1.   A number of hazardous substances are resistant to biodegradation.

2.   Afterwards, the city discovered the hazardous substances in the groundwater that threatened the nearby public drinking water supply.

3.   Employees who were exposed to hazardous substances are now claiming compensation.

4.   Lead is one of the most hazardous substances known, causing cancer and nerve damage.

5.   There are also other consents which are required, for example, before introducing hazardous substances.

6.   Dr John Bromley admitted exposing two-year-old John Storey to a hazardous substance.

7.   But health workers who scoured the premises could identify no gas or other hazardous substance to account for the symptoms or odor.

8.   He is also being appointed administrator of the Agency for Toxic Substances and Disease Registry, which is concerned with preventing health damage from exposure to hazardous substances.

9.   Nowadays, the triggers are usually fears of exposure to hazardous substances and pollution.