Sequoia National Park: home to Earth’s oldest organisms, and some of the country’s worst air. The California forest, which contains the renowned giant Sequoia redwoods, has the worst air pollution of any national park in the country, comparable to those in urban Los Angeles. As a result, awe-inspiring views of California’s geologic wonders are often marred by a cloud of gray smog.
The long-term impact of the pollution on the park’s 3,000 year-old redwoods is unclear, but trees in Sequoia and surrounding forests are already showing symptoms of ozone toxicity, with yellowing needles and an increased danger to sequoia seedlings. Guests, park workers and job applicants are warned that the air in the park can cause lung and heart damage.
Already this year, the level of ozone in Sequoia Park has exceeded federal health standards, even though it’s still early in the summer ozone season. Last summer season, the park violated the National Ambient Air Quality standard at least 87 times.
“It’s tragic that the National Park Service is known for clean air, and then you see a sign saying it’s unhealthy to breathe,” said Annie Esperanza, a park scientist who has studied air quality there for 30 years. “It’s so contrary to the national parks idea.”
The park owes much of its smog pollution to its location near the San Joaquin valley, which houses California’s two busiest trucking highways, diesel freight train corridors, food processing plants and tens of thousands of diesel tractors.
The EPA’s Clean Air Act protects the park’s immediate region, but does not account for pollutants from the San Joaquin valley, one of the worst air quality basins in the country. As bad air destroys some of America’s greatest natural resources, the need to protect the Act from attacks by big polluters and their political allies is more urgent than ever.