Children attending schools located in high-traffic zones have a 45 percent increased risk of developing asthma, even though time spent at school only accounts for about one-third of a child’s waking hours, according to new research. Asthma is the most common chronic childhood illness in developed countries and has been linked to environmental factors such as traffic-related air pollution. "While residential traffic-related pollution has been associated with asthma, there has been little study of the effects of traffic exposure at school on new onset asthma," says Rob McConnell, professor of preventive medicine at USC’s Keck School of Medicine. "Exposure to pollution at locations other than home, especially where children spend a large portion of their day and may engage in physical activity, appears to influence asthma risk as well." The study appears online in the journal Environmental Health Perspectives. The study drew upon data from the Children’s Health Study (CHS), a longitudinal study of children in Southern California communities that was designed to investigate the chronic effects of air pollution on respiratory health. Using a cohort of 2 497 kindergarten and first grade children who were asthma-free when they entered the study, researchers examined the relationship of local traffic around schools and homes to diagnosis new onset asthma that occurred during three years of follow-up. Traffic-related pollution exposure was assessed based on a model that took into account traffic volume, distance to major roadways from home and school and local weather conditions. Regional ambient ozone, nitrogen dioxide (二氧化氮) and particulate matter were measured continuously at one central site in each of the 13 study communities. The design allowed investigators to examine the joint effects of local traffic-related pollution exposure at school and at home and of regional pollution exposure affecting the entire community. Researchers found 120 cases of new asthma. The risk associated with traffic-related pollution exposure at schools was almost as high as for residential exposure, and combined exposure accounting for time spent at home and at school had a slightly larger effect. Although children spend less time at school than at home, physical education, and other activities that take place at school may increase ventilation rates and the dose of pollutants getting into the lungs, McConnell notes. Traffic-related pollutant levels may also be higher during the morning hours when children are arriving at school. Despite a state law that prohibits school districts from building campuses within 500 feet of a freeway, many Southern California schools are located near high-traffic areas, including busy surface streets. "It’s important to understand how these micro-environments where children spent a lot of their time outside of the home are impacting their health," McConnell says. "Policies that reduce exposure to high-traffic environments may help to prevent this disease. " The study was funded by grants from the National Institute of Environmental Health Sciences, the US Environmental Protection Agency, the South Coast Air Quality Management District, and the Hastings Foundation. The method of preventing asthma is to______.
A. reduce exposure to schools
B. do more activities at home
C. reduce exposure to heavy traffic zones
D. understand the micro-environments
Globally, recovery is going slightly better than expected, according to the IMF, which released its latest World Economic Outlook today. After shrinking by 0.6% last year, the global economy is likely to expand by 4.2% in 2010, 0.3% faster than the IMF projected in January. But economic performances will continue to vary widely around the world. Much of the upward revision to global growth can be attributed to a better outlook for the American economy. The IMF revised its forecast for American economic expansion in 2010 up 0.4%, to 3.1%. There was no change, by contrast, for the euro area, which already faced a poorer growth outlook. The Euro area economy may only grow by 1% in 2010 and 1.5% in 2011. And much of the job of expansion will be handled by Germany and France, while southern European growth continues to lag. Spain’s economy will continue to shrink in 2010. But the outlook is brightening for many emerging economies, including those in central and eastern Europe, for which growth forecasts were revised up by 0.8%. Developing Asia is enjoying a strong recovery, and the IMF indicated that both India and Brazil are likely to perform much better this year than initially anticipated, notching (赢得) growth rates of 8.8% and 5.5%, respectively. The report suggested that planned stimulus measures for 2010 should be fully implemented, given the fragility of recovery, but it also noted that sovereign debt worries will become more severe as the year progresses. Debt issues are likely to prove especially problematic in Europe, which has the highest debt ratios and the slowest expected growth rates. The stressed southern European nations are in a damned-if-they-do-damned-if-they-don’t position. If little action is taken on debt, rising debt costs will choke of an already weak recovery. If aggressive action is taken, the blow to aggregate demand will likewise undermine growth. Around the world, trade and production have recovered strongly, but employment remains well below prerecession levels in most countries. Labour market weakness is helping to keep inflation expectations in check; the IMF forecasts consumer price increases in developed nations of 1.5% in 2010 and 1.4% in 2011. But the return to strong growth is boosting commodity prices once more. Oil prices may increase by 30% in 2010, said the IMF, a rise 7% larger than projected in January. The overall picture is of a remarkable turnaround in global fortunes, given the depth of the recession. The year’s performance is much better than many would have dared to hope early last year. But in parts of Europe, the future is somewhat less certain, and because that uncertain future could lead to sovereign debt crises that could potentially rattle financial markets, world leaders should remain vigilant. By saying "damned-if-they-do-damned-if-they-don’t" (Line 4, Paragraph 3), the author means______.
A. the situation will become worse no matter what they will do
B. southern European nations will take actions to solve the problem
C. the situation will become better if they take actions
D. The growth of economy will be hindered if they take actions