An Analysis of Peak Grass Pollination in New York and New Jersey

Abstract

RATIONALE: Pre-seasonal precipitation has been found to correlate with grass pollen levels.1 In this study, we compared the historical trends of grass pollen data from seven collection stations in New York and New Jersey with temperature and precipitation levels.METHODS: A retrospective analysis was done on data from the National Allergy Bureau from March 14, 2005 to July 30, 2009. We examined monthly precipitation, average temperature, and the number of dry days preceding peak grass pollen count obtained from Accuweather.com.RESULTS: Peak grass pollen counts increased four fold (20/m3 to 80/m3) from 2008 to 2009 in Brooklyn. The peak in 2009 was preceded by a period of 15 dry days. In Newark, the peak grass pollen level increased 24 fold (10/m3 to 238/m3) from 2007 and 2008, preceded by a period of 18 dry days. Variations in average temperature or pre-seasonal precipitation at these two stations during this time were not sufficient to explain the increases. No significant variations in peak grass pollen counts at other stations. The grass pollen level tends to peak earlier in Brooklyn (May) compared to upstate areas such as Albany and Olean (June).CONCLUSIONS: There were variations in timing and magnitude of peak grass pollen counts among seven counting stations throughout New York and New Jersey. Temperature and pre-seasonal precipitation were not associated with peak grass pollen count, whereas a prolonged period of dry days was found to be linked to a peak in grass pollen at two collecting stations, a trend previously demonstrated for tree pollens.2 RATIONALE: Pre-seasonal precipitation has been found to correlate with grass pollen levels.1 In this study, we compared the historical trends of grass pollen data from seven collection stations in New York and New Jersey with temperature and precipitation levels. METHODS: A retrospective analysis was done on data from the National Allergy Bureau from March 14, 2005 to July 30, 2009. We examined monthly precipitation, average temperature, and the number of dry days preceding peak grass pollen count obtained from Accuweather.com. RESULTS: Peak grass pollen counts increased four fold (20/m3 to 80/m3) from 2008 to 2009 in Brooklyn. The peak in 2009 was preceded by a period of 15 dry days. In Newark, the peak grass pollen level increased 24 fold (10/m3 to 238/m3) from 2007 and 2008, preceded by a period of 18 dry days. Variations in average temperature or pre-seasonal precipitation at these two stations during this time were not sufficient to explain the increases. No significant variations in peak grass pollen counts at other stations. The grass pollen level tends to peak earlier in Brooklyn (May) compared to upstate areas such as Albany and Olean (June). CONCLUSIONS: There were variations in timing and magnitude of peak grass pollen counts among seven counting stations throughout New York and New Jersey. Temperature and pre-seasonal precipitation were not associated with peak grass pollen count, whereas a prolonged period of dry days was found to be linked to a peak in grass pollen at two collecting stations, a trend previously demonstrated for tree pollens.2