CHARLESTON, W.Va. -- During a court-ordered mediation Tuesday, about 300 plaintiffs gathered at the Marriott Hotel in Charleston to see if they could resolve a class action lawsuit against Monsanto -- just one week before a trial against the former Nitro chemical plant is scheduled to begin.For more than 50 years, the former Monsanto plant churned out herbicides, rubber products and other chemicals. The plant's production of Agent Orange created dioxin as a toxic chemical byproduct.Charleston lawyer Stuart Calwell alleges in a class-action case, filed in 2004, that Monsanto unsafely burned dioxin wastes and spread contaminated soot and dust across the town, polluting homes with unsafe levels of the chemical.Judges Booker Stephens, of McDowell County, and Alan D. Moats, of Taylor County, ordered both sides to meet to discuss a possible deal and avoid the trial, which is set to begin Jan. 3. The trial is expected to last about three months.The lawsuit seeks medical monitoring for at least 5,000 -- and perhaps as many as 80,000 -- current and former Nitro residents.In October, mediation failed to produce any settlement.Dioxin has been linked to cancer, birth defects, learning disabilities, endometriosis, infertility and suppressed immune functions. The chemical builds up in tissue over time, meaning that even a small exposure can accumulate to dangerous levels.One plaintiff, who requested anonymity because he was advised not to discuss the case, told the Gazette Tuesday that the judges holding the mediation said if the case doesn't settle it could last another seven years.Another plaintiff said he was told to be available to attend the mediation three or four days this week.The trial was originally set to begin in September. However, Putnam Circuit Judge O.C. Spaulding had to step down after being diagnosed with Lou Gehrig's disease. The state Supreme Court appointed Mercer Circuit Judge Derek Swope to hear the case. He upheld all of Spaulding's prior rulings and rescheduled the trial for January. On Aug. 22, Spaulding refused another effort by Monsanto lawyers Charles Love and Robert Hogan to block trial of the medical monitoring claims on a class-action basis, a move that would have forced thousands of residents to file individual cases. However, Spaulding previously had ruled that residents could not sue collectively to seek remediation of homes they allege are contaminated with dioxin.Swope was among the judges who led the mediation sessions in July that produced a $35 million settlement in a case against Massey Energy over alleged contamination of drinking water with coal slurry pollution in Mingo County.Reach Kate White at firstname.lastname@example.org or 304-348-1723.