Executive Summary

Executive Summary


Environmental Research and Community Health Studies in Northwest Florida


K. Ranga Rao, Project Director

Center for Environmental Diagnostics and Bioremediation

University of West Florida, Pensacola, FL 32514


September 30, 2009


Reports of the Grand Jury impaneled by the First Judicial Court of the State of Florida

addressed the deterioration of environmental health in Northwest Florida due to pollution

from a variety of point and non-point sources affecting air and water quality (Grand Jury

report, 1999) and contamination of ground water (Grand Jury report, 2004). In response

to these reports and to address related concerns from the community, the U.S. Congress

provided funding to the University of West Florida (UWF) via EPA and CDC to conduct

environmental health studies in Escambia and Santa Rosa counties. UWF formed an

alliance, Partnership for Environmental Research and Community Health (PERCH), with

the regional public health departments—Escambia County Health Department and Santa

Rosa County Health Department—and developed collaborative relationships with other

academic institutions (Georgia Institute of Technology, University of South Florida, and

Florida State University) to undertake comprehensive assessments of environmental

health in Northwest Florida. The studies undertaken for the PERCH project have been

embodied in five different proposals that have been reviewed and approved for a

cooperative agreement awarded by EPA Region 4 (2002-2009) and two proposals

reviewed and approved for two grants awarded by CDC (2002-2004; 2005-2007).


Based on the availability of funds, it was necessary to propose specific projects

that could be completed within each budget/project period. Accordingly, we conducted a

series of interrelated studies, each building upon the results and problems revealed by a

preceding study, with a goal of performing comprehensive assessments to address issues

of concern related to environmental and community health in Northwest Florida. These

comprehensive studies address the concerns of our community, with the results and

conclusions having broader applications/implications for our area and for other regions of

the state and the country. Our project results have been disseminated widely through

peer-reviewed publications, presentations at professional meetings, presentations to state

and federal agencies as well as to stakeholder organizations in the region, and posting of

our detailed reports at the UWF-CEDB website for public access:




  1. Construction of an environmental bibliography for Northwest Florida
  2. Air quality studies



The Grand Jury report addressed the difficulty in finding relevant information, because of

the diffuse sources and difficult access to various reports. In order to alleviate this

problem, we created an electronic database of environmental studies in Northwest

Florida, including more than 2000 citations (with annotated summaries), and posted it on

UWF library's web site accessible to the general public. This bibliography is being used

widely, with more than 4,000 hits during the recent three years on this server with visitors

from the United States and abroad.




These studies, conducted by our collaborators at Georgia Institute of Technology,

included evaluations of historic data, an intensive 30-day field monitoring done utilizing

Georgia Tech's mobile laboratory deployed on the grounds of O.J. Semmes Elementary

School, and comprehensive air quality and air toxics modeling. Initial evaluations

showed that, with regard to public health, particulate matter (PM2.5) pollution is of greater

concern, than are ozone and air toxics for the Pensacola area. Detailed analysis showed

that sulfate was a large fraction of the observed ambient PM2.5 loading, with high

concentrations most often associated with northerly flow. Coal and gasoline combustion

were observed to account for most of the Pensacola atmosphere’s particle load during a

high pollution event, although open fires were also a possible source of particles during

this event. Source apportionment of PM2.5 indicated that sulfate constitutes half or more

of the particulate load in the Pensacola area for the modeled episode. Rather than local

sources, however, sulfate concentrations were more sensitive to distance sources. In

contrast, ammonium concentrations were more sensitive to local sources. As in the case

of ozone, a combination of regional and local controls may be necessary to effectively

manage particulate air pollution in the Pensacola area.

Risk assessment of air toxics from various sources (e.g., point source emissions;

mobile source air toxics) for cancer risks and non-cancer health risks, was done utilizing

the RAIMI (Regional Air Impact Modeling Initiative) tools developed by EPA. This

analysis enabled the identification of four risk zones for cancer based on point source

emissions, and much higher risks emanating from mobile source emissions (additional

details in the following section). In view of the community’s concern for sizable and

sole-source of emissions of HCl and HF from Plant Crist, an assessment was made of the

potential health risks. HCl and HF are not known to be carcinogenic and, at the levels

released, they do not appear to present a significant acute health risk via inhalation.


  1. Health outcomes analysis
  2. Clinical toxicology and health evaluation of communities near Superfund sites



There is considerable interest in environmental health tracking studies, in which

geographic patterns of exposure to pollution are being compared to variation in the health

status of populations. We conducted such evaluations in Northwest Florida on the

association between air pollution and health outcomes. Initial evaluation dealt with

health outcomes comparisons at zip code level geographic units. This analysis showed

that the overall health of the population in Escambia and Santa Rosa counties is not

significantly different from that of socioeconomically and demographically similar

populations in Central and North Florida regions. The health outcomes varied spatially,

with some zip codes having significantly higher or lower levels of adverse health

outcomes than matching zip codes elsewhere in Florida. Among the health outcome

indicators examined, Escambia and Santa Rosa counties showed notably higher

incidences of mortality related to birth defects, infant mortality, and mortality in blacks

for multiple diseases.




