January 05, 2006
The Kids Are All Right (In a Passenger Car)
This isn't really news, in that we've known for a while that SUVs aren't necessarily safer than cars, but a new study in Pediatrics shows that, compared with sedans, driving an SUV doesn't make your kids any safer. To some extent, bulk may give SUVs an advantage in collisions with smaller vehicles. But because of their height and weight, SUVs are twice as likely to roll over than are cars -- and rollover accidents are particularly dangerous to kids, with three times the risk of serious injury as accidents with no rollover. On net, the increased rollover risk cancels out the purported benefit of a heavier vehicle.
So SUVs don't make your kids safer. But there are things that will help -- including properly restraining children with car seats and seat belts. Restrained children face a 2 or 3 percent injury risk in passenger cars and SUVs respectively--not much difference there. By contrast, leaving children loose in a car or SUV quadruples their risk in a crash. And in an SUV rollover, the risk is twenty-five times higher.
Another recent study works through the physics of rollovers (pdf): SUVs with a King-of-the-road view can raise the center of gravity--especially when loaded with passengers and cargo--enough to tip on a hard turn. This same study also goes over what makes light trucks more dangerous to other cars, even when ignoring their worse handling and longer stopping distance.
Greater weight and stiffness mean that light trucks mean the other vehicle in a crash has to absorb more force. And their greater height can cause their frame to intrude more into the body of the other car. In a back-of-the-envelope calculation, the authors estimate that if all light trucks that are used only as "car substitutes" were replaced with passenger cars, it would save three to four thousand lives a year
Now, some people will argue that they need a truck/SUV for the couple of times a year they [insert heavy-duty use here]. To that, I suggest buying a well-designed, fuel efficient passenger car for most of the year while renting an SUV for that fishing trip in the summer. Your children will be just as safe, you'll spend less on gas, and you'll also save your own car the wear and tear from rutted dirt roads.
January 03, 2006
Washington state's health department just released some mortality statistics for 2004. And there's quite a bit of good news: for Washington residents, 2004 was the healthiest year ever. Life expectancy -- the number of years a newborn can expect to live, given the year's mortality patterns -- surged by more than 7 months, an unusually large jump. For the first time ever, the average infant's life expectancy in the state topped 79 years: baby girls could expect 81.6 years of life; baby boys, 76.9 years.
Another bright spot: vehicle fatalities declined. The risk of dying in a car crash in Washington is at its lowest point since the health department started keeping records: holding population structure constant, crash risk has declined by more than half since 1980.
Of course, British Columbia maintained its health lead, with substantially higher life expectancy and lower crash risk than Washington. But the gap, at least for life expectancy, seems to have narrowed a bit.
Of course, it's worth noting that we'll have to wait another full year to find out whether these health trends held up during 2005. And we'll have to wait even longer for information for Oregon and Idaho. Apparently, we Americans do a far better job of tracking our financial health (GDP, unemployment, wages, and the like) than our physical health. Which may be one reason that the US is among the richest nations in the developed world -- but also one of the least healthy.
December 19, 2005
All I Want for Christmas is a Sidewalk
It's the most dangerous time of year to be a pedestrian or a bicyclist: short days mean commutes in the dark, overcast weather obscures pedestrians even during daylight, and rain and snow increase the stopping distance for both drivers and cyclists. But as the Seattle Times reports, better infrastructure, such as in Washington's recently updated wish list of pedestrian and cyclist projects, can make walking and biking both safer and more convenient -- not just in wintertime, but year round.
Periodically King County compiles reports on the causes and situations surrounding pedestrian deaths, most recently for the years 2000 through 2003. In short, most fatalities occur when pedestrians either (a) do not follow traffic regulations, and/or (b) are impaired by age (old or young) or alcohol.
This suggests two things to me. First, that walking is fairly safe if you are a sober, law-abiding adult, especially if you have a safe place to walk. But in King County nearly 13 percent of the pedestrians were hit walking on a road without a sidewalk. And while people over the age of 60 made up one out of every four deaths, most were following the law and crossing in a crosswalk. With limited mobility, seniors often take more time to cross, so changes such as longer signal times and better lighting at crosswalks can make a big difference.
Second, because responsible walking is not as dangerous, building safer places to walk, and advertising them, could not only reduce pedestrian fatalities, but also encourage more walking. (And as we've reported before, there seems to be safety in numbers for pedestrians -- that is, the more pedestrians there are on the streets, the lower the odds that they'll be struck by a car.)
Reading this and other pedestrian fatality and safety studies, it seems to me that, yes, pedestrians need to be visible, follow the law, and look well before crossing the street, but they also need a decent infrastructure for walking -- including sidewalks, bike paths, streetlights, and signaled street crossings. Other countries with much higher pedestrian rates also have much lower fatality rates. We can do better, too.
November 15, 2005
Sloth: Perhaps not a sin, but still deadly
Today's Seattle Times summarizes the findings of a long-term study of how exercise improves health:
People who engaged in moderate activity — the equivalent of walking for 30 minutes a day for five days a week — lived about 1.3 to 1.5 years longer than those who were less active. Those who took on more intense exercise — the equivalent of running half an hour a day for five days every week — extended their lives by about 3.5 to 3.7 years, the researchers found.
