Plant Pollen

Increasing concentrations of atmospheric carbon dioxide and changes in climate, such as increasing temperatures and altered precipitation patterns, are expected to contribute to increases in levels and distribution of plant pollen. Pollen from trees and grasses is a common allergen that can trigger health effects such as allergic rhinitis (hay fever) and asthma. In the United States in 2017, 8 percent of adults reported suffering from hay fever. Eight percent of adults also reported suffering from asthma, and this population of asthmatics accounts for 1.7 million emergency department visits yearly. These health effects lead to economic costs. For asthma, medical expenses and indirect costs, such as missed work days, added up to $56 billion in 2007. Medical spending to treat hay fever was estimated at $11 billion in 2005.