Hurricane season is here. The sea surface temperatures in the Gulf of Mexico are higher now than they were at this time for the last few years. NOAA is forecasting an active hurricane season. The impact of oil on hurricanes and vice versa is unclear. One thing is clear. There is more in The Soup than just oil.
To date, most conversations have focused on the scenario of wind-whipped oil raining down on shore. That will probably not happen. However, this eruption contains significant amounts of volatile organic compounds; benzene, tuolene, ethylbenzene, xylene and naphthalene. These are chemical compounds containing carbon bonds that readily vaporize in air. They are probably responsible for the "gas station odor" people in Louisiana are complaining about.
Here's the experiment we are about to embark on:
What happens when you put all those compounds into the air and rain them down on people?
One of the VOC worth noting is methane. It is known that massive amounts of methane are being released from this gusher. According to estimates from the US Geological Survey "flow team", this gusher is releasing about 2,900 cubic feet of methane for every barrel of oil it pumps out into the Gulf. Current conservative estimates by the US Coast Guard and NOAA put the flow rate at somewhere between 35,000 and 60,000 barrels a day.
Assuming the conservative 35,000 barrels per day for the last two months, that means approximately 6 billion cubic feet of methane have already been released. (2,900 cubic feet/barrel * 35,000 barrels * 60 days) A hurricane churning the water will certainly release a lot of this gas into the air along with water vapor and other volatile organic compounds.
Benzene levels in crude oil can be as high as 1% by weight, but it probably comprises an even higher percentage of the volatile fraction. The same is true for napthalene. These concentrations are generally converted to parts per million (ppm) when air sample results are reported by the EPA. Unfortunately, the air samples don't break down total VOC into constituents. In general, reports prior to the gusher were on the order of .1 ppm for all VOC. If you look into the dowloadable air monitoring data (links at bottom of page), some locations are reporting VOC measurements as high as 3.9 ppm.
For reference, the Louisiana Dept. of Environmental Quality has pegged the following concentrations as regulatory standards for specific compounds:
Benzene = .004 ppm
Napthalene = .22 ppm
So far, levels reported from mobile EPA Trace Atmospheric Gas Analyzers in late April and early May as high as
Benzene = 0.09 ppm
Napthalene = 0.003 ppm
I expect these numbers will increase even further in the event of a hurricane making landfall in the Gulf. It is unclear what impact this will have. However, acute respiratory consequences are likely to be seen first in people with underlying respiratory disease—such as emphysema, chronic bronchitis or even moderate or severe asthma. The long-term impact of these known carcinogens is unclear. But we are about to test that.