In other words, sloth kills, and even moderate exercise can lead to a longer, healthier life. Which is something to keep in mind next time you're in the market for a place to live -- choosing a home where it's as convenient to walk to the store as to drive could actually save your life.
November 03, 2005
Eat For Your Life
New research from the Harvard School of Public Health shows that American levels of overweight and obesity may be responsible for 10 percent of all cancers. In addition to causing elevated rates of diabetes, heart disease, and stroke, researchers believe that if no Americans were overweight or obese the United States would see a...
- 14 percent reduction in colon cancer
- 11 percent reduction of breast cancer
- 49 percent reduction in endometrial cancer
- 31 percent reduction in kidney cancer
- 39 percent reduction in esophageal cancer
- 14 percent reduction in pancreas cancer
October 21, 2005
Bowling Together, One Last Time
Today in the Seattle Post-Intelligencer, a sweetly-sad story about the closing of a bowling alley in north Seattle. There's nothing terribly profound, of course, about one business closing down, but columnist Susan Paynter does a terrific job of characterizing the place as a nexus of social capital, though she doesn't use the term herself. In light of the recent dialogue on this blog about the role of density, gentrification, and community, I thought I'd toss out this article as food for thought.
"You should start the day off with a little bit of laughter," Wayne Luders told me. He and wife Ruth come from home a few blocks away for the friendship, the circle of acquaintances they count on around the tabletop, and down-to-earth servers like Louise Adams who, Wayne admits, sometimes calls him worse names than "Sweetpea."
Like the other regulars -- the serious night-league bowlers with monogrammed bags, the daytime senior señoritas sporting matching shirts, and the every Tuesday and Thursday railroad retiree -- they dread March when they'll loose their moorings.
That the business closing is actually a bowling alley, gives a certain literal heft to the worry that social capital is declining, a worry that is most commonly connected to Robert Putnam's book Bowling Alone. But more to the point, Leilani Lanes is not closing because business is slow (though it's worth noting that league bowling there has declined sharply, as it has almost everywhere). No, the alley is closing in part because real estate values have gotten so high that it's hard for the owners to justify the building's current use.
There's much more money in re-developing the alley into apartments, condos, retail outlets, or more profitable businesses. It strikes me that the closing of this alley--like the passing of many timeworn elements in any city--should not just be shrugged off as a matter of amoral invincible "market forces." It's truly regrettable when places of close community pass away, but it's a problem that's damnably hard to fix.
I'm certainly not a no-growther. I believe, for instance, that much of the new development in Seattle over the last two decades has made the city healthier and better in a thousand and one ways. A profusion of new commercial districts, walkable neighborhoods, and even farmer's markets is breathing a great deal of life into the city. But at the same time, there's something lamentable about the loss of "great good places" like the bowling alley--places where the community has gathered for years--places that forge the bonds that keep cities vibrant and may even keep people healthier too.
Waldal worries it will be the end of social contact for many. That they will sit, immobile and isolated by their separate TV screens.
Longtime bowling-league secretary Mary Pelan, a self-described senior citizen, started bowling at age 17. She guesses she'll walk for exercise -- probably alone -- when the place shuts its doors. "So many connections will be shredded and that's just a shame," she said.
But what to do? In the face of a growing population and the practical need for increasing density (not to mention the environmental and social needs), how do we preserve the "great good places" that make the places where we live worth living in?
October 19, 2005
Geography of Fast Food
An article in the Seattle Times today highlights another link between land use and obesity: access to healthy food. By overlaying maps (pdfs) of house prices, grocery stores, and fast food restaurant locations, UW researchers demonstrate that lower income areas, such as Kent and Auburn, have fewer grocery stores and more fast food restaurants per square mile than higher income areas, such as Ballard and Redmond. Obesity rates show a similar pattern: 27.8 percent of Auburn residents are obese compared to 7 percent of Capitol Hill/East Lake residents.
Access to safe places for exercise may be another factor. Lower income people who don't feel safe walking in their neighborhoods may not be able to afford a gym membership or even bus fare to a community center.
This is just one more link coupling poverty and obesity. Previous research has demonstrated that energy dense foods (like burgers) are generally cheaper than nutrient dense foods (like fruits and vegetables).
Healthy choices have long term benefits, but fast food is easiest in the short term especially if the grocery store is harder to get to. I'd be tempted by the grease too if the kids were hungry now, three fast food joints were closer than the grocery store, plus they're cheaper and I wouldn't have to cook or clean up.
Seems to me that a healthy lifestyle is really a choice only when your life is not overly constrained by time, money, and geography.
Out of Sight, Out of Mouth
New research indicates that we eat more candy when it's close by and visible--and then we underestimate how much we've eaten. But on the other hand, according to the researchers, "If we move food away from us, even 6 feet, we eat less and we overestimate how much we have eaten."
