PUBLIC HEALTH ASSESSMENT
KELLY AIR FORCE BASE
SAN ANTONIO, BEXAR COUNTY, TEXAS
Community residents questioned whether gas from the contaminated groundwater plume under their neighborhood could be migrating through the soil and into their homes and causing health effects. ATSDR reviewed the data contained in the Soil Vapor Survey (28) and the Quintana Road Health Evaluation (29) and determined that soil gas migration at levels of health concern has not occurred in the Quintana Road neighborhood and is unlikely to occur in the North Kelly Gardens neighborhood. Gas migration cannot be predicted in the East Kelly neighborhood until groundwater characterization is complete and data is evaluated.
ATSDR's review of environmental testing by Kelly AFB indicated separate shallow aquifer groundwater plumes extend off base under the neighborhoods of Quintana Road, North Kelly Gardens, and East Kelly. The contaminants present in all plumes were similar, consisting mainly of volatile organic compounds (VOCs), fuel components, and some metals (2). ATSDR evaluated the potential for soil gas migration from the contaminated shallow groundwater to the soil surface.
VOCs are known to volatilize (or evaporate) from soil when exposed to air or from surface waters. Under favorable conditions, VOCs can migrate from groundwater through soil to the surface, where they are dispersed by surface air. Volatilization from groundwater is more likely to occur if the chemical is present in high concentrations. Scientific evidence indicates that a dilute concentration of VOCs in groundwater (below about 1% of its solubility level) is unlikely to be present in a pure or concentrated form and will likely remain dissolved in the groundwater (29,30).
Table 8 shows the contaminants that are present and the maximum concentrations of these contaminants detected in both the North Kelly Gardens and Quintana Road groundwater plumes. Table 8 also shows the value for each contaminant that represents 1% of the solubility level. Therefore, one can determine which contaminants would be likely to volatilize by comparing this value with the maximum detected concentration. Screening indicates that tetrachloroethylene is most likely to volatilize in the Quintana Road neighborhood. Xylenes in both neighborhoods may slightly volatilize. Concentrations are generally greater in the Quintana Road neighborhood.
Once volatilization occurs, gas leaves the groundwater and migrates to the soil surface. As the gas rises, it spreads out (disperses). The longer the distance to the soil surface, the more it spreads out. The more it spreads out, the lower the concentration at the surface. Therefore, the deeper the groundwater, the more dispersed the gas is when it reaches the surface. In addition, the longer the distance from the groundwater to the surface, the more chance the gas has of becoming degraded or adsorbed.
Comparison of North Kelly Gardens and Quintana Road
ATSDR compared the groundwater plume in the North Kelly Gardens neighborhood with the groundwater plume in the Quintana Road neighborhood. When the groundwater plume in the Quintana Road neighborhood was discovered in 1988 by a city construction crew, it contained "free product" JP-4 jet fuel. "Free product" means that the jet fuel was floating in its natural form on top of the groundwater so it was more likely to volatilize. Kelly AFB and the San Antonio Metropolitan Health District investigated the potential for gas migration from the contaminated groundwater plume by air sampling and analysis at the soil surface and inside homes that were over or near the plume. Results indicated that gases from the contaminated groundwater plume were not present in homes at levels of health concern (29).
The shallow groundwater plume under the North Kelly Gardens neighborhood contains lower concentrations of contaminants, there is little "free product" of contaminants, and the depth from the soil surface to the groundwater table is as great or greater than Quintana road. The soil type and housing construction are also similar. Therefore, if gases from the contaminated groundwater were not detected at levels of concern in the Quintana Road community, ATSDR would not expect to find gases in the North Kelly Gardens community at levels of health concern. Soil gas vapor surveys conducted at Kelly AFB indicate that soil gas from contaminated groundwater is present only in discrete areas in which spills occurred (28). This indicates that concentrations of contaminants are low or dispersion is great, or both.
East Kelly
The contamination in the East Kelly area has not been fully characterized. ATSDR cannot predict whether concentrations of contaminants would be high enough to be more likely to volatilize than contaminants in the Quintana Road or North Kelly Gardens. Kelly AFB is scheduled to collect soil gas samples. ATSDR has provided comments to the soil gas collection plan.
Conclusions
It is unlikely that VOCs from groundwater have migrated into homes in North Kelly Gardens or the Quintana Road neighborhoods at levels of health concern.
