Particulate matter associated air quality at USEPA sampling stations along US Gulf Coast - snapshot indication. Image credit:AirNow, Gulf of Mexico Air Quality
This summer has seen huge amounts of volatile or "low boiling" petroleum fractions released into the Gulf of Mexico, including dispersants. These 'volatiles' are aromatic (strong smelling), and rapidly evaporate when warm. Evaporation can take place directly from sea water. Once in the air, volatiles can react to form photochemical smog, which contains ozone. Ground-level zone is known for irritating bronchial tubes and eyes, and for causing leaves to hang wilted and deathly looking, shortly after sunrise when concentrations are typically the worst. Combine ozone and un-degraded volatile aromatics in the air and you get a mess of unpleasantness. Note: burning oil on water doesn't make all the volatiles go away. The fire forms particulates and carries unburned components up into the clouds, and down again with the rain (hence the 'on your head' part of the headline).
I've been wondering when someone in authority would acknowledge the spill-associated air quality issues, or if we have to wait for cable news to document symptoms. Looks like both are happening at once. See some explanations below.From Christian Science Monitor, the paper no longer printed on paper:
Last week, the EPA said that residents of two hard hit coastal communities in Louisiana - Grand Isle and Venice - face a "moderate health risk" due to hydrocarbon fumes. In Terrebonne Parish, residents of the town of Cocodrie and the surrounding area are also reporting strong odors of petroleum.Conservation of matter frames this issue. Petroleum volatiles can only go so many ways, initially. The major, initial steps toward where volatiles end up include:
For months since BP's Deepwater Horizon oil well blew, residents along the Gulf Coast, including many in New Orleans and other metro regions miles away from the shore, have said they smell fumes from the oil spill. Some have reported symptoms ranging from red eyes and runny noses to sinus infections and flu-like symptoms.
- Dissolving in sea water.
- Becoming attached to, or dissolved in, organic matter within the sea (things living and dead)
- Biodegrading after processes #1 or #2 occur, as above.
- Evaporating directly into the air, from the air/sea interface.
- Carried with sea water aerosols formed by wind and waves, and evaporating as the aerosols evaporate.
- Lapping up on hot beaches with the waves, and evaporating at a higher rate in contact with the warm beach sand and other objects.
- Forming photochemical smog, and partially degrading during that process
On putting the micrometer on a volatiles fog bank.
Take note of how far, in the above graphic, air quality sampling stations are shown to be from the actual coast line. The sampling respults poorly represent conditions where the oil meets land.
Sure, agencies can send out industrial hygiene techs to pull air samples using equipment designed for fairly steady state industrial situations. Unfortunately, nature does not operate at the convenience of Dreaeger Tube sampling devices. Hot scum and blobs lapping up on a beach, an on shore wind diverted skyward as the sun warms the shore, atmospheric stratification, and all those other things that can't be controlled make snapshot surveys of questionable value for understanding the hazard and the smell.
Exposure is down.
If well-to-do beach home owners and tourists and vacationers were lining the shores as usual, I bet there would be a lot more symptomatic complaints and grumbling property owners.