Life Expectancy on the Rise
Researchers looked at data on life expectancy in 51 large U.S. cities and found that, overall, life expectancy in those cities increased three years from 1980 and 2000. This is an important finding because people have been predicting that U.S. life expectancy is actually on the decline due to the rise in lifestyle related diseases like obesity and diabetes. These data show that life expectancy continues to improve in the U.S.When the researchers further broke down the numbers, they could (through various fancy statistical methods) determine that 5 months of the three year increase over the time period could be attributed to cleaner air and a reduce in air pollution.
Proving Clean Air Matters
It may seem common sense that cleaner air should be linked to a longer life expectancy, but this is one of the first (very) clear links between cleaner air and life expectancy. Let me clarify, we know that high levels of air pollution and high levels of particles in the air are linked to health and life expectancy. What we didn’t know, before this study, was that even minor improvements in air quality can significantly improve health for an entire population. In other words, it is well worth it (from a health perspective) for cities to continue to improve air quality and reduce air pollution.Even Cleaner Air Means Even Longer Lives
Not only did the effect of cleaner air and less air pollution matter on average, researchers also saw that the cleaner the air was in a city, the bigger the impact on life expectancy. For example, cities with the cleanest air added 10 full months to their resident’s life expectancy. This is gives great information for cities to use is setting air pollution standards.How Does Much Pollution Harm?
When doing statistical research like this, researchers are able to figure out how much a change in one variable impacts another variable (in this case, how much a change in the amount of air pollution impacts life expectancy). Sure, it is nice to hear that clean air and life expectancy are linked and it is good to know how important the link is, but that does not help anyone set air pollution regulations. What the real genius of this study is that the researchers were able to prove mathematically that when the level of air pollution decreases by 10 micrograms per cubic meter then life expectancy for that area increases by more than seven months. With this knowledge, we can predict the impact of pollution on life expectancy and calculate the cost-benefit of tightening regulations. Hopefully agencies and cities will use this information to examine their air pollution regulations and encourage industries to create even cleaner air.Source(s): Pope, C., New England Journal of Medicine, Jan. 22, 2009; vol 360: pp 376-386.