Recommendations
ATSDR will evaluate soil gas data from East Kelly and report findings of the evaluation in Phase III of the public health assessment.
Table 8
Groundwater Solubility Comparison of Quintana Road
and North Kelly Gardens.
|
Chemical
|
MAXIMUM CONCENTRATIONa
(Quintana Road) |
MAXIMUM CONCENTRATION
(North Kelly Gardens) |
1% OF
SOLUBILITY |
| Benzene | 3.3 | 0.68 | 17.8 c |
| Chlorobenzene | 0.65 | 0.54 | 5.0 d |
| Ethyl benzene | 0.21 | NDb | 1.6 e |
| Tetrachloroethylene | 46.0 | 0.64 | 1.5 f |
| Toluene | 2.0 | 0.12 | 5.3 g |
| Trichloroethylene | 6.9 | 0.58 | 13.6 h |
| Xylene | 1.9 | 2.1 | 1.3 I |
a All concentrations expressed in milligrams/liter. Shaded
values indicate greater than 1% of solubility. Values less than 1% of solubility
are not likely to volatilize from groundwater at levels of health concern. Chemical
data from Kelly AFB, Baseline Risk Assessment, 1995 Annual Report, Volume I.
July 1996.
b ND: not detected
c Hazardous Substances Data Base. 1994. National Library
of Medicine, National Toxicology Information Program, Bethesda, MD.
d Verschueren 1983. Verschueren K. 1983. Handbook of
environmental data on organic chemicals. 2nd Ed. New York, NY: Van Nostrand
Reinhold Company, 356-359, 712-717.
e Amoore and Jautala 1983. Odor as an aid to chemical
safety: Odor thresholds compared with threshold limit values and volatilities
for 214 industrial chemicals in air and water dilution. J Appl Toxicol 3:272-290.
f Hazardous Substances Data Base. 1994. National Library
of Medicine, National Toxicology Information Program, Bethesda, MD.
g Hazardous Substances Data Base. 1993. National Library
of Medicine, National Toxicology Information Program, Bethesda, MD.
h Tewari et al. 1982. Tewari YB, Miller MM, Wasik SP,
Martire DE. 1982. Aqueous solubility and octanol/water partition coefficient
of organic compounds at 25.0 degrees C. J Chem Eng Data 27: 451-454.
i
Sax NI, Lewis RJ. 1989. Dangerous properties of industrial chemicals. Vol. III,
7th edition. New York, NY: Ban Nostrand Reinhold Company, 3495-3497.
Concern was expressed by some residents regarding the noise from engine run-up maintenance operations. Run-ups by C-5s can occur close to the Kelly boundary near the Quintana Road neighborhood, and residents report that sometimes the engine run-ups occur after 10:00 pm. The residents complain that this interferes with their sleep and question if living close to Kelly AFB will cause hearing damage. Kelly AFB reports that 100% of the maintenance routinely occurs during the day and run-ups occurring after 10:00 pm would have to be deemed "mission critical" (3). A study conducted by the Air Force indicates that jet engine run-ups had occurred between the hours of 10:00 pm and 7:00 am (this time period was selected to coincide with the time period used as night sound level penalties, as discussed below) approximately 15% of the time during the study period of one year, or on about 37 occasions (31). The Air Force reports that administrative policy changes exercising more strict control have rectified previous unfavorable circumstances (32). A community resident recently reported that late night run-ups had not occurred in several months (33).
Day-Night Level (DNL) is a day-night average sound level which is an accepted unit for quantifying human annoyance to general environmental noise, including aircraft noise. DNL is the average A-weighted sound level over a 24-hour period with a 10-decibel (dB) adjustment added to the nighttime noise levels (10 pm-7 am). This adjustment is an effort to account for the increased human sensitivity to nighttime noise events. A-weighting is a procedure whereby adjustments are made by assigning increased weight or emphasis to the frequencies in the range in which the ear perceives low noise. A-weighting provides a good assessment of noise associated with speech interference and community disturbance conditions.
