PORTLAND, Ore. -- The Port of Portland has joined eight cities and the state of Washington in suing Monsanto for widespread contamination by toxic PCBs.

Monsanto manufactured PCBs for more than 40 years, until they were banned in 1979. They've been associated with cancer and damage to the immune, reproductive and nervous systems, according to the EPA.

EPA: Learn about PCB's

PCBs were widely used in plastics, paints, caulks, lubricants, coolants and other products before the ban and can still be released into the environment through improper maintenance of waste sites, illegal dumping or burning. They can also leak from electrical equipment, including transformers.

"The Port has evidence that Monsanto became aware of how toxic and dangerous PCBs were during the time they manufactured their PCB containing products, and that they concealed that information," said Port of Portland spokesman Steve Johnson.

Click to read the Port of Portland complaint

He said PCBs are the main focus of the $750 million cleanup at the Portland Harbor Superfund site.

"The Port has invested millions of dollars studying the legacy contamination in and along the Willamette River and Portland Harbor," he said. "However, the impact of PCB contamination is broader than the Superfund site, including McBride Slough at Portland International Airport."

Monsanto is not listed as a "responsible party" on the Superfund site, and therefore does not have to help pay for the cleanup. A spokesman for Monsanto said the entities that used Monsanto's PCBs and dumped waste in to waterways are responsible for the contamination.

In a statement, Monsanto said the lawsuit singles out the company for using PCBs when they were legal and widely used.

“The Port’s case targets a product manufacturer for selling four to eight decades ago a lawful and useful chemical that was used by the U.S. government, the state of Oregon and local cities, and incorporated by industries into many products to make them safer. PCBs have not been produced in the U.S. for four decades, and the Port is now pursuing an experimental case on grounds never recognized in Oregon history and which threatens to delay and derail years of Portland Harbor Superfund allocation proceedings involving the responsible parties who actually discharged PCBs. Most of the prior cases filed by the same out-of-state contingency fee lawyers have been dismissed, and Monsanto believes this Port case similarly lacks merit and conflicts with the ongoing Portland Harbor case,” the company said.

The city of Portland announced in May that it would sue Monsanto for the PCB contamination.

The port also joins the cities of Seattle, Spokane, San Jose, Oakland, Berkeley, Long Beach, San Diego, and the state of Washington in filing suit. All nine agencies are represented by law firm Baron & Budd, P.C. and Gomez Trial Attorneys.

“It’s time Monsanto do the right thing and contribute to the cleanup of their own toxic chemicals,” said attorney John Fiske, who will help prosecute the case.

Related: City of Portland suing Monsanto for contaminating waterways