In the next phase, we evaluated whether the observed variations in health

outcomes at the zip code level are related to the geographical distribution (proximity and

discharges) of air pollution emitters. This study did not find clear evidence for an

influence of proximity to emission sites on “cumulative” health outcomes at the zip code

level. Some of the “specific” health outcomes, however, seem to be related to the

proximity to emission sites as evidenced by relationships at the zip code level within

Northwest Florida and similar areas elsewhere in the state. The zip codes with a high

incidence of some of the specific outcomes—mortality due to cardiac disease in whites

aged >65; mortality due to lung cancer in blacks aged >65; mortality due to birth defects

in blacks; morbidity (sickness/hospitalizations) due to asthma in blacks, cardiac diseases

in blacks aged >65, and pneumonia in whites aged >65—have a higher proximity index

than zip codes with lower incidence, pointing to an influence of the proximity of

emission sources on these health outcomes.

Our geospatial statistical analysis of data for the greater Pensacola area showed

that high risk of mortality due to COPD (chronic obstructive pulmonary disorder), stroke,

and lung cancer was found in areas with low income level and high air pollution levels

(from point sources and mobile sources), and also in blacks and population aged 65 and

above. High risk of mortality due to chronic coronary heart disease (CCHD) was found in

areas with elevated levels of outdoor aerosol pollution (which is correlated to PM2.5

particulate pollution) in the eastern United States. Escambia and Santa Rosa counties of

Florida (at the county level) have relatively lower rates of CCHD (SMR<1), although

they have high AOD (Aerosol Optical Density) values. Nevertheless, the periodic

episodes of high PM2.5 levels observed in our area and their potential impacts on health

outcomes merit further investigation.

An additional follow-up assessment included the application of EPA’s RAIMI

(Regional Air Impacts Modeling Initiative) tools, designed to evaluate the potential for

health impacts as a result of exposure to multiple contaminants from multiple sources, at

a community level resolution. In this analysis, three areas in Santa Rosa county and one

area in Escambia county were estimated to have a possible elevated risk of cancer due to

emissions from point sources (stationary or industrial sources). While of concern, the

estimated risks are of a magnitude that is consistent with risks found near other industrial

sources. Analysis using RAIMI seems to suggest that toxic emissions from point sources

are not a widespread source of cancer risk via the inhalation pathway in the Pensacola

area (with the caveat that we did not study other exposure pathways).

When similar modeling is done for mobile source emissions using RAIMI,

elevated cancer and non-cancer risks are found to be ubiquitous in the Pensacola area

with higher risks generally along more highly traveled roadways. Arising from the

emissions of formaldehyde, benzene, and butadiene from cars and trucks, the health risks

diminish several orders of magnitude a few hundred meters off the roadway. It is

important to note that residential and other populated areas immediately adjacent to busy

roadways may incur significantly elevated cancer and non-cancer risks.

Continued reductions in industrial emissions, along with improved traffic flow

and reduction/modifications in fuel consumption of automobiles, would help improve

outdoor air quality. Exposure to outdoor pollution, infiltration of outdoor pollution into

buildings, emissions from indoor sources, and uptake of pollutants through food are all

known to be important factors to consider in reducing overall personal risk to hazardous

air pollutants.





We provided health evaluations and biomonitoring for contaminants of concern for a

228-person subset of the eligible workers/residents, including 202 blacks, identified in

the CEHP (Community Environmental Health Project) who had been potentially exposed

to chemical contaminants at the ETC (Escambia Treating Company) Superfund site. The

consulting physicians discussed the results of the evaluations individually with the

participants. In a follow-up survey, 84 to 92% of the participants were very satisfied with

the health evaluations performed as part of the PERCH project.

We found that the ETC cohort exhibited elevated levels of serum dioxins/furans

relative to levels in the general population, and the dioxin congener profiles in the

participants appeared to reflect patterns commonly observed in persons exposed to wood-treatment facilities using pentachlorophenol (PCP). We published our results in a peerreviewed

journal (Karouna-Renier et al., Chemosphere, 69 (2007): 1312-1319). Diseases

usually associated with PCP/dioxin exposure, such as chloracne and/or skin cancer, were

not prevalent in the ETC cohort. The ETC population exhibited a higher prevalence rate

of uterine/cervical and prostate cancers than national levels, although we were unable to

establish a direct link between the cancer prevalence and exposure to contaminants from

the ETC site. This population also showed elevated prevalence of diabetes, hypertension,

obesity, and hepatitis A, B, and C, relative to national levels.

We have conducted a supplemental health evaluation and biomonitoring for an

additional 31-person subset of residents who live or had lived in the Clarinda Triangle

Area near the ETC site, since EPA's re-evaluation indicated elevated levels of dioxins

and arsenic in the soil samples from this area and the agency's proposed follow-up action

involves relocation of residents from this area. The population from the Clarinda Triangle

Area showed health profiles generally similar to those noted with the 228-person cohort

examined above. In the case of hepatitis, only hepatitis A showed elevated prevalence in

the Clarinda Triangle Population, whereas hepatitis A, B, and C were elevated in the

ETC-cohort. The mean serum dioxin levels of Clarinda Triangle population was lower

than that of ETC-cohort, possibly because the latter included data from former workers at

ETC some of whom had substantially elevated dioxin residues. The overall serum dioxin

levels and congener profiles of Clarinda Triangle Area residents were comparable to

those seen in individuals near wood treatment plants. It was not possible to establish a

link between serum dioxin levels and health status of the residents, because of the small

sample size and due to the fact that our measurements occurred many years after the plant

operations ceased.


