Whether in this trial, or in any number of other cases that one or the other of the couple has been involved with over the years, the Smith-Hawes view of the manufacturing processes in Silicon Valley might be simply stated: The places where chips, circuit boards and hard disks are made may be known as clean rooms, but that does not mean they are necessarily safe places to work.

In this region where so much of the economy depends on designing or making electronics, the couple's activism has not made them universally popular.

Married 29 years, Ms. Hawes, who is 60, and Mr. Smith, 58, are established residents of the valley, having sent their three children, now grown, through San Jose public schools and having taken their places alongside their neighbors at many a children's soccer game over the years. (One of their children, Kyle Smith, 25, is now a professional soccer player with the Seattle Sounders.)

But they say that, especially during the 1980's, they were careful never to mention their children outside of their circle of friends or to give out their home address. Mr. Smith says the family has received threatening phone calls and mail, and both his home and office have been vandalized.
"It's the nature of the beast," he said, "and what happens to people who stick their necks out."

Executives in the chip industry tend to resent and dispute the couple's accusations that the industry has compromised the health and safety of workers. Many maintain that Mr. Smith simply does not know enough about how semiconductor manufacturing works to be making such claims.

"It's ludicrous for someone to say we've been irresponsible with our workers," said Jeff Weir, a spokesman for the National Semiconductor Corporation, who worked for the Semiconductor Industry Association in the 1990's. "I think it's injurious to the industry and irresponsible."

He added: "Where did Ted Smith get his information about chip companies? I don't think he has any."

And some people in the chip industry have questioned the propriety of the couple's professional relationship, with Mr. Smith's nonprofit group sending business to Ms. Hawes's firm, a criticism Mr. Smith describes as yet another effort to discredit their work.

For Ms. Hawes, the I.B.M. case is the culmination of years of preparation.
The trial is being closely watched by the local and national media, and has even received attention in Europe, where workers in Scotland have filed a similar suit against National Semiconductor. Legal experts say an outcome in favor of the I.B.M. workers would very likely lead to other liability suits throughout the industry.

Although Ms. Hawes's law partner, Richard Alexander, is the courtroom litigator, they spent months jointly preparing for the case, and she has been with him at the plaintiffs' table each day since the trial opened on Nov. 5 in Santa Clara County Superior Court.

In its defense, I.B.M. is arguing that the workers' illnesses could have been caused by many factors other than chemical exposure at work, and that the company did not conceal any information from the employees.

So far, the jury of 11 women and one man has heard testimony from the retirees, James Moore and Alida Hernandez, and I.B.M.'s lead lawyer, Robert Weber, has nearly finished his cross examination.

As for Mr. Smith, whose campaigns have helped earn Santa Clara County the distinction of being the home of more federally designated Superfund toxic cleanup sites than any other county in the United States, his coalition is now confronting the computer industry over the nation's growing accumulation of discarded computer equipment.

The group is calling for more and safer recycling programs. Last spring, the coalition was instrumental in Dell's decision to stop using prison labor in its recycling program. Mr. Smith's group had said that the workers were exposed to hazardous materials and that the PC industry needed a more formal, long-term approach to recycling.

Those who worry about toxic chemicals see the business of Silicon Valley as being fraught with peril. To make a single six-inch-wide silicon wafer disk requires 20 pounds of chemicals, 22 cubic feet of hazardous gases and 2,275 gallons of water, according to Mr. Smith's coalition, and the byproducts include 7 gallons of hazardous waste.

Likewise, computer manufacturing typically involves as many as 1,000 different materials, many of which are toxic, according to the coalition.

Too little is known, Mr. Smith says, about the hundreds of chemicals used in the industry - a problem he says is compounded as more electronics manufacturing moves to foreign countries where economics often overshadows environmental issues.

Mr. Smith and Ms. Hawes have been confronting big business their entire careers, although the corporate targets were different when they met nearly 30 years ago - she a recent graduate of Harvard Law School, he of Stanford Law School. Back then Santa Clara County was primarily agricultural and known affectionately as the Valley of Heart's Desire. It was perhaps the perfect setting for two idealistic young lawyers, who had taken up the cause of cannery workers, to fall in love and get married.

As the technology foundries of the nascent semiconductor industry began to replace the canneries in the early 1970's, Ms. Hawes founded the Santa Clara Center for Occupational Safety and Health. Soon, she said, she began meeting electronics workers with signs of chemical sensitivity, including skin rashes.

"It was very discouraging,'' she said, "to find how few legal options there were for people who endanger themselves at their jobs."

As more technology companies began sprouting up around residential neighborhoods in San Jose, Mountain View and other towns, the potential environmental effects became a topic of public discussion.

One galvanizing event was the discovery in 1982 that an underground tank at Fairchild Semiconductor in San Jose was leaking industrial solvents into the ground water. Living in San Jose with three children, the youngest only a year old, the couple's concerns were as personal as they were political.

"Suddenly, overnight, people said, "Oh, my God, this could be my drinking water,' '' recalled Mr. Smith, who was working at a small private law firm at the time.

Mr. Smith recalls his first meeting with officials of the Environmental Protection Agency, where he presented his findings and public petitions seeking action on ground water contamination.

"They looked stunned," Mr. Smith said. "They'd apparently bought into the 'clean industry' myth, like the rest of them."

The E.P.A. responded and began designating pollution sites throughout Silicon Valley as so-called Superfund sites - polluted areas eligible for federally financed cleanup. The valley now has 29 Superfund sites.

"I thought at the time it would be a short-term thing and I would go back to practicing law," Mr. Smith said. Instead, his effort, which led to the formation of the Silicon Valley Toxics Coalition in 1982, has continued, and his is considered perhaps the loudest voice on the region's environmental issues.

"Ted would be the first person anyone would call," said James Puckett, founder of the Basel Action Network, an environmental group in Seattle that has worked closely with Mr. Smith's on toxic waste issues. "He takes a hard line without being shrill."

Mr. Smith says that the technology industry has recently been much more attuned to environmental issues. Relationships that used to be adversarial have turned more collegial, he said. "They've finally realized that it's cheaper to prevent pollution than clean it up."