Scientists project a longer allergy season due to climate-driven changes across the United States.
According to new research from Nature, atmospheric conditions will continue to affect pollen emission season by making spring start 10-40 days earlier and possibly extend pollen emissions to fall up to 15 days later.
Researchers say this is worrisome because while wind-driven pollen plays a vital role in plant fertilization and gene dispersal, it also alters climate by interacting with clouds and radiation and triggers allergic diseases such as allergic rhinitis and asthma.
Pollen-induced respiratory allergy affects up to 30% of the world population, particularly children, and is a worldwide health concern. In addition, it results in significant economic loss because of medical expenditures, missed work and school days, and early deaths.
“Because pollen emission is closely associated with environmental drivers, climate change could influence pollen emission and consequently the incidence of allergic disease,” the researchers wrote.
“Longer and more intense pollen seasons have been observed over the past few decades, which is expected to contribute to the exacerbation and aggravation of pollen allergic rhinitis and asthma.”
Pollen emissions are also directly correlated with meteorological conditions, such as temperature and precipitation.
Temperature impacts the number of winter chill hours and spring frost-free days.
According to the study, it is also strongly associated with the timing of pollen seasons, including the start date, peak emission date, end date, and duration.
Precipitation also plays a role in both short-term and long-term effects on pollen emissions.
For example, significant short-term heavy rain can reduce pollen concentrations.
At the same time, “changes in long-term accumulated precipitation may favor or disadvantage plant growth and therefore alter the total pollen production.”
“In the future, temperature and precipitation are projected to change heterogeneously across the United States [US], and both driving climate variables could directly affect future US pollen emission change patterns,” the researchers wrote.
“Moreover, the distribution and composition of plant communities are likely to change in the future due to climate change and further influence the corresponding pollen emission.”