AQUACULTURE: A Second Look at Sea Lice

global estimate of ShS Burden Call it what you will—passive smoking, environmental tobacco smoke, or secondhand smoke (SHS)—worldwide, exposure to the emissions from smokers’ cigarettes caused the premature death of an estimated 603,000 people in 2004, according to a team of academic and World Health Organization (WHO) researchers. This first global assessment of the burden of SHS was led by Mattias Öberg of the Karolinska Institute and sponsored by the Swedish National Board of Health and Welfare and Bloomberg Philanthropies. SHS was first confirmed in the mid1980s to cause adverse health effects. The associated effects now include heart disease, lung cancer, worsening of asthma, sudden infant death syndrome, and more. But until now, data on deaths and disease among nonsmokers have not been compiled at the global scale. “There have been estimates made before for specific countries on the impact of SHS,” says epidemiologist Jonathan Samet of the University of Southern California, who did not participate in the new study. “The new paper by Öberg and colleagues is important for putting together a global picture.” The researchers searched the scientific literature, public health reports, and govern ment databases for reliable data on smoking according to age and sex. Where needed data did not exist, they created models to extrapolate from well-studied regions to countries with low data availability. One main data source for exposure among children was the Global Youth Tobacco Survey, cosponsored by the U.S. Centers for Disease Control and Prevention in more than 120 countries. The schoolbased survey is administered annually to 13to 15-year-olds to assess children’s use of tobacco products and exposure to SHS. Öberg says the team took a conservative approach in its assessment. For example, the researchers chose not to include deaths or diseases without clear and strong evidence for a causal relationship to SHS exposure (stroke was one such disease). They excluded diseases that have been causally linked to SHS if strong and comparable international health statistics were unavailable (one such example was sudden infant death syndrome). The team also did not include premeno pausal breast cancer, as the relationship between this disease and SHS remains controversial in the scientific community. “It’s difficult to find really good data [for some of these outcomes],” Öberg says. Moreover, he adds, it’s hard to relate some effects directly to SHS exposure. For instance, despite strong suggestive evidence of links between stroke and chronic