HOT SPRINGS MERCURY -- 100 BAYOU POINT CONDOMINIUMS
HOT SPRINGS, GARLAND COUNTY, ARKANSAS
CERCLIS NO. AR0002007870
September 30, 1997
Arkansas Department of Health
Little Rock, Arkansas
Under a Cooperative Agreement with the
Agency for Toxic Substances and Disease Registry
BACKGROUND AND STATEMENT OF ISSUES
The Environmental Protection Agency (EPA), Region 6, requested that the Arkansas Department of Health (ADH) and the Agency for Toxic Substances and Disease Registry (ATSDR) review the environmental data collected on elemental mercury contamination in Complex B of the Bayou Point Condominiums located at 100 Bayou Point in Hot Springs, Arkansas.
At the end of July 1997, ADH was contacted by the Garland County Health Unit about a couple living at 100 Bayou Point Condominiums in Hot Springs. The couple were seeking help to determine if they were being exposed to elemental mercury. They informed the representative for the county health unit that their initial exposure to elemental mercury had occurred in Lincoln, Nebraska. This information was forwarded to the Division of Epidemiology at the ADH, and contact was made with the Nebraska Department of Health (NDH). NDH confirmed the couple's report concerning exposure to elemental mercury/mercury vapor in Lincoln, Nebraska. NDH also confirmed the possibility that the elemental mercury was transferred to their vehicles and Hot Springs residence.
On Thursday, August 7, 1997, ADH conducted an exposure investigation. ADH personnel monitored for mercury vapor using a direct read instrument--a Jerome 431 X--in the residence, vehicles, and storage warehouse of the couple. The Jerome 431 X has a detection limit of 1 microgram mercury/cubic meter (µg/m3) of air. Numerous samples were collected at these sites. All of the readings were above 1 µg/m3 of air. The instrument was pegged at two sites during these activities: once in the back seat of one of the vehicles and again in the storage area near the couple's vacuum cleaner. These readings exceeded 999 µg/m3 of air. With the Jerome 431 X meter, the levels measured in the condominium at 4 to 6 feet from the floor ranged from 0.02 milligram/cubic meter (mg/m3) of air to 0.030 mg/m3 of air. Other samples in selected areas near the floor were as high as 0.072 mg/m3. The levels of elemental mercury in the adjacent condominiums were less than 0.001 mg/m3 as measured with the Jerome 431 X meter.
The levels measured in the rental storage unit using the Jerome 431 X meter ranged from <0.001 mg/m3 in air in the general space to levels >1.0 mg/m3 in air in the box containing a vacuum cleaner. Several items were shown to be contaminated when measured in the open air, i.e., unbagged.
The levels of mercury vapor inside the cars ranged from 0.007 near the ceiling of one car to >1.0 mg/m3 of air near the surface of the back seat. Most samples from the back seat of one of the cars yielded levels greater than 0.020 mg/m3 of air.
A total of 42 head space samples were taken inside of sealed plastic bags containing various items removed from the contaminated condominium and currently located at the campsite where the past residents of the condominium are camping. On the basis of procedures used at another elemental mercury site (1), the property of the resident was screened for elemental mercury contamination. The Jerome 431 X meter was used for these measurements. With these results, items were segregated into three categories: those reading <0.001 mg/m3 of air, those reading >0.001 but <0.010 mg/m3 of air, and those reading >0.010 mg/m3 of air. Of the total samples taken, 14 were <0.001 mg/m3, 9 were >0.010 mg/m3, and 19 were >0.001 and <0.010 mg/m3. A large foam pad that one of the residents was sleeping on measured as high as 0.103 mg/m3 of air. Items <0.001 mg/m3 were immediately released for use.
Items with readings >0.001 and <0.010 mg/m3 were taken from the plastic bags and laid out in the sun. After 24 hours these were released for reuse. Those items reading >0.010 mg/m3 were placed in a secured area for future assessments. Several items were checked inside the residents' condominium. Only those items with head space readings <0.010 mg/m3 of air were allowed to be taken from the unit for use by the residents.
The following week, readings were taken from adjoining condominiums using the Jerome 431 X. No readings were documented above 1 µg/m3 of air, except at one site where several candles were being burnt. Since the mercury readings were below the 1 µg/m3 detection limit of the Jerome 431 X meter, a more sensitive method--the National Institute for Occupational Safety and Health's (NIOSH) method 6009--was used to determine the presence of mercury vapor in the adjoining condominiums during follow-up sampling.
