Evaluation of Environmental Monitoring Data Collected in Support of the Sargeant Avenue Soil Cleanup
(Broad Street Soil Piles)
SARGEANT AVENUE SOIL CLEANUP
(BROAD STREET SOIL PILES)
NASHUA, MERRIMACK COUNTY, NEW HAMPSHIRE
This health consultation has been prepared in response to the request made by the City of Nashau to the New Hampshire Department of Health and Human Services (DHHS) for assistance in evaluating the health hazard associated with potential exposure to asbestos contaminated soils excavated during a public works project in the City of Nashua. Specifically, this document evaluates the soil and air sampling data that was collected to evaluate the potential release of asbestos fibers to the community during removal activities at the Sargeant Avenue and Broad Street sites. This health consultation has been prepared by the New Hampshire Department of Health and Human Services, Office of Community and Public Health, Bureau of Environmental and Occupational Health (DHHS) through a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR).
During early April, 2003, while involved with the construction of a storm water detention pond on Sargeant Avenue, in the area of the Holman Athletic Stadium, the City of Nashua (City) discovered that soils being removed from this location were contaminated with asbestos wastes (1). An initial investigation by the City revealed the presence of suspect asbestos wastes in the form of plate and bag house wastes in subsurface soils. Prior to the discovery, excavated soils from this project were being transported to the City's municipal landfill (Four Hills Landfill) for disposal and to a nearby location within the city at 523 Broad Street where it was being stockpiled for use as fill at Majestic Heights, a local residential development. Once asbestos was discovered, the City suspended soil excavations, notified the New Hampshire Department of Environmental Services, and contracted with an asbestos abatement firm to begin characterizing the nature and extent of contamination in the remaining soils in the detention pond area, preparatory to removal.
The City asked DHHS for assistance with evaluating the potential health risk for local residents who may have been exposed to asbestos contaminated soils as the result this project (1). DHHS provided comments on a draft risk assessment report prepared for the City by its consultant that qualitatively evaluated potential exposure to contaminated soils. Although environmental sampling data was not available at this time, the consultant found that, based on a number of factors, including the limited presence of asbestos contamination at the site, seasonal weather conditions (frozen ground conditions in winter followed by unusually wet conditions in spring) and limited opportunities for exposure to outdoor soils during that time of year, that there was little likelihood that local residents would have been at appreciable health risk (2). At the City's request, DHHS also participated, along with the New Hampshire Department of Environmental Services (DES), in a public meeting that the City held on April 16, 2003, at the Amherst Street Elementary School to hear local residents' health concerns and to discuss plans for clean up of the contaminated soils (3). Following this meeting, DHHS was able to speak with several residents from the Broad Street neighborhood that expressed concern about the materials being stockpiled on the adjacent development property.
Site Characterization and Clean Up
Shortly after the discovery of asbestos, the City's asbestos abatement contractor began work at Sargeant Avenue to identify the nature and extent of asbestos contamination in soils in the detention pond area. Between April 3-9, 2003, a total of 124 subsurface test borings were made at approximate 25-foot intervals throughout the excavated area (4). Test borings were made to a depth of 2 ½-3 ft. to determine the possible presence of asbestos wastes at shallow soil depths. Of the total number of borings made, visual inspection showed that suspect asbestos wastes, in the form of plate or baghouse wastes, were present in some 33 test borings. During this characterization, three samples were collected and submitted to a laboratory for analysis by Phase Contrast Microscopy (PCM). The three samples that were analyzed consisted of one sample each of bag house waste, plate waste and board type material. The three samples analyzed were positive and shown to contain 20% chrysotile asbestsos (4). It is important to note that normally the results of asbestos analyses are reported on a "weight" basis; however, the exact method used to analyze the three samples was not contained in the documents reviewed for this health consultation. At the same time, air sampling was also conducted in the Sargeant Avenue area to determine whether asbestos, in the form of airborne fibers, was being released from the excavated portion of the site. A total of 14 air samples were collected while the soil characterization work was underway. All of the air samples collected showed asbestos at concentrations of less than 0.002 fibers per cubic centimeter (fibers/cc), which is significantly lower than the ATSDR community action level of 0.01 fibers/cc, indicating that the airborne release of asbestos from the site was not a public health concern.
In response to the discovery of a new asbestos waste site in a heavily populated residential neighborhood, the City developed and submitted a clean up plan to DES for the Sargeant Avenue site. Later in April, following the initial discovery of asbestos, the remaining contaminated soils were transported to the Four Hills Landfill for disposal and the detention pond excavated area was covered in accordance with appropriate federal and state environmental regulations.
