A California judge's ruling this week that three companies must pay $1.1 billion to reduce lead-paint exposure in the state generated wildly diverse opinions about both the merits of the case and its future. The only certainty is that the fight isn't over.

Look first for the companies—Sherwin-Williams, NL Industries, and ConAgra—to file objections with the ruling and seek either a mistrial or a new trial, Bonnie Campbell, a spokeswoman for the three companies, told the Los Angeles Times. If they lose those bids, the companies will appeal the decision to a higher court.

Legal Newsline quoted a law school dean and expert in class-action lawsuits and mass torts as saying he wouldn’t be surprised if the ruling isn't upheld by an appeals court and at least one of the defendants ends up settling.

“If past practice holds, there will be some back-channel communications going on between the defendants and the plaintiffs," David A. Logan, dean and professor at Roger Williams University School of Law in Rhode Island, said. “Some [of the defendants] have been down this road before.”

Superior Court Judge James Kleinberg's decision in the 13-year-old case, filed on Dec. 16 in a Santa Clara County court, concluded that the three companies violated the state's public nuisance laws by promoting the use of lead paint while they knew it was dangerous. (ARCO and DuPont also were named in the lawsuit, but Kleinberg held they weren't liable.)

Bloomberg columnist Megan McCardle wrote that the decision sets a dangerous precedent. "If these sorts of cases become widespread, we could see something like what happened with asbestos, where every company that ever touched asbestos, or a company that used it in their products, ended up bankrupt," she wrote. "That’s not the most likely outcome—the verdict may well be overturned on appeal, and even if it isn’t, the law in other states won’t necessarily be so friendly to this sort of suit. But it’s worth watching. If this theory of liability stands- and spreads—paint manufacturers could be in big trouble.

In summarizing the case made by 10 California cities and counties, Kleinberg said the defendant companies "assisted in the creation of this nuisance by concealing the dangers of lead, mounting a campaign against its regulation, and promoting lead paint for interior use."

"The People further claimed defendants did so despite their knowledge for nearly a century that such a use of lead paint was hazardous," Kleinberg added. "Had defendants not done so, it is asserted, lead paint would not have been incorporated into the interiors of such a large number of structures and would not have created the public health hazard that the People contend now exists."

To those assertions, Kleinberg concluded that each of the defendants had evidence of lead's potential health dangers dating back to 1878, and both scientific journals and the companies' own manuals suggest that the defendants had "constructive knowledge" that lead paint was a hazard, even if they didn't have "actual knowledge" of its potential harms. Lead is regarded as particularly harmful to small children and the elderly, even in tiny amounts.

"Defendants’ assertion that they were not aware of the effects of low-level lead exposure until long after they stopped producing and promoting lead paint is of no moment," Kleinberg wrote. "Each defendant certainly knew or should reasonably have known that exposure to lead at high levels, including exposure to lead paint, was fatal or at least detrimental to children’s health. That knowledge alone should have caused each defendant to cease its promotion and sale of lead pigment and/or lead paint for home use. Instead, after becoming aware of the hazards associated with lead paint, they continued to sell it."

The nine California cities and counties that entered into the lawsuit—a group that includes both the Los Angeles and San Francisco Bay metro areas—have said they planned to use the money from the defendants to target homes built in their counties before 1978 that pose the greatest risk of lead poisoning to children. They intend to create outreach and education programs, have trained individuals inspect homes for lead paint, and then use approved abatement techniques to eliminate the lead-paint hazard. Those abatement techniques include testing interior surfaces for lead-based paint, removing dust, and repairing buildings.

Similar suits have been unsuccessful in seven other states, SFGate.com notes. The difference in California may have been a state law that allows judges to order a halt to practices that harm the "community at large" or large numbers of people.