EPA Releases Initial Results from Air Monitoring Networks in Hurricane-Affected Areas

Contact:  Eryn Witcher, 202-564-4355 / witcher.eryn@epa.gov


(Washington, D.C.-Nov. 9, 2005) The existing air quality monitoring networks in Louisiana and Mississippi were badly damaged by hurricanes Katrina and Rita, making it difficult to measure and report air quality status in parts of the Gulf Coast region.  To provide the public with this information, EPA, in coordination with the states of Louisiana and Mississippi, has been working to restore the air quality monitoring networks in the hurricane-damaged areas.  Results of limited sampling, which began the first week of October, are now available on EPA's Web site at: http://www.epa.gov/katrina/testresults/air/index.html

The newly available data include results from samples collected at three Louisiana sites on Oct. 9 - 11, 2005, and six Mississippi sites, collected Oct. 7 - 19, 2005.  All samples were analyzed in a laboratory. EPA compared the particle pollution measurements to the Air Quality Index, EPA's index for reporting daily air quality.  For other pollutants reported, EPA, in consultation with the Agency for Toxic Substances and Disease Registry (ATSDR), has developed health-based screening levels based on one year of exposure -- the period of time the agency expects hurricane recovery activities to continue.  These screening levels are drawn from ATSDR's intermediate minimal risk levels (for up to 1 year exposure), and similar EPA values for those pollutants for which minimal risk levels are not available. Levels of most pollutants measured at the nine sites to date are below the screening levels.  These pollutants include:  particle pollution, lead and arsenic, most volatile organics compounds (such as benzene), and polynuclear aromatic hydrocarbons, which are associated with burning activities. Two sites showed elevated levels of two volatile organic compounds, and the state of Mississippi and EPA are looking into their potential sources on the dates sampled:  

At one site near the county health department in Pascagoula, Miss., samples showed levels of formaldehyde on Oct. 18 and 19, 2005 that were much higher than levels detected on Oct.  7, 11 and 12 -- the first levels at this site available for comparison.  EPA has continued to monitor in these communities, and a review of preliminary data collected on more recent dates indicates that formaldehyde concentrations are returning to lower levels.

A monitor located at the Stennis Space Center in Mississippi measured levels of acrolein on Oct. 17 and 19, 2005 that were much higher than levels measured beginning on Oct. 7 -- the first levels at this site available for comparison.  Preliminary acrolein levels continue to fluctuate between undetected and elevated above the screening levels. While reported concentrations of formaldehyde and acrolein were above EPA's health-based screening levels for exposures of one year, they were well below federal emergency management levels for short-term exposures ranging from 10 minutes to 8 hours.  At the concentrations measured, however, temporary irritation of the eyes, nose and throat could have resulted.  While such exposures would not be acceptable on a regular basis extended over weeks at a time, isolated exposures to such concentrations are not believed to be associated with long-term health problems. Formaldehyde is formed during combustion:  in forest fires; in wood stoves; in cigarette smoke; in power plants; and in vehicle exhaust. The largest sources of directly emitted formaldehyde are from combustion of fuels from mobile sources and process emissions from oil refineries. Formaldehyde is associated with ground-level ozone. Acrolein is primarily used to make other chemicals and may also be found in some livestock feed.  Acrolein can be formed and can enter the air when organic matter such as trees and other plants (including tobacco) are burned and also when fuels such as gasoline and oil are burned. As part of a larger regional air quality monitoring effort, this new data provide more detailed information on pollutants than previous data from earlier air screening and real-time measurements. EPA will provide additional air quality information as it becomes available.