HOUSTON — According to the laws of economics, a $5.25-an-hour night cleaning woman with breast cancer is no match for the multibillion-dollar corporations that run the energy capital of America. But that's only one of the assumptions being tested in a strike of 1,700 Houston janitors that began almost four weeks ago.

Ercilia Sandoval, 42, and her impoverished co-workers have become international celebrities of the Service Employees International Union's debut campaign in the right-to-work South. The union's Justice for Janitors campaign organized local janitors last year and this week is staging noisy protests and civil disobedience here, nationally and even internationally as it demands higher wages. Janitors have walked off the job at buildings that house more than half of Houston's office space.

One of the union's prime tactics is shaming this oil-rich city's business leaders with international publicity about the poverty-level wages of their cleaning people. As part of the campaign, Sandoval, a Salvadoran immigrant who works a four-hour shift cleaning the Aon building in Houston's posh Galleria district, has been telling her story on Web sites, in speeches and in interviews.

She has no health insurance, and she says it took her four months to qualify for the public assistance she needed to begin chemotherapy treatments. She lost her hair from the procedure and is scheduled for a mastectomy next month.

"I am supporting the union," Sandoval said, "for all the other Ercilias who are out there or who might have already died because of no health insurance."

WORLD PUBLICITY

Union pickets have publicized the janitors' cause in multiple languages, from Moscow to Miami to Sacramento, targeting buildings owned by the same multinational companies that own the Houston towers where the janitors work. Besides the low wages, the union is also drawing attention to the unusually high rate of medically uninsured in Harris County, which includes Houston: 31 percent, compared with the national rate of 15.9 percent.

A picket in Germany carried a sign saying, "Houston, we have a problem" in German — echoing the famous line from the Apollo 13 space mission.

"We learned over many years that these fights can't be just about unions," said SEIU President Andrew Stern. "They're symbolic of what's wrong in our country. The voters in this last election said loud and clear that we're growing apart, not growing together in this economy, and they want it to change."

Democratic congressional leaders have said one of their first priorities as a majority will be raising the minimum wage from $5.15 to $7.25 an hour, which would go a long way toward meeting the union's goals.

The Houston janitors are demanding more — $8.50 an hour plus health insurance. They also are demanding full-time work instead of four-hour shifts. Their proposed package, equivalent to a 60 percent pay increase, would fall short of what SEIU janitors make in other cities. In many other cities, union janitors work full time and get health benefits.

BAD FAITH CHARGE

Five major cleaning contractors that employ the janitors did not respond to the SEIU package, and the union accused them of bad faith, calling the strike on Oct. 23 at 58 buildings. Tenants say they have not noticed a difference, however, because the cleaning companies hired replacement workers. Spokesmen for three of the cleaning companies said none of them would comment until the dispute is resolved.

All day Wednesday and Thursday, hundreds of striking janitors moved about the city, accompanied by drums and makeshift maracas — empty soda cans filled with beans. Several hundred of them gathered outside the Chevron headquarters on Wednesday, where 14 out-of-town protesters were arrested for chaining themselves to the front door of the 40-foot-tall tower of glass, steel and granite.

On Thursday, protesters from around the country — dubbed "freedom flyers" by the SEIU — flew to Houston to join the janitors and to liken their struggle to the Boston Tea Party and the anti-slavery, civil rights and women's movements.

As in other cities, the union has organized the entire labor market, not just one cleaning company — an approach that means no company would be put at a disadvantage by paying union wages and benefits. Its success, according to Stern, has knocked down the conventional wisdom that "you can't organize immigrants." Here, as in many cities, the cleaners are predominantly Latino and female.

SAME ADVERSARIES

The SEIU is facing some of the same adversaries it has battled in other cities because ownership of downtown real estate and building services is highly concentrated.

Here, as elsewhere, the union is applying pressure not only to cleaning contractors but to owners of the buildings where they clean because owners would absorb most of the cost of higher wages and benefits for janitors. Union supporters say the building owners — Hines Interests, Crescent Real Estate, Brookfield Properties, Transwestern and P.M. Realty — could end the strike tomorrow by giving cleaning contractors the go-ahead to meet the union's demands.

Among the demonstrators on Wednesday was Rene Ramirez, a lead cleaner in the Chevron Corp. headquarters whose job is to check up on janitors and carpet cleaners and to mix the chemicals used to wipe down restrooms and offices. He said he had continued working in the early days of the strike but changed his mind when he went to a weekly meeting with supervisors from the cleaning contractor GCA Services Group Inc.

Flora Aguilar, 51, another striking janitor, was making $5.15 an hour after more than two years on the night crew for the cleaning contractor OneSource at the 55-floor Enterprise Plaza downtown. She was taking home $209 every two weeks, of which $20 went to bus fares. She said she had seen two managers fire women for refusing to stay past the end of their shift — even though the women would have missed their last bus home.

U.S. Rep. Sheila Jackson Lee, D-Texas, said she made an impassioned plea to the Greater Houston Partnership, the voice of the business community.

"The image of a city standing against working people who are trying to elevate themselves is not an image that represents Houston," she said. "I'm not going to let my city be projected that way."