The noise levels were modeled using the Air Force Procedure for Predicting Aircraft Noise Around Airbases: Noise Exposure Model (NOISEMAP) for Kelly AFB by the type of aircraft, takeoffs and landings, and flight tracks corresponding to the published approaches for the airfield. The NOISEMAP model for Kelly AFB indicates that DNLs greater than 65 decibels would be annoying to individuals. Noise levels greater than 65 dBs might be annoying by interfering with intelligible speech, and levels greater than 80 dB might interfere with all speech communication. For comparison with roadway noise, a 65-dB level exists about 150 feet from the center line of a road, such as Quintana Road above Dunton Street, with levels of 70 dBs or greater not extending beyond the road bed (3). Levels less than 80 dB for 24-hour exposures would not be expected to result in injury or hearing loss, and threshold limit values (TLV) indicate that no noise would be allowed for any duration above 140 dBs. TLVs are conditions under which it is believed that nearly all workers may be exposed day after day without adverse effects. TLVs depicting the relationship between noise level and duration are found in Figure 9 (page 57)(34). In addition, compatibility guidelines for noise and designated land use were developed by the Federal Interagency Committee on Urban Noise, and yearly DNLs equal to or greater than 65 decibels are not considered compatible with mobile home parks or other residential land use (35).
It appears that some areas of some neighborhoods adjacent to Kelly AFB would be considered to be incompatible with residential land use under this definition. Therefore, some level of annoyance and interference with activities such as intelligible speech during flyovers is to be expected.
Noise must enter the home in order for sleep to be disturbed, and the level of a sound generated outside the home would be lower when heard inside the home due to attenuation by the structure (walls, windows, insulation, and so on). The amount of reduction of sound from outside to inside is variable and depends on construction as well as such factors as whether the windows are opened or closed. The national average attenuation factors are 25 dB for closed windows and 15 decibels for open windows (36)(attenuation factors are values that are used to adjust the outside level to the inside level). When applied to the outdoor noise level predicted by NOISEMAP, it appears that a small portion of the population near Kelly AFB would be disturbed (less than 10%). When applied to the noise level possible during jet engine run-ups, a significantly higher portion of the population nearest Kelly AFB may be disturbed (20%-25%). This increase in the number of people disturbed during jet engine run-ups indicates that utmost consideration should be given to conducting the run-ups during routine maintenance times. The actual numbers of people disturbed may be lower, because many people adapt and become habitualized to regular noise.
ATSDR also considered whether base activities could potentially cause hearing loss or injury. Although the NOISEMAP model does not predict hearing loss or injury from routine flight line applications, it does not consider site-specific maintenance operations. A bioenvironmental engineering flight study was conducted by the 76th Aerospace Medical Squadron to determine the actual A-weighted decibel levels for the duration of jet engine run-ups, jet engine resonance checks, and reverse thrusting exercises, measured by dosimeters located in the Quintana Road community under varying conditions of temperature, humidity, and physical obstruction (31).
Results indicate that the duration of the great majority of engine run-ups is less than an hour and that these run-ups would not generate a hazardous noise dose at off-base locations from aircraft located on any of the maintenance pads. Results of the study further indicate that, under certain specific worst-case conditions, it may be possible to exceed the recommended noise dose to the closest off-base dosimeter location. While these circumstances were not observed, research by the 76th medical group hypothesized that such a scenario might be possible under certain worst-case conditions. These worst-case conditions include (1) maintenance performed only on certain aircraft receiving modification to their malfunction detection, analysis and recording system (MADARS) while at Kelly; (2) the longest type of engine resonance checks to be performed; (3) run-ups occurring under the worst humidity conditions; (4) run-ups occurring on Pad 1; and (5) receptors must be outside and with an unobstructed pathway to the noise source for at least three hours.
Although it is unlikely that all of these conditions would occur at the same time, it is possible. Therefore, in light of the potential effects such conditions may precipitate, it is recommended that the Air Force consider institutional controls to insure that worst-case conditions do not occur. For example, if Pad 1 were not used for aircraft receiving modification to their MADARS system and receiving the longest type of engine resonance check, there would be no potential to exceed the recommended hearing dose, according to the study. The same type of institutional controls could result in less noise disturbance as well. Kelly AFB has stated that they were aware of the need for more stringent institutional controls and have adopted certain controls (32). In addition, MADAR modification tests were limited to depot maintenance on C-5s which has subsequently moved to Robbins AFB in Georgia.