  1. Environmental follow-up assessments for children with elevated blood lead levels



We provided lead assessments (in paint chips, soil, and wipe samples) for 33 homes built

before 1979 in Escambia County. Among the homes tested 51.5% had detectable levels

of lead contamination, and 21.2% had lead contamination levels above the HUD

guidelines. In order to help protect the health of children, we provided educational

materials and specific recommendations for reducing lead hazards at home to the affected


  1. Mercury levels in hair samples from child-bearing age women
  2. Atmospheric deposition of mercury and trace elements to the Pensacola Bay




Nearly 75% of the fish consumption advisories in the United States have been issued due

to mercury contamination. Florida has issued fish consumption advisories due to mercury

levels for three freshwater fish (largemouth bass, bowfin, and gar) and multiple marine

fish (cobia, barracuda, tuna, shark, and mackerel). Thus the human population in Florida,

especially in coastal areas, is potentially exposed to mercury through fish consumption.

In view of the potential risks of mercury exposure, especially neurodevelopmental

problems in children, we examined the mercury levels in hair samples from child-bearing

age females. Our target was to recruit 400 volunteers from Escambia and Santa Rosa

counties, but we accommodated 602 participants in view of the overwhelming interest.

This in-depth assessment was not done earlier in any part of Florida. Of the 602 women

sampled, 95 (15.8%) had hair mercury levels that exceeded the US EPA advisory level of

1.0 μg/g. Of these 95 women, 62.5% ate more than three seafood meals in the 30 days

prior to sampling. Women who consumed one, two, three, or more than three fish meals

during the 30 days prior to sampling had significantly higher hair mercury levels than

women who did not consume fish/shellfish in that period. We published our results in a

peer-reviewed journal (Karouna-Renier et al., Environmental Research, 108: 320-326,


We relayed the hair mercury results to individual participants, and the feedback

indicates that women who were pregnant or planning to be pregnant utilized the results to

make informed choices in fish consumption. Our surveys of the study participants

indicated that nearly 70% are unaware of fish consumption advisories. Recently the

Escambia County Health Department launched a campaign (billboards, news releases,

and wallet cards) to increase public awareness of fish consumption advisories due to

mercury, and provide information on fish with low mercury loads. We recommend that

follow-up studies include the analysis of hair mercury in children, men, and families of

recreational fishers as they may also be subject to neurological and cardiovascular

problems associated with excessive mercury accumulation.





Mercury contamination associated with increased fossil fuel combustion poses a growing

problem in many areas. The southeast, and in particular the Gulf coast, experiences the

highest levels of mercury deposition in the United States. Yet, there has not been any

monitoring for mercury deposition in Northwest Florida. We have measured the

concentrations of mercury, trace metals, and major ions in rainwater samples collected at

3 sites in the Pensacola Bay watershed over a three-year period. Data from our

comprehensive analysis will be useful to the State of Florida as it develops a TMDL

(Total Maximum Daily Loads) for mercury.

Mercury fluxes and total mercury deposition at the Pensacola Bay sites are similar

to those noted at the MDN (Mercury Deposition Network) sites along the central Gulf of

Mexico region. The total mercury deposition at all these sites follows the historical

pattern of relatively high mercury deposition rates in the Southeastern United States.

Mercury concentrations in rainwater samples show strong correlation with selenium,

antimony, arsenic, and sulfate, pointing to their derivation from coal/fossil fuel

combustion. We estimate that 25 to 51% of the mercury in our rain samples is

attributable to coal combustion. Because of the large number of emission sources in the

region and mixing of air masses from the different regions, it is difficult to determine the

contribution of local sources for mercury deposited to the Pensacola Bay watershed.

Plant Crist in Pensacola is adding scrubbers to reduce emissions of sulfate and mercury.

Since emissions from coal-fired plants in the nearby State of Alabama far exceed the

emissions from Plant Crist, it is desirable to reduce mercury discharges from coal-fired

power plants at various regional locations.

The deposition rates in rain for several ions at our monitoring sites and at several

other sites in Florida and Alabama show significant correlation to air emissions, with

correlation coefficients of 0.95 (ammonium), 0.80 (nitrate), and 0.68 (sulfate). This is in

agreement with air quality studies (reported above) in which the source apportionment of

  1. PM5 in the Pensacola area revealed that ammonium concentrations were more sensitive
  2. Pollution of surface soils in Escambia and Santa Rosa counties

to local sources, whereas sulfate concentrations were more sensitive to distance sources.

This, again, points to the need for emission reductions at local and regional levels for

improvement of air quality, ecosystem health, and human health.

