British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - Acid precipitation definition

Definition: Normally, rainwater or drinking water has a pH of around 6.5 to 8.5. Acid precipitation or rain however has a pH of about 4. When factories or other buildings emit smoke into the air that also contains nitric oxides or sulphur dioxide, it mixes with rainwater to become acid precipitation or rain.