1.   Use aquarium gravel, as it should not leach harmful substances into the water.

2.   And while various locks and latches are available for keeping cabinet doors and medicine cabinets secure, such devices are useless unless harmful substances are stored inside.

3.   As the mix cools, the ions recombine to form less harmful substances.

4.   At that time, the Health and Welfare Ministry ordered the recall of imported wine that appeared contaminated with a harmful substance.

5.   Barring that, he said, it assumes a court system where people who are damaged by harmful substances can seek redress.

6.   Adolescence is a common time to begin using harmful substances.

7.   But despite the demographic changes, the use of some potentially harmful substances has continued to rise.

8.   But Grace was fighting such battles monthly, former company officials said, and state and federal officials began pushing for disclosure of any amount of a harmful substance.

9.   But the dust at the epicenter showed slightly elevated levels of some harmful substances and could harm unprotected rescue workers, particularly those who smoke, they added.

10.   Each session began with a pledge to resist using harmful substances followed by a series of safety questions.