The World Health Organization says the lack of food and unsafe sex are the two leading killers in the developing world. A new report, released in London Wednesday, says life expectancy could rise dramatically if resources are spent on cutting the top 10 risks to health.

The director general of the World Health Organization, Gro Harlem Brundtland, said the report should be what she terms "a wake up call to the global health community."

At a London news conference, Dr. Brundtland described the world's 10 leading killers. "The top 10 are childhood and maternal underweight, unsafe sex, high blood pressure, tobacco, alcohol, unsafe water, sanitation and hygiene, high cholesterol, indoor smoke from solid fuels, iron deficiency and overweight/obesity," she said.

The health organization says that out of the 56 million deaths that occur worldwide annually, more than 22 million are caused by the 10 leading inflictions.

Dr. Brundtland says the world faces a crisis of those who have too little, and those who have too much. In both cases, people's health is endangered. "We are six billion people co-existing on our fragile planet, many of whom are dangerously short of the food, water, and security they need to live. In contrast, there are the millions and millions who suffer because they use too much. All of them face high risks of ill health," she said.

Dr. Brundtland says the epidemic of HIV and AIDS in Africa is having a huge impact on the average length of life on the continent, and there is an urgent need for sex education and condom use. "Life expectancy at birth in sub-Saharan Africa is currently estimated at 47 years. Without AIDS, it is estimated that it would be around 62 years. That is a dramatic difference. Current estimates suggest that 95 percent of the HIV infections prevalent in Africa in 2001, are attributable to unsafe sex," she explained.

The report says that if the 10 main health risks were reduced by one-quarter, then within a decade life expectancy could rise by 10 years in developed countries, and five years in developing nations.