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December 1, 1999


Will the Volatile Organic Chemicals Detected in Prichard Influence the Air Quality Study of Mobile?

by Edmund Tsang


Alabama Coastal Foundation - Lisa Adams

Alabama Department of Environmental Management - James W. Warr

Alabama Power Company - Bernie Fogarty

City of Mobile - Mike Dow, Mayor (Chair)

City of Pritchard - Dr. Mentor Catlin

Higher Education/University of South Alabama - Dr. Judy Stout

Mobile Area Chamber of Commerce - Jim Apple

Mobile Bay Watch, Inc. - Casi Callaway

Mobile County - Sam Jones/Gary Tanner, Commissioners

Mobile County Health Department - Dr. Bert Eichold

Medical Society of Mobile County - Dr. Ken Brewington

Mobile United - Dr. George Crozier

National Estuary Program - Lisa Mills

One Hundred Black Men - Damon Wickware

The Forum - Steve Perry

While the representatives on the Envision Mobile-Baldwin Air Quality Study Task Force who have ties to heavy industries downplay the results of the Prichard Air Quality Study, which was conducted by the Environmental Protection Agency (EPA), they nonetheless say it will influence the direction of future air quality studies in Mobile County.

Lisa Adams of the Alabama Coastal Foundation (ACF), which she says is a coalition consisting of industry, business, government and citizens, said, "sampling in Prichard is definitely under consideration because it is in a central location for emissions from north and south of the county." Steve Perry, who is a spokesperson of The Forum representing heavy industries in Mobile County, said the Prichard Air Quality Study will be a "factor" used by the eventual contractor selected for the air quality study to assess Mobile's air.

But both Adams and Perry point to the deficiencies of the Prichard Air Quality Study. While she is "not minimizing the sampling effort," Adams said the grab-sample methodology of the Prichard study provides only a "snap shot." Perry said he would "hesitate to call it a study" because of the limited data contained in the air sampling. Without "meteorological data, which is the key when looking at studies such as this," Perry said the Prichard study at best "provides only a cursory indicator."

The Prichard Air Quality Study

Ken Mitchell, Ph.D., a scientist for EPA, wrote a report based on his analysis of the air samples collected over a three-day period in January, 1999, to "assess the concentrations of Volatile Organic Compounds (VOC) in ambient air" in six sites in and around the City of Prichard.

The reported noted "[T]he samples taken during this study indicate the wide-ranging presence of air pollutants in and around east Prichard, Alabama and area locations. Especially noteworthy is the presence of chlorinated hydrocarbons and aromatic hydrocarbons in all samples, including the control location." The reported also noted that chemicals other than the volatile organics "may be present at levels of potential concerns," including chromium, formaldehyde, hydrochloric acid, and manganese.

While readily acknowledging the "caveats" of the analysis, Mitchell said "it is not possible to say that the samples do not represent acutely toxic concentrations" and "the number of chemicals identified here as exceeding conservative health based benchmark may be under represented."

A limitation of the study identified by Mitchell is the sampling time. While most of the samples collected were "composite samples...taken continuously over 24 hours," the "grab samples were taken over approximately 1 minutes." The sampling times "do not match the 1- hour exposure presumption of RELs (Reference Exposure Levels)." Because of this difference, "it is not possible to say that the samples do not represent acutely toxic concentrations" because "a high spike in concentration in a 24-hour sample could be diluted to below the REL; likewise, a grab sampling time may not have been long enough to collect sufficient material to determine whether a REL was exceeded."

One of the difficulties in using the results of the Prichard air sampling to assess health risk is that "there are no inhalation exposure values that were derived using a consistent basis to protect the general public from planned industrial emissions. Values designed for protection of the general public exist, but they are intended to address accidental releases and use methodologies that are often not reproducible."

With these "caveats," Mitchell wrote in the report that "[T]he number of chemicals identified here as exceeding conservative health based benchmark may be under represented for the following reasons: (a) There are a number of detected chemicals for which the RBC (Risk-Based Concentration) table does not provide a health-based screen benchmark.....Not assessing such detected chemicals...will tend to underestimate the potential public health threat presented by airborne pollutants. (b) The RBC health-based screening benchmarks for non- carcinogenic effects have traditionally been derived for adult-only exposure, rather than for children. This may tend to underestimate the potential public health threat presented by airborne pollutants since non-carcinogenic RBC values derived specifically for children would be slightly lower than those derived for adult-only exposures."

