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PubMed2001

Air pollution and hospital admissions for respiratory conditions in Rome, Italy.

Most of the evidence regarding the association between particulate air pollution and emergency room visits or hospital admissions for respiratory conditions and asthma comes from the USA. European time-series analyses have suggested that gaseous air pollutants are important determinants of acute hospitalization for respiratory conditions, at least as important as particulate mass. The association between daily mean levels of suspended particles and gaseous pollutants (sulphur dioxide, nitrogen dioxide, carbon monoxide, ozone) was examined. The daily emergency hospital admissions for respiratory conditions in the metropolitan area of Rome during 1995-1997 were also recorded. Daily counts of hospital admissions for total respiratory conditions (43 admissions day(-1)), acute respiratory infections including pneumonia (18 day(-1)), chronic obstructive pulmonary disease (COPD) (13 day(-1)), and asthma (4.5 day(-1)) among residents of all ages and among children (0-14 yrs) were analysed. The generalized additive models included spline smooth functions of the day of study, mean temperature, mean humidity, influenza epidemics, and indicator variables for day of the week and holidays. Total respiratory admissions were significantly associated with same-day level of NO2 (2.5% increase per interquartile range (IQR) change, 22.3 microg x m(-3)) and CO (2.8% increase per IQR, 1.5 mg x m(-3)). No effect was found for particulate matter and SO2, whereas O3 was associated with admissions only among children (lag 1, 5.5% increase per IQR, 23.9 microg x m3). The effect of NO2 was stronger on acute respiratory infections (lag 0, 4.0% increase) and on asthma among children (lag 1, 10.7% increase). The admissions for all ages for asthma and COPD were associated only with same-day level of CO (5.5% and 4.3% increase, respectively). Multipollutant models confirmed the role of CO on all respiratory admissions, including asthma and COPD, and that of NO2 on acute respiratory infections. Among children, O3 remained a strong indicator of acute respiratory infections. Carbon monoxide and photochemical pollutants (nitrogen dioxide, ozone) appear to be determinants of acute respiratory conditions in Rome. Since carbon monoxide and nitrogen dioxide are good indicators of combustion products from traffic related sources, the detected effect may be due to unmeasured fine and ultrafine particles.

Adolescent↗

PubMed1990

Absenteeism and respiratory disease among children and adults in Helsinki in relation to low-level air pollution and temperature.

The weekly changes in ambient sulfur dioxide, nitrogen dioxide, and temperature were compared with the figures for respiratory infection in children and adults and for absenteeism from day-care centers (DCC), schools, and workplaces during a 1-year period in Helsinki. The annual average level of sulfur dioxide was 21 micrograms/m3 and of nitrogen dioxide 47 micrograms/m3; the average temperature was +3.1 degrees C. The levels of these pollutants and the temperature were significantly correlated with the number of upper respiratory infections reported from health centers. Low temperature also correlated with increased frequency of acute tonsillitis, of lower respiratory tract infection among DCC children, and of absenteeism from day-care centers, schools and workplaces. Furthermore, a significant association was found between levels of sulfur dioxide and absenteeism. After statistical standardization for temperature, no other correlations were observed apart from that between high levels of sulfur dioxide and numbers of upper respiratory tract infections diagnosed at health centers (P = 0.04). When the concentrations of sulfur dioxide were above the mean, the frequency of the upper respiratory tract infections was 15% higher than that during the periods of low concentration. The relative importance of the effects of low-level air pollution and low temperature on health is difficult to assess.

Absenteeism↗

PubMed2001

The role of symptomatic colds in asthma exacerbations: Influence of outdoor allergens and air pollutants.