Potential Non-auditory Effects of Noise
Children may be more susceptible than adults to certain nonauditory effects of noise because they have less precise speech, limited vocabulary, and less developed familiarity with language rules (54).
ATSDR reviewed noise contours and locations of schools around Kelly AFB.
Conclusions
ATSDR concludes that noise levels around Kelly AFB would not likely result in damage to hearing. The noise levels might be annoying and might interfere with intelligible speech and possibly sleep.
ATSDR concluded that noise levels were not high enough at locations of schools that adverse nonauditory effects would be likely.
Recommendations
None.
|
Duration per Day
|
Sound Level (dBA)**
|
|
| Hours |
24
|
80
|
|
16
|
82
|
|
|
8
|
85
|
|
|
4
|
88
|
|
|
2
|
91
|
|
|
1
|
94
|
|
| Minutes |
30.
|
97
|
|
15.
|
100
|
|
|
7.5
|
103
|
|
|
3.75
|
106
|
|
|
1.88
|
109
|
|
|
0.94
|
112
|
|
| Seconds |
28.12
|
115
|
|
14.06
|
118
|
|
|
7.03
|
121
|
|
|
3.52
|
124
|
|
|
1.76
|
127
|
|
|
0.88
|
130
|
|
|
0.44
|
133
|
|
|
0.22
|
136
|
|
|
0.11
|
139
|
|
* Data from Threshold Limit Values for Chemical Substances
and Physical Agents. Biological Exposure Indices. Second Printing. American
Conference of Governmental Industrial Hygienists. 1996.
**
dBA A-weighted decibel
Residents of the North Kelly Gardens community reported that the jettisoning of fuel by aircraft landing at Kelly AFB occurred frequently during the Vietnam era. Residents recall feeling the fuel on their skin and smelling the fuel while outside during these events, and question whether these events may have contributed to their health problems. The absence of official records concerning emergencies and fuel jettisoning precludes documentation of jettisoning events and does not allow ATSDR to determine potential risks that might be attributed to fuel jettisoning.
Fuel jettisoning, or fuel dumping, refers to the discharge of unburned fuel directly into the atmosphere by an aircraft while still airborne. The fuel is generally released through ports which are specifically designed for fuel jettisoning, usually located in the wingtips. Many aircraft are required to take off with a gross weight much higher than their maximum safe landing weight. If an emergency or change in operational plans requires the aircraft to land prematurely, fuel is jettisoned to reduce weight to a safe level. In some cases, the nature of an emergency may lessen the airworthiness of the aircraft. In such cases, reducing weight even below the normal landing weight may be desired to permit a slower landing speed and improve control.
In 1972, the Air Force initiated a study to determine the nature, extent, and environmental impact of fuel jettisoning by Air Force aircraft (37). Air Force Regulation 19-3, "Reporting of Aircraft Fuel Jettisoning," March 15, 1973, required the reporting of all noncombat fuel jettisoning episodes using Air Force Form 161. Reporting requirements included size and location of fuel jettison, altitude, airspeed, dump rate, and meteorological factors. This regulation was passed to ensure sufficient reporting during the period of the study, and was rescinded in 1978, at which time it was felt that a sufficient database had been collected to meet the purpose of the regulation. The report contains only those months when all commands appeared to be fully complying with the reporting requirement over the 3½ years that the study was conducted.
C-5s reported only 1 dump per year representing 0.1% of the Air Force total and was therefore a minor contributor to fuel jettisoning by the Air Force. The report describes fuel jettisoning as occurring over unpopulated or sparsely populated terrain, such as oceans, mountain ranges and forests. Some commands direct that, when circumstances permit, jettisoning should be carried out over unpopulated areas (38). Most bases have predesignated fuel jettisoning areas which are selected to minimize any impact, "located so that prevailing winds will not carry fuel spray to urban areas, agricultural regions, or water supply sources" (39).
ATSDR has examined the Fuel Dump Listings, which contain the actual fuel jettisoning events during the study period, categorized by location, plane type, and command (40). ATSDR found no record of any fuel jettisoning event in the area of Kelly AFB for the reporting period. ATSDR asked the Air Force to review emergency events to determine if fuel was jettisoned during any of the emergency landings. The Air Force reported that they had no knowledge of fuel jettisoning at Kelly AFB, even in emergency situations; however, they acknowledge that under some emergency conditions, it would have been possible that fuel had been jettisoned and not reported. One newspaper report was located describing an emergency in which fuel tanks were jettisoned by an aircraft from Kelly AFB, but the jettisoning did not occur in the neighborhoods surrounding the base (41).
