher exposures would be useful.

Topics: Air Pollutants; Airway Obstruction; Asthma; Child; England; Female; Humans; Longitudinal Studies; Male; Nitrogen Dioxide; Oxidants, Photochemical; Peak Expiratory Flow Rate; Respiratory Tract Infections

The aim of a one year study was to ascertain whether air pollution measured as NO2-concentration has an measurable influence on the health of infants in Switzerland. Measurements of NO2-concentration were carried out by means of passive collectors in ambient air, living room and at the child itself. The results of 1225 children printed to a significant coherence between respiratory symptoms per day and child and the NO2 load of ambient air as an guide pollutant. Even in consideration of other childish, familiar and environmental factors the coherence remains. Although no causal relation thereby proved this factor supports the observation of parents and physicians that children more often fall ill of respiratory diseases in polluted air being in accordance with similar investigations abroad.

Topics: Air Pollutants; Child, Preschool; Female; Humans; Infant; Male; Nitrogen Dioxide; Respiratory Tract Infections; Risk Factors; Switzerland

Previous studies have shown that exposure to nitrogen dioxide at concentrations of 5 and 10 parts per million (ppm) decreases intrapulmonary killing of Mycoplasma pulmonis, and that this decrease is related to increased lung lesions and mortality. The specific objectives of the present study were to titrate the effects of nitrogen dioxide on pulmonary clearance of M. pulmonis, determine the mechanisms by which this organism is killed within the lungs, and determine the target that the nitrogen dioxide affects. Pathogen-free C57BL/6N mice were exposed to 0, 0.5, 1, 2, or 5 ppm of nitrogen dioxide (contamination with other oxides of nitrogen compounds was 5% or less) for four hours and then immediately were exposed to aerosols of viable, radiolabeled M. pulmonis strain UAB CT. One-half of the animals in each group were killed immediately after exposure to the infectious aerosols, and the rest were killed 24 hours later. The amount of radioactivity and the number of viable M. pulmonis were determined for each group. Exposure to less than 5 ppm of nitrogen dioxide had no effect on intrapulmonary killing of M. pulmonis, although exposure to 1 ppm of nitrogen dioxide did increase mechanical removal. We were unable to develop a completely in vitro mycoplasma killing method. However, we were able to demonstrate the in vitro killing of M. pulmonis that had been allowed to associate with alveolar macrophages in vivo. Thus, mouse lungs contain unidentified factors that allow cells to kill M. pulmonis. Furthermore, we obtained evidence that suggests that prior exposure to nitrogen dioxide abrogates killing in these experiments. We also have shown that exposure to nitrogen dioxide does not increase the protein content of bronchoalveolar lavage fluid. Using immunofluorescence, more than 95% of the cells recovered by lavage were macrophages; with double-label immunofluorescence, more than 98% of the cell-associated mycoplasmas were on or in alveolar macrophages. In assessing the cytological parameters of lung lavage cells from mice exposed to nitrogen dioxide, M. pulmonis, or both, we found that both insults affected the viability of recovered macrophages. Viability immediately after exposure as measured by trypan blue exclusion or by fluorescein diacetate uptake, was 89% +/- 4% and 88% +/- 4% in the control group, respectively; 56% +/- 19% and 64% +/- 11% in the group receiving M. pulmonis alone; 23% +/- 7% and 48% +/- 9% in the group receiving nitrogen dioxide alone;

Topics: Air Pollutants; Animals; Bronchoalveolar Lavage Fluid; Fluorescent Antibody Technique; Lung; Macrophages, Alveolar; Mice; Mice, Inbred C57BL; Mycoplasma; Mycoplasma Infections; Nitrogen Dioxide; Respiratory Tract Infections; Specific Pathogen-Free Organisms

A study of 1225 preschool children was conducted in four regions of Switzerland with different levels of air pollution to investigate the relationship between air pollution and respiratory symptoms. Daily symptoms were recorded by parents on a diary form and air pollution exposure assessed by personal NO2 samplers. Each family participated for 6 weeks and personal samplers were changed every week. The frequency of respiratory symptoms per child and day was found to increase with increasing levels of NO2 measured outdoors. This relationship remained significant in a multiple regression model in which the factors smoking, origin, indoor air pollution, age and sex, season, and parents appreciation of air pollution at the living site were taken into account.

