A new study shows that premature deaths from tobacco, alcohol, and other illegal drugs are rising worldwide.

According to Professor Juergen Rehm, director of Switzerland's Addiction Research Institute, an estimated 7 million people worldwide die each year from smoking, drinking, and taking illicit drugs.

"One reason for this is increased worldwide exposure to these substances, especially in the highly populated emerging economies of Southeast Asia and China," said Rehm. "Another is that the relative share of diseases associated with substance abuse, such as chronic disease, accidents and injuries, as well as HIV and hepatitis, are predicted to increase."

The study found that tobacco was the world's number-one killer in 2000, causing 4.9 million deaths. That is an increase of more than one million since 1990. While the research shows that most of the deaths occurred in developing nations, the majority of smoking-related diseases were found in industrialized countries.

The study also found that 1.8 million deaths worldwide were a result of alcohol use, while all illegal and illicit drugs caused 123,000 deaths, the vast majority which were heroin and cocaine.

Rehm presented the study's findings during an international drug-research symposium in Perth, Australia.