Also: A new discovery that chimps can get an AIDS-like condition. And better news about overfishing.
This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.
And I'm Barbara Klein. This week, we tell about deaths around the world linked to drinking alcohol. We tell about a new discovery that chimps get the disease AIDS. And we tell better news about overfishing around the world.
A Canadian study says drinking alcohol is linked to one in every 25 deaths around the world. Alcohol was linked to deaths caused by accidents, injuries and violence. It was also linked to medical conditions like heart disease, liver disease and cancer.
The study was released in a series of articles published in the Lancet. It found that almost four percent of deaths around the world in 2004 were linked to drinking alcohol. The study also found that alcohol drinking disabled a large number of people around the world. It was responsible for more than four and one-half percent of all the years people lived with disability. The study concludes that the worldwide health effects from drinking are about the same as that of smoking nine years ago.
One of the researchers was Jurgen Rehm. He works at the Center for Addiction and Mental Health in Toronto, Canada. Mr. Rehm says the average person around the world has about 12 alcoholic drinks a week. One drink equals a bottle or can of beer, a medium glass of wine or a very small glass of liquor.
However, the amount of alcohol that people drink is different around the world. For example, people in Europe drink the most alcohol, about 22 drinks a week. People drink the lowest amount in eastern Mediterranean countries, about one drink a week.
And alcohol drinking is rare in many parts of the world, including Muslim countries and India. Mr. Rehm said the high death rate is even more surprising because the large majority of adults around the world do not drink alcohol at all. This is often because of religious or cultural reasons.
The study found that alcohol-related deaths were highest in Europe -- one in ten. Within Europe, the former Soviet Union countries had the highest rate. In Russia, about one in seven deaths were linked to alcohol. The report said these risks are also increasing in developing countries, especially Asian countries like China and Thailand.
Earlier studies have shown a positive effect of moderate drinking, especially of wine, on heart health. But Mr. Rehm said heavier drinking can lead to heart disease. Drinking large amounts of alcohol over long periods of time has also been linked to a number of cancers. These include cancers of the head and neck, esophagus, breast and colon.
The researchers say two kinds of alcohol drinking affect health. They are the amount a person drinks on average and heavy drinking at one time, called "binge drinking." Jurgen Rehm said having one or two drinks a day is not as harmful as having seven drinks at once. And he said it is better to drink alcohol with meals.
Mr. Rehm suggested that countries where alcohol is a problem should take action. He says they should make alcohol more costly and harder to get. This would result in people drinking smaller amounts that are not as harmful.
Another recent study showed the effects of alcohol drinking on road deaths. Researchers studied 178 countries. They found that between 30 and 40 percent of road deaths are caused by drinking alcohol. Experts from the World Health Organization said drunk driving is more than a law enforcement issue. It is also a public health concern.
Many scientists have long believed that non-human primates were the source of the human immunodeficiency virus, H.I.V. They believe the simian immunodeficiency virus, S.I.V., probably crossed from chimpanzees to humans in the last 100 years. H.I.V. in humans can cause AIDS, acquired immune deficiency syndrome. It weakens the body's natural defense system against disease. Scientists have believed that S.I.V. did not cause a similar immune system problem for primates. Now, researchers say they have evidence that chimpanzees with S.I.V. suffer a condition like AIDS.
Beatrice Hahn is a professor of medicine and microbiology at the University of Alabama in Birmingham. She is an expert in the development and genetics of immune deficiency viruses in primates. Her team spent nine years studying 94 chimps in Gombe National Park in Tanzania. The chimps are among a group that Jane Goodall and her team have been studying since the 1960s.
Doctor Hahn and her team gathered liquid and solid waste from chimpanzees in the park. They tested the material for genetic information to identify the virus in two chimp communities.
17 chimps were found to be infected with S.I.V. Seven of them died of the disease or disappeared and were believed to have died.
Each day, a team of researchers followed one of the 94 chimps. Doctor Hahn says the scientists discovered that infected chimps were 10 to 16 times more likely to die in any given year than uninfected chimps. She says infected females were three times less likely to have babies. Four babies were born to infected mothers, but all of these babies died during their first year.
The scientists found the strongest evidence of AIDS in studies of tissue from the chimps that died. Animal doctor Karen Terio of the University of Illinois carried out some of those examinations. She says the chimpanzee tissue showed a severe loss of immune system cells. She said they looked similar to tissue from human patients who had died of AIDS.
Doctor Hahn notes that chimpanzees are 98 percent genetically identical to humans. She says the discovery that chimps can develop AIDS may help researchers understand the disease in humans.
Doctor Hahn says she suspects chimps first got infected with S.I.V. much longer than 100 years ago. She believes the chimp virus infection is not quite as damaging as H.I.V. is in humans. The difference is the way the virus damages tissue. She suspects that chimps may be a step ahead of humans in how their bodies deal with the virus. The research was published in the journal Nature.
Three years ago, a study of overfishing led to sharp debate. It warned that the world's ocean fish could be almost gone by the middle of the century. Now, a new study offers more hope. It shows that the risk of fisheries collapse has recently decreased in some areas, but not all.
Boris Worm at Dalhousie University in Canada and Ray Hilborn at the University of Washington in Seattle were lead authors of the new study. They led a team that studied ten areas. In five of them, the rate at which fish are being taken out of the sea has dropped to a level that should let the populations recover. Three areas still had overfishing, but corrective measures have begun.
Yet, in all, almost two-thirds of fish populations studied worldwide still need rebuilding. Only two areas did not have an overfishing problem in either the new study or the earlier one. They are New Zealand and the American state of Alaska.
The new study found that overfishing has been reduced in Canada's Newfoundland-Labrador area and in Iceland and southern Australia. It also found improvements in the northeastern United States and the California Current that flows south along the West Coast. The study found that better controls are still needed in the North Sea, the Baltic Sea and the Bay of Biscay between France and Spain.
Several methods can help reduce overfishing. They include using nets that let smaller fish escape and agreeing not to fish in certain areas. The study showed that these measures helped fish populations grow in Kenya. The findings from two years of research appeared in the journal Science.
This SCIENCE IN THE NEWS was written by Marisel Salazar, Caty Weaver and Jeri Watson. Brianna Blake was the producer. I'm Bob Doughty.
And I'm Barbara Klein. For transcripts, MP3s and podcasts of our shows, go to our Web site, voaspecialenglish.com. You can also post comments about our programs. Listen again next week for more news about science in Special English on the Voice of America.
esophagus: the muscular membranous tube for the passage of food from the pharynx to the stomach; the gullet 食管
colon: the section of the large intestine extending from the cecum to the rectum 结肠
binge drinking: the practice of drinking excessive amounts of alcohol regularly 豪饮
primate: a mammal of the order Primates, which includes the anthropoids and prosimians, characterized by refined development of the hands and feet, a shortened snout, and a large brain 灵长类动物
simian: relating to, characteristic of, or resembling an ape or a monkey 和类人猿或猴有关的
Alcohol, the 'Asian flush' and the risk of cancer
Study finds some ocean fisheries are recovering
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