523 Broad Street
Prior to the discovery of asbestos on Sargeant Avenue, some asbestos contaminated soils from the detention pond excavation had been transported to another location at 523 Broad Street for use in the Majestic Heights Development. This residential development is located in another heavily populated residential area within Nashua. These soils had been placed in piles located throughout the entrance of the development. When it was learned that asbestos contamination was a problem, the City took immediate steps to limit the potential release of asbestos from these soil piles. The soil piles were kept wetted and temporary tarps were put in place to prevent the release of contaminated soils , as dusts, to off site locations. As with the Sargeant Avenue Site, the City began efforts to characterize the nature and extent of asbestos contamination in the stockpiled soils in this location.
Two on site stockpiles located at the entrance of the development were identified for characterization. These stockpiles were selected because of their proximity to existing residences in the adjoining neighborhood. A combined total of 14 surface (grab) and test pit (composite) soil samples were collected on April 15, 2003, and were analyzed for asbestos. Three of the surface soil samples tested positive for asbestos (minimum 20% chrysotile asbestos) and were found to contain small pieces of transite board and insulation wrap. The remaining grab samples and all of the test pit samples were negative for asbestos (5). While characterization of the soil piles was underway, a total of three air samples were collected to determine if asbestos fibers were possibly being released from the site. Test results for all of the air samples showed asbestos fiber concentrations of less than 0.003 fibers/cc.
As with the Sargeant Avenue Site, the City prepared an asbestos site abatement plan for this location. Between May 20 and June 9, 2003 contaminated soils from the two soil piles previously discussed, plus four, smaller piles of suspect materials were removed from the site. Soil piles were wetted down during removal to prevent the release of asbestos; all contaminated soils were taken to the Four Hills Landfill for disposal. Clearance sampling was conducted to insure that all of the contaminated soils had been removed. A total of 56 soils samples, including soil samples collected from the base of stockpile removal work areas, side wall sampling locations, and random samples from throughout the site, were analyzed and found to be negative for asbestos (6). In addition, individual swipe samples from the windows of residences at 520, 524, 526 and 528 Broad Street (directly opposite 523 Broad Street) were collected to determine whether contaminated dusts from the site might have migrated to off site residential areas. The sampling results for these residences were also negative for asbestos (6).
Asbestos is the name given to a group of six naturally occurring fibrous minerals. Asbestos is a known human carcinogen and has been classified by EPA as a Group A carcinogen (7). Inhalation has been shown to be the most significant route of exposure for asbestos and increases the risk of developing lung cancer and mesothelioma, a rare cancer of the membrane surrounding the lungs and other internal organs. Breathing air contaminated with asbestos over a prolonged period of time can lead to scarring of the lungs, a condition known as asbestosis. There is some limited evidence that ingesting asbestos fibers may cause an increased risk of developing cancer of the esophagus, stomach, pancreas, and prostate but this evidence has not been conclusive (8).
The concern with asbestos contaminated soils excavated from the Sargeant Avenue Site is that residents may have been exposed to asbestos fibers in this material either at the excavation site on Sargeant Avenue or at the location on Broad Street where soils were being stockpiled for use in a residential development. At both sites, actual exposure would have been through either the inhalation of asbestos fibers in air or through the incidental ingestion of asbestos materials in soils. As had been discussed in the qualitative risk assessment that the City had prepared in early April, the potential for local residents to be exposed was limited due to the short time period that the contaminated soils had been excavated before discovery, prevailing weather conditions and the time of year that limited outside activities. Once the contamination had been discovered, the City was proactive in taking steps to reduce the potential release of contaminants from the two sites (wetting soil piles, tarping) while it moved quickly to clean up the asbestos wastes. Relative to airborne releases of asbestos fibers, DHHS utilized ATSDR's screening level of 0.01 fibers/cc to evaluate potential exposure to the community. There were no exceedances of this screening level; air samples that had been collected at the two locations did not show that asbestos fibers were being released from these sites at concentrations that would constitute a health concern.
With respect to asbestos contamination in soils, soil sampling revealed that asbestos was present, although it was encountered primarily in the form of plate and bag house wastes. Soil sampling conducted at both sites coupled with the visual inspection of the excavated area on Sargeant Avenue indicated that suspect asbestos wastes were found in relatively low frequencies. The control measures taken coupled with the clearance sampling data made available for review indicates that any potential release of asbestos was not likely to be significant and that the removal actions were successful in eliminating this hazard from the community.
