Buses a solution to national park pollution, studies say

Recent studies describe the high levels of air pollution in America’s national parks and recommend solutions that include replacing lots of automobiles with “alternative transit options.” In other words, buses.

All but a handful of America’s national parks “are plagued by significant air pollution problems,” the National Parks Conservation Association (NPCA) stated in a new study.

Entrance traffic at the Grand Canyon

Meanwhile, the National Park Service will impose new permit requirements and higher entrance fees on buses and motorcoaches entering parks across the country next year. The motorcoach industry believes the additional bureaucracy and costs will discourage bus tourism although each bus replaces dozens of individual automobiles and their exhaust pipes.

Most air pollutants enter the parks from cities and factories near and far, according to the NPCA study, “Polluted Parks: How America is Failing to Protect Our National Parks, People and Planet from Air Pollution.” Air pollution created within parks, much if it from motor vehicles, also is “damaging sensitive species and habitat.”

Previous studies have cited engine exhaust for pollution that settles into soil and water, where it affects vegetation and, in turn, insects and mammals that feed on plants.

The NPCA study said pollution causes unhealthy air, harm to nature, hazy skies and climate change. “The key finding of our report is that 96 percent of the 417 national parks assessed are plagued by significant air pollution in at least one of the four categories.

“We found that 85 percent of national parks have air that is unhealthy to breathe at times and nearly 90 percent of parks suffer from haze pollution. At 88 percent of parks, air pollution deposits into soils and waters, damaging sensitive species and habitats. We also found that climate change is a significant concern for 80 percent of our national parks, though all parks are affected at some level.”

Air pollution may travel hundreds of miles from “industrial-scale agricultural operations” and power plants burning fossil fuels, the study stated. “In the past two years the transportation sector has become the greatest overall source of greenhouse gas pollution.”

Ozone, nitrogen and sulfur pollution arrive from distant sources or visiting motor vehicles and are highly damaging to plants. As a result, this changes the number and types of plants and animals able to survive in the parks. For example, the report stated, flowering plants at Rocky Mountain National Park are being replaced by grasses.

Nitrogen oxide (NOx) levels measured in air samples beside roads in Grand Canyon National Park were 52 percent higher than levels found 98 feet away, according to a 2013 study published in Park Science, the research journal of the National Park Service in the paper “Cars and Canyons: Understanding Roadside Impacts of Automobile Pollution in Grand Canyon National Park.”

“Automobile emissions affect local air quality and, over time, this chronic nitrogen fertilization is likely to affect ecological communities along adjacent roadways. Input of nitrogen from automobile exhaust is particularly high at the south entrance, where more than one million cars, with engines idling, line up each year for admittance to the park.”

In addition to cleaning up the country’s air overall, the NPCA study recommends measures that reduce pollution within parks. A shuttle service at Acadia National Park in Maine is credited with replacing 2.5 million private automobile trips since 1999. But the science paper also recommended other “alternative transportation options” and cited parks that “have successfully adopted public transportation systems to limit traffic congestion, increase public access to the park and conserve park natural resources. Continued development of public transportation alternatives allows visitors to enjoy their national parks and the natural resources within them.”

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