As pandemic lockdowns went into effect in March 2020 and millions of Americans began working from home rather than commuting to offices, heavy traffic in America’s most congested urban centers – like Boston – suddenly ceased to exist. Soon after, the air was visibly cleaner. But that was not the only effect. A team of Boston University biologists, who are studying the impact of human-made sounds on natural environments, took the opportunity to learn how reducing the movement of people would impact local ecosystems. They found – surprisingly – that noise levels increased in some nature conservation areas, as cars drove faster on roads that were no longer suffocated by traffic.
BU environmentalist Richard Primack and Carina Terry, an undergraduate student working in Primack’s research lab, ventured into Boston-area parks, iPhones in hand, to take environmental sound recordings for see how sound levels had changed from pre-pandemic times, when there were more people on the move, construction going on, and cars on the road. Primack, a biology professor at the BU College of Arts & Sciences, has studied noise pollution for more than four years and has trained more than 100 students and environmental citizens to collect noise samples at natural sanctuaries in Massachusetts .
The team focused their study on three sites in Massachusetts: the Hammond Pond Preserve in Newton, Hall’s Pond Sanctuary in Brookline, and the Blue Hills Preserve – by far the largest of the three – which covers parts of Milton, Quincy, Braintree, Canton, Randolph and Dedham. They collected noise samples from all three parks using a specialized iPhone sound detection app called SPLnFFT. Then, by referencing the enormous library of sound data previously collected from the Primack lab, the study authors compared the sound levels collected over the months during the pandemic to measurements collected before the pandemic began. The resulting article was recently published in the journal Biological conservation.
They found that the Hammond Pond Preserve and Hall’s Pond Sanctuary, both located in suburban residential areas, had lower noise levels. But at Blue Hills Reservation, they found the opposite: sound levels increased dramatically in all areas of the park, “which was very surprising,” says Terry. Blue Hills is a popular destination for local hiking and is crossed by several highways and major roads. Although there are fewer cars on the roads these days, the researchers say their sound recordings indicate that the cars are moving much faster, generating more noise. This finding matches a trend that has been seen across the country – the pandemic has seen traffic jams replaced by more and more reports of recklessly fast drivers on open roads.
“Before the pandemic, traffic was relatively slow [I-93] because it was so crowded, “says Primack, the study’s lead author. Now the noise of faster cars” permeates the entire park, “he says, measuring about five decibels louder, even at inside the park, compared to pre-pandemic time.
“It’s not so much the [number] cars, but speed, “says Terry, the lead author of the study. The study was part of her undergraduate thesis from the Department of Earth and Environment and Kilachand Honors College from which she received her undergraduate thesis. degree in 2020, and earned him the Francis Bacon Award for Excellence in Writing in the Natural Sciences.
For animals, road noise (and other forms of noise pollution like leaf blowers and airplanes above their heads) can interfere with their ability to hear threats and communicate with each other. , especially for some birds that are vulnerable to predators or have calls that cannot. penetrate through the noise. Noise pollution can then have an impact on species able to survive in areas where noise levels due to human activity are high.
“There is a growing volume of studies that say wildlife is very sensitive to noise pollution,” says Primack. “Animals rely heavily on their hearing to detect predators and social interactions.”
“The big impact [of noise pollution] is filtering out the species that can live in an area, because if you have a species that you need to conserve, you can’t keep it if it won’t be able to survive in a noisy area, or the conservation area is right next to it of a road, ”said Terry.
According to the researchers, noise pollution also has well-measured health effects, including high blood pressure, heart attacks, inability to sleep, increasing irritability, mood swings and anxiety.
“When you are [recreating] in a protege [nature conservation] region, people want to relax and experience a natural environment, especially after being in town all day, “says Primack.” If people hear a lot of noise, it means that they cannot benefit from the rejuvenating effects of the park. .
Primack and his lab will continue to measure noise pollution levels in Boston-area parks and around the BU campus, documenting how noise levels change as vaccinated people begin to repopulate offices, drive more. and return to more normal activities. Terry is applying for graduate studies, where she hopes to continue her research on wildlife ecology and human impacts on the environment.
And for nature lovers behind the wheel, the takeaway from the study is clear: slow down.