ATSDR recognizes that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than adults from certain kinds of exposures to toxic chemical substances released to the environment. They are more likely to be exposed because children spend a significant amount of their time playing outdoors. They are generally of shorter stature than adults, which means they breathe dust, soil and heavy vapors close to the ground. Children are also smaller, resulting in higher doses of chemical exposure per body weight. The developing body systems of children can sustain permanent damage if exposures to certain toxic substances occur during critical growth stages. Most importantly, children depend completely on adults for risk identification and management decisions, housing and access to medical care.
Children are potentially more likely to expose themselves to asbestos contaminated soils through activities such as exploration and playing in areas near where soil may have been excavated or stockpiled. Asbestos fibers in soil can cling or adsorb to their outerwear, and potentially expose individuals not directly associated with the site (family members, friends).
DHHS assumes that children are among those individuals who were potentially exposed to contaminated soils in the Sargeant Avenue and Broad Street areas and, for the reasons mentioned above, represent the age group that would be most at risk from exposure to contaminants in soils. As stated above, however, adverse health effects are not expected to result from exposure to these contaminated soils.
The excavation of asbestos-contaminated soils from the Sargeant Avenue detention pond area and their subsequent removal from this location and at Broad Street was conducted in a manner that did not cause any significant release of asbestos to the surrounding community. According to the ATSDR public health hazard classification system, these events constituted no public health hazard because the control measures were successful in limiting exposure to asbestos contaminated soils and the monitored air levels of asbestos were well below a concentrations that could result in an adverse impact on human health.
No recommendations are indicated at this time.
The purpose of the Public Health Action Plan is to ensure that this health consultation not only identifies any current or potential exposure pathways or related health hazards, but also provides a plan of action to mitigate and prevent adverse human health effects resulting from exposures to hazardous substances in the environment. The first section of the Public Health Action Plan contains a description of completed, ongoing, or planned actions to mitigate exposures to environmental contamination. In the second section, there is a list of additional public health actions that DHHS recommends be implemented in the future.
- Upon identifying the presence of asbestos contaminated soils at the Sargeant Avenue excavation site and in stockpiled soils on Broad Street, the City of Nashua worked quickly to prevent the potential release of contaminants from these sites.
- The City of Nashua collected air and soil samples in the Broad Street area to determine if local residents were at health risk from exposure to asbestos-contaminated soils temporarily stored at this location.
- Contaminated soils at Sargeant Avenue and Broad Street were disposed at an approved landfill site.
- DHHS reviewed soil and air sampling data that was collected during the soil removal project. This evaluation indicated that local residents were not at risk from the excavated soils on Sargeant Avenue or the soil piles temporarily stored at Broad Street.
Ongoing or Planned Actions
- No additional actions are warranted at this time.
Dennis A. Pinski
Supervisor, Risk Assessment Section
Bureau of Environmental and Occupational Health
New Hampshire Department of Health and Human Services
Concord, New Hampshire
(603) 271-3991 (fax)
- City of Nashua. Personal Communication with Amy Gill, Project Manager, Nashua Department of Public Works. April 11, 2003.
- Camp, Dresser & McKee Inc. April 11, 2003. Qualitative Risk Assessment of Asbestos Contaminated Fill Material Sewer Separation Project, Contract No. 005.
- City of Nashua. Personal Communication with Amy Gill, Project Manager, Nashua Department of Public Works. April 14, 2003.
- Alpha Asbestos Abatement, Inc. April 14, 2003. Asbestos Disposal Site Characterization, City of Nashua, Holman Stadium Detention Pond. Job # 2003-18-03.
- GZA GeoEnvironmental Inc. April 15, 2003. Field Summary Report: Stockpiles at 523 Broad Street.
- GZA GeoEnvironmental Inc. June 13, 2003. Clearance Sampling Results Stockpile Removals 523 Broad Street (Site) Nashua, New Hampshire.
- U.S. Environmental Protection Agency. Integrated Risk Information System (IRIS). Last Update: March 10, 2003.
- Agency for Toxic Substances and Disease Registry. 1995. Toxicological Profile for Asbestos
The Health Consultation for the Sargeant Avenue Soil Pile in Nashua, New Hampshire was prepared by the New Hampshire Department of Health and Human Services 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.
Greogory V. Ulirsch
Technical Project Officer, SPS,SSAB,DHAC
The Division of Health Assessment and Consultation (DHAC), ATSDR, has reviewed this Health Consultation and concurs with its findings.
Chief, SPS, SSAB,DHAC,ATSDR