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Rich Kassel’s Blog

Pollution inside school buses: Still a problem, but NYC has a model for solving it

Rich Kassel

Posted July 8, 2011

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Articles about pollution inside school buses always get my attention. 

In a new article in Chemical and Engineering News, Janet Pelley writes that new tailpipe emission control technologies are effective at reducing tailpipe pollution that is emitted from the back of the bus, but mostly ineffective at reducing emissions inside the bus.

This relates to an old problem that NRDC first exposed ten years ago, when we rented a series of school buses in California and drove them around with pollution monitors inside the bus and inside adjacent cars. 

Back in 2001, our report, “No Breathing in the Aisles,” found that pollution levels were up to four times as high inside the buses as in our “control cars” in front of the bus.  We also found that excess exhaust levels on the buses were 23- 46 times higher than EPA’s cancer risk threshold.

This report got a ton of attention back then, as parents and school leaders grappled with the notion that the yellow school bus in their community was a moving, leaking smokestack.

Luckily, it soon became apparent that this was a fixable problem.  The pollution mostly wafts into the bus cabin, thanks to an open crankcase system commonly found in older buses.  For less than $500 per bus, older buses can be retrofit with a closed crankcase system that mostly solves the problem. 

New buses sold in the U.S. all have closed crankcases now, thanks to EPA’s 2007 Highway Diesel Rule.

Over the past five years, communities around the nation—in all fifty states—have used Diesel Emission Reduction Act (DERA) funds to retrofit buses, trucks, construction equipment and other old, dirty diesels.  Roughly a half-billion dollars of federal funds, generally matched by about three times as much state or local funding, has brought thousands of effective tailpipe emission control devices to these communities.  These technologies, including diesel particulate filters and oxidation catalysts, can range in price from a couple thousand dollars to almost $20,000, depending on the device and its complexity.  (Side note:  It's not clear whether Congress will include funding for DERA in the budget for FY 2012.  Bottom line:  They should.)

But the simplest fix for school bus pollution inside the bus may be the cheapest.  Simply closing the crankcases on the thousands of older school buses still in service would be an relatively inexpensive -- and extremely effective -- way to make sure our kids are not breathing extra pollution on their way to school (or summer camp) every morning.

Here in New York City, our local law governing school buses requires closed crankcases on all buses.   (I previously wrote about it here).  Local Law 61 of 2009 requires all new buses to have closed crankcases, and requires older buses to be retrofit with closed crankcases (or retired) by September 1, 2011. 

That’s a model that other communities can, and should, replicate.

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