Topics: Air Pollutants; Child, Preschool; Humans; Nitrogen Dioxide; Respiratory Tract Infections; Risk Factors; Switzerland; Tobacco Smoke Pollution

In four regions of Switzerland (2 towns, 1 municipal agglomerate, 1 rural area) the relationship between the degree of air pollution measured in terms of NO2 and the incidence of airway symptomatology was investigated in 1,225 young children. The airway symptoms were recorded by the parents in a diary; the NO2 loading was measured with the aid of personal collecting tubes at the place of residence of the child. A significant relationship was found to exist between the mean incidence of airway symptomatology per child and day, and the individually measured NO2 concentration in the outside air at the child's place of residence. This relationship remained significant even when, in a multiple regression analysis, account was also taken of other major factors, such as smoking, nationality, individual susceptibility to airway diseases, the season of the year, and the subjective assessment of the air pollution at the place of residence, were also taken into account.

Topics: Air Pollutants; Child, Preschool; Cross-Sectional Studies; Humans; Incidence; Infant; Nitrogen Dioxide; Respiratory Tract Infections; Risk Factors; Switzerland

Laboratory and human studies have raised concern that exposure to nitrogen dioxide may increase the frequency and severity of respiratory infections in children and adults. Cooking with a natural-gas-fueled stove exposes a home's residents to short-term peaks of nitrogen oxides and to higher average levels of nitrogen oxides than are measured in homes with electric stoves. We have designed a longitudinal study of infants to determine if nitrogen dioxide exposure from cooking stoves increases the incidence or severity of respiratory infections during the first 18 months of life. Pilot investigations for the longitudinal study were conducted from 1984 through 1986. This report provides the results of the pilot investigations. The first study, conducted in 1984 and 1985, was designed to document (1) that appropriate subjects could be recruited; (2) that nitrogen dioxide concentrations in Albuquerque homes were in the range of interest; (3) that an infant's personal exposure to nitrogen dioxide could be estimated; and (4) that a valid, feasible approach for surveillance could be implemented. To accomplish these goals, the families of infants were recruited at two Albuquerque hospitals, and their homes were monitored for nitrogen dioxide using a passive sampling tube. With this approach, we successfully recruited 147 households; monitoring for nitrogen dioxide showed substantially higher levels in homes with gas stoves than in homes with electric stoves, as previously found in other U.S. cities. More detailed investigations in a sample of the homes showed that personal exposures of the infants, who did not attend day care, could be satisfactorily estimated by room concentrations. We also demonstrated that mothers would complete a daily calendar-diary on respiratory symptoms and provide information every two weeks on illnesses occurring since the previous surveillance call. The second pilot study, conducted in 1986, was designed to refine the system for illness surveillance. Additional goals were to test further the methods for exposure assessment and to evaluate recruitment of subjects through pediatric practices. We recruited 75 infants and followed them over a four-month period. Information from the surveillance system was compared with the clinical assessments of the project's nurse practitioner and the subjects' physicians, and with the results of viral cultures. We also evaluated biweekly versus weekly surveillance calls. Overall, the results of the secon

Topics: Cohort Studies; Cooking; Environmental Exposure; Environmental Monitoring; Epidemiological Monitoring; Fossil Fuels; Humans; Infant; New Mexico; Nitrogen Dioxide; Nursing Assessment; Pilot Projects; Respiratory Tract Infections

Topics: Air Pollutants; Humans; Influenza, Human; Nitrogen Dioxide; Research; Respiratory Tract Infections; Risk Factors

