The side gate beside the modest shingle house on Overbrook Road swings open. Inside, the living room is empty, except for a high chair and a couple of children's toys tossed aside as though the family ran from a natural disaster.

John and Karen Bierly wish they had fled from a flood or hurricane.

But things weren't that simple. The catastrophe that struck the Bierlys brought no rescue workers and no chance to rebuild. They left their Baltimore County home in 1989 because they feared it was permanently contaminated with chlordane, a pesticide used to kill termites. They believe the chemical triggered a seizure in one son and threatened the health of the rest of their family.

They moved to an Ocean City trailer two years ago, but they have been unable to escape their house. They haven't seen a dime from the person who applied the pesticide or from various insurance companies.

The mortgage has gone unpaid, but the bank hasn't foreclosed.

They have tried starting over with new jobs, but they have found themselves struggling with debt and lingering anxiety. And they must depend on the generosity of friends and family.

"How would you feel if one day, puff, everything you worked for is gone?" Mr. Bierly said.

It isn't clear whether the house contains levels of chlordane high enough to be a health risk. But the Bierlys don't have enough money to have tests done to find out.

"I moved out on my own because I knew there was a problem," said Mr. Bierly, 35. "I wasn't going to jeopardize my family."

Their tale began in November 1987, when Robert Boyer, a 30-year-old Baltimore man, came to their door to ask if they wanted a free termite inspection. When Mrs. Bierly was told the house was infested and needed treatment with a pesticide, she called her husband. They hesitated briefly before saying yes.

When Mr. Bierly came home from work that day, he said the small shingle house was filled with a visible mist of chemicals.

But they didn't suspect anything was wrong. They didn't know that the chemical the exterminator had used had been banned by the Environmental Protection Agency four months earlier. (The use of the chemical was not illegal because existing stocks could be used.)

And they didn't know until later that Mr. Boyer was not licensed by the state, that he had no insurance and that the truck he drove and his equipment were borrowed from his employer, Delmarva Pesticide Co. of Annapolis. Worst of all, he misapplied the chemical. Instead of putting it into the ground around the house, the proper method, he drilled holes through the walls of the basement and injected it into the house.

Mrs. Bierly said she began to suspect the pesticide had been misapplied. "I was downstairs doing laundry and it was real sunny out and I saw sun coming through the walls," she said. "I looked around and there were holes everywhere. The next week Brandon had his seizure."

The 6-year-old was playing in his basement bedroom on Jan. 23, 1988.

"He started getting real hyper. His face was numb. He was drooling and he vomited mucus," Mr. Bierly said. For a couple of hours after he was taken to St. Joseph's Hospital, "he couldn't even say, 'Mom.' "

They don't know for sure what caused the seizure. But Brandon's pediatrician wrote a letter saying it could have been triggered by the chlordane, Mr. Bierly said.

The Bierlys stayed in their house for another year. Evidence mounted that something was wrong.

The Department of Agriculture came to investigate. "It was a misuse of the pesticide and a violation of label directions because of the way it was injected into the house," said John Schneaitman, a supervising inspector with the department.

Mr. Boyer could not be reached for comment.

The state brought criminal charges against Mr. Boyer for operating without a license. In November 1989, he was found guilty of an agricultural violation and sentenced to 60 days in jail.

Chlordane levels were worst in the basement, where the Bierly boys, Brandon, now 9, and Bryan, now 7, had their bedroom. So the family had the two boys sleep upstairs on the living room floor each night.

L Each time the Bierlys turned on the heat, their eyes burned.

They could never really get away from the maddeningly persistent chemical, they learned. It cannot be scrubbed or cleaned off any surface.

"It lasts for about 20 to 30 years," said James Roelogs, a U.S. Environmental Protection Agency official who was in charge of the agency's scientific review of the pesticide. In some cases, the owners of contaminated buildings are forced to "rip up everything that was contaminated and throw it away," he said. In the worst cases, houses are bulldozed.

The Bierlys hired a lawyer but were unable to recover any damages because Mr. Boyer had no insurance and few assets. Robert Winkler, their current attorney, said the Bierlys have filed suit against the estate of the man who owned the Delmarva Pesticide Co.

Even if they win, they will be forced to stand in line with a lot of

other creditors, Mr. Winkler said.

In the meantime, Mr. Bierly, 35, became increasingly frustrated about his family's plight. He worried about Brandon, whose body fat still contains traces of the suspected carcinogen.

"At first the hardest part was watching John," said Mrs. Bierly, 33. "He was a basket case." Her husband started having trouble at his maintenance job at Union Memorial Hospital and needed psychiatric counseling.

Finally, the family decided to leave their house. Mr. Bierly quit his job and found a new one, as an assistant chief engineer at the Holiday Inn in Ocean City.

At first they tried paying both the rent and the mortgage on the house, but their new jobs didn't pay as well. So they stopped making mortgage payments. Two years later the bank, Regal Savings Bank, has still not foreclosed. The bank's attorney, Brian Frank, says, "The bank wants to work with them. It is a terrible circumstance."

Mr. Winkler points out that the bank would have to notify the public of the chlordane contamination before auctioning it. "They don't want to be stuck with it either," he said.

The Bierlys have filed suit against State Farm, the insurance company that carried their homeowner's policy. But Mr. Winkler admits that he has little money to pay for expert witnesses or testing. He is challenging an insurance Goliath.

While there is no question the pesticide was improperly injected into the house, there is doubt over how badly it is contaminated.

Air sampling done about six months after the contamination by a firm hired by the Bierlys suggested chlordane levels in the basement were so low they could not be considered harmful.

But some chlordane experts say the testing may have been done improperly. To get a proper reading, the house should have been closed up for two weeks with the heat on, they said. Instead, Mr. Bierly said, the testing was done in June after the house had been closed up for a couple hours.

Tests of Brandon Bierly's fatty tissue show that he has the chemical in his body. But whether the levels are low or moderate is a matter of debate. Dr. Boon P. Lim, a physician and an administrator of the environmental health program at the state Department of the Environment, said the levels in the house and the boy are not unusually high.

Because the chemical was widely used, many people have low levels of it in their bodies.

But Brandon was tested nearly a year after the seizure and the levels may have gone down in that time, said Samuel Epstein, a toxicologist at the University of Illinois and an authority on chlordane.

"Certainly the symptom [the seizure] is entirely consistent with high levels of chlordane," he said.

But he agrees that the levels in the air are low.

The Bierlys feel caught. They can't always pay the rent. The medical bills have piled up. Once the phone was disconnected and the electricity turned off.

"I am mad. I just wish it would be over with. It just feels like a black cloud," Mrs. Bierly said. "Right now Brandon is fine. Ten years from now, you don't know."

Adding to the frustration is one simple, haunting fact.

The Bierlys say they have been told their house never had termites.