The Ponca Tribe of Oklahoma is joining a federal lawsuit against a chemical plant that is allegedly causing pollution.

Tribal members and local residents say the Continental Carbon's plant sends black dust into the air, causing breathing problems and damaging food crops. Some also say their land has been damaged by a black substance leaking from the plant.

The state has issued notices of violation to Continental Carbon. The plant makes carbon black, a possible carcinogen.

Get the Story:
Federal lawsuit planned in Ponca City pollution case (AP 4/6)
pwpwd

Related Stories:
Ponca Tribe protests pollution from chemical plant (03/08)
Groups protest Okla. chemical plant (08/30)
Okla. tribe taking part in protest (8/29)
Tribe and union fight pollution (6/20)
Tribe fights chemical plant (5/10)