The monitoring we conducted during 2005-2007 for this project is continuing

uninterrupted with support from the Electric Power Research Institute. The extended

monitoring is expected to complement the EPA study done in February 2008, “Mercury

Speciation in Coal-fired Utility Boiler Emission Plume,” at Plant Crist in Pensacola, and

also aid in evaluating the effects of scrubbers being added to Plant Crist on air emissions.




This project focuses on pollution of soils in public places such as parks, playgrounds, and

sports fields where most interaction takes place between people and soils. The results,

presented in a GIS format, are based on analysis of samples from 126 locations in the two

counties, including 12 from the Palafox industrial corridor, and 5 locations that had CCAtreated

wood structures.

Dioxin/furan TEQs (Toxic Equivalency Quotient) in surface soils in the Palafox

industrial corridor are below the EPA screening level for children (50 ng/kg), and these

levels quickly drop off to background levels outside the corridor. PAHs show a very

similar pattern with elevated levels being limited to the Palafox industrial corridor, except

that 5 of the 12 samples exceeded Florida DEP’s residential SCTL (Soil Cleanup Target

Level) of 0.1 mg/kg, which merits further evaluation. Now that the clean up and burial of

the contaminated soils on and around the ETC (Escambia Treating Company) Superfund

Site have been completed by EPA, exposure to contaminated soils of concern has been

abated. The residues we found in the areas outside the cleaned up zone, within the

industrial corridor, represent the remnants of past contamination.

Concentrations of Cr, Cu, and As are markedly higher near CCA (Chromated

Copper Arsenate)-treated wood structures than in the whole data set, although only As

exceeded SCTL. It would be best to avoid contact with soils in very close proximity to

the CCA-treated structures.

Trace metal concentrations (Cd, Cr, Cu, Hg, Ni, Pb, Zn) in samples from all other

locations are generally below their respective RSCTLs, except for arsenic with levels

exceeding its RSCTL of 2.1 mg/kg at 33 of the sites in both rural and urban settings

without a clear spatial pattern. This indicates that these levels may reflect regionally high

arsenic background concentrations (derived from parent materials of soils and/or

atmospheric deposition) and also from agricultural operations. Trace metal concentrations

are higher near the road, due to traffic-related activities/releases, but the levels decrease

between 2 and 20 meters from the edge of the road. We have also measured radioactivity

of surface soils, and the observed levels are near background levels and do not pose a

health concern.


  1. Pollutants in the sediments of urban bayous (Texar, Chico, and Grande) and

the Escambia Bay/River






The Pensacola Bay System components are invaluable resources for the area, as

they add to the scenic beauty of the region, facilitate recreational activities, serve as

navigation sources, and support tourism. Chemical pollutants from point and non-point

sources affect the environmental health of the Pensacola Bay System. We conducted

comprehensive assessment of selected contaminants in the sediments of urban bayous

and in the Escambia Bay/River system, and presented the results in a GIS format so that

this database can serve as a reference for evaluating changes in the future as well as assist

agencies responsible for improving environmental and public health. Our detailed reports

are accessible at our website as noted above.

Bayou Texar: This bayou receives pollutants from a variety of sources—storm

water runoff, input from carpenter’s Creek, and groundwater plumes from Superfund

sites. We found that the groundwater plume from the AGRICO Superfund site (ACC)

continues to discharge fluoride from groundwater into the northern part of the bayou.

Although the groundwater plume from the Escambia Treating Company (ETC) site is

known to be migrating towards Bayou Texar, we did not find evidence for its discharge

into the bayou. Pollutants derived from other (non-point) sources, such as PAHs and trace

metals, are elevated with the highest levels being found in surficial sediments in the

northern section of the bayou, because of diminished flushing in this part of the bayou. In

this area, the PEL (probable effect level) for lead, mercury, copper, and zinc are

exceeded, indicating that there is a probable effect on benthic biota. Organochlorine

pesticide levels are generally low. PCB concentrations are generally lower than in the

other bayous. Reflecting the non-industrial nature of this bayou’s watershed, total TEQs

(Mean: 3.85 ng/kg) due to dioxins/furans/dioxin-like PCBs are lower in Bayou Texar

than in Bayou Chico and Bayou Grande.

Bayou Chico: This bayou has a long history of industrial pollution and is

considered the most polluted of the three urban bayous in Pensacola. The bayou is

adjacent to the American Creosote Works (ACW) Superfund site and the Omni-Vest

landfill, and is also subject to pollution from storm water runoff from an industrial area.

Two areas—a spoil island in the central part of the bayou, and an area south of the Navy

Blvd bridge—have highly elevated levels of pollutants such as PAHs, PCBs, and trace

metals. Vibracores taken in shallow water just offshore of Sanders beach at the mouth of

the bayou did not show significant PAH concentrations in the lower levels, but similar

cores taken on Sanders beach itself contained high concentrations of PAHs of creosote

origin, likely originating from the ACW site. Trace metal concentrations are generally

high in Bayou Chico, exceeding their TEL (As, Cr, Cd) or PEL (Cu, Pb, Hg, Zn). PCBs

are ubiquitous, and their levels exceeded the PEL at 5 out of 17 sites and an additional 8

exceeded the TEL. Dioxins/furans are contaminants of concern at ACW, but they are not

present in high concentration in the Sanders beach area or the mouth of the bayou. The

total TEQs often exceeded their AET in the rest of the bayou, with high levels near the

spoil island. There is periodic dredging in the navigation channel of Bayou Chico, and

the recent and future placement of the dredged spoils and their potential impacts on

pollution of groundwater and on the bayou need to be followed. The spoil island (created

from the past dredged spoils), as noted above, is a major hot spot for pollutants in this

