High Pollen Days Linked to 7.4% Rise in Suicides, Study Finds
A Wayne State University economist's research links high-pollen days to a 7.4% rise in suicides, projecting 1,200 extra deaths a year as warming boosts pollen.
Days with very high pollen levels see about a 7.4% increase in suicides, according to research by Shooshan Danagoulian, an associate professor of Economics at Wayne State University.
Danagoulian said her team examined the relationship between pollen and suicide by tracking day-to-day variation in both pollen levels and suicides, comparing days when pollen rose to see whether suicides also went up. Pollen originates mostly from trees and plants in spring.
While the daily percentage rise may appear modest, its cumulative effect is substantial. Danagoulian noted that counties record fewer than one or two suicides a day, so a 7.4% increase is not very significant on its own. But added up over time and across the entire country, she projected that pollen levels account for 1,200 extra deaths per year.
She said that figure is considerable, and that the toll could grow. Pollen levels are anticipated to increase over the coming decades as longer and hotter summers cause plants to produce more pollen, which she expects will push the number of deaths higher over time.
The research also points to a wider relationship between temperature and mental health. Danagoulian said there is suggestive evidence that as temperatures have risen in recent decades, so have suicides, and that pollen — which also increases with temperatures — may have a direct relationship with suicide as well.
She explained the physical mechanism behind the link by describing what happens during an allergic reaction. The itchy eyes, runny nose, congestion and throat symptoms that people experience are signs of the body's reaction to pollen or other irritants it is trying to fight off. When people experience those symptoms, she said, the body is experiencing something potentially much bigger.
The findings carry public health implications. Danagoulian stressed that treating allergies is important for the ability to stay alert and think clearly, and urged people who experience allergy symptoms to pause and consider whether the mood they are feeling may itself be the result of those symptoms.