LONDON - Christine Gosden, a gentle, grandmotherly English geneticist, went where no member of her profession has gone before, into a town of lingering death and human suffering that is unique in the world.

The town is Halabja in northern Iraq, which 10 years ago was subjected to the most devastating chemical-weapons attack against a civilian population in history.

At least 5,000 of the town's 45,000 Kurdish population died immediately as Iraqi forces shelled them with a cocktail of chemicals - mustard gas and the nerve agents sarin, tabun and VX. What has happened to the survivors since then is much worse, says Gosden, than she could have imagined.

Western military manuals say chemical weapons disperse after a few days, and are generally silent on the question of long-term effects. But in Halabja, 10 years later, people are still dying, of cancers and respiratory ailments that Gosden says are directly attributable to chemical weapons.

Many are covered with horrible skin eruptions. People have gone blind and suffered severe neurological damage. Couples have become infertile, or produced children with mental retardation, heart defects, hare lip, cleft palate and other major malformations. Miscarriages are alarmingly frequent.

Crops have been blighted to this day. Domestic animals are producing few progeny, and many that are born are malformed. Snakes and locusts have mutated, becoming larger and more aggressive.

And Halabja, forgotten by the world, has sunk into a collective state of depression. Some people have gone insane, and suicides are increasingly common.

"Nobody is doing anything, and people are getting very angry," said Gosden. "It is a living hell. My sleep is disturbed by memories of the people of Halabja, and I can weep just talking about it."

Gosden, a professor of medical genetics at the University of Liverpool, went into Halabja in January with the British documentary filmmaker Gwynne Roberts. His television films from Halabja in 1988 and again this year have brought the plight of the town to a worldwide audience.

In Roberts' latest film, she says what is happening in Halabja is "a genetic time bomb." She said poison gas attacks DNA, the building block of cells, and has effects similar to nuclear radiation.

Together she and Roberts are trying to mobilize world governments and aid agencies to end what they see as the scandalous 10-year neglect of Halabja. Gosden met with officials of the British Foreign Office this week and will visit the State Department within two weeks.

She and Roberts also have gained the support of the International Rescue Committee in New York, which has created a Halabja Fund to raise money for a concerted effort to re-equip the town's main hospital. The hospital has but three doctors and no chemotherapy or radiotherapy equipment with which to treat cancers, no laboratory and no rehabilitation unit.

Roberts is convinced Western governments are content to have Halabja remain a forgotten town because of what he says is the complicity of Western chemical companies that supplied President Saddam Hussein's government with the chemicals that went into his deadly weapons.

`Complicity' of chemical makers

"War crimes were being committed in Halabja, and these companies are complicit in a way," he said.

United Nations officials have refused to release names of companies that supplied chemicals to Iraq, on grounds this would end the cooperation they get from the companies in tracking down Saddam's hidden supplies.

"It's not a good argument," said Roberts. "They have not received additional information, and Western governments are lax in pursuing the companies because it affects the national interest. Naming the companies is the only way to stop this happening again."

The attack on Halabja, which is a few miles from the Iranian border in the Kurdish region of northern Iraq, occurred on March 16, 1988, near the end of the eight-year Iran-Iraq war when Saddam enjoyed a measure of Western support.

One Kurdish faction that was in revolt against the Baghdad government brought some Iranian Revolutionary Guards into the town on March 15, and the following day the Iraqis, having been driven out, began shelling Halabja.

The Guards and the Kurdish faction headed by Jalal Talabani stopped people attempting to flee the town. Around 6 p.m., the Iraqis switched from conventional artillery to shells with chemical warheads. Many fell dead within minutes. Others have suffered a slow, agonizing death since.

Yet in 10 years no international agency has gone into Halabja to survey the short- and long-term effects of a chemical-weapons attack on a large population. No one, according to Gosden and Roberts, knows whether the soil and water supply are still contaminated, whether the meager crops still being grown are safe to eat or how long-lasting the environmental and human damage will be.

"It is astonishing this town has not been researched properly before," Roberts said. "The findings in Halabja could help protect American and British troops in future. The British Ministry of Defense and the Pentagon have a responsibility to look into it."

Kurdish factions fight

Aid agencies have been reluctant to go in because fighting between rival Kurdish factions in recent years has resulted in the deaths of some aid workers and journalists.

Halabja now is controlled by the Islamic Movement of Kurdistan, which has close ties with Iran and allows Iranian intelligence officers to operate there. The town is just south of the so-called safe zone in northern Iraq created by the United Nations in 1991.

Iraqi government spies make life difficult for anyone trying to investigate conditions there, she said. Local people told her and Roberts the Iraqi government had put a price on their heads, and warned them to leave for their own safety.

Roberts attempted to take a group of scientists to Halabja, but all backed out except Gosden. She is the first scientist who has been able to view Halabja with an expert eye.

She said mustard gas, which affects the skin, eyes and membranes of the nose, throat and lungs, has long-term mutagenic and carcinogenic effects. It was used against soldiers in World War I, and she said 10 percent of them developed lung cancer.

The nerve agents used in Halabja, she said, cause convulsions, paralysis, loss of muscle control and death, and also appear to have serious long-term effects.

"Some people in Halabja were absolutely soaked in it. If you don't wash it off within two minutes, the effects are irreversible. There is no antidote," she said.

Roberts said some workers trying to remove the rubble of destroyed buildings recently got burns on their skin that appeared to be mustard-gas burns, and some developed a reddening around the eyes that is characteristic of attacks with the gas.

Gosden said people are dying more slowly in Halabja now, but predicted the death rate will increase as more develop cancers. The cancers caused by mustard gas, she said, are unusually aggressive and kill quickly.

The death rate in Halabja, she said, is three or four times greater than in the neighboring town of Sulimaniyah, which suffered no chemical-weapons attack.

Gosden said the symptoms she has seen in Halabja are exactly the same in some cases as those reported by Gulf War veterans who claim to be victims of the so-called Gulf War syndrome, as yet undiagnosed.

She said the main hospital in Halabja has to turn away people with psychiatric disturbances and neurological damage. "These are kind, sympathetic, wonderful people, but there is nothing they can do," she said. "There are no drugs, no chemotherapy, no psychiatrist, no antidepressants. There is no pediatric surgeon to repair the hare lips and cleft palates in children, and other children cruelly tease those who do not look normal.

"Many people are shooting themselves. Women do not often shoot themselves, but they do in Halabja because they are desperate."

She described fields around the town in which vegetation has withered, pomegranate and nut trees have shriveled and wheat fields that once produced 20 bags of wheat now yield 2 or 3.

The chemical weapons, she said, killed all birds and their eggs. But locusts and snakes mutated and became larger, and the snakes multiplied because the birds that were their natural predators had disappeared.

"There used to be one person dying of snake bite per month, and now it is 20 every few months," Gosden said. "The snakes may even be more venomous."

She said it is imperative that major aid agencies get together and develop a comprehensive program to help Halabja, "or people will continue to die before our eyes."

"As much as I pray that this is the last time chemical weapons are used against a civilian population, I'm afraid it won't be," she said. Gosden described her own experience in Halabja as "terrifying."

"But I had a wonderful TV crew with me, and they were so concerned for my safety," she said. "Very sweetly, they didn't want me to die. We were all fearful of each other's lives."

After local people warned them they were in danger, she said, their Islamic escorts provided them with guards armed with machine guns.

"Politicians say it is difficult and dangerous to do anything there, but we got in and got out," she said. "Something must be done to help. There is not an alternative in my mind."