To determine whether exposure to nitrogen dioxide (NO2) affects respiratory tract susceptibility to viral infection, CD-1 mice were inoculated intratracheally with murine cytomegalovirus (MCMV) during exposure to varying concentrations of NO2. Exposure lasted for 6 h per day; it began 2 consecutive days prior to instillation of MCMV and continued for 4 days after virus inoculation. Exposure to 5 ppm NO2 resulted in MCMV proliferation and a mild bronchopneumonia in some animals inoculated with 10(2) plaque-forming units of virus. Importantly, this inoculum was too low to produce either viral replication or histologic abnormalities in the lungs of air-exposed animals. We also found that the amount of virus required to infect animals exposed to 5 ppm of NO2 was 100-fold lower than that needed to consistently produce infection in air-exposed animals. Animals exposed to 5 ppm NO2 also exhibited depressed phagocytosis of colloidal Au198 in vivo as well as diminished macrophage destruction of instilled MCMV compared to air-exposed animals. These results demonstrate that exposure to 5 ppm NO2, although not associated with evidence of overt lung injury per se, is nevertheless capable of predisposing the lower respiratory tract to viral infection.

Topics: Animals; Bronchoalveolar Lavage Fluid; Cytomegalovirus Infections; Disease Susceptibility; Macrophages; Mice; Nitrogen Dioxide; Phagocytosis; Pulmonary Alveoli; Respiratory Tract Infections

The scientific literature suggests that ambient levels of nitrogen dioxide increase susceptibility to respiratory infections. However, this association has not been conclusively demonstrated. The epidemiologic data regarding this relationship are inconclusive because these studies have used parameters of "acute respiratory illness" that are not necessarily related to infectious episodes. Previous animal studies have used either mortality after bacterial infection with virulent bacteria or decreased rate of intrapulmonary killing of bacteria with low virulence. Studies using appropriate bacterial and viral challenge organisms, with morbidity as an endpoint, provide a better basis for extrapolation to humans. The investigations in animals suggest a relationship between nitrogen dioxide and increased susceptibility to respiratory infection, but studies in which functional parameters of host resistance to such infections have been used are few. The aim of this work was to determine the threshold level of acute nitrogen dioxide exposure that would induce increased susceptibility to, and increased severity of, viral and bacterial infections. Physiologic parameters of host resistance to respiratory infections were used as endpoints. A composite picture was developed of dose-response relationships between nitrogen dioxide and the impairment of a spectrum of defense parameters in the murine respiratory tract against viral and bacterial challenges. The salient findings of this study are as follows: (1) the intrapulmonary killing of Staphylococcus aureus was impaired at 5 ppm of nitrogen dioxide; (2) this effect was found at 2.5 ppm or less when nitrogen dioxide exposure was superimposed on lungs predisposed to lowered resistance through immunosuppression with corticosteroids; (3) the adverse effect of nitrogen dioxide occurred at lower concentrations when exposure followed bacterial challenge; and (4) during the course of murine Sendai virus infection, exposure to nitrogen dioxide for four hours per day did not alter the infection in the lungs, but rather it enhanced lung pathology. The implications of these findings are that the antibacterial defenses of the lungs are susceptible to the inhibiting effects of short acute exposures of lower concentrations of nitrogen dioxide when the lungs are predisposed by bacteria present or, even more so, by immunosuppression. The alveolar macrophage phagocytic system is the defense component of the lungs that is most susceptibl

Topics: Animals; Female; Immunosuppression Therapy; Lung; Macrophages; Mice; Nitrogen Dioxide; Parainfluenza Virus 1, Human; Paramyxoviridae Infections; Pulmonary Alveoli; Respiratory Tract Infections; Staphylococcal Infections

A review of the health effects of relative humidity in indoor environments suggests that relative humidity can affect the incidence of respiratory infections and allergies. Experimental studies on airborne-transmitted infectious bacteria and viruses have shown that the survival or infectivity of these organisms is minimized by exposure to relative humidities between 40 and 70%. Nine epidemiological studies examined the relationship between the number of respiratory infections or absenteeism and the relative humidity of the office, residence, or school. The incidence of absenteeism or respiratory infections was found to be lower among people working or living in environments with mid-range versus low or high relative humidities. The indoor size of allergenic mite and fungal populations is directly dependent upon the relative humidity. Mite populations are minimized when the relative humidity is below 50% and reach a maximum size at 80% relative humidity. Most species of fungi cannot grow unless the relative humidity exceeds 60%. Relative humidity also affects the rate of offgassing of formaldehyde from indoor building materials, the rate of formation of acids and salts from sulfur and nitrogen dioxide, and the rate of formation of ozone. The influence of relative humidity on the abundance of allergens, pathogens, and noxious chemicals suggests that indoor relative humidity levels should be considered as a factor of indoor air quality. The majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40 and 60%. This would require humidification during winter in areas with cold winter climates. Humidification should preferably use evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens.