Bayou Grande: Pollutants affecting the water and sediment quality of the

southern half of the bayou were studied previously in reference to possible releases from

the Pensacola Naval Air Station (NAS). We conducted a more detailed study and

presented the contaminant data in a GIS format. In the case of trace metals, several have

exceeded TELs (As, Cr, Hg, Ni) and others exceeded PELs (Cd, Pb, Zn). Naphthalenes

(reported to occur in NAS groundwater) are detected at higher concentrations in

subsurface sediment in the main basin of the bayou and also in surface sediment near the

shore of NAS, pointing to the influence of contaminated groundwater on the bayou.

Sediment guideline levels are exceeded by several PAH species. PAHs in this bayou

seem to have multiple origins, with combustion of various materials being the major

source and do not seem to be caused by petroleum spills. In 15 out of 23 samples, PCBs

exceeded the TEL. PCBs in the bayou do not seem to be derived solely from NAS

sources, but also from other sources in the watershed. Total TEQs for 17 of the 23

samples exceeded the NOAA sediment quality guidelines, seven of them being 3-fold

higher than NOAA AET. Overall the contribution of PCB-like dioxins to the TEQ was

44%, the highest proportion (relative to dioxin/furan contribution) found among other

water bodies in the region.

Escambia Bay and River: In addition to addressing the community’s concern for

lingering residues of PCBs spilled in the 1960s from a point source (former Monsanto

Company) into the Escambia River, we conducted a comprehensive analysis of various

pollutants in the sediments of Escambia Bay/River System. With a few exceptions, the

levels of PAHs and total petroleum hydrocarbons were generally low in the sediments.

Among the trace metals, arsenic was the only one that consistently exceeded sediment

quality guidelines (30 samples exceeded the TEL, and none exceeded the PEL). In some

of the samples, several other metals (Cd, Cr, Cu, Pb, Ni, and Zn) exceeded their

respective TELs but not PELs. Overall, the sediment concentrations of trace metals in

the Escambia Bay/River System are lower than in the urban bayous of Pensacola.

Pesticide levels are generally low, as in the bayous, except for the finding of DDT in 25%

of the sediment samples. DDT levels in all but one sample exceeded the Florida DEP’s

PEL (4.77 μg/kg). The detected DDT was generally associated with sediments in

wetlands and the river, and is of concern as some of these areas may serve as nurseries

for marine life and DDT could impact fish and shrimp populations. The concentrations

of PCBs varied with the region, with sediments from lower Escambia River and upper

regions of Escambia Bay having PCBs near the TEL (21.6 μg/kg), with the highest value

(125.9 μg/kg) near the original spill site. Lower Escambia Bay sediments had mean PCB

concentrations of 11.9 μg/kg, and upriver of the spill site they were even lower (5.06

μg/kg). A majority of the samples (56%) in the Escambia Bay/River System had TEQs

exceeding NOAA TEL, and 23% exceeding the NOAA AET. For the combined TEQs,

however, PCB-like dioxins accounted for 7% and dioxins/furans accounted for 93%.

Spatially, the distribution of dioxin-like PCBs did not coincide with the dioxin/furan TEQ

distribution, due to differences in their origin, degradation, and transportation.

Relative pollutant loads and temporal changes: In the case of groundwater

plumes from Superfund sites, the release of ACC plume contents continues to be at the

same level (based on fluoride in sediments and pore water) as reported by ENTRIX in

1993. EPA has recently completed the first phase of remediation of the ETC site,

involving the burial and capping of contaminated soils, and is planning to remediate the

contaminated groundwater. These efforts should aid in limiting the spread of

contaminants from this Superfund site. The migration and discharge of contaminated

groundwater plume from NAS into Bayou Grande needs to be followed and documented.

Omni-Vest Landfill does not appear to impact Bayou Chico. The creosote found under

Sander’s beach is in the path of the ACW plume, and merits follow-up.

Based on the samples we analyzed, the PCB concentrations are highest in Bayou

Chico (Mean: 158 μg/kg), with other water bodies having mean concentrations of 61.7

μg/kg (Bayou Grande), 30.7 μg/kg (Bayou Texar), and 17.9 μg/kg (Escambia Bay/River).

