1.   Antioxidants help control and repair the damage done to cells by free radicals, the toxic byproducts of metabolism.

2.   According to the lawsuit, the oil companies dumped toxic byproducts into hundreds of unlined pits instead of injecting them safely into the ground.

3.   Agent Orange, a chemical defoliant, contained a toxic byproduct, dioxin, that veterans have blamed for serious health problems.

4.   Environmentalists, particularly Greenpeace, consider PVC among the most toxic chemical byproducts.

5.   Every single child, Ruzzamenti said, has tested positive for methamphetamine or a toxic byproducts.

6.   Mercury, another toxic byproduct of incineration, causes damage to the nervous system.

7.   Other polymerases likely will help overcome routine breaks in DNA caused by toxic metabolic byproducts as well as exposure to pollution and other environmental carcinogens, he said.

8.   Selenium is a toxic byproduct of petroleum refining.

9.   The soil bacteria convert chlorinated pesticides to less toxic byproducts by using enzymes known as dehalogenases to chop out offending chlorine groups.

10.   Toxic byproducts ended up in underground tanks, supposedly on a temporary basis, and have remained there for decades.