11.   Too much onion or too many chiles could throw off the pH, or acid level, and make it unsafe to keep on the shelf for long-term storage.

12.   Drugs with a high acid level can cause blood to coagulate.

13.   Funding will be restored for the only three sites in the nation that monitor acid levels in clouds, the Environmental Protection Agency announced Friday.

14.   High domoic acid levels prompted a partial shutdown of mussel harvesting along Prince Edward Island in Canada last month.