Bats across Germany are riddled with residues of pesticides and persistent organic pollutants, according to the largest study to sample such exposure in a European bat population.
at Ludwig-Maximilians University of Munich and his colleagues collected 387 dead insect-eating bats from five species: serotine bats (Eptesicus serotinus), greater mouse-eared bats (Myotis myotis), common noctules (Nyctalus noctule), common pipistrelles (Pipistrellus pipistrellus)聽and聽brown long-eared bats (Plecotus auratus). They tested their livers for 209 different compounds.
Of the 28 chemicals found, the most common were polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs), legacy pollutants long banned due to their known environmental impacts, including high toxicity and the potential to interfere with hormone systems.
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All of the bats sampled were exposed to both OCs and PCBs. One bat tested positive for four compounds, while another contained residues from 25 compounds. Bats can be exposed to pesticides and pollutants via their food, water or contamination of their roosts.
鈥淲e expected residues of 鈥榦ld鈥� chemicals like PCBs [and] OCs,鈥� says M眉ller. But the high amounts of residues found was surprising, he says. 鈥淧CBs are still byproducts of industrial production, so a new spread of these chemicals is not impossible.鈥�
Lower amounts of pesticides and fungicides that are currently in use were detected, as they degrade faster in the environment and are used in lower doses.
Insectivorous bats are considered at high risk from pesticide pollution due to their low reproductive rate, which can limit the ability of populations to recover from contamination. indicate that exposure to pesticides can negatively affect bats鈥� immune systems and reproduction.
鈥淒ue to European [Union] regulations concerning pesticide use, we expect similar circumstances all over Europe,鈥� says M眉ller. He says there should be more awareness of potential impacts on species such as bats and growers should reduce pesticide use to only the minimum amount required.
Chemosphere
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