Posted on 04/06/2005 2:29:38 PM PDT by Brian328i
WASHINGTON (Reuters) - Children riding on school buses are breathing in more pollution than people standing out on the streets, U.S. researchers reported on Tuesday.
They found that exhaust from the buses was leaking into the passenger cabin, and probably affecting the children. Older buses were the worst, they found.
And exhaust "scrubbers" did little to help, perhaps because the exhaust is coming inside before it gets to the devices, the team at the University of California, Berkeley, found.
"In a single day, a child riding a school bus will breathe in anywhere from seven to 70 times more exhaust from that bus than a typical Los Angeles resident will inhale from all school bus emissions in the area," said Julian Marshall, a researcher who led the study.
"For every metric ton of pollution emitted by a school bus, the cumulative mass of pollution inhaled by the 40 or so kids on that bus is comparable to, or in many cases larger than, the cumulative mass inhaled by all the other people in an urban area," Marshall added in a statement.
"That the values were even close was shocking."
The report did not specify whether the problem was caused by damaged exhaust pipes or faulty design.
Writing in the journal Environmental Science and Technology, Marshall and colleagues said they analyzed results from tracer-gas experiments conducted by scientists at UCLA and UC Riverside.
They measured the air in six empty school buses traveling through established routes in Los Angeles, with windows both opened and closed.
Five of the buses were diesel and built between 1975 and 1998. One 1998 model was equipped with a particle trap to reduce emissions. A sixth bus, built in 2002, ran on compressed natural gas.
The researchers put a gas called sulfur hexafluoride into the exhaust system and then set tracers to detect it. The gas is not normally found in air, so the researchers could tell whether emissions came from the bus's own exhaust.
"We determined that concentrations of key air pollutants were higher inside the bus cabins than outside the cabins," said Eduardo Behrentz, who also worked on the study.
"Because so many children ride school buses, reducing the emissions of a school bus would give policymakers more bang for their buck than the same reduction of emissions from other diesel vehicles, such as an 18-wheeler or a construction truck," said Marshall.
This is extremely odd, sulfur heaxafluoride is 5 times heavier than air; fluid flow around the moving bus must account for this somehow.
hexafluoride, my fingers, so clumsy.
That has to be some sort of record.
School buses are large, cheaply constructed, poorly sealed vehicles with a very long exhaust pipe that invites problems. Most are essentially adapted medium-duty box trucks. They almost always have exhaust leaks, and anyone who's ridden on one in the winter knows how poorly insulated and drafty the things are. Of course, in the summer their internal temps get somewhere around nine billion degrees, or so they seem. Anyway, I am not surprised at all.
It's just bad design for the school busses. Normally they have the engine at the front with those huge, long exhaust pipes leading right underneath the kids. Any leak from the entire system would be dangerous.
Time to use the kinds of busses they use for city transportation, with the engine in the back.
We must demand the end to ALL busing everywhere.. it's for the children !!
We must pass a new law to make it a crim to not be wearing a hepa filter gas mask in public. Who cares ? I survived shool bus rides back in the old days with 1960's technology buses.
"He who smelt it, dealt it."
The older buses were better sealed and better constructed than the garbage that's been around since the 70s. Union malaise got the schoolbus industry AND the maintenance facilities.
Ding Ding, and the winner is...
Perhaps forced bussing was a vile plot by Leftist judges to gas minority children, somewhat along the lines of the Tuskegee Syphilis Experiment... :-)
That must explain why I always thought the busses smelled so bad. Couldn't stand having to ride them during middle school and high school.
You were probably just an inocent bystander in an unspoken Flatu-War.
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