Feeling like your allergies have been getting worse over the years? A new study suggests climate change could be to blame.
The study found a "substantial intensification" of pollen seasons in the United States after looking at data spanning nearly three decades. Scientists say pollen trends are likely to get worse in the coming years as well.
The study examined yearly pollen data collected from 1990 to 2018 alongside model simulations that quantified the role of climate change. The pollen data was taken from 60 National Allergy Bureau stations across the U.S., including a station in Alaska and even Canada.
Scientists say the data shows pollen seasons are starting about 20 days earlier and lasting about eight days longer, and that concentrations of pollen have increased by 21%.
The largest and most consistent pollen increases were seen in Texas and the midwestern United States.
Scientists said warm temperatures are the biggest factor in the changing pollen seasons, but other factors such as precipitation, frost days and carbon dioxide concentrations were also looked at. Other factors that could play a role as well include changes in urban vegetation patterns, species composition and biomass.
The intensification of pollen seasons can bring major health issues for those who have allergies or asthma.
As study authors wrote, pollen is an important trigger for many allergy and asthma sufferers, and pollen concentrations are strongly linked to both medication purchases and emergency hospital visits, as well as susceptibility to viral infections.
The study was published in the Proceedings of the National Academy of Sciences.