The report concluded that "[G]iven the frequency at which these chemicals were observed and that concentrations often exceeded conservative health-based screening benchmarks, this limited sampling event provides sufficient evidence that additional study of the area's air quality may be warranted. Specifically, the scope of the current study is insufficient to fully evaluate the impact of Prichard air quality on public health; nevertheless, the study does provide adequate evidence that a potential threat to public health may exist. In order to assess the priority for additional monitoring in Prichard, the result of this study will be compared to CEP (Cumulative Exposure Project) data for other urban areas in the near future to determine if the chemical concentrations observed in Prichard are significantly higher than in other urban areas."

Other Opinions

George Crozier, Ph.D., is the director of the Dauphin Island Sea Lab and a member of the Envision Mobile-Baldwin Air Quality Task Force. Crozier said the Prichard Air Quality Study contains "caveats so sweeping that it is of little help. The author basically said he has no confidence in anything." Nevertheless, Crozier acknowledges that the EPA report "points out the need for the air quality study" that the task force is currently planning. Crozier said the task force met on November 19 to consider "the next step," including "how to find an expert contractor" for the study.

Regarding the EPA report on air quality in Prichard, Crozier said the study points out that the problem is "nationwide," but it "does not compare to other urban centers or draw any conclusion as to whether the air quality [in Prichard] is worse or better than the national average."

Dr. Crozier was asked to comment on a statement in the EPA report that "many of the compounds that exceed a conservative health-based screening benchmark were also reported as released to air in 1996 by TRI (Toxic Release Inventory) facilities within 5 miles of Prichard." The EPA report stated that in 1996, slightly more than one million pounds of hazardous pollutants that were detected in the 1999 study were released into the air. Crozier said one cannot extrapolate the results in the 1999 study back to the early 1990's, when local industries released five to six times more TRI pollutants. "You may conceptually do that," Crozier said, "then we have to wonder how we all could still be alive." Crozier said the EPA report noted that the detected chemicals may also come from mobile sources.

Steve Perry of The Forum also took issue with this part of the EPA report. While heavy industries in Mobile County did have higher TRI emissions in the early 1990s, there are many "contributing factors," including weather patterns that must be considered to get "the whole picture." The presumption that TRI emission is the only possible contribution "ignores mobile sources." Perry said that assessing the health impact of higher TRI emissions in the early 1990s "requires someone with expertise in air dispersion that I don't have."

Lisa Adams of Alabama Coastal Foundation said "it's very hard to tie the recent results (of the Prichard Air Quality Study) to what it was like in the early 1990's, considering all the variables involved."

Crozier said the issues of health impact might revolve around point source versus non- point source air pollution, for example due to automobile emissions. Concerning respiratory illness, "no one knows how to quantify that," Crozier said. "I want to see data related to health impact." "The greatest impact per dollar spent in addressing the Mobile air quality" is the question the task force will be asking in the future, Crozier added.

Mobile County Commissioner Freeman Jockisch said "Our goal is to place monitors in three different areas of the county. We then could use the information collected to identify the pollutants and emissions in the air that cause health problems too our citizens. Our goal is to eliminate these health problems."

"Concerns have been raised and designations have been made that Mobile County has surpassed a standard set by EPA for ozone, placing us in a non-compliance status at the federal level," county commissioner Gary Tanner said. "I want all those concerns addressed in this study."

County Commissioner Sam Jones said, "Mobile County's main goal is to be pro-active." "We all know that there is a problem with the air quality. Therefore it's important for us to have accurate data, work hand in hand with industry, environmental groups and business to find a solution."

Bernie Fogarty of Alabama Power Company said his company was invited to join the air quality study by Mayor Mike Dow, who is the chair of the task force. "The Alabama Power Company impacts the community with our operation," Fogarty said, "We release materials into the community on behalf of our customers. We are invited to offer comments and solutions to meeting state and federal requirements." Fogarty said the air quality study should not focus on emission from individual plants, but rather "what does the mix look like because there are a lot of industries emitting."

The Alabama Power Company and its parent company, The Southern Company, are the targets of a recent lawsuit by the U.S. Department of Justice, alleging the utilities companies knowingly violated the Clean Air Act.

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