Topics: Aerosols; Allergens; Bacterial Infections; Communicable Diseases; Formaldehyde; Fungi; Humans; Humidity; Hypersensitivity; Mites; Nitrogen Dioxide; Occupational Diseases; Ozone; Respiratory Tract Infections; Skin Diseases; Sulfur Dioxide; Virus Diseases

The department of social and preventive medicine of the University of Basle is conducting an epidemiologic study on the health effect of air pollution on preschool children. Nitrogen dioxide in childrens' immediate surrounding measured with personal samplers is used as reference substance for air pollution. Meteorologic and Data on air pollution of all permanent air quality control stations are included in the analysis. Health data are collected by means of a diary in which parents record daily respiratory symptoms of their child. Physicians in pediatric services record daily attendance of children with respiratory diseases.

Topics: Air Pollutants; Child, Preschool; Environmental Monitoring; Humans; Infant; Nitrogen Dioxide; Respiratory Tract Infections; Risk; Sulfur Dioxide; Switzerland; Weather

The success or failure of the respiratory system to defend itself against airborne infectious agents largely depends upon the efficiency of the pulmonary defenses to maintain sterility and to dispose of unwanted substances. Both specific and nonspecific host defenses cooperate in the removal and inactivation of such agents. Several studies have shown that these defenses are vulnerable to a wide range of environmental agents and that there is a good relationship between exposure to pollutant and the impaired resistance to pulmonary disease. There are numerous immunological, biochemical and physiological techniques that are routinely used to identify and to characterize individual impairments of these defenses. Based on these effects, various hypotheses are proposed as to what health consequences could be expected from these effects. The ultimate test is whether the host, with its compromised defense mechanisms, is still capable of sustaining the total injury and continuing to defend itself against opportunistic pathogens. This paper describes the use of an experimental airborne infectious disease model capable of predicting subtle changes in host defenses at concentrations below which there are any other overt toxicological effects. Such sensitivity is possible because the model measure not just a single "health" parameter, but instead is capable of reflecting the total responses caused by the test chemical.

Topics: Air Microbiology; Air Pollutants; Animals; Disease Models, Animal; Guinea Pigs; Immunity; Metals; Mice; Nitrogen Dioxide; Ozone; Rats; Respiratory Tract Infections

Topics: Animals; Environmental Pollutants; Epidemiologic Methods; Hot Temperature; Household Articles; Humans; Mice; Nitrogen Dioxide; Nitrogen Oxides; Respiratory Tract Infections

Topics: Air Pollutants; Air Pollutants, Occupational; Ammonia; Animals; Chemical Industry; Nitrogen Dioxide; Rats; Respiratory Tract Infections

Topics: Animals; Environmental Exposure; Haplorhini; Klebsiella Infections; Nitrogen Dioxide; Orthomyxoviridae Infections; Respiratory Tract Infections; Spirometry; Time Factors

Topics: Air Pollution; Child; Disease Outbreaks; Environmental Exposure; Female; Humans; Influenza, Human; Male; Mass Screening; Nitrogen Dioxide; Respiratory Tract Diseases; Respiratory Tract Infections; Tennessee

Topics: Aerosols; Air Pollution; Animals; Environmental Exposure; Haplorhini; Isoenzymes; Klebsiella Infections; L-Lactate Dehydrogenase; Liver; Lung; Nitrogen Dioxide; Respiratory Tract Infections; Time Factors

Topics: Animals; Glucose; In Vitro Techniques; Macrophages; Nitrogen Dioxide; Phagocytosis; Pulmonary Alveoli; Rabbits; Respiratory Tract Infections

Topics: Air Pollution; Animals; Cricetinae; Haplorhini; Klebsiella; Mice; Nitrogen Dioxide; Respiratory Tract Infections