A new study found that a disease decimating local bat populations for nearly two decades may be linked to an increased number of infant deaths.
The study, published on Sept. 6 by researcher Eyal Frank from the University of Chicago, discussed the relationship between the rapidly decreasing bat population in the U.S. because of a fungal disease called white-nose syndrome, or WNS, and the impact this population change has had on American farmers’ use of pesticides to combat insects.
According to the data obtained for the study, the increased use of chemical pesticides on North American farms has increased as the U.S. bat population has declined. At the same time, the infant mortality rate has increased.
A press release announcing the study states that bats serve as a natural pesticide, “widely relied on by farmers as an alternative to chemical pesticides to protect their crops from insects.”
As WNS — which according to the National Park Service has been decimating the U.S. bat population across several species since it was introduced in 2006 — continues to spread, this study argues that the increased use of chemical pesticides may be linked to an increase in the internal infant mortality rate (IIMR).
According to the study, U.S. farmers began using about 31% more chemicals after bats became insufficient to prevent insects from attacking crops. Pesticides have previously been linked to health issues in humans and the U.S. Environmental Protection Agency states that they can cause issues in the nervous system, hormone or endocrine system, the skin and eyes are more.
Infant mortality rates are a “common marker to study the health impacts of environmental pollution,” the press release states. Data showed that the rate increased by nearly 8%, or 1,334 infant deaths — or about 0.25% increase in infant mortality for every 1% increase in the use of chemical pesticides.
Additionally, the study found that chemical pesticides aren’t as good as bats at keeping insects away from crops.
The National Park Service states that one colony of bats can eat hundreds of thousands of insects in an hour, and the study found that farmers’ revenue from crop sales decreased by nearly 29% after more pesticides were introduced. The study also found that the total economic cost of the decreased bat population was over $39 billion.
“Bats have gained a bad reputation as being something to fear, especially after reports of a possible linkage with the origins [of] Covid-19,” Frank added in the press release. “But bats do add value to society in their role as natural pesticides, and this study shows that their decline can be harmful to humans.”