A study on the epidemiology of asthma in children in Philadelphia: The relation of weather and air pollution to peak incidence of asthmatic attacks☆
Abstract
A continuing study of the possible correlations between weather patterns, air pollution, and bronchial asthma in a group of asthmatic children was carried out at St. Christopher's Hospital for Children. During the 676 days of the study, 1,346 patients were seen. There was an average of 2.5 visits of patients for treatment of acute bronchial asthma in 24 hours, with a standard deviation of less than two. On any day we considered there to be significant increase in asthmatic attacks when 5 or more patients were seen in the Receiving Ward for treatment of asthma. (The number on these days ranged from 5 to 14 per 24 hours.) There were 70 such 24 hour periods. There was a threefold greater incidence of bronchial asthma during days of noteworthy high air pollution. There was a greater incidence of bronchial asthma during days of high barometric pressure over Philadelphia (this was a four-fold increase). There were 117 days during the study when there was a combination of high pressure and an increase in atmospheric pollution. Thirty of the 70 days of increased frequency of asthma (43 per cent) coincided with these days. With these combined conditions, meteorologic factors of stagnant air plus noteworthy days of high air pollution, the asthma incidence was found to rise to nine times the rate found on the control days of cleaner and less stagnant air. Of the 280 days which had neither high barometric pressure nor increased air pollution, there were only 8 days (3 per cent) with an increased frequency of asthma (p was less than 0.001). Occurrence of stable weather conditions with stagnant air over Philadelphia seems to correlate with peak incidences of bronchial asthma. There are indications that the increased air pollution associated with these weather conditions is a causative factor. It is suggested that an asthma index may be derived from meteorologic and air pollution data to help predict such peak incidences.
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Cited by (42)
Asthma in children, acute effects of air pollution. An epidemiological study in Le Havre area
1997, Revue Francaise d'Allergologie et d'Immunologie CliniqueLes relations asthme et pollution atmosphérique restent largement ouvertes au débat. L'asthme a dans l'agglomération du Havre (250 000 habitants) une prévalence de 7,8 p. cent. Une étude épidémiologique prospective menée d'Octobre 1989 à Septembre 1991 a inclus tous les enfants (âgés de 6 mois à 16 ans) admis pour une crise d'asthme au lieu d'accueil exclusif des urgences pédiatriques de l'agglomération. Les données météorologiques utilisées ont été la pression atmosphérique, l'hygrométrie et la présence de brouillard. Pour les polluants, les données quotidiennes de l'acidité forte — reflet des taux de dioxyde de soufre (SO2), du dioxyde d'azote (NO2) et de l'ozone (O3) ont été recueillies à partir d'un réseau automatisé de surveillance de la qualité de l'air. En 24 mois, 416 enfants ont été admis pour crise d'asthme aux urgences pédiatriques. L'analyse n'a pas montré de liaison significative entre les facteurs météorologiques ou le niveau des polluants, et le nombre de crises aiguës d'asthme admises aux Urgences pédiatriques les jours suivants; toutefois la liaison entre le niveau de SO2 et les admissions approchait le seuil de signification, pour un décalage dans le temps de 3 à 5 jours.
Asthma is a public health problem and the leading chronic illness in pediatrics. The prevalence of asthma in Le Havre area is 7.8 per cent in children. Among the environmental determinants of acute asthma, the role of outdoor pollution has often been suggested. The aim of this epidemiologic contribution was to study the relationship between acute asthma in children, outdoor air pollution and weather parameters. All children with acute asthma admitted to the Pediatric Hospital, from October 1989 to September 1991, were enrolled in the study. The weather parameters selected were: atmospheric pressure, humidity of air and fog. For pollutants, we studied the daily variation of high acidity — reflecting sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone. Over this 24 month périod, 416 children were enrolled. The analysis did not show any significant relationship between weather parameters, outdoor air pollution and acute asthma requiring pediatric admission. However, logistic regression showed a trend (r = 0.08) between SO2 level and the number of admissions, with a delay of 3 to 5 days. Pollution and asthma are possibly related, but this study does not provide any conclusive results.
Asthma exacerbations during Santa Ana winds in southern California
1996, Wilderness and Environmental MedicineThis study investigated the relationship between Santa Ana wind conditions and visits for asthma at a southern California emergency department. Visits to the emergency department for asthma were analyzed retrospectively to determine whether the incidence increased during Santa Ana wind conditions. These northeasterly winds are common during fall and winter in southern California and belong to a class known as Foehn winds. They are characterized by gusty winds, decreased relative humidity, warm temperatures, and decreased levels of airborne pollutants. During a 4-year period, we noted that emergency department visits for asthma increased (3.12 vs. 2.16 visits per day, P < 0.0001) during Santa Ana winds compared with other weather conditions. Asthmatics presenting during Santa Ana winds appeared to be more ill, as judged by higher admission rates (21.9 vs. 18.7%, P < 0.05). These winds were also associated with reduced paniculate matter (PM10) counts (P < 0.0001). Although the magnitude of the increase in emergency department visits was small, it occurred at a time when typical inciters of respiratory disease should be minimal. An as yet unidentified factor associated with these winds may be a stimulant for some asthmatics. Similar wind patterns in other localities might affect respiratory disease as well.
