The Air Near the BP Oil Spill
By now most people know about the BP oil spill in the Gulf of Mexico and its effects or potential effects on water quality and wildlife. Now the National Oceanic and Atmospheric Administration (NOAA) had released measurements of the air quality in the area. Scientists found common air pollutants, such as ozone, nitrogen oxides and carbon monoxide, in amounts typical of urban areas in U.S. cities. However, 15 to 70 kilometers downwind from the oil spill, concentrations of certain hydrocarbons were much higher than than would be found in urban air.
Particulate matter downwind of the oil slick was comparable to concentrations in moderately polluted urban air, but the particles were almost entirely organic material, as opposed to those typically found in urban particulate matter. Scientists also measured large amounts of black carbon from smoke from a controlled burn of crude oil on the water.
NOAA scientists measured the air pollutants in four areas, including in the immediate vicinity of the spill, downwind from the spill, and along the Mississippi, Alabama and Florida coastlines. They also measured background air in an area far from the spill to serve as a control sample. In analyzing the levels of the pollutants, scientists compared them to typical concentrations of a typical U.S. urban area (Los Angeles).
The near shore measurements(20 to 25 miles from shore) showed pollution concentrations generally lower than those typically found in urban areas. The background air was also relatively free of pollution from the oil spill.
Typical examples are as follows in ppb:
Maximum Carbon Monoxide
Los Angeles: 90
Near Shore or Background: 168
Downwind of Spill: 152
Maximum Total Aromatics
Los Angeles: 1.2
Near Shore or Background: <0.01
Downwind of Spill: 21
The air quality measurements were conducted to support the efforts of the EPA and OSHA to assess air quality for coastal residents and oil spill response workers.
"In order to evaluate worker exposure, OSHA has been conducting its own air monitoring in the Gulf, as well as reviewing all additional available data. Our findings are consistent with NOAA’s data," says Dr. David Michaels, Assistant Secretary of Labor for Occupational Safety and Health. EPA also agreed in terms of their own findings.
Measurements were taken from as low as 3,000 feet above sea level and up to 300 feet above sea level, with most flight paths being about 500 feet above the Gulf.
The net result is that the air quality over the Gulf is worse in terms of hydrocarbons than a downtown city.
For further information: http://www.noaanews.noaa.gov/stories2010/20100721_p3_oilspill.html or http://www.noaanews.noaa.gov/stories2010/PDFs/NOAA_P3_Gulf%20Mission%20Report_final.pdf