BACKGROUND: Both air pollutants and respiratory viral infections have been recognized to be important triggers of asthma exacerbations, but the possible interaction of these has not been assessed in an epidemiologic study. OBJECTIVE: In this study, we aimed to assess the possible associations of symptomatic colds with outdoor allergens and air pollutants in exacerbating asthma. METHODS: A total of 57 adults and children with asthma participated in a 1-year study in Vancouver, British Columbia. Diary cards recording symptoms of asthma and colds, medication usage, and peak expiratory flow rates were completed twice daily. Outdoor air pollutant levels and levels of pollen and fungal spores were measured. Levels were examined for associations with exacerbations of asthma with symptoms of a cold, as compared with asthma exacerbations with no cold symptoms and colds in the absence of asthma exacerbations. RESULTS: Of 130 asthma exacerbations, 47% were associated with cold symptoms (accounting for 44% of episodes of colds). Asthma exacerbations with colds were associated with higher levels of sulfur dioxide, and nitric oxide during March to November in comparison with asthma exacerbations without cold symptoms (P <.018). Cold-symptom days overall were more common in winter and were significantly associated with lower temperatures, lower ozone levels, and higher sulfur dioxide, nitrogen dioxide, nitrogen oxide (NO and NO(x)), and carbon monoxide levels. CONCLUSIONS: Asthma exacerbations are commonly associated with cold symptoms. These episodes are associated with higher levels of sulfur dioxide and nitrogen oxides from March to November in comparison with asthma exacerbations without cold symptoms.

Adolescent↗

PubMed2003

Air pollution and daily mortality in a city with low levels of pollution.

The concentration-response relationship between daily ambient inhalable particle (particulate matter less than or equal to 10 micro m; PM(10)) concentrations and daily mortality typically shows no evidence of a threshold concentration below which no relationship is observed. However, the power to assess a relationship at very low concentrations of PM(10) has been limited in studies to date. The concentrations of PM(10) and other air pollutants in Vancouver, British Columbia, Canada, from January 1994 through December 1996 were very low: the 50th and 90th percentiles of daily average PM(10) concentrations were 13 and 23 micro g/m(3), respectively, and 27 and 39 ppb, respectively, for 1-hr maximum ozone. Analyses of 3 years of daily pollution (PM(10), ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide) concentrations and mortality counts showed that the dominant associations were between ozone and total mortality and respiratory and cardiovascular mortality in the summer, and between nitrogen dioxide and total mortality in the winter, although some association with PM(10) may also have been present. We conclude that increases in low concentrations of air pollution are associated with increased daily mortality. These findings may support the notion that no threshold pollutant concentrations are present, but they also raise concern that these effects may not be effects of the measured pollutants themselves, but rather of some other factor(s) present in the air pollution-meteorology mix.

Air Pollutants↗

PubMed1994

Effects of low-level winter air pollution concentrations on respiratory health of Dutch children.

During three consecutive winters acute effects of air pollution on respiratory health of more than 1000 children living in four nonindustrial communities in the Netherlands have been investigated. Each child performed between 6 and 10 pulmonary function tests on predetermined days. The occurrence of acute respiratory symptoms in the children was registered in a daily diary filled out by the parents of the children for periods of 3 months. Exposure to air pollution was characterized by the ambient concentration of sulfur dioxide, nitrogen dioxide, PM10, fine particle sulfate, fine particle nitrate, and nitrous acid. No major winter air pollution episode occurred during these winters. Concentrations of acid aerosol were low. A weak negative association between the concentrations of nitrogen dioxide, PM10, aerosol sulfate, aerosol nitrate, nitrous acid, and pulmonary function was found. Sulfur dioxide concentration was not associated with pulmonary function. No association of the concentration of the measured pollutants with daily incidence and prevalence of acute respiratory symptoms was found.

Aerosols↗

PubMed1983

Ambient air quality in the vicinity of a works manufacturing sulphuric acid, phosphoric acid and sodium tripolyphosphate.

