FRIDAY, Nov. 27, 2009 (HealthDay News) -- Encouraging city dwellers to walk and bicycle instead of using cars would offer much greater public health benefits than increased used of low-emission vehicles, U.K. researchers have found.
The study compared the projected health effects in 2030 of alternative urban land transport scenarios for London, England, and Delhi, India: business-as-usual (no greenhouse gas reduction policies); motor vehicles with lower carbon emissions; increased walking and cycling (active travel) plus less motor vehicle traffic; and a combination of increased walking/cycling and low-emission vehicles.
In both cities, reductions in carbon dioxide emissions achieved through increased active travel and less use of motor vehicles offered much greater health benefits than increased use of low-emission vehicles. The benefit was over 40 times greater in London and over seven times greater in Delhi. The greatest health benefits would be achieved by combining active travel and increased use of low-emission vehicles, according to the report published online Nov. 27 in The Lancet.
The most significant health gains in London would include reductions in: ischemic heart disease (10 percent to 19 percent reduction resulting in 1,950 to 4,240 fewer deaths per year); cerebrovascular disease (10 percent to 18 percent reduction resulting in 1,190 to 2,580 fewer deaths per year); dementia (7 percent to 8 percent reduction resulting in 200 to 240 fewer deaths per year); and breast cancer (12 percent to 13 percent reduction resulting in 200 to 210 fewer deaths per year). There would also be reductions in cases of depression and colon cancer, the study authors noted.
In Delhi, the largest health benefits would include reductions in: ischemic heart disease (11 percent to 25 percent reduction resulting in 2,490 to 7,140 fewer deaths per year); cerebrovascular disease (11 percent to 25 percent reduction resulting in 1,270 to 3,650 fewer deaths per year); and diabetes (6 percent to 17 percent reduction resulting in 150 to 460 fewer deaths per year). There would also be reductions in acute respiratory infections in children, lung cancer and depression, the researchers found.
"Important health gains and reductions in CO2 emissions can be achieved through replacement of urban trips in private motor vehicles with active travel," wrote James Woodcock, of the London School of Hygiene and Tropical Medicine, and colleagues. "Technological measures to reduce vehicle pollutants might reduce emissions, but the health effect would be smaller."
The researchers added that an "increase in the safety, convenience and comfort of walking and cycling, and a reduction in the attractiveness of private motor vehicle use (speed, convenience and cost) are essential to achieve" a major switch to active travel in cities.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about walking.