It is unlikely that fuel would be jettisoned on a routine basis or in a nonemergency event because of the potential for human and environmental effects, the change in handling characteristics during landings, the high cost of fuel, and the potential fire hazard. ATSDR also considered factors concerning fuel jettisoning, including the following: (1) more than 98% of JP-4 fuel, jettisoned at more that 1,500 meters elevation and above freezing temperatures (32º F), will evaporate before reaching the ground; and (2) no liquid fuel could be detected by ground observers when fuel was jettisoned as low as 750 meters (at 52º F) (42). In addition, the more volatile compounds found in JP-4 (such as benzene, ethyl benzene, toluene, and xylenes) would be the first to evaporate.
Conclusions
The Air Force does not have a system for reporting routine or emergency fuel jettisoning. Therefore, ATSDR cannot determine the extent of potential exposure. Based on the Air Force fuel jettisoning study, the Air Force policy and procedure regarding fuel jettisoning, the nature of physical and chemical characteristics of jettisoned fuel, and the intermittent exposure scenario, ATSDR considers it unlikely that sufficient fuel was jettisoned in the neighborhoods surrounding Kelly AFB to cause adverse health effects.
Recommendations
None.
It is not likely that fruit and vegetables watered with contaminated groundwater from private irrigation wells or through uptake from groundwater, would contain contaminants at levels of health concern. Citizens were concerned about the safety of eating fruits and vegetables that had either been watered with contaminated groundwater or had absorbed contaminants through the soil from the contaminated shallow aquifer. The contaminants in the groundwater are mostly VOCs. VOCs are not taken up well in plants (43). The groundwater is 15 to 30 feet below the surface and capillary action is not likely to be operable over this distance. Capillary action is a way that plant roots can get water from the soil below the roots. Moreover, the contaminants would volatilize when exposed to air or surface soil.
The soil analysis data from Kelly AFB does not indicate that contamination of off-base soils is likely from soil transportation events (8), and soil samples collected in the neighborhood by community representatives are not at levels of public health concern (7). The nature of the potential contaminants would not allow sufficient uptake into plants. Soil containing contaminants would be unavailable for uptake by plants because it is insoluble and binds tightly to the soil. Morever, if the chemical-containing soil were in contact with the root system of a plant, its lipophilic (fat loving) nature may allow its adherence to the exterior cell walls of the root system, but uptake and transport through the plant would be unlikely.
A study was conducted in which fruit and vegetable monitoring of carrots, tomatoes, peaches, apples, cantaloupe, nectarines, and plums was conducted after watering by flooding with TCE- contaminated (300 ppb) water for a growing season. The groundwater source was located 12 feet below the growing area. TCE above the detection level of 5 ppb was not found in any of the fruit or vegetables (44).
Conclusions
ATSDR concludes that VOCs in groundwater under neighborhoods near Kelly AFB are not likely to be found in home-grown fruits and vegetables at levels of health concern.
Recommendations
None.
Low-level radioactive waste buried on base does not pose a health hazard to off-base residents now, in the past, or in the future.
Prior to 1958, Kelly AFB buried low-level radioactive waste materials at two sites in Zone 1. These sites are now buried under the golf course. Records of the site located 250 feet west of Leon Creek indicate that the type of waste disposed was radioactive electron tubes and radium waste (such as dials and gauges, marked with radio-luminescent paint). These wastes were sealed in concrete pipe and buried. The other site is located 550 feet west of Leon Creek and contains animal carcasses which had been used in research involving radiolabels at Brooks AFB. The waste carcasses were placed in 55-gallon drums (although some may not have been placed in drums) and buried between 1961 and 1966.
|
The no public health hazard category is used
to indicate that there is no known exposure to hazardous chemicals.
|
The main radioactivity that could still be emitted from either site would be tritium and carbon-14, both beta-emitters with long half-lives. Beta radiation will not penetrate the surrounding materials and a receptor would have to ingest the waste or inhale a form of it for it to be harmful. While Radium-225 could emit gamma radiation, no gamma radiation was detected at the site. Radiation measurements indicated only emissions within the range of background radioactivity levels found in local soils (45). Since the disposal area is buried on base and the area will become a part of Lackland AFB after base closure, and therefore retain restricted access, there is no danger of community members becoming exposed. The site is listed as a radioactive burial site by state personnel who periodically inspect the site.
