California’s Sequoia National Park is plagued with the worst air pollution of any U.S. National Park.
The park is home to the giant sequoias–the oldest and biggest living things on Earth. But due to the pollution, the livelihood of the trees is being threatened. That pollution mostly comes from the San Joaquin Valley, which is home to the state’s busiest north-south trucking highways, diesel freight train corridors and food processing plants.
To improve the air quality in the park, the conditions in San Joaquin Valley must be improved.
‘We don’t create a disproportionate amount of pollution; it’s just that we have these natural challenges so that the pollution we do create can take literally weeks or months to clean out. It just builds up over time,’ said Jaime Holt, spokeswoman for the valley air district.