A new study shows that noise pollution from humans has doubled in over half of protected areas in the US, including state and national parks, as well as local nature areas. Some of these locations have become 10 times louder, according to the study. These changes threaten both the ability of animals to hunt and forage, as well as human well-being.
The study mapped noise pollution across the US, and could help scientists identify specific areas that need to be kept quiet, such as habitats for endangered species. University of Colorado ecologist Nathan Kleist, who was not involved in the study, said it was a “call to arms.” He added: “If you’re missing noise, you’re missing a huge driver of habitat suitability.”
Noise pollution from human activity can affect human health by disturbing sleep and adding to stress and concentration issues. The 1972 Noise Control Act granted the Environmental Protection agency the authority to set limits on noise from cars and construction. However, these rules have largely remained unenforced in parks and wilderness areas, which account for 14 percent of the country.
80 percent of the US is now within 1 kilometer of a road, due to the growth of industrial and residential areas.
In the study, National Park Service and Colorado State University in Fort Collins (CSU) researchers recorded noise levels at 492 locations with various levels of protection. Those recordings were used to predict noise levels in protected areas nationwide. The researchers also used a computer model to estimate the ambient noise that would naturally occur at each location. They compared noise levels in protected areas without noise from human activities to the noise that would occur there naturally.
They found that noise pollution doubled noise levels in 63 percent of protected areas. In 21 percent of these sites, there was a 10-fold increase. The research was published Thursday in the journal Science.
Lead author of the study Rachel Buxton, a conservation biologist at CSU said the researchers “were surprised we found such high levels of noise pollution in such high amounts of protected areas.”
Increased noise levels can disrupt animal communities, in the process interfering with seed dispersal for some plants. Birds who communicate with songs, prey who must listen for predators, and other animals are all affected by noise pollution.
Clinton Francis, an ecologist at California Polytechnic State University in San Luis Obispo, who was not involved in the study, said “In so many landscapes, both people and other organisms are living in shrunken perceptual worlds.”
For humans, excess noise can cancel out the benefits of time spent in natural areas, such as better mood and memory.