The mean values for the combined TEQs for dioxins/furans/dioxin-like PCBs were: 44.59

ng/kg (Bayou Chico), 8.3 ng/kg (Bayou Grande), 3.85 ng/kg (Bayou Texar), and 2.62

ng/kg (Escambia bay/River). The relative contributions of dioxin-like PCBs to the total

TEQ were: 43.8% (Bayou Grande), 21% (Bayou Chico), 16% (Bayou Texar), and 7%

(Escambia Bay/River). Although the mean concentrations of total PCBs and TEQs in

Escambia Bay/River were the lowest in comparison to the urban bayous, due to the large

geographic area covered by the Escambia Bay/River system, there are hot spots of

contamination. It is also important to note that whereas PCBs pose non-cancer risks, the

homologs contributing to TEQs (dioxin-like PCBs) along with dioxins/furans pose cancer

risks to humans. We do not have historic comparable data on TEQs in the water bodies

studied to assess what temporal changes (if any) occurred. For PCBs, such data is

available with the implicit understanding that—because of differences in the number and

location of samples, and analytical methods—there are difficulties in drawing reliable

conclusions on temporal trends. Nevertheless, it appears that, whereas PCB levels in

Bayou Texar are relatively unchanged from the levels noted in the 1990s, the PCB levels

in Bayou Grande and Bayou Chico seem to have increased (more so in the latter) which

needs to be evaluated. In Escambia Bay the PCB levels seem to have gone down by

nearly 50%, but it should be noted that our study included analysis of only surface

sediment samples, which would not have identified buried contamination that may be

exposed by bioperturbation, storms, dredging, construction, or other activities. In sum,

the contamination of sediments with PCBs, dioxins/furans, and dioxin-like PCBs is of

concern and should continue to be monitored.

PAH levels in the sediments of Bayou Texar, Bayou Chico, and Escambia

Bay/River did not seem to change over two decades, but appear to have increased

dramatically (8-fold) in Bayou Grande, although the latter may be attributable to our

sampling at more sites including the most polluted areas compared to previous studies.

Compared to the levels detected in the 1990s, the organochlorine pesticide levels in the

sediments have decreased substantially although the current levels of DDT in the

sediments of Escambia River and wetlands are of concern. Trace metal concentrations

frequently exceeded SQAGs but to varying degrees in the bay/bayous. Zinc and Hg had

the highest concentrations in Bayou Chico and Texar, whereas Cd and Cr were higher in

Bayou Grande. Escambia Bay had the lowest trace metal concentrations, but was highest

in arsenic—possibly because of its larger watershed that could contribute to the drainage

of As from surface soils (natural high background levels, derived from parent soils and/or

or from atmospheric deposition) and also from agricultural operations. Since the 1990s

Cr, Hg, and Ni concentrations declined in all of the area estuaries. Overall, the

concentrations of trace metals declined to a greater extent in Bayou Texar possibly due to

stormwater management efforts in its watershed.


  1. Accumulation of pollutants in fish and shellfish




The greatest vector for exposure to environmental contaminants in water bodies

for wildlife and humans is through consumption of contaminated food. Although fish

consumption advisories due to mercury content are issued for many locations in the State

of Florida, including advisories for several freshwater and coastal fish in Northwest

Florida, there have not been systematic surveys for other pollutants in fish/shellfish

consumed by humans. Our study has contributed to filling this data gap for Northwest

Florida, and our comprehensive survey of PCBs and dioxins/furans in seafood is

An initial screening level assessment of contaminants in blue crabs (Callinectes

sapidus) and oysters (Crassostrea virginica) revealed several chemicals of concern

(dioxins/furans/PCBs, arsenic, mercury, cadmium, and zinc) in crab muscle, crab

hepatopancreas, total crab tissue, and oysters based on contaminant levels exceeding

Screening Values (SVs). The locations that exceeded SVs and had the highest

carcinogenic or non-carcinogenic health risks were generally located in urbanized water

bodies (Bayou Texar, Bayou Grande, and Bayou Chico) or downstream of known

contaminated areas (Western Escambia Bay). Oysters collected from commercial oyster

beds in Escambia and East Bays, and crabs collected from East, Blackwater, and Perdido

Bays generally had the lowest levels of contaminants. Despite accounting for only 15%

of the total tissue, inclusion of hepatopancreas in a crab meal increased contamination to

levels above many SVs, and therefore, direct or indirect consumption of hepatopancreas

from crabs in the Pensacola Bay system should be discouraged.

In the next phase, we conducted a survey of contaminant levels in largemouth

bass (Micropterus salmoides) from rivers in Northwest Florida and striped mullet (Mugil

cephalus) from rivers, bays, and bayous in the region. Largemouth bass collected from all

of the study locations exceeded mercury SV (0.4 mg/kg, EPA SV for recreational fisher

consumption), and the HQ (Hazard Quotient, non-cancer hazard risk) for nearly all

samples exceeded a value of 1, indicating that non-cancer health effects may occur. In

contrast, the levels of mercury were very low (0.008 to 0.026 mg/kg) in mullet. This is

due to differences in feeding habits: bass are a top level predator, that readily

accumulates mercury through the food chain, whereas mullet primarily feed on detritus

and sediments.