Respiratory hospital admissions and summertime haze air pollution in Toronto, Ontario: Consideration of the role of acid aerosols
1994, Environmental ResearchA study of air pollution and daily hospital admissions for respiratory causes was conducted in Toronto, Ontario. Fine aerosol (da < 2.5 μm) samples were collected daily at a central city site during July and August 1986, 1987, and 1988 and were subsequently extracted and analyzed for daily particulate phase aerosol strong acidity (H+) and sulfates (SO4=). Daily counts of respiratory admissions to 22 acute care hospitals and daily meteorological and environmental data (e.g. ozone [O3], total suspended particulate matter [TSP], and thoracic particle mass [PM10] were also obtained. Regression analyses indicated that only the O3, H+, and SO4= associations with respiratory and asthma admissions remained consistently significant after controlling for temperature. Even after excluding days with maximum 1-hr O3 > 120 ppb, O3 was still strongly significant. In the various model specifications considered, the relative particle metric strengths of association with admissions were generally H+ > SO4= > FP > PM10 > TSP, indicating that particle size and composition are of central importance in defining the adverse human health effects of particulate matter. On average, summertime haze air pollution was associated with 24% of all respiratory admissions (21% with O3, 3% with H+). On peak pollution days, however, aerosol acidity yielded the highest relative risk estimates (e.g., RR = 1.5 at 391 nmole/m3 H+), and summertime haze was associated with roughly half of all respiratory admissions.
To determine whether meteorologic conditions affect the respiratory status of individuals with chronic lung disease, we asked 14 patients who had completed outpatient pulmonary rehabilitation to record the following information daily during the spring and summer of 1991: (1) dyspnea on arising (morning dyspnea); (2) dyspnea throughout the day (daytime dyspnea); (3) peak expiratory flow rate (PEFR); (4) mood; and (5) the presence of lower respiratory tract infection (LRI). The effect of local meteorologic conditions and LRI frequency on morning and daytime dyspnea, PEFR, and mood were analyzed for spring and summer seasons using a linear regression technique that controlled for first-order autocorrelation. The LRI frequency and the preceding day's respiratory status were the most significant predictors of either season's daily variation in respiratory status. During spring, the only meteorologic condition associated with respiratory status was precipitation: rainfall was directly related to increased morning and daytime dyspnea. Meteorologic conditions were not related to changes in PEFR or mood. During summer, the combination of higher temperature, rise in barometric pressure, and increased LRI frequency best predicted increased morning dyspnea, while the combination of higher temperature and rise in barometric pressure best predicted reduced PEFR. Meteorologic conditions were not related to changes in daytime dyspnea or mood. Precipitation in spring and a combination of high temperature and rise in barometric pressure in summer best predicted deterioration in the respiratory status of this group of patients with chronic lung disease.
Morbilidad respiratoria en la zona industrial de tarragona
1988, Gaceta SanitariaSe realiza un estudio descriptivo de las urgencias respiratorias (Asma, EPOC), correspondientes al municipio de Tarragona y que fueron atendidas en el servicio de urgencias del Hospital «Joan XXIII» de Tarragona durante 1985. Los resultados indican una mayor tasa de casos de asma, sobre todo en la infancia. Analizando su distribución geográfica, Ilama la atención que las zonas con una mayor tasa, se encuentran más cercanas a los complejos industriales (química y petroquímica) que las zonas con menor tasa. Sería interesante el poder realizar un estudio más exhaustivo para determinar la influencia que las industrias de esta zona pueden tener sobre la salud de la población.
A retrospective study has been made of respiratory emergencies (asthma and COLD) in the city of Tarragona who received treatment in the accident and emergency department of Joan XXIII during 1985. The results show a higher rate of asthma, particularly in childhood. Analysing the geographical distribution, it is noticeable that the zones with the highest rates are those nearer to industrial complexes (chemical and petrochemical) than zones with lower rates. It would de interesting to undertake a more exhaustive study to determine the influence of the industries in this zone on the health of the population.
A POINT-SOURCE ASTHMA OUTBREAK
1986, The LancetEpidemiological data for the eighth asthma epidemic in Barcelona were available from the whole city. They reveal a striking space clustering, an hour-time clustering, and simultaneous time and space clustering, which indicate that the outbreak was a point-source epidemic. Air pollution by smoke and oxides of sulphur and nitrogen was unlikely to have been the cause of the epidemic, as was an unusual level of pollen or fungal spores. The industrial area adjacent to the neighbourhood in which the epidemic occurred was a probable source of the cause of the outbreak
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Presented at the Twenty-second Annual Meeting of the American Academy of Allergy, New York, Feb. 22, 1966, and at the Fourth International Biometeorological Congress, Rutgers University, New Brunswick, Aug. 29, 1966.