Airborne concentrations of sulphur dioxide, nitrogen dioxide, sulphate and fluorides have been determined in the vicinity of a large industrial producer of sulphuric acid, phosphoric acid and sodium tripolyphosphate. The results indicate that the Works does not contribute significantly to 24-h average levels of nitrogen dioxide or sulphuric acid, but does cause an elevation in local sulphur dioxide and fluoride concentrations. Measurements of phosphate deposition demonstrate that the Works is a source of both condensed phosphate and orthophosphate emissions. It is concluded that ambient air pollution concentrations are well within accepted standards for human health, but that alleged damage to garden plants may be due to airborne fluorides and/or phosphate deposition.

Air↗

PubMed2006

The relationship of air pollution to ED visits for asthma differ between children and adults.

The purpose of this study was to evaluate the relationship between air pollution and asthma exacerbation in children and adults. Pearson analysis was used to establish correlations between air pollutants-sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, and particles with an aerodynamic diameter of 10 microm or less (PM(10))--and ED visits for asthma in 2004. Among children, there were significant positive correlations between nitrogen dioxide (r = 0.72), carbon monoxide (r = 0.65), and PM(10) (r = 0.63) and ED visits for asthma. Among adults, only weakly positive, non significant correlations between all air pollution measures and ED visits for asthma were found. This study suggests that air pollution plays a role in acute exacerbation of asthma in children but not in adults.

Adolescent↗

PubMed1998

Evaluation of external breathing in children living in a region with industrial pollution.

BACKGROUND: The changes in respiratory functions are among the most sensitive indicators available for the evaluation of the influence of air pollution on health. OBJECTIVE: The objective of the present study was to evaluate the respiratory functions of children from three schools situated at a different distance from the major sources of air pollution--an asbestos-cement plant, a fertilizer plant and a steam-power plant which utilize brown coal as a main source of energy. METHODS: Comprehensive functional investigation of breathing (FIB) was performed on 97 children from the town of Dimitrovgrad--mean age 10.4 +/- 0.1 years and height 145 +/- 0.6 cm (mean +/- Sx) in a special university medical center laboratory. The characterization of the degree of air pollution was based on the analysis of the mean yearly concentrations of particulate matter, sulfur dioxide, nitrogen dioxide, ammonia and hydrogen sulphide in the three zones of exposure in the town on the basis of the criteria outlined in the Uniform National System for Control of Air Pollution in Bulgaria. RESULTS: The mean yearly concentrations of particulate matter up to 0.19 mg/m3, of hydrogen sulphide--up to 0.07 mg/m3, of nitrogen dioxide--up to 0.025 mg/m3, of ammonia--up to 0.16 mg/m3, of hydrogen sulphide--up to 0.13 mg/m3 and lead aerosols--up to 0.00012 mg/m3 recorded at the different stations reached statistical significance at some of them. No significant differences were found in the values of lung function parameters of the healthy children from all three zones. MEF50% (94 +/- 2%) and the Single Breath Transfer Factor (TLCO = 93 +/- 1.5%) showed a tendency towards lower values. CONCLUSIONS: In the low-grade pollution that we found in the present study no significant differences were found in the lung function parameters of the children from the three regions.

Air Pollutants↗

PubMed2004

Gaseous air pollutants and asthma hospitalization of children with low household income in Vancouver, British Columbia, Canada.

Associations of gaseous air pollutants (including carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone) with asthma hospitalization, stratified by sex and socioeconomic status, were examined among children 6-12 years of age in Vancouver, British Columbia, Canada, between 1987 and 1998. Relative risks for an exposure increment corresponding to the interquartile range for each gaseous air pollutant were estimated for asthma hospitalization after adjustment for weather conditions, including daily maximum and minimum temperatures as well as average relative humidity. Similar results were obtained by using locally weighted smoothing functions (LOESS) with default convergence criteria and by using natural cubic splines with a more stringent setting. Exposures to nitrogen dioxide were found to be significantly and positively associated with asthma hospitalization for males in the low socioeconomic group but not in the high socioeconomic group. For females, this same pattern of association was observed for exposures to sulfur dioxide. No significantly positive associations were found between carbon monoxide and ozone and asthma hospitalization in either low or high socioeconomic groups.

