Previously unknown bacteria and viruses blooming in the Earth's warming oceans are killing some marine life and threatening human health, researchers say. There are increasing reports of dying coral, diseased shellfish and waters infected with human virus as the seas rise in temperature and pollution from the land intensifies, researchers said Friday in studies presented at the national meeting of the American Association for the Advancement of Science. About 10 percent of the coral worldwide has died, said James W. Porter, an ocean studies specialist at the University of Georgia, and if present trends and conditions continue, another 20 to 30 percent of the coral could be lost. In many cases, he said, the pathogens -- viruses, bacteria and fungi -- killing the coral had not been previously identified by researchers. There has been a 446 percent increase in disease at 160 coral sites being monitored along the Florida coast since 1996. One reef experienced a death rate of 62 percent, said Porter, and nearly all of the killing pathogens ``are new to science.''

Many of the disease-causing viruses that infect humans directly or through eating contaminated shellfish cannot be detected by the routine monitoring of water pollution, said Rose. Porter said the increase in pathogens in the world's oceans may be linked to a 1.8 degree rise in sea surface temperature detected in many areas.

Doctors estimate that up to a quarter of a million men in Western Europe will die from an asbestos-related cancer in the next 35 years. Professor Julian Peto of the Institute of Cancer Research and the London School of Hygiene and Tropical Medicine predicted a European epidemic in mesothelioma, a cancer of the lining of the lung caused by exposure to asbestos. Deaths from the disease are expected to rise from just over 5,000 in 1998 to about 9,000 by 2018. There is no effective treatment for the illness and few people live more than three years after getting it. Building, engineering and shipyard workers are at the highest risk and nearly all victims are male.

Millions of people along a crescent from North Korea into Siberia and on to China suffer from a disfiguring bone disease that confounds medical science, Reuters reported. Doctors and researchers gathered in Beijing on Friday to swap notes on Kashin-Beck disease, commonly known by its Tibetan name - "Big Bone" disease. There is no cure in sight, although the disease is thought to be preventable through diet. Between two and three million people in China - mostly in poor western regions including Tibet - suffer from the disease, which is accompanied by arthritic-like pain and immobile joints. In some villages, more than 90 percent of the population is afflicted.

The black rat, responsible for spreading the bubonic plague that killed 25 million people in Europe in the 14th century, is making a comeback in Britain. Six infestations of the rat have been discovered thriving along the Thames in east London. There are fears that the rats, thought to be nearly extinct in Britain, may be spreading towards the center of the capital. The rats can grow to 15 inches long, including their tail. They are sexually mature at five weeks and can produce more than 2,000 offspring a year.

So far, the newly discovered colonies have not been found to carry the fleas that cause bubonic plague, known as the black death. However, the disease has not disappeared entirely. Between 1980 and 1994 there were more than 18,000 infections and 1,852 deaths around the world. Last year a case resistant to antibiotics was reported in Paris.

Cancer will be the major global health problem within two decades, the World Health Organization forecast. By the year 2020, the number of cancer cases is expected to have soared from the current 10 million a year to 20 million. In Britain, it is predicted that one in two people will develop the disease, compared with the one in three today.

LILONGWE, Malawi -- The patients lie two to a bed and on the floor, waiting to be sent home to die. The sounds of sawing and hammering in the streets testify to the booming business done by the capital's coffin-makers. Public offices grind to a halt because so many workers are away at funerals. Businesses are crippled when key employees die.

After coursing through other parts of Africa, AIDS is rampaging in southern Africa, turning the region into the epidemic's supernova and changing the nature of existence. Extraordinarily high death and infection rates are devastating families, threatening economies, creating a generation of orphans and lowering life expectancy in Zambia, Zimbabwe, South Africa, Malawi, Swaziland, Botswana and Namibia.

"It's worse than anything else southern Africa has seen," said Dr. Peter Piot, executive director of the U.N. AIDS program in Geneva. "What other catastrophe is going to kill 20 to 30 percent of the adults?"

All told, Africa south of the Sahara has two-thirds of the world's people infected with the AIDS virus, or 21 million. Four of every five women with the virus live there, as do virtually all the 8.2 million children orphaned by AIDS.

In Botswana and Zimbabwe, one of every four adults is infected with the AIDS virus, the UN AIDS program estimates.

In Zimbabwe, where bodies are filling morgue corridors, 1.2 million adults will die from the disease by 2005, the government says.

AIDS has cut average life expectancy in Malawi to 37, from 51.

Zambia has 360,000 children orphaned by AIDS.

The continent's biggest economic and military power, South Africa, is reaching its own state of crisis. From 1994, when free elections ended apartheid, to last year, the infection rate rose from 7.6 percent to 17 percent. In the worst-hit province, KwaZulu-Natal, nearly one-third of pregnant women are infected with the AIDS virus.

"In South Africa … you're talking about a lost generation due to AIDS," said Alan W. Whiteside, who runs an AIDS-economics research division at the University of Natal in Durban, South Africa.

The epidemic is "killing off a lot of young people, leaving behind orphans, destroying small businesses, taking its toll on most (institutions) and leaving a lot of grief behind," said Owen Kalua, planning director for Malawi's National AIDS Control Program. "We are already so overwhelmed. And now this. There's a sense of giving up."