(Ponca City-AP) -- Members of the Ponca tribe are protesting environmental pollution from a carbon black factory in Ponca City.
Tribal members say they're filing a lawsuit against the state Monday. They claim environmental agencies aren't enforcing laws at Continental Carbon Company.
Tribal members say particles of carbon black seep into their houses, mouths, noses and lungs and are responsible for a high rate of cancer and blood disorders among people who live nearby.
Carbon black is a substance used to make tires.
Continental Carbon spokesman Blake Lewis says the claims are part of an ongoing campaign of negative publicity.
Lewis says the company has passed numerous inspections from regulatory agencies in the last two years.