15 December 2010

Chemicals unleashed: Air quality during the Deepwater Horizon oil spill

Posted by mohi

Oil spills release pollutants into the air in addition to fouling waterways and shorelines. Photo courtesy of NASA/JPL-Caltech/Dryden/USGS/UC Santa Barbara

For me, the term volatile organic compounds sounds like a group of renegade chemicals on a bender. Sadly, there were no pictures of “chemicals gone wild” in this morning’s poster session A31B Gulf of Mexico Air Quality and Climate Impacts: Urban and Regional Pollution Including the 2010 Oil Spill I Posters.

It turns out that volatile organic compounds, like benzene or propane, are actually chemicals known to evaporate quite readily. The gasoline we put in our cars is full of these compounds.

Thus, the oil released when the Deepwater Horizon rig exploded and sank not only pumped pollution into the ocean. It affected the air too. And Barbara Barletta from the University of California, Irvine was on hand to measure the different types and relative amounts of volatile organic compounds cast into the atmosphere  following this disaster.

Barletta compared the air from several areas—right around the spill site as well as areas further away–to figure out what affects the oil had on air quality. She used the air samples from further away to gauge background levels of volatile organic compounds. Barletta found that air samples from right around the spill site were loaded with carcinogenic chemicals like benzene and toluene. Other groups of compounds called alkanes, like propane and butane, were also present in high concentrations.

Although alkanes like propane and butane aren’t directly harmful to humans, they can cause their own brand of mischief. When alkanes mingle with other chemicals in our atmosphere, they form new chemicals like ozone. And ozone at ground levels is a problem for human health, causing problems such wheezing and inflammation of airways.

Scary as it sounds–having such dangerous chemicals running amok in our atmosphere–the compounds are relatively short-lived. Alkanes live on the order of hours to days, while carcinogens like benzene live for about a day. This isn’t to say that they disappear. Their original chemical configurations may be short-lived, but if they combine with other compounds to create things like ozone, then they can live on in their altered forms.

This “live fast and die young” way of life is certainly in keeping with my original image of dissolution. Evidence shows that volatile organic compounds crash the party, create some chaos, and disappear without paying the check.

–Jane Lee is a science communication graduate student at UC Santa Cruz