Largemouth bass had PCB levels exceeding EPA recreational fisher consumption

SV (20 ng/kg) in the samples from lower part of Escambia River, downstream of a PCB

(Aroclor 1254) spill that occurred in the late 1960s, and had relatively low levels of PCBs

in samples from upstream of the spill site in Escambia River and in all other locations

(Blackwater, Shoal, Yellow, and Perdido rivers). The highest levels of PCBs in the

mullet from the Escambia River/Bay System in this phase of the study were in fish

caught in the lower Escambia River. PCB loads exceeding the EPA SV were also found

in mullet from NE Escambia Bay, SW Escambia Bay, and in the upper reaches of

Escambia River, whereas much lower levels were found in mullet from SE Escambia

Bay. After reviewing our findings, the State of Florida Department of Health (DOH)

issued a fish consumption advisory based on PCB loads (exceeding 50 ng/kg screening

value, set by FL-DOH), warning consumers to restrict their consumption of mullet and

bass from the Escambia River from south of State Route 184 to the mouth of the river to

one meal per week. In a subsequent evaluation, we determined PCB levels in mullet and

several other fish species sampled in Escambia Bay following a demolition blast of a part

of the old 1-10 Bridge. Mullet collected from this sampling had the highest levels of

PCBs in any of the fish we studied (280 to 1,580 ng/kg). Following our findings, Florida

DOH conducted an independent analysis of mullet from several locations in the

Pensacola Bay System, found PCB levels exceeding 50 ng/kg in mullet caught from

Escambia Bay, and issued (on October 1, 2009) a consumption advisory for mullet

caught from the Escambia Bay, thereby extending the previous advisory for fish from

lower Escambia River.

We found that mullet from East Bay, Perdido River, and Yellow River have

relatively low levels of PCBs (3.8 to 8.8 ng/kg), whereas higher levels were noted in

mullet from urban bayous, with levels above the EPA SV for recreational fisher

consumption in mullet from Bayou Chico. In all of the sampling locations, however,

TEQs were above the EPA SV for recreational fisher consumption (0.256 ng/kg). In

locations with elevated PCB residues in the environment, the accumulation of dioxin-like

PCBs adds to the TEQ load. Thus, the relative contribution of dioxin-like PCBs to the

total TEQ varies with the species (differences in uptake/accumulation), and the relative

concentrations of bio-available dioxins/furans and dioxin-like PCBs in the environment.

Our studies show that the relative contribution of dioxin-like PCBs to TEQ loads in

mullet varies by location: 29% (Bayou Texar), 52-53% (Bayou Chico and Bayou

Grande), 57% (lower Escambia River), and 98% (Escambia Bay, samples near I-10

bridge). The PCB homolog profile seen in fish sampled near I-10 bridge was nearly

identical to the profile of congeners in Aroclor 1254, the formulation that was spilled into

Escambia River in the 1960s. This suggests that the bridge construction/demolition

activities have disturbed the sediments, causing the PCB-laden deeper sediments to be

brought up to the surface and increasing the availability of PCBs to biota in the bay.

Mullet samples from the rest of Escambia Bay and River show a moderate affinity for

Aroclor 1254 (due to attenuation through biotic transfers and partial degradation of the

raw product), whereas PCBs in mullet samples from industrialized bayous (Chico and

Grande) cluster with Aroclor 1260 homolog pattern, suggesting either enrichment of

more highly chlorinated homologs with partitioning into the biota, or alternate sources of

In evaluating the health risks from PCBs, it is necessary to consider not only the

non-cancer risks posed by PCBs as a whole, but also the cancer risks posed by dioxin-like

PCBs along with dioxins/furans. Mullet that were caught in the lower Escambia River

had elevated levels of total PCBs for which the hazard quotient (HQ) exceeded 1, which

indicates that non-cancer health effects may occur. Bass caught in the lower Escambia

River had high levels of both PCBs and mercury, resulting in an HQ above 1. Mullet

collected from the Escambia Bay near I-10 bridge yielded much higher HQs (3.55 to

19.75). Excess LCR (Life Time Cancer Risk) exceeded 1x10-4 (more than one excess

cancer per 10,000), for two samples—in mullet from Bayou Chico and in bass from

lower Escambia River. In both cases, the primary contributors to the excess LCR were

dioxins/furans and dioxin-like PCBs. For mullet from Escambia Bay I-10 bridge

sampling, the estimated Life Time Cancer Risks from consumption exceeded 1 per 1,000,

attributable almost entirely to dioxin-like PCBs. These findings clearly point to the need

for conducting systematic surveys of critical toxic pollutants—not only mercury, but also

PCBs, dioxin-like PCBs, and dioxins/furans—in commonly caught and consumed fish

from various locations.

In the final phase of our study finfish from seventeen zones within Pensacola Bay

and Perdido Bay watersheds were surveyed for mercury and PCB loads, including TEQ

loads. This study has compiled an unprecedented dataset on the accumulation of

dioxins/furans in estuarine and marine biota. These contaminants are widespread, and in

many instances TEQ values exceeding acceptable thresholds were found. The overall

data for contaminants, coupled with earlier analysis done on offshore fishes in relation to

the sinking of ex-Oriskany, includes information on contaminant loads in 1199 specimens

within 48 species. Individual species information has been posted in a series of web

pages at:




Blackwater-East Bays, lower Pensacola Bay, Santa Rosa Sound, and Perdido Bay

are relatively clean zones (based on oyster, blue crab, and mullet data), but this pattern

does not hold true for fish that are highly mobile and of high trophic status—e.g., large

red drum caught in East Bay and Santa Rosa Sound had the highest PCB loads recorded

for this species (60 and 40 ng/kg, respectively). While most species bioaccumulate

dioxins/furans, PCBs, and mercury with age, there are exceptions: Spotted seatrout and

Spanish mackerel show increased loads of mercury with age, but not for PCBs. On the

other hand, king mackerel has much higher loads of both mercury and PCBs with

increase in age. Red snapper and groupers also show bioaccumulation of PCBs and

mercury with increasing age, pointing to the need for Gulf-wide investigation of pollutant

loads in offshore fishes.

