Marijuana use among youth ages 12 to 17 fell significantly to 6.7 percent last year from 8.2 percent in 2002, the agency said in a statement. Underage drinking, however, was unchanged from 2002 at 28.3 percent in 2006.
On the other hand, the agency said it was concerned about an upswing in misuse among young people of prescription drugs, notably painkillers. Some 6.4 percent of adolescents abused prescription drugs in 2006, up from 5.4 percent in 2002.
In general, 22.6 million people aged 12 and older had either substance abuse or dependency problems in the last year, SAMHSA's 2006 survey found. Of those, 3.2 million abused both alcohol and illicit drugs, 3.8 million abused illicit drugs but not alcohol, and 15.6 million abused alcohol but not illicit drugs.
Some 2.5 million people in the United States received treatment for substance abuse at specialty facilities in 2006, the agency said.
Fresh Tomatoes Source of Salmonella: CDC
As many as 190 confirmed cases of salmonella poisoning from eating contaminated fresh tomatoes were reported in four multi-state outbreaks last year, the U.S. Centers for Disease Control and Prevention said Thursday in its Morbidity and Mortality Weekly Report.
And because about 97.5 percent of salmonella infections are never confirmed by culture, the number of people sickened from contaminated tomatoes was probably substantially higher, the CDC said.
Last year's outbreaks originated from producers in Florida, Ohio, and Virginia. Sources may have included feces from domestic animals, and contaminated ponds or drainage ditches, the agency said. About 5 billion pounds of fresh tomatoes are eaten each year in the United States.
To help lessen their risk of salmonella infection, consumers should avoid buying bruised or damaged tomatoes, the CDC said. All tomatoes, regardless of their source, should be thoroughly washed under running water just before eating. Tomatoes that appear spoiled should be thrown out, and cut, peeled, or cooked tomatoes should be refrigerated at 40 degrees F (4.4 degrees C) within two hours or discarded.
Global Warming May Worsen Heart Problems: Experts
The human heart may be the latest known casualty of global warming, some experts attending a cardiology conference in Vienna say.
"If it really is a few degrees warmer in the next 50 years, we could definitely have more cardiovascular disease," the Associated Press quoted Dr. Karin Schenck-Gustafsson, a cardiologist at Sweden's Karolinska Institute, as saying at the European Society of Cardiology's annual meeting.
As the human body sweats in higher temperatures, blood is sent to the skin where temperatures are cooler, the wire service explained. This opens up blood vessels, increases a person's heart rate and drops blood pressure. This sequence of events can be dangerous for older people, especially those with heart problems.
Dr. Gordon Tomaselli, chief of cardiology at Johns Hopkins University, likened the hardening of the arteries (called atherosclerosis) to rust that forms on a car. "Rust develops much more quickly at warm temperatures, and so does atherosclerosis," he said.
But because of all of the uncertainties about the effects and pace of global warming, and a lack of positive proof of a connection between climate change and heart problems, "there are too many unknowns to make predictions about how many more people will have heart problems in the future," the AP reported.