In accordance with Air Force regulations, long-term annual monitoring of the site is currently being conducted. The base radiation safety officer monitors the site annually in accordance with Air Force Technical Order 00-011-0N-2. ATSDR recommends that monitoring should continue because of the possibility of loss of container integrity resulting in contamination of soil and groundwater. In addition, institutional controls should be maintained to prevent worker exposure in the event future construction is initiated.
Conclusions
Low level radioactive waste buried on base does not pose a health hazard to off-base residents or on-base personnel.
Recommendations
ATSDR recommends that monitoring should continue because of the possibility of future loss of container integrity resulting in contamination of soil and groundwater. In addition, institutional controls should be maintained to prevent worker exposure in the event future construction is initiated.
|
The purpose of ATSDR's community activities is to
set up two-way communication with communities, and make sure that
the public takes part in our decisions at a site. ATSDR learns important
information about the community through conversations and meetings.
Some of the most important information ATSDR learns is how people
get information, as in newspaper, television, or radio. It is also
important to know how and where meetings should be held. ATSDR learns
what the community's health concerns are, and what they know about
the area. This lets ATSDR know what information (environmental or
health-related) it needs to look into about an area. It also tells
ATSDR what questions should be answered in our documents (Public Health
Assessments and Health Consultations). This ensures that the documents
ATSDR shares with the public are useful and acceptable to them. Also,
it ensures that follow-up activities ATSDR does are right for the
community, and address their needs. ATSDR made many visits to communities
around Kelly AFB and participated in many meetings with community
members and area leaders to learn and share information in a meaningful
way.
|
Background
In July 1997, ATSDR staff members met with members of the community, local government, local school districts, local media, the San Antonio Metropolitan Health District (SAMHD), and other public health officials in the course of conducting the public health assessment at Kelly AFB. The purpose of these meetings was to gather information about the community and the site, investigate the community health concerns, and determine the best means to communicate with area residents. This community involvement work has been coordinated by a Kelly AFB site team that includes representatives from the various divisions of ATSDR and the Texas Department of Health.
In initial visits, the site team met with Kelly AFB personnel and members of the San Antonio Metropolitan Health District to identify community concerns. In addition, ATSDR had a copy of a 1996 survey of residents in the North Kelly Gardens area that clarified community concerns. The survey was conducted by two grassroots environmental groups, Foundation for a Compassionate Society (FCS) and Committee for Environmental Justice/Action (CEJA), as well as the Southwest Public Workers' Union (SPWU), with technical assistance from the University of Texas Medical Branch at Galveston. Interviews were conducted with community residents, and a summary report stated that "91% of the adults and 79% of the children [in the area] are suffering multiple illnesses," including central nervous system disorders and ear, nose, and throat conditions. Many North Kelly Gardens residents associated these disorders with contamination from Kelly AFB. Consequently, the site team organized meetings with representatives from FCS, CEJA, and SPWU. The site team also met with residents from the southeast area outside of the base (the Quintana Road neighborhood) and the areas farther north and northwest of Kelly AFB that were not included in the North Kelly Gardens survey. ATSDR planned community visits to:
Community Concerns
Many community concerns are presented in the North Kelly Gardens Community Health Survey, which is available in Appendix F. Issues and concerns that the community expressed to ATSDR in our meetings include the following:
Health-related
Environmental
Educational
Children's Health
Southside residents' concerns
Information
Communications and community meetings
In the course of initial visits by the site team, several misconceptions arose regarding ATSDR's role, ATSDR's independence from the Air Force and from other agencies, and the purpose of the public health assessment. The site team made additional visits to meet with community groups and address these misconceptions. Also discussed were issues that clarified ATSDR's role and capabilities as a federal nonregulatory public health agency.
The site team used these additional visits to expand community outreach efforts. Topics discussed in these meetings included communications with the community and selecting the most appropriate ways to communicate (for example, direct mail, flyers, newspapers, public meetings, radio, television, and word-of-mouth); locations and convenient times to hold meetings; locations for repositories to house ATSDR materials; and the possibility of Spanish language materials or the use of interpreters.
