You’d have to be a real gas pump aficionado to notice the new gear that gas stations across California are required to have installed by April 1st. California’s gas nozzles have been outfitted for some time with vapor-capture devices, designed to cut back on the amount of volatile organic compounds – those smelly fumes – that escape when you pump gas. This explains that accordion-style rubber sheath that bunches up against your gas tank when you pump – a feature you don’t necessarily find in states with less stringent air quality laws.

When those fumes combine with sunlight, along with other emissions, they form ground-level ozone, an air pollutant which acts as a greenhouse gas, contributing to global warming much like carbon dioxide does.

Take a look at this nifty, infra-red video footage from the California Air Resources Board, showing how fumes disperse from the gas pump when they aren’t properly collected.

Ground-level ozone is also a real problem for human health, especially for people with asthma and respiratory disease. Just this week, UC Berkeley released a study finding that people living in areas with high ozone levels, like Los Angeles and the Central Valley, have a 25-30% greater risk of dying from respiratory disease than those in less ozone-heavy parts of the state, like San Francisco.

By the way, if you’re wondering what “ground-level ozone” has to do with that ozone hole we used to hear so much about, here’s the short answer: Turns out ozone does different things, depending on where you find it. In the atmosphere, ozone’s a good thing. It forms a protective layer that shields the Earth from the sun’s radiation – a layer that’s been steadily eroded by chlorofluorocarbons, found in aerosol sprays and other places. Here at ground level, ozone’s much less likable: a toxic air pollutant, as I said above.

If every station in California installs the new, hi-tech “enhanced vapor recovery system” they’ll collectively cut back statewide, ground-level ozone emissions by ten tons a day – that’s roughly equivalent to taking 450,000 cars off the road, according to CARB.

Listen to the Changes at the Pump radio report online.


37.981081 -122.56678

Reporter’s Notes: Changes at the Pump 12 June,2013Amy Standen


Amy Standen

Amy Standen (@amystanden) is co-host of #TheLeapPodcast (subscribe on iTunes or Stitcher!) and host of KQED and PBSDigital Studios' science video series, Deep Look.  Her science radio stories appear on KQED and NPR.

Email her at

Sponsored by

Become a KQED sponsor