Air Pollutants↗

PubMedDate not supplied

Association of ambient air quality with children's lung function in urban and rural Iran.

During the summer of 1994, a cross-sectional epidemiological study, in which the pulmonary function of children in Tehran was compared with pulmonary function in children in a rural town in Iran, was conducted. Four hundred children aged 5-11 y were studied. Daytime ambient nitrogen dioxide, sulfur dioxide, and particulate matter were measured with portable devices, which were placed in the children's neighborhoods on the days of study. Levels of these ambient substances were markedly higher in urban Tehran than in rural areas. Children's parents were questioned about home environmental exposures (including heating source and environmental tobacco smoke) and the children's respiratory symptoms. Pulmonary function was assessed, both by spirometry and peak expiratory flow meter. Forced expiratory volume in 1 s and forced vital capacity-as a percentage of predicted for age, sex and height-were significantly lower in urban children than in rural children. Both measurements evidenced significant reverse correlations with levels of sulfur dioxide, nitrogen dioxide, and particulate matter. Differences in spirometric lung function were not explained by nutritional status, as assessed by height and weight for age, or by home environmental exposures. Reported airway symptoms (i.e., cough, phlegm, and wheeze) were higher among rural children, whereas reported physician diagnosis of bronchitis and asthma were higher among urban children. The association between higher pollutant concentrations and reduced pulmonary function in this urban-rural comparison suggests that there is an effect of urban air pollution on short-term lung function and/or lung growth and development during the preadolescent years.

Air Pollutants↗

PubMed1999

A GEE moving average analysis of the relationship between air pollution and mortality for asthma in Barcelona, Spain.

Several studies have assessed the association between air pollution and hospital admissions or emergency room visits for asthma. Because of both the presence of missing data and the small number of observations, the relationship between air pollution and mortality for respiratory causes has been rarely analysed, and when it has, the results are very inconclusive or even inconsistent. The objective of this study is to assess the relation between levels of air pollutants (black smoke, sulphur dioxide, nitrogen dioxide and ozone), meteorological variables (24th average temperature and relative humidity) and daily mortality for asthma (ICD-9 493, 2 to 45 years old) in Barcelona, Spain, during the period 1986-1989. Since the range of daily mortality for asthma (2 to 45 years old) during the period 1986-1989 was 0-1), we have preferred to consider this variable as dichotomous. First, the relationship between air pollutants, meteorological variables and daily mortality (controlled for the occurrence of asthma epidemics) was estimated using logistic regression models. As was expected, the residuals from this regression were autocorrelated, showing a complex moving average (MA) structure. If covariates were not time dependent the so-called generalized linear mixed models, could be applied. In our case the covariates vary. As a consequence the likelihood is numerically intractable because it involves the evaluation of n-fold integral. An alternative method that avoids these numerical problems is the generalized estimating equations method (GEE). It is a multivariate analogue of quasi-likelihood estimation. In the absence of a likelihood function the parameters can be estimated by solving a multivariate analogue of the quasi score function. We have modified the GEE method in this paper, allowing for a different structure in the error covariance matrix (MA). Both air pollutants and meteorological variables are related with the occurrence of a death for asthma. In this sense, nitrogen dioxide, NO(2) (ss=0.037, p<0. 05), ozone, O(3) (ss=0.021, p<0.06) and high temperature (the ss's were in the range (0.098-0.182), p<0.05) increased the probability of dying for asthma in Barcelona during the period 1986-1989.

Adolescent↗

PubMed1994

The impact of pollution on allergic disease.