I wonder if this lesson can be broadened to include the larger urban environment. Do we eat more fast food if it's accessible and visible? In light of the growing obesity epidemic, can we realize health benefits simply by making it harder to get to unhealthy food?
Personally, I think our behavior--or at least mine--is often powerfully affected by subtle forms of suggestion. In fact, even as I type this I'm munching on my third or fourth handful of candy corns that someone put in a bowl in the office kitchen. I don't even like candy corns.
October 14, 2005
A Beacon in the Smog
I doubt that most residents of leafy suburbs paid a lot of attention to air quality when they chose their homes. But it’s not hard to believe that, when suburban commuters return home from work each night, they breathe a little easier in the belief that they’ve escaped the smog and fumes of the city.
Only, maybe they haven’t. At least, not in the greater Puget Sound, anyway.
The Puget Sound Clean Air Agency maintains a network of air monitoring stations throughout the region. Some are in central Seattle, some in smaller cities, and some in suburbs and rural locations. And--perhaps surprisingly--there doesn’t appear to be a decisive air quality advantage to living in the suburbs. (See this pdf for more details.)
Or, to be a little more accurate: air quality tends to be both highly variable and very localized. Monitoring stations in the neighborhoods surrounding Seattle’s downtown tend to report that the air is pretty clean -– cleaner, in some cases, than at more suburban monitoring stations in Bellevue, Lynnwood, or Lake Forest Park. On the other hand, the air in Seattle’s industrial zones can be pretty dirty; but then again, so can the air in Kent and Marysville.
The Beacon Hill monitoring station, a mile or so southeast of downtown Seattle, is worth a special mention.
The Beacon Hill neighborhood is just to the east (i.e., downwind) of I-5, the heavily trafficked West Seattle Bridge, and the Port of Seattle; to the north it's bordered by I-90. Given its location, you might expect the air quality on Beacon Hill to be pretty bad. In fact, if you had to pick one residential neighborhood in Seattle that’s likely to have outdoor air quality problems, Beacon Hill might well be it.
But Beacon Hill’s air is, surprisingly, pretty clean. For fine particulate matter (i.e., soot, largely from diesel vehicles), it does moderately well: 3rd best of 7 regional monitoring stations by one measure, 7th of 16 by another, best among 5 by yet another. It has less ozone than any other monitoring station in the region (not surprisingly, as concentrations of ground-level ozone are typically lower in city centers than in leafy suburbs and exurbs). And its carbon monoxide levels were the lowest among 7 stations. I'm not sure why Beacon Hill does as well as it does -- perhaps it's just a function of altitude and prevailing wind patterns. But whatever the reason, it's good news for the people who live there.
Clearly, the monitoring station results don't offer definitive proof that Beacon Hill residents have nothing to worry about from their air. But it does mean that a move from Beacon Hill to, say, Lynwood or Bothell or Lake Forest Park or Marysville—all suburban locations—won’t necessarily buy cleaner air.
Three more points are worth mentioning here. First, as we mentioned in this post, the air in your car is typically among the worst you’ll breathe all day. Second, for most pollutants, indoor air is more polluted than outdoor air –- and most people spend 90% or more of their time indoors. And third, outdoor air quality seems to have improved pretty substantially since the early 1980s; King County has had no “unhealthy” air quality days since 1999, and only 31 days in 6 years in which the air has been “unhealthy for sensitive groups.” That’s not a perfect record, obviously, but it does represent a substantial improvement from where we once were.
To me, these facts suggest that at this point improving the air that you breathe depends, in large measure, on keeping yourself off the highway, and keeping hazardous products out of your home. Obviously, clean outdoor air matters too -– it’s just that living in the suburbs doesn’t necessarily guarantee that you’ll get it.
Update: I should mention that "A Beacon In The Smog" is, or at least was, the official tag line of Grist Magazine. Plagiarism, like imitation, is a sincere form of flattery.
October 11, 2005
Biomonitoring Bill Terminated
In California, Gov. Schwarzenegger just vetoed a bill that would have required the state to begin monitoring synthetic chemical pollutants in the bodies of California residents, and to explore the connection (if any) between such chemical "body burdens" and human health.
To me, what seems notable here is the reason the governor gave for the veto:
"While the intent of the measure is worthy...the bill will only provide a partial snapshot of chemicals present in tested participants without proper context of what the presence of (a) specific chemical means or how it interacts with other health factors.
Translation: it's better to keep flying blind than to start opening our eyes. According to the Oakland Tribune, the governor has pretty much lifted this argument from the chemical industry's talking points -- so I'm sure it won't be the last time we hear it.
Of course, it's not quite true that we're flying blind here. Plenty of people are doing biomonitoring, including the US Centers for Disease Control. But those programs have pretty definite limitations -- biomonitoring studies by academics, state labs, and public interest groups tend to be one-off affairs, rather than long-term, coordinated efforts; and the CDC data provides a useful baseline for some contaminants, but doesn't look at chemical combinations or health effects. Those are gaps the California program could have filled. Too bad it was Terminated.