Bats, pesticides, and an unexpected toll on human health: A shocking new study reveals the hidden costs of losing a key species

A new study published in Science has stunned researchers by revealing a surprising link between bat die-offs, increased pesticide use, and rising infant mortality rates. The findings, authored by environmental economist Eyal Frank of the University of Chicago, show how the loss of a keystone species can have far-reaching consequences for human health. In 2006, a fungal disease called white-nose syndrome began killing off bat populations in the United States after being introduced from Europe. As bat numbers plummeted, farmers in affected counties had to turn to insecticides to control pests, since bats eat thousands of insects per night and act as natural pest control. But this increased use of pesticides came at a steep cost. Frank found that these same counties saw more infant deaths, which he linked to the increased use of harmful insecticides, especially those that can negatively impact babies and fetuses. The study was greeted with widespread praise from unaffiliated scientists for its methodology and important takeaways. However, some researchers cautioned that while the data shows a clear correlation between bat loss, pesticide use, and infant mortality, the exact causal mechanism isn't known. It's possible that the economic impacts of losing agricultural income could also be connected to increased deaths in complex ways beyond just food contamination or water supply issues. Nonetheless, this study joins a growing body of evidence dating back decades that links pesticide use with negative human health outcomes. As historian David Rosner notes, we often dump synthetic materials into our environment without fully understanding their impacts—a shocking realization made all the more apparent by Frank's groundbreaking research. The loss of bats also has other far-reaching consequences beyond just increased pesticide usage. Other studies have shown a reduction in land rents and hundreds of billions in agricultural losses as natural pest control disappears. The fungal disease that attacks hibernating bats, while not affecting all species, has killed off more than 90% of three key bat populations. This sobering study should be a wake-up call for everyone to clamor for the protection and restoration of biodiversity before we lose even more keystone species like bats. As environmental economist Roel Vermeulen puts it, we need to move beyond human-centric health impact analysis toward a broader planetary health assessment that considers entire ecosystems. In a world where our own health is inextricably linked to the health of the natural environment around us, this study is an urgent reminder of the hidden costs of losing species like bats. As Benji Jones writes in Vox, when we overlook the link between human and environmental health, industries enabled by short-sighted policies can destroy wildlife habitats without a full understanding of what we lose in the process. It's only through studies like Frank's that reveal, in terms most people can relate to, how the ongoing destruction of biodiversity affects us all that we can hope to fight chemical pollution and make better-informed decisions