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[ar:Finally tonight: What was seen as a temporary fix to overcrowded schools in the U.S. now appears to present unintended long-term costs in dollars and children's health.]
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[by:¾Å¾ÅLrc¸è´ÊÍø¡«www.99Lrc.net]
[00:01.48]When you think of a school, you might imagine something that looks like this. But many students actually spend a lot of time in buildings that look like this, this, and this.
[00:13.00]Portables are definitely a problem. I have been in portables for around seven years.
[00:16.86]These prefab structures are the go-to quick fix when school populations surpass a school's capacity. 
[00:23.67]Compared to permanent school buildings, portables are about a third of the cost to construct. 
[00:28.29]And they only take a few of days to install, compared to the many months it takes to build brick-and-mortar schools. But more than a few children we found are sick of studying in portables.
[00:38.81]It feels like you have got your priorities out of order, and I feel a little bit ignored.
[00:44.47]Portables are supposed to be temporary; something to help schools deal with overcrowding until student numbers drop or new schools can be built. Try telling that to Billie Lane.
[00:53.96]Pass this forward.
[00:55.04]She's been teaching in this portable classroom at Kalles Junior High in Puyallup, Washington, for 16 years.
[01:01.98]The one advantage of a portable is the walls are like ¡ª it's like one big bulletin board. You can put it up anywhere and leave it. So the kids have left their mark.
[01:10.67]Her students call it Lane's world.
[01:13.36]This one's going on the wall.
[01:15.14]They say a dynamic teacher helps make up for the shortcomings of portable life. But Lane admits not all portable classrooms are as cozy as hers.
[01:24.23]In some of the other portables that I have been in, smell has been an issue. You walk in and they have a real bad odor in them. The lighting is really bad. 
[01:33.25]It's dark. It's dank. When it's that kind of an atmosphere, it sets a tone.
[01:38.23]And it turns out portables actually can be harmful to student health.
[01:43.02]Dave Blake is an indoor air quality specialist for the Northwest Clean Air Agency. He's tested air quality in more than 3,000 classrooms in Washington state.
[01:52.25]We have a lot of fancy equipment, but you don't really necessarily need it. You can walk into a classroom. 
[01:56.82]And, right away, if you can smell the humanity and taste the humidity, you know you have got a ventilation issue.
[02:02.68]Blake measures carbon dioxide levels first.
[02:06.00]About 1,400 coming in. Fresh outside air is about 400 parts per million now worldwide. 
[02:11.31]We like to keep classrooms below about 800 or 1,000 parts per million. So if it's above that, we want to know why.
[02:18.83]High CO2 indicate that students are breathing too much of their own exhaust. They're taking in germs from coughs and sneezes that hang in the air.
[02:27.33]Other airborne particles are likely building up as well, things like dust and allergens, or volatile organic compounds like formaldehyde. 
[02:35.88]The Tacoma-Pierce County Health Department is one of the few Washington State agencies with consistent CO2 data for schools. 
[02:42.22]They found that on average portable classrooms didn't meet the federal standard for acceptable CO2 levels in spaces used for human occupancy.CO2 is dropping in here with the kids gone.
[02:52.59]Other studies show that, as CO2 levels rise, student performance falls.
[02:57.68]As CO2 goes up, so does absenteeism. And it's notable that it's a little worse in portables, but we don't know why.
[03:06.67]Blake also looks for signs of moisture by using infrared cameras and moisture meters.
[03:12.36]Eight percent, that's essentially bone-dry.
[03:15.73]When a building takes on water, there's likely to be mold, a common trigger for asthma. 
[03:21.59]Problems get worse as portables age. Yet schools often use them well beyond their life expectancy.
[03:27.34]Critics say portables should be reinvented. They should be made from formaldehyde-free, nontoxic materials. 
[03:34.01]They should have open ceilings, larger windows, skylights, and solar panels to generate electricity. 
[03:40.36]Instead of noisy HVAC units, they should have natural ventilation systems that exchange more fresh air.
[03:46.51]But a portable like this is out of reach for most schools. Rudy Fyles is the chief operations officer for the Puyallup School District; 20 percent of their classrooms are portable. 
[03:57.22]That's four times the national average.
[03:59.68]Portables are considerably less expensive than permanent space.
[04:04.74]But those savings are only short-term. Studies show that over the course of their lifetimes, portables actually cost twice as much as typical permanent classrooms. 
[04:15.22]In addition to higher maintenance costs, portables are also highly inefficient and take more energy to heat and cool. 
[04:22.55]And because portables are independent structures, they often are charged residential electricity rates.
[04:28.93]It's kind of a double whammy. Not only do you use more power, but you pay a higher rate for the power you're using.
[04:35.22]Portable classrooms aren't going away anytime soon. But there might be a solution on the horizon.
[04:40.63]One of the greenest portables is being installed in a Seattle elementary school. 
[04:44.94]In this time-lapse video, we're seeing the first portable classroom built to meet the Living Building Standards, the world's strictest rules in sustainable building.
[04:53.91]What we're trying to do is take something that was previously the weakest aspect of the school and turn it into a true asset.
[05:02.62]This classroom is designed to generate its own energy and harvest its own water. Inside, the classroom looks fundamentally different.
[05:10.48]You guys want to start with a little bit of show and tell?
[05:12.86]Ric Cochrane helped design this classroom. Today, he's showing it to some fifth graders for the first time.
[05:17.15]You will see that all of this is exposed, and we do that because we want to show how the structure is made.
[05:23.72]And what's that white thing up there?
[05:25.51]That white thing is a carbon dioxide monitor, so we make sure that the air quality is good.
[05:30.60]And it has little gauges and knobs and tubes everywhere that ¡ª that are just really cool to look at that you would never find that in a building that had that all covered up, because it looks ugly.
[05:39.98]We wanted to play with the center beam, which is structural here. And, again, that's also sustainably harvested wood.
[05:45.27]When they see systems like are in this building, that will encourage them to ask questions. And, for many students, that will encourage them to just poke around.
[05:54.03]We're trying to expose things to make every single part of the building a learning opportunity.
[05:59.59]Right now, the price tag is about $200,000. That's more than twice the cost of a conventional portable. 
[06:05.91]Over time, they say lower operations and maintenance costs will more than make up the difference. For the kids who will get to use this space, the difference is priceless.