Thunderstorms and asthma admissions

Relationship between biometeorological factors and the number of hospitalizations due to asthma

The incidence of asthma exacerbation depends on atmospheric conditions, including such meteorological factors as the ambient temperature, relative air humidity or concentration of atmospheric aerosols. An assessment of relations between the frequency of asthma exacerbation and environmental conditions was made according to the meteorological components, the biometeorological index UTCI (Universal Thermal Climate Index), as well as selected air quality parameters, including concentrations of PM₁₀ and PM_2.5. The study was conducted on the basis of a retrospective analysis of medical data collected at the Independent Public Hospital of Tuberculosis and Pulmonary Diseases in Olsztyn (Poland). Our analysis of patient data (from 1 January 2013 until 31 December 2017) showed a significant correlation between the number of asthma exacerbation and the UTCI value. More frequent asthma exacerbations are observed in patients aged over 65 years when air humidity increases. The UTCI values contained within class 5, describing thermoneutral conditions, correspond to an average frequency of asthma exacerbation. A decline in the UTCI value leads to a reduced number of asthma exacerbation, while a rise makes the cases of asthma exacerbations increase.

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.

Frequency of emergency room visits for childhood asthma in Ottawa, Canada: the role of weather

The aim of this study was to evaluate associations between meteorological conditions and the number of emergency department visits for asthma in a children's hospital in Ottawa, Canada. A case-crossover study design was used. Hospital emergency department visits for asthma between 1992 and 2000 were identified based on patients' presenting complaints. We obtained hourly measures for the following meteorological variables: wind speed, temperature, atmospheric pressure, relative humidity, and visibility. Particular emphasis was placed on exploring the association between asthma visits and fog, thunderstorms, snow, and liquid and freezing forms of precipitation. In total, there were 18,970 asthma visits among children between 2 and 15 years of age. The number of visits and weather characteristics were grouped into 6 h case and control intervals. The occurrence of fog or liquid precipitation was associated with an increased number of asthma visits, while snow was associated with a reduced number (P<0.05). Stratified analyses by season found no association in any of the four calendar intervals between the number of asthma visits and visibility, change in relative humidity and change in temperature. In contrast, summertime thunderstorm activity was associated with an odds ratio of 1.35 (95% CI=1.02-1.77) relative to summer periods with no activity. Models that incorporate calendar and meteorological data may help emergency departments to more efficiently allocate resources needed to treat children presenting with respiratory distress.

Are high barometric pressure, low humidity and diurnal change of temperature related to the onset of asthmatic symptoms?

BACKGROUND

Meteorologic factors play a role in the expression of asthmatic symptoms; however, there are controversies about the causal relationship between meteorologic factors and asthma. The relationship between meteorologic parameters and emergency admissions for asthmatic symptoms in this hospital were analyzed.

METHODS

A total of 205 patients (130 boys and 75 girls, 0.1-16.6 years of age) who were admitted to Hakodate Chuo General Hospital for asthmatic symptoms between 1 January and 31 December 1997 were submitted to our study. We divided a total of 365 days into two groups of days with and without any admissions. Meteorologic factors for the days with admissions and 1-3 days before hospitalization were compared with those of the days of no admissions. Statistical analysis was done with the Mann-Whitney U-test.

RESULTS

On the days with admissions and 1 day before hospitalizations, barometric pressure was higher and relative humidity lower than on days with no admissions. The diurnal difference between maximum and minimum temperature for days 1 day before days with admissions was larger than that for 1 day before days with no admissions.

CONCLUSIONS

It is thought that change in barometric pressure, relative humidity and temperature had some influence on the worsening of asthmatic symptoms.

Emergency room visits of asthmatic children, relation to air pollution, weather, and airborne allergens

BACKGROUND

The worldwide increase in the incidence, prevalence, and severity of asthma may suggest that environmental factors play a role in these epidemiologic changes.

OBJECTIVE

To examine the correlations between air pollutants, weather conditions, airborne allergens, and the incidence of emergency room (ER) visits of children with acute asthma attacks.

DESIGN

One-year prospective study. Data of daily concentration of air pollutants, weather conditions, and selective airborne allergens were collected and compared with the number of ER visits of asthmatic children.

SUBJECTS

1076 asthmatic children (aged 1 to 18 years) who presented at the Pediatric ER between January 1 and December 31, 1993.

RESULTS

Correlations between fluctuations in ER visits of asthmatic children and various environmental parameters were more relevant for weekly than for daily values. Emergency room visits correlated positively with concentrations of NOx, SO2 and with high barometric pressure; and negatively with O3 concentration and minimal and maximal temperature. There were no significant correlations with concentrations of particulates, humidity, or airborne pollen and spores. An exceptionally high incidence of ER visits of asthmatic children was observed during September. This peak coincided with the beginning of the school year and the Jewish holidays. The correlations between ER visits and the environmental factors increased significantly when the September peak was excluded, revealing that 61% of the variance in ER visits was explained by NOx, SO2, and 03 concentrations, 46% by weather parameters, 66% by NOx, SO2 and barometric pressure, and 69% by the combination of air pollutants and weather parameters.

CONCLUSION

The major factors found to be associated with ER visits of asthmatic children were high NOx, high SO2, and high barometric pressure. Negative correlation was found between ER visits of asthmatic children and ozone concentrations. The particularly high number of ER visits at the beginning of the school year and the Jewish holidays was probably associated with an increase in the number of viral infections and/or emotional stress.