In these visits, the site team met with representatives from the following organizations, agencies, or community groups.
Local/City Government
Community Groups/Representatives
Media
Schools (Independent School Districts) Representatives
Media availability sessions were held to promote ATSDR community meetings, answer questions, and explain ATSDR activities and involvement at Kelly Air Force Base. Personal interviews were conducted with television or newspaper reporters during site visits in July 1997, November 1997, and at the City/County Community Forum held by San Antonio city and county officials (council members and mayor's office) in March 1998. Guidance for media outreach and communications was provided by ATSDR's Office of Policy and External Affairs. Such assistance will be continued for future ATSDR communication activities.
Additional meetings which focused on ATSDR's "Nursing Initiative" were also held. ATSDR has a cooperative agreement with the American Association of Occupational Health Nurses that provides for the environmental health education of health professionals and communities. Educational activities regarding environmental medicine and health will be conducted in cooperation with local nurses and other health professionals, and will be coordinated and overseen by ATSDR's Division of Health Education and Promotion and the American Association of Occupational Health Nurses. This activity was discussed in contacts with the following.
Issues discussed at these meetings included the following.
The site team also attended two community forums sponsored by the city of San Antonio to address community concerns related to Kelly AFB. At these forums, representatives from ATSDR and the Texas Department of Health spoke with members of the community and with staff members from other agencies involved with environmental issues at the base. At the second of these forums, ATSDR explained the public health assessment process. City council members and personnel from Kelly AFB, the San Antonio Metropolitan Health District, the Texas Natural Resource Conservation Commission, and the Bexar Metropolitan Water District were also in attendance.
With guidance from community members, repositories for housing ATSDR materials and documents related to the Kelly AFB public health assessment process were set up. These repositories give community members access in their neighborhoods to ATSDR information about Kelly AFB. These repositories are in four libraries in neighborhoods around Kelly AFB: the Pan American Library, the Las Palmas Library, the J.F. Kennedy High School library, and Memorial Library. The public health assessment public comment draft, fact sheets, educational materials, community correspondence, announcements, press releases, flyers, and other official correspondence produced by ATSDR will be included in the notebooks at these repositories.
Folders of information were given to community members who attended meetings held in March and April of 1998. These folders included two general fact sheets on ATSDR, a fact sheet on ATSDR petitioned public health assessments, a fact sheet on ATSDR's Division of Health Studies, a listing of the ATSDR/TDH site team members with names and addresses, and Kelly AFB repository information.
Recommendations (from meetings and visits)
ATSDR addressed community concerns by:
More specific recommendations for follow-up health education activities will be determined and considered when the public health assessment document is released and community meetings are held to discuss the document and the options for follow-up activities.
|
Health Outcome Data (HOD) is health information about
a group of people. It tells what diseases are common in a group of people,
and how many people got sick or died from different illnesses. HOD also
gives numbers of births and certain problems related to any births.
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The evaluation of the health outcome data to date is currently located in Appendix G of this document (Phase I), but will be included in this section of Phase II of the public health assessment.
ATSDR has requested additional health outcome data from the Texas Department of Health and this information will be included in Phase II. Also, the evaluation of past air emissions is not complete and may impact the comprehensive analysis of health outcome data. Once the additional health outcome data and past air emission information has been received, ATSDR will complete the evaluation of health outcome data and include these finding in Phase II.
ATSDR's Child Health Initiative recognizes that unique vulnerabilities are inherent in the developing young, whether fetus, infant, or child. Health assessors must consider these vulnerabilities in analyzing potential effects on the young. Children are not just "small adults." Differences in metabolism, stage of development of various body systems, physical characteristics, and behavioral characteristics, among others, must be considered in evaluating the potential health effects of a child exposed to hazardous substances. For example, children have a higher ingestion rate in comparison to body weight than adults do, and therefore children exposed to some substances (in the same time and place as adults) could receive comparatively higher doses of the substances than adults would.
Certain other physical characteristics of children must also be considered in evaluating the effects of their exposure to hazardous substances. For instance, the fact that they are shorter means their "breathing zone" is closer to the ground than the breathing zone of adults. This is a factor to consider when evaluating soil chemicals. Airborne contaminants also often have a denser concentration closer to the ground, and a child in the same area as an adult may inhale more of the substance than the adult would.