Evidence suggests that allergic disease is becoming more common, particularly in industrialized societies. Two studies of schoolchildren from Aberdeen, Scotland aged 8-13 years were undertaken in 1964 and 1989 using identical questionnaires, and found that the reported prevalence of asthma had risen from 4.1% to 10.2% during this period, hay fever from 3.2% to 11.9% and eczema from 5.3% to 12%. Indication that air pollution may contribute to this increase has come from several studies. In Japan, allergic rhinoconjunctivitis was found to be more prevalent in individuals living near motorways than in cedar forests. Severe asthma also occurs more commonly than mild asthma in children living in polluted areas. Exercise-induced asthma and the use of asthma medication were twice as high in a town near two power stations compared with a non-polluted town. A recent study in Finland showed that admissions to hospital with severe asthma correlated with atmospheric levels of nitrogen dioxide. Deterioration in peak flow recordings in asthmatics and exacerbations of symptoms in hay fever sufferers correlate with ambient levels of ozone. Elucidation of the mechanisms by which exposure to air pollutants may influence the frequency of allergic disease or exacerbate symptoms has come from in vitro and in vivo experiments in animals and man. Animals exposed to ozone, sulphur dioxide, nitrogen dioxide and particles from diesel exhaust, together with allergens, show more ready development of allergic sensitization compared with those exposed to allergen alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution↗

PubMedDate not supplied

Acute asthma exacerbations and air pollutants in children living in Belfast, Northern Ireland.

The incidence of childhood asthma, a common condition, is on the rise worldwide. Despite reductions in the emission of urban smoke, traffic pollution is now a major worldwide problem. Belfast, Northern Ireland, is an old industrial city with major pollution problems. In this study, the authors investigated the rates of acute asthma admissions to Belfast's major children's emergency department. The admissions were studied, relative to day-to-day fluctuations in thoracic particulate matter, sulfur dioxide, nitrogen dioxide, nitric oxide, oxides of nitrogen, ozone, carbon monoxide, benzene, temperature, and rainfall. Daily admissions for acute asthma at the emergency department of the Royal Belfast Hospital and average daily pollution were recorded for the 3-yr period between January 1, 1993, and December 31, 1995. The authors used Poisson regression to assess independent association(s). Individually, small associations were seen for thoracic particulate matter (relative risk = 1.10), sulfur dioxide (relative risk = 1.09), nitrogen dioxide (relative risk = 1.11), nitric oxide (relative risk = 1.07), oxides of nitrogen (relative risk = 1.10), carbon monoxide (relative risk = 1.07), and benzene (1.14); no associations were noted between meteorological factors (temperature and rainfall) or ozone and asthma emergency-department admissions. The authors adjusted for the aforementioned parameters, and benzene level was the only variable associated independently with asthma emergency-department admissions in children. Benzene may be a more reliable method of measuring exposure to vehicle exhaust emissions than measurements of other pollutants.

Acute Disease↗

PubMed1994

Acute effects of summer air pollution on respiratory symptom reporting in children.

A daily diary of respiratory symptoms was collected from the parents of 1,844 school children in six U.S. cities to study the association between ambient air pollution exposures and respiratory illness. A cohort of approximately 300 elementary school children in each of six communities were asked to keep a daily log of the study child's respiratory symptoms for one year. Daily measurements of ambient sulfur dioxide, nitrogen dioxide, ozone, inhalable particles (PM10), respirable particles (PM2.5), light scattering, and sulfate particles were made, along with integrated 24-h measures of aerosol strong acidity. The analyses were limited to the five warm season months between April and August. Significant associations were found between incidence of coughing symptoms and incidence of lower respiratory symptoms and PM10, and a marginally significant association between upper respiratory symptoms and PM10. There was no evidence that other measures of particulate pollution including aerosol acidity were preferable to PM10 in predicting incidence of respiratory symptoms. Significant associations in single pollutant models were also found between sulfur dioxide or ozone and incidence of cough, and between sulfur dioxide and incidence of lower respiratory symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed2001

Environmental contributions to allergic disease.