In terms of protecting public health, it is necessary to conduct a systematic

analysis of target contaminants in commonly caught and consumed fish and shellfish to

establish justifiable and uniform (national/state) standards to enable consumers to make

informed choices. Given species-specific patterns of contaminant accumulation, it is also

necessary to evaluate and communicate about the risks resulting from elevated loads of

multiple contaminants found, rather than issuing advisories based on only an individual

contaminant. This would alleviate some of the difficulties consumers may encounter in

selecting fish as they weigh the risks/benefits of fish consumption. Public health

education efforts in this regard need to be augmented, as most people are unaware of fish

consumption advisories or about choices in fish consumption.




Health Outcomes in Escambia and Santa Rosa counties

The noted higher health risks in infants, elderly (age >65), blacks, and the poor need to be

followed, and appropriate measures implemented for correcting the apparent disparity in

health outcomes for an overall improvement in community health.


Population near the Escambia Treating Company (ETC) Site

Although no direct link could be established between disease prevalence and exposure to

toxicants from the ETC site, the relatively higher prevalence of cervical/uterine and

prostate cancers, hypertension, diabetes, and hepatitis among the examined individuals

requires follow-up evaluation and treatment.


Lead assessments for older homes

These assessments should continue for homes built prior to 1979, to determine potential

exposure risks from lead contamination and to undertake appropriate remediation

measures to protect children’s health.


Air Quality

A combination of regional and local controls should be implemented to effectively

manage particulate (PM2.5) pollution in the Pensacola area.


In order to achieve reductions in atmospheric deposition of mercury to the Pensacola Bay

watershed, it would be necessary to reduce emissions from coal-fired power plants at

various regional locations. Corrective measures are being implemented at Plant Crist in

Pensacola, and such measures are needed throughout the southeast.


In view of the elevated cancer and non-cancer risks from emissions along highly traveled

roadways, efforts should be directed towards improved traffic flow, improved fuel

consumption efficiency of automobiles, usage of hybrid or electric-powered vehicles, and

increased usage of mass transit systems.


Reductions in personal risks from hazardous air pollutants require measures to decrease:

exposure to outdoor pollution, infiltration of outdoor pollution into buildings, emissions

from indoor sources, and uptake of pollutants through food.


Surface Soils

CCA (Chromate Copper Arsenate)-treated structures should be removed from public

places and playgrounds.


Areas with arsenic above RSCTL should be monitored in relation to residential



The elevated PAH levels, exceeding Florida DEP’s SCTL, detected at some locations in

the Palafox industrial corridor need to be followed.


Pollutants in the Pensacola Bay System

The presence of contaminated aquifers (mostly groundwater plumes from Superfund

Sites) requires continued monitoring of the sediments, pore water, and the waters of local


The impacts of point source historical discharges of pollutants (e.g., PCBs discharged to

Escambia River/Bay system) need to be monitored, and appropriate corrective/protective

actions should be taken.


Whereas periodic dredging is needed to facilitate navigation in rivers/bays/bayous, the

placement of the dredged spoils and the potential impacts of pollutants from this source

on the corresponding water bodies have to be considered.


Monitoring of sediments for pollutant loads should continue, especially for those areas

currently known to contain elevated levels of toxic pollutants in the Pensacola Bay


The unexpected detections of DDT above the PEL in the Escambia River and associated

wetlands merit further investigation.


Contaminants in fish and shellfish

A systematic survey of target contaminants (not only mercury but also PCBs,

dioxins/furans and dioxin-like PCBs) in fish/shellfish needs to be undertaken at the state

level, and also extended by appropriate agencies for similar Gulf-wide surveys of

contaminants in commonly caught and consumed fishes.


Screening values used to establish consumption advisories differ considerably at state and

national levels, even between federal agencies, and efforts should be made to establish

uniform standards to protect public health.


Among the pollutants of concern from local water bodies, the screening value adopted by

the State of Florida for PCBs (50 ng/kg) is higher than that set by EPA (20 ng/kg) for

recreational fisher consumption, and the former threshold should be reevaluated and

given the same resolution in its application as done for mercury screening thresholds in

relation to sensitive/general population groups and variable consumption rates.


In view of the widespread dioxin/furan loads, along with dioxin-like PCBs, in

fish/shellfish, the State of Florida should establish guidelines for issuing consumption

advisories based on TEQ loads.


As is done in several other states, State of Florida should issue an advisory against

consumption of blue crab hepatopancreas, based on toxicant loads.


At the state and national levels, there is a need to augment public awareness of fish

consumption advisories and provide information that would enable consumers to

understand the benefits/risks from consumption of fish/shellfish.