Research Program Area: Health & Exposure
Frequency and severity of day-time symptoms, night-time symptoms and medication requirements among a group of 34 volunteers with asthma were correlated to levels of pollutants and pollens and to meteorologic characteristics continuously recorded over a period of eight months, utilizing three analytic strategies:
(A) Correlations between several parameters of respiratory health and levels of sulfates were consistently noted among three of the 34 volunteers. Significant correlations were also noted among several additional volunteers in one or more of the respiratory health parameters. Levels of sulfates correlated to levels of total oxidants, carbon monoxide and oxides of nitrogen but these correlations were not responsible for correlations observed between the respiratory parameters in volunteers and sulfate levels.
(B) The mean symptom and medication scores of panel members on days falling in the highest and in the lowest tertile of all sulfate levels ( > l0 pg/m3 a n d 6 pg/m3, respectively) were compared. The same three volunteers showed significant increases in respiratory symptoms and medication usage on days which were in the upper third of all sulfate levels.
(C) In the final analysis, the number of days on which the participant's symptom or medication score was above his/her mean was calculated for sulfate days above and below 10 µg/m3, the upper tertile of all sulfate levels. The three consistent sulfate responders all had significantly fewer symptoms and medication needs on days which were below the 10 pg/m3 sulfate cut point. Although the number of individuals was necessarily small, the results of this longitudinal study suggest that as many as 9% of asthmatics may be sensitive to levels of sulfate in the ambient air and that reduction of sulfate levels to below 10 µg/m3 would significantly reduce the frequency of symptoms and needs for medication in these individuals.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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