Technical Assistance to the Oldtown Community Advisory Group
POLES, INCORPORATED WOOD TREATING FACILITY
OLDTOWN, BONNER COUNTY, IDAHO
The Bureau of Environmental Health and Safety (BEHS), Idaho Division of Health, Department of Health and Welfare, prepared this Health Consultation under its cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR) to document the BEHS response to several Oldtown Community Advisory Group e-mails requesting more in-depth explanations about our activities and decisions. The health consultation addresses those specific issues raised in the e-mails. In the discussion section you will see a bold heading with accompanying explanatory text. The bolded, italicized heading delineates the issue/question posed to BEHS. The text that follows is our explanation to the issue/question raised.
Poles Inc. is located in Oldtown just south of Pend Oreille River in the Panhandle of Northern Idaho. The facility has produced pentachlorophenol-treated utility poles since 1945. The facility currently operates nine months out of the year. An elementary school (Idaho Hill Elementary) and multiple residences are within proximity of the site.
In fall 2000, teachers from Idaho Hill Elementary and community members formed the Healthy Building Committee. The committee requested the Idaho Department of Environmental Quality (IDEQ) to investigate an irritating chemical smell coming from the facility during its pole treating process. Following the request, IDEQ performed an evaluation of potential inhalation exposure to PCP using two air dispersion models called the Back Model and the SCREEN3 Model (IDEQ 2001). BEHS reviewed IDEQ's report and determined that modeled PCP concentrations may pose a public health concern if they are representative of actual exposure levels. Therefore, because of multiple uncertainties regarding the use of computer models, BEHS recommended that a thorough environmental investigation be conducted at the Oldtown site. Details are summarized in the previous Health Consultation titled "Evaluation of Potential Pentachlorophenol Air Contamination Based on the Idaho Department of Environmental Quality April 2001 Air Modeling Results" (BEHS 2001a). BEHS formed the Community Advisory Group (CAG) during the process of drafting the previous Health Consultation to ensure community involvement. In summary, BEHS suggested that the environmental investigation should include multiple environmental media and that it should be expanded to focus on potential contaminants other than PCP. In August 2001, the Environmental Protection Agency (EPA) Superfund Technical Assessment and Response Team (START) completed an Integrated Assessment (IA) Sampling and Quality Assurance Plan (SQAP) for Poles Inc., and subsequent environmental sampling. BEHS reviewed the SQAP and provided review comments in the health consultation titled, "Evaluation of EPA's Integrated Assessment Sampling and Quality Assurance Plan for Poles, Inc." Prior to the start up of the sampling activities, START reviewed the suggestions and agreed to incorporate them in its IA SQAP.
This health consultation addresses questions raised by the Oldtown CAG before the EPA IA final report was released in January 2002. By the time this health consultation is published, BEHS will have reviewed the IA sampling results and begun preparation of a public health assessment for the site.
BEHS and ATSDR assess chemical exposures or the potential for exposures and assess whether or not people may experience harmful health effects from those exposures. Unlike the EPA health risk assessment process that addresses current or future exposures from a regulatory perspective, the public health assessment process looks at past, present and future exposures from a human health effects perspective. BEHS and ATSDR determine the chemical(s) of concern based on environmental data collection conducted by others, assess the hazards associated with those chemicals and determine if there was, is or will be exposure. The level of hazard to people based on the magnitude and duration of the exposure is then assessed. In the case of Oldtown, BEHS is still awaiting the sampling data results from EPA to conduct the public health assessment. Until environmental sampling data is received, BEHS cannot definitively state that people are being exposed to pentachlorophenol at levels that would result in adverse health effects.
BEHS has never received the names of teachers at Idaho Hill Elementary School who are said to have cancer. To date, only anecdotal information about the numbers of people with cancer in the school and community has been received. BEHS has approached the school districts to try and obtain information about the teachers to compare to the Cancer Data Registry of Idaho's (CDRI) database. The school districts were reluctant to provide the key pieces of information (birthdates and social security numbers if available) necessary for the CDRI to conduct a meaningful cancer analysis for the school. The school districts were willing to provide CDRI with the names and dates of employment. However, the CDRI did not feel that the name identifiers alone could be effectively validated against their database because the chance of errors in matching individuals on name alone was too high. Because of privacy and confidentiality issues, BEHS and CDRI are not in a position to take the list of names and contact people individually to see whether or not they have been diagnosed with cancer in Idaho.