On Tuesday, August 19, 1997, ADH personnel conducted time-weighted average (TWA) sampling using NIOSH method 6009 at the five condominiums in Complex B. Two samples were collected at each unit. One field blank was collected. All of the samples taken detected mercury vapor. The highest level recorded at these sites was 0.00089 mg/m3 of air. Elemental mercury levels inside the condominiums ranged from 0.00024 to 0.00089 mg/m3 of air. The average levels ranged from 0.00025 to 0.00072 mg/m3 of air in the same condominiums.
In addition to the environmental data, biomedical data showed
that the persons living in the heavily contaminated condominium
were exposed to mercury. The couple living at the residence
where the primary source of mercury was found had urinary mercury
levels collected before undergoing chelation therapy. The
urinary mercury level was 67 micrograms/liter (µg/L) for the male
resident and 11 µg/L for the female resident. After chelation
therapy began, their urinary mercury levels rose to 260 µg/L
(male) and 70 µg/L (female). No other residents in the complex
have been tested for mercury exposure. Two children live in this
Inhaled metallic mercury rapidly enters the bloodstream and goes to other parts of the body. The metallic mercury can stay in the bloodstream of the body for weeks or months. It accumulates in the kidney and brain. A completed pathway of exposure via inhalation has been confirmed through monitoring activities and human biomarker data. The highly contaminated condominium was found to have mercury vapor levels in ambient air of 20 µg/m3 ; these levels exceeded the ATSDR minimal risk level (MRL) of 0.014 µg/m3 for chronic inhalation exposures. This level has been confirmed by both the Jerome 431 X meter and by TWA samples (NIOSH method 6009).
Exposure to the levels reported in the highly contaminated unit could result in immunological and neurological effects in humans (2). Current levels in at least two other condominiums have already exceeded the ATSDR chronic inhalation MRL; however, health effects are not expected to occur in these residents if the exposure to the mercury is eliminated in the near future. If action is not taken, the mercury vapor levels in the other affected units could continue to rise.
The urinary mercury levels for all samples collected are above the normal range of 4-5 µg/L. One individual is exhibiting signs of neurotoxicity associated with mercury exposure.
The residents in the highly contaminated condominium are undergoing medical treatment for their mercury exposure. Urinary mercury levels have not been obtained for the residents of the adjacent units.
The mercury contamination is not confined to the complex
building. A storage unit containing the vacuum may be the major
contributing source of the mercury. The two contaminated
vehicles have been taken by the couple's auto insurance carrier.
Current plans are for the insurance company to dispose of these
vehicles through hazardous waste methods. The residents of the
highly contaminated condominium continue to camp at a lake.
Mercury-contaminated property has been identified at this
- The levels of mercury reported in ambient air of the highly contaminated condominium pose a public health hazard to residents that may occupy that unit. The residents of that unit have urinary mercury levels exceeding normal values. One resident is exhibiting signs of mercury neurotoxicity.
- Levels of mercury have been detected in adjacent condominiums that exceed the ATSDR MRL for chronic inhalation exposure. It is not known if the levels of the mercury will continue to increase in ambient air. However, these residents may be at health risk if the levels continue to increase in their units and the source of mercury is not abated in the near future.
- Significant mercury contamination has been found in property extending beyond the confines of the condominium complex.
- A biological measure of mercury exposure has not been obtained for the other residents of the condominiums. Small children reside in some of the units of the complex.
- Measures should be undertaken immediately to dissociate residents from exposure to mercury vapors in the complex.
- All mercury-contaminated property should be identified and disposed of properly to prevent any further exposures.
- Urinary mercury levels should be obtained for all other residents of the complex.
- Health education should be provided to all residents regarding the toxic effects of mercury.
PUBLIC HEALTH ACTION PLAN
A number of actions have already been undertaken by the ADH, as follows:
- ADH conducted an exposure investigation to determine the status of mercury contamination of the condominium units of the complex and the property of the residents.
- ADH has notified the residents of the highly contaminated condominium that they should not occupy their unit.
- Health education has been provided to all residents regarding the health effects of exposure to mercury.
- An occupational physician has consulted with the ADH regarding the medical treatment of the couple residing in the highly contaminated unit.
- All residents will be given the opportunity to have the status of their mercury exposure assessed (urinary mercury levels).
PREPARERS OF REPORT
Arkansas Department of Health
ATSDR Region 6
Technical Project Officer, ATSDR
- Orloff K, Ulrich G, Wilder L, Block A, Fagliano G, Fasquao J. Human exposure to elemental mercury in a contaminated residential building. Archives of Environmental Health 1997 May/June;52:3.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for mercury (update). Atlanta: US Department of Health and Human Services, Public Health Service; 1994 May.
The 100 Bayou Point Condominiums Health Consultation was prepared by the Arkansas Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the Health Consultation was initiated.
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this Health Consultation and concurs with its findings.
Chief, SPS, SSAB, DHAC, ATSDR