While the effects of polluted air are well documented in humans, far less is known about how animals with different physiologies respond. A new doctoral thesis from Lund University provides fresh evidence of how vehicle exhaust affects wildlife, focusing primarily on birds and, to a lesser extent, bumblebees. Led by biologist Susana Garcia Dominguez, the research identifies several clear physiological impacts. These include DNA damage, suppressed immune function and shortened telomeres – protective chromosome caps associated in humans with ageing and increased disease risk.
“All these responses are well-established early warning signs of declining health, particularly under repeated or long-term exposure,” says Garcia Dominguez.
The findings show that even relatively low pollution levels can affect urban wildlife. In Malmö – often regarded as comparatively clean – the study links air pollution to measurable immune changes in two common species: the blue tit and the great tit. One unexpected finding was the birds’ ability to clear inhaled particles. Following short-term exposure, more than half of the soot particles were eliminated from their lungs within two weeks.
“This suggests birds possess an efficient mechanism for removing very fine particles,” says Garcia Dominguez.
However, she cautions that this does not offset longer-term risks. Even with some capacity to clear pollutants, soot exposure can still disrupt vital biological systems over time. The results point to a clear conclusion: sustained exposure to traffic-related air pollution may lead to chronic health effects in birds.
“One key priority is to continue reducing urban air pollution levels,” Garcia Dominguez adds.
Read the thesis in the Research Portal “Soot is in the air: the physiological impacts of air pollution in birds and bumblebees”