BEHS is currently conducting another cancer incidence analysis for the combination of three zip codes (Oldtown, Newport, and Priest River). The analysis results will be compared to the rates in both the remainder of the state of Idaho and the remainder of the county (rural area). BEHS will then evaluate over 24 cancer types, as well as all cancer types combined by gender. CDRI has a 99.6% case completeness rate and a 98.6% accuracy rate. In other words, BEHS has great confidence that those people in your communities that were diagnosed with cancer in Idaho or neighboring states are included in their database.
Lastly, BEHS is waiting for environmental data to provide evidence that an epidemiological study or biological testing (for example, urine, blood, or fat testing) is warranted. Unfortunately, there is no other comprehensive, non-cancer disease registry in the State of Idaho. BEHS will utilize the data that is currently available. Current efforts at the Federal level to begin tracking chronic diseases other than cancer may give local, state, and federal public health agencies more extensive health outcome data to use in the future.
Specific questions have been asked about the costs, invasiveness, and logistics of having body fat tested for the, presence of dioxin (impurity found in pentachlorophenol). BEHS does not recommend body fat testing for dioxin until environmental data support the need for such testing. However, BEHS has done some research and found that there are very few laboratories that have the ability to analyze body fat for dioxin. The laboratory analytical techniques are complicated, therefore the tests are expensive. The cost is dependent upon the number of samples submitted to the laboratory and the detection limit that is requested. An individual analysis is approximately $1,500. The amount of body fat that is required for analysis varies by analytical technique, but the approximate amount is 10 or more grams of body fat. The fat extraction process is dependent upon the physician, as well as the physician costs. ATSDR's toxicological profile for pentachlorophenol cites references that evaluated body fat testing for dioxin.
BEHS and ATSDR use the term "health effects" to denote that there may be a change in the health status of an individual or an effect on health. The agencies judge that the terminology "health effect" is appropriately used in the BEHS health consultation and is consistent with how other public health agencies present information. BEHS does not feel that it implies a "healthy effect" from exposure to pentachlorophenol and did not assume that others would think that it implied a positive change in one's health status.
Until BEHS has received environmental sampling data identifying that contaminants are leaving the site resulting in off-site exposures, BEHS does not feel it is appropriate to eliminate the word "potential." BEHS, as a public health agency, can not definitively state there is exposure to pentachlorophenol or determine resulting impacts on human health without supporting environmental data.
As partners with ATSDR, BEHS uses Minimal Risk Levels (MRL's) to calculate non-cancer risk and adopts a cancer slope factor from EPA to calculate cancer risk. At or below that MRL and at or below calculated cancer unit risk, we consider the exposure to be without apparent risk of health effects.
The ATSDR toxicological profile for pentachlorophenol documents that the following MRL has been established: 0.005 mg/kg/day for acute-duration oral exposure and 0.001 mg/kg/day for both intermediate-duration and chronic-duration oral exposure. Currently there are no inhalation MRLs available for pentachlorophenol. However, oral data is used to assess inhalation exposure when inhalation data are not available, as in the case of pentachlorophenol.
EPA has developed an oral slope factor for pentachlorophenol, 0.12 (mg/kg/day)-1, based on a feeding study in mice conducted as part of the National Toxicology Project. Since there is no inhalation slope factor available for pentachlorophenol, BEHS adopted the EPA oral slope factor value as an inhalation slope factor to assess risk. BEHS is aware that there are uncertainties associated with using an oral factor for inhalation purposes. The State of California published an inhalation slope factor for pentachlorophenol, 0.018 (mg/kg/day)-1. It is not known if the California value more accurately represents the carcinogenic toxicity of pentachlorophenol than the EPA value. BEHS will use EPA's value to be more protective and to determine a site-specific risk-based ambient air concentration. In order to do so, the potential for exposure to pentachlorophenol via other exposure routes, such as dust inhalation, incidental soil ingestion, or dermal uptake, should also be evaluated. If there are other complete exposure pathways, then the acceptable concentration of pentachlorophenol vapor in air would have to be lower because other pathways also contribute to cumulative cancer risk. So far, BEHS does not have data from other environmental media needed to make a final decision.
Finally, BEHS is using the standard risk assessment/public health assessment procedures currently recommended by EPA and ATSDR, respectively. Pentachlorophenol is presently under EPA's review for a new oral cancer slope factor. As soon as that is finalized, BEHS will adapt the new EPA factor. ATSDR's MRLs were revised and published in September 2001. BEHS is confident it is utilizing the most up-to-date peer-reviewed science for conducting the public health assessment.
BEHS stated in its first health consultation for Oldtown that "there is weak evidence pