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Correlation between Atmospheric Tree Pollen Levels with Three Weather Variables during 2002-2004 in a Tropical Urban Area
AB170 Abstracts
647
Aerobiology of Juniperus ashei Pollen in Texas and Oklahoma E. Levetin1, L. Bunderson1, P. Van de Water2, J. C. Luvall3; 1University of Tulsa, Tulsa, OK, 2California State University, Fresno, Fresno, CA, 3 NASA Marshall Space Flight Center, Huntsville, AL. RATIONALE: Juniperus ashei (JA), mountain cedar, pollen is a major allergen in the south central states. JA trees cover millions of acres, especially in central Texas. This study was undertaken to estimate pollen production in JA woodlands to develop improved pollen-forecasting systems to warn of potential exposure risks. METHODS: Air sampling was conducted within natural populations of JA using Burkard samplers at four sites in Texas and two in Oklahoma during the 2009-2010 JA pollen season. Slides were prepared and analyzed using standard methods. Fieldwork in adjacent JA woodlands examined tree density and male cone production; cone samples were collected to determine pollen per cone. RESULTS: There was a great deal of variability in airborne pollen concentrations and pollen production. Junction, TX registered the highest average daily pollen concentration for the season at 863 pollen/m3, the highest single daily concentration at 18,073 pollen/m3 and the highest hourly concentration at 70,367 pollen/m3. Peak seasonal levels were recorded on Jan 1819 at five locations. Cone production depended on tree size, percent live vegetation, and location, ranging from 15,000 to 1.3 million cones per tree. Preliminary estimates of pollen production found 300,000 to 400,000 pollen/cone resulting in possibly 500 billion pollen/tree. Using these estimates, the JA woodlands around Junction were found to have the highest potential pollen production at 2.3231013 pollen/hectare, which supports the air sampling data. CONCLUSION: Data from airborne pollen levels and cone production will be used in forecast model development. Additional work is needed to determine year-to-year changes in pollen and cone production.
648
MONDAY
Ragweed Pollen Allergy in Austria: a Retrospective Analysis of Sensitization Rates from 1997 to 2007 W. Hemmer1, U. Schauer2, A. Trinca2, C. Neumann3, R. Jarisch1; 1Floridsdorf Allergy Center, Vienna, AUSTRIA, 2Office of the Provincial Government of Nieder€osterreich, Dept. of Environmental Health, St. P€ olten, AUSTRIA, 3Office of the Provincial Government of Nieder€osterreich, Dept. of Regional Development & Policy, Statistics Unit, Maria Enzersdorf, AUSTRIA. RATIONALE: Common ragweed (Ambrosia artemisiifolia) is a major pollen allergen in Hungary and has progressively spread over Europe during the last decades. A rising prevalence of ragweed pollen allergy claimed for several European countries is insufficiently validated by longitudinal observation studies in large patient populations. We explored the progression of ragweed sensitization in Austria since 1997. METHODS: Routine skin prick test results to ragweed pollen and other inhalant allergens were retrospectively analysed in 13,719 atopic patients diagnosed between 1997 and 2007. Sensitization rates were compared between different geographical areas with dissimilar ragweed infestation. RESULTS: Although the frequency of ragweed pollen sensitization increased from 8.5% in 1997 to 17.5% in 2007, its mean prevalence (11.1%) was still much lower than that of other pollens (grass 56%, birch 42%, mugwort 22%), house dust mite (37%) and cat (33%). Ragweed sensitization was commonly associated with concomitant sensitization to mugwort (1066/1523; 70%) and multiple pollen allergy (551/1523; 36%) suggesting a role of cross-reactions with mugwort allergens and pollen panallergens in positive prick test reactions to ragweed. The prevalence of ragweed sensitization was highest in the Eastern lowlands adjoining Hungary (20.8%) and lowest in alpine regions (4.7-6.0%). CONCLUSIONS: The increase in sensitization rates to ragweed pollen in the observation period is still moderate even though sensitization is more frequent in areas with high local ragweed load. Discrimination between genuine ragweed sensitization and cross-reactivity is crucial in future epidemiologic studies. In all, ragweed still plays a secondary role compared to other locally important inhalant allergens.
J ALLERGY CLIN IMMUNOL FEBRUARY 2011
649
Correlation between Atmospheric Grass Pollen Levels and Three Weather Variables during 2002-2004 in a Tropical Urban Area A. M. Cepeda1,2, M. Wilson1, S. E. Villalba1,2, H. Avila1, J. Hahn1; 1Universidad del Norte, Barranquilla, COLOMBIA, 2Universidad Metropolitana, Barranquilla, COLOMBIA. RATIONALE: We explored the relationship of atmospheric grass pollen levels (grains/m3) with precipitation (mm), wind velocity (m/s) and temperature (Celsius) in Barranquilla, Colombia. We are unaware of any similar studies in this region. METHODS: The data were collected from January, 2002 to December, 2004. We collected the pollen data using a Rotorod at the Universidad Metropolitana. We obtained the local weather data from IDEAM. Statistical analyses consisted of regression diagnostic plots, the DurbinWatson statistic and linear regression. RESULTS: The Durbin-Watson statistic was 1.53, indicating no significant problems with autocorrelation. Regression diagnostics showed linearity with only minor deviations from normality. The r2 revealed that about 41% of the variability in atmospheric grass pollen level is explained by the model. Wind velocity was not significantly correlated with grass pollen in the presence of the other two variables. The coefficient for precipitation was -0.272 (std. error50.082, p-value50.002). Thus, when temperature is held constant, for every millimeter increase in precipitation we expect an average decrease of 0.272 grass pollen grains/m3. The coefficient for temperature was -22.995 (std. error59.578, p-value50.022). Thus, when precipitation is held constant, for every degree increase in temperature we expect an average decrease of 22.995 grass pollen grains/m3. CONCLUSIONS: Grass pollen levels were negatively correlated with temperature and precipitation, but were not significantly correlated with wind velocity during the period of this study. This study reveals that even in a tropical region with perennial warm weather, some weather variables can have a marked effect on grass pollen variability and be used in predictive modeling.
650
Correlation between Atmospheric Tree Pollen Levels with Three Weather Variables during 2002-2004 in a Tropical Urban Area M. D. Wilson1, S. E. Villalba1,2, H. Avila1, J. Hahn1, A. M. Cepeda1,2; 1 Universidad del Norte, Barranquilla, COLOMBIA, 2Universidad Metropolitana, Barranquilla, COLOMBIA. RATIONALE: This study explores the relationship of tree pollen (grains/ m3) levels with precipitation (mm), wind velocity (m/s) and temperature (Celsius) in Barranquilla, Colombia. We are unaware of any existing similar studies in this region. METHODS: The data were collected from January, 2002 to December, 2004. We collected the pollen data using a Rotorod at the Universidad Metropolitana. We obtained the local weather data from IDEAM. Statistical analyses consisted of regression diagnostic plots, the DurbinWatson statistic and linear regression. A log10 transformation of the pollen variable was used to correct for non-linearity and heteroscedasticity. RESULTS: The Durbin-Watson statistic was 1.186, indicating no significant problems with autocorrelation. Regression diagnostics showed only minor deviations from normality. The r square value revealed that about 53% of the variability in atmospheric tree pollen level is explained by the model. The coefficient for precipitation was b150.003 (std. error50.001, p-value50.001). The coefficient for temperature was b250.362 (std. error50.077, p-value50.000). The coefficient for velocity was b350.129 (std. error50.052, p-value50.018). For every unit increase in each predictor variable, all others held constant, we expect average atmospheric tree pollen to increase by a factor of 10b. That is, an increase of 0.7% for precipitation, 230% for temperature, and 35% for wind velocity. CONCLUSIONS: Tree pollen levels were positively correlated with temperature, wind velocity and precipitation during the three years of this study. This study reveals that even in a tropical region with perennial warm weather, some weather variables can have a marked effect on tree pollen variability and be used in predictive modeling.
647
Aerobiology of Juniperus ashei Pollen in Texas and Oklahoma E. Levetin1, L. Bunderson1, P. Van de Water2, J. C. Luvall3; 1University of Tulsa, Tulsa, OK, 2California State University, Fresno, Fresno, CA, 3 NASA Marshall Space Flight Center, Huntsville, AL. RATIONALE: Juniperus ashei (JA), mountain cedar, pollen is a major allergen in the south central states. JA trees cover millions of acres, especially in central Texas. This study was undertaken to estimate pollen production in JA woodlands to develop improved pollen-forecasting systems to warn of potential exposure risks. METHODS: Air sampling was conducted within natural populations of JA using Burkard samplers at four sites in Texas and two in Oklahoma during the 2009-2010 JA pollen season. Slides were prepared and analyzed using standard methods. Fieldwork in adjacent JA woodlands examined tree density and male cone production; cone samples were collected to determine pollen per cone. RESULTS: There was a great deal of variability in airborne pollen concentrations and pollen production. Junction, TX registered the highest average daily pollen concentration for the season at 863 pollen/m3, the highest single daily concentration at 18,073 pollen/m3 and the highest hourly concentration at 70,367 pollen/m3. Peak seasonal levels were recorded on Jan 1819 at five locations. Cone production depended on tree size, percent live vegetation, and location, ranging from 15,000 to 1.3 million cones per tree. Preliminary estimates of pollen production found 300,000 to 400,000 pollen/cone resulting in possibly 500 billion pollen/tree. Using these estimates, the JA woodlands around Junction were found to have the highest potential pollen production at 2.3231013 pollen/hectare, which supports the air sampling data. CONCLUSION: Data from airborne pollen levels and cone production will be used in forecast model development. Additional work is needed to determine year-to-year changes in pollen and cone production.
648
MONDAY
Ragweed Pollen Allergy in Austria: a Retrospective Analysis of Sensitization Rates from 1997 to 2007 W. Hemmer1, U. Schauer2, A. Trinca2, C. Neumann3, R. Jarisch1; 1Floridsdorf Allergy Center, Vienna, AUSTRIA, 2Office of the Provincial Government of Nieder€osterreich, Dept. of Environmental Health, St. P€ olten, AUSTRIA, 3Office of the Provincial Government of Nieder€osterreich, Dept. of Regional Development & Policy, Statistics Unit, Maria Enzersdorf, AUSTRIA. RATIONALE: Common ragweed (Ambrosia artemisiifolia) is a major pollen allergen in Hungary and has progressively spread over Europe during the last decades. A rising prevalence of ragweed pollen allergy claimed for several European countries is insufficiently validated by longitudinal observation studies in large patient populations. We explored the progression of ragweed sensitization in Austria since 1997. METHODS: Routine skin prick test results to ragweed pollen and other inhalant allergens were retrospectively analysed in 13,719 atopic patients diagnosed between 1997 and 2007. Sensitization rates were compared between different geographical areas with dissimilar ragweed infestation. RESULTS: Although the frequency of ragweed pollen sensitization increased from 8.5% in 1997 to 17.5% in 2007, its mean prevalence (11.1%) was still much lower than that of other pollens (grass 56%, birch 42%, mugwort 22%), house dust mite (37%) and cat (33%). Ragweed sensitization was commonly associated with concomitant sensitization to mugwort (1066/1523; 70%) and multiple pollen allergy (551/1523; 36%) suggesting a role of cross-reactions with mugwort allergens and pollen panallergens in positive prick test reactions to ragweed. The prevalence of ragweed sensitization was highest in the Eastern lowlands adjoining Hungary (20.8%) and lowest in alpine regions (4.7-6.0%). CONCLUSIONS: The increase in sensitization rates to ragweed pollen in the observation period is still moderate even though sensitization is more frequent in areas with high local ragweed load. Discrimination between genuine ragweed sensitization and cross-reactivity is crucial in future epidemiologic studies. In all, ragweed still plays a secondary role compared to other locally important inhalant allergens.
J ALLERGY CLIN IMMUNOL FEBRUARY 2011
649
Correlation between Atmospheric Grass Pollen Levels and Three Weather Variables during 2002-2004 in a Tropical Urban Area A. M. Cepeda1,2, M. Wilson1, S. E. Villalba1,2, H. Avila1, J. Hahn1; 1Universidad del Norte, Barranquilla, COLOMBIA, 2Universidad Metropolitana, Barranquilla, COLOMBIA. RATIONALE: We explored the relationship of atmospheric grass pollen levels (grains/m3) with precipitation (mm), wind velocity (m/s) and temperature (Celsius) in Barranquilla, Colombia. We are unaware of any similar studies in this region. METHODS: The data were collected from January, 2002 to December, 2004. We collected the pollen data using a Rotorod at the Universidad Metropolitana. We obtained the local weather data from IDEAM. Statistical analyses consisted of regression diagnostic plots, the DurbinWatson statistic and linear regression. RESULTS: The Durbin-Watson statistic was 1.53, indicating no significant problems with autocorrelation. Regression diagnostics showed linearity with only minor deviations from normality. The r2 revealed that about 41% of the variability in atmospheric grass pollen level is explained by the model. Wind velocity was not significantly correlated with grass pollen in the presence of the other two variables. The coefficient for precipitation was -0.272 (std. error50.082, p-value50.002). Thus, when temperature is held constant, for every millimeter increase in precipitation we expect an average decrease of 0.272 grass pollen grains/m3. The coefficient for temperature was -22.995 (std. error59.578, p-value50.022). Thus, when precipitation is held constant, for every degree increase in temperature we expect an average decrease of 22.995 grass pollen grains/m3. CONCLUSIONS: Grass pollen levels were negatively correlated with temperature and precipitation, but were not significantly correlated with wind velocity during the period of this study. This study reveals that even in a tropical region with perennial warm weather, some weather variables can have a marked effect on grass pollen variability and be used in predictive modeling.
650
Correlation between Atmospheric Tree Pollen Levels with Three Weather Variables during 2002-2004 in a Tropical Urban Area M. D. Wilson1, S. E. Villalba1,2, H. Avila1, J. Hahn1, A. M. Cepeda1,2; 1 Universidad del Norte, Barranquilla, COLOMBIA, 2Universidad Metropolitana, Barranquilla, COLOMBIA. RATIONALE: This study explores the relationship of tree pollen (grains/ m3) levels with precipitation (mm), wind velocity (m/s) and temperature (Celsius) in Barranquilla, Colombia. We are unaware of any existing similar studies in this region. METHODS: The data were collected from January, 2002 to December, 2004. We collected the pollen data using a Rotorod at the Universidad Metropolitana. We obtained the local weather data from IDEAM. Statistical analyses consisted of regression diagnostic plots, the DurbinWatson statistic and linear regression. A log10 transformation of the pollen variable was used to correct for non-linearity and heteroscedasticity. RESULTS: The Durbin-Watson statistic was 1.186, indicating no significant problems with autocorrelation. Regression diagnostics showed only minor deviations from normality. The r square value revealed that about 53% of the variability in atmospheric tree pollen level is explained by the model. The coefficient for precipitation was b150.003 (std. error50.001, p-value50.001). The coefficient for temperature was b250.362 (std. error50.077, p-value50.000). The coefficient for velocity was b350.129 (std. error50.052, p-value50.018). For every unit increase in each predictor variable, all others held constant, we expect average atmospheric tree pollen to increase by a factor of 10b. That is, an increase of 0.7% for precipitation, 230% for temperature, and 35% for wind velocity. CONCLUSIONS: Tree pollen levels were positively correlated with temperature, wind velocity and precipitation during the three years of this study. This study reveals that even in a tropical region with perennial warm weather, some weather variables can have a marked effect on tree pollen variability and be used in predictive modeling.