Some of the normal behavioral characteristics of children must also be considered in evaluating childhood exposure. A child's hand-to-mouth behavior has the potential to increase the ingestion of toxicants in soil or dust. Children also play close to the ground, thereby increasing their chances of being exposed to contaminated soil and dust and low-lying vaporous substances. Pesticides used in the home and outside thus have the potential for higher exposures to children than to adults (10).
In addition to physical and behavioral differences, the young have heightened susceptibility stemming from other reasons. A child's metabolic pathways, especially in the first months after birth, are immature compared to those of adults. Although it is true that in some instances children are better able to deal with environmental toxins than adults are, children are typically less able and thus are more vulnerable. Some chemicals that are not toxic to adults are highly toxic to infants (46).
Rapid growth and development occur in the first months and years of life. Some organs systems, especially the nervous and respiratory systems, may experience permanent dysfunction if exposed to high concentrations of certain contaminants during this period. In addition, because of this more rapid period of growth and development, a child's DNA is more likely to be exposed than later in life. Exposure at this stage may result in damage to the DNA, resulting in genotoxic insult (a condition with the potential to cause genetic change).
Children have more years of life ahead of them than adults do, and therefore exposure early in life means that there will be more years of life during which chronic disease may develop. This is especially important in multistage diseases that take many years to develop from earliest onset to actual manifestation.
Finally, children have less ability to avoid hazards, and they are dependent on adults making decisions for them. Because circumstances that would not be hazardous to adults could be hazardous to children, adults may not recognize a circumstance as hazardous to children and may not make decisions that will prevent children's exposure to a hazard.
In summary, of all people who live near hazardous waste sites, children often have the greatest exposures, the greatest potential for health problems, and the least ability to avoid hazards. Therefore, in this public health assessment of Kelly Air Force Base, ATSDR evaluated certain hazards specifically for children and identified issues needing further investigation and follow-up activities.
Potential Air Exposures
Past air exposures may have resulted in exposures of health concern for children. Many of the contaminants of concern are volatile organic compounds (VOCs) with the ability to cross the placenta and blood-brain barrier. Physiological changes in pregnancy result in increased absorption. It may be possible that a pregnant woman would absorb more VOCs than she would if she were not pregnant. The timing of the exposure and the dosage, in relation to gestational stage, would determine the likelihood for expected health effects. In addition, VOCs are stored in maternal body fat, and these VOCs may be released during the last trimester, perhaps resulting in additional or significant exposure.
An infant may have been exposed to VOCs and solvents through inhalation and also through dissolution of VOCs in the mother's milk (47). A fetus may also have been exposed through maternal blood. Children inhale more air per body weight than adults and tend to engage in more strenuous activity than adults while playing outside, resulting in increased inhalation rates (48). The bone marrow of children is more active than that of adults, making it more vulnerable to toxic effects.
The predominant contaminants identified in the air exposures in the past included benzene, hexavalent chromium, PCE, and other VOCs. Potential health outcomes of exposure to these contaminants may include hyperactive airways, leukemia, and neurological and hepatic effects. Because there may be many reasons for disease other than environmental contaminants, ATSDR must obtain more information before evaluating occurrence of these diseases. ATSDR therefore investigated information concerning adverse birth effects, such as low birth weight and birth defects, along with data from Texas cancer registries concerning leukemia (discussed in the Health Outcome Data section).
Potential Lead Exposures
Residents are concerned with potential lead in soil which may have affected children's achievement scores. ATSDR will conduct health education activities to explain and promote local programs that test children's blood lead levels. Children whose tests show elevated blood lead levels will be retested to confirm the condition. Environmental testing will be conducted for those children with confirmed elevated blood lead levels to determine whether the children could be exposed to excessive amounts of lead from such sources as lead-based paint, soil, or water pipes. After the environmental investigation, appropriate follow-up activities will be recommended.
Potential Nonauditory Exposures
Children may be more susceptible than adults to certain nonauditory effects of noise because they have less precise speech, limited vocabulary, and less developed familiarity with language rules (49). ATSDR reviewed noise contours and locations of schools around Kelly AFB. ATSDR concluded that noise levels were not high enough at locations of schools that adverse nonauditory effects would be likely.
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