Occurrence of Attributes in Original Text
The text related to the cultural heritage 'Great Smoky Mountains National Park' has mentioned 'Acid rain' in the following places:
| Occurrence Sentence | Text Source |
|---|---|
| [33][34] In 2013, Colorado State University reported that, due to the passing of the United States Clean Air Act in 1970, and the subsequent implementation of the Acid Rain Program, there had been a "significant improvement" to the air quality in the Great Smoky Mountains from 1990 to 2010. | WIKI |