The environment is a major contributor to allergic disease, and great effort is being expended to identify the chemical pollutants and allergens that make a significant impact. Exposure to high levels of ozone, sulfur dioxide, nitrogen dioxide, and diesel exhaust particles is known to reduce lung function. Studies continue to delineate the role of these particles as adjuvants and carriers of allergens into the respiratory system. Current studies also show the exacerbation of allergic disease through fungal spore inhalation and continue to document the role of pollen in allergic rhinitis. Pollen also was recently associated with asthma epidemics, especially after thunderstorms. Forecasting models currently are being developed that predict the trajectories of pollen dispersal and may allow increased avoidance of dangerous outdoor conditions.

Air Pollutants↗

PubMed1992

Air pollution and daily mortality: associations with particulates and acid aerosols.

The association between total daily mortality and air pollution was investigated for a 1-year period (September 1985 through August 1986) in St. Louis and in the counties in eastern Tennessee surrounding Kingston/Harriman. The purpose of this study was to evaluate the relative importance of various measures of particulate and gaseous air pollution as predictors of daily mortality. Concentrations of inhalable particles (PM10), fine particles (PM2.5), the elemental composition of these particles, and aerosols acidity were measured daily during the period of study. The effect of each air pollutant on daily mortality was estimated after controlling for meteorologic and seasonal influences. Total mortality in St. Louis was found to increase 16% (95% CI-1 to 33%) for each 100 micrograms/m3 increase in PM10, and by 17% (95% CI-12 to 57%) in eastern Tennessee. Positive but progressively weaker associations were found with PM2.5, sulfate, and aerosol acidity concentrations in both communities. Associations with gaseous pollutants--sulfur dioxide, nitrogen dioxide, and ozone--were all far from statistical significance. Because of the short monitoring period for daily particulate air pollution, the power of this study to detect associations was limited. Nevertheless, statistically significant associations with PM10 were found in St. Louis, and, more importantly, the estimated effects were consistent between the two communities studied and with other reported analyses of the effects of particles on daily mortality. These data suggest that the acidity of particles is not as important in associations with daily mortality as the mass concentrations of particles.

Aerosols↗

PubMedDate not supplied

[Effects of air pollution on human health and their importance in Mexico City].

The impact of air pollution on human health is a complicated problem. In this review, we describe the main health effects of exposure to ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and particulate matter. Geographical characteristics of the metropolitan area of Mexico City that favor pollutant persistence with adverse effects on the population are described; the use of the Indice Metropolitano de la Calidad del Aire (IMECA), current norms, and present programs to diminish this problem are discussed. Evidence shows that through these actions, air quality has improved. However, some pollutants such as ozone and particulate matter, still exceed the standard. To further improve air quality in the city, existing programs should continue and multidisciplinary research, both basic and applied, is required.

Air Pollutants↗

PubMed1982

[Comparison of concentrations of inorganic and organic compounds occurring inside and outside closed rooms].

Although many people spend more than two thirds of their day indoors, most epidemiological studies on the health effects of air pollutants have up to now only been based on ambient air quality measurements. Using data from the literature, information is collected on the indoor-outdoor relationship of pollutant concentrations in order to estimate in which cases data on ambient air quality have to be completed by the results of indoor air measurements during epidemiological studies. For air pollutants like sulphur dioxide, nitrogen dioxide, carbon monoxide, suspended particulate matter, polycyclic aromatic hydrocarbons and nitrosamines the long-term average concentrations found indoors exceed those found outdoors only when tobacco smoke or other visible sources, e.g. gas appliances, are present in the room. A table is given which shows average indoor-outdoor ratios for the different cases. A number of organic substances, however, can be expected to be encountered in much higher concentrations indoors than outdoors. One of the main reasons for this is the use of a great variety of organic substances in modern building materials and household products. During the application of one or more of the multiple consumer products offered nowadays it is not unusual that the indoor air for several hours may show concentrations of organic substances which exceed those found in ambient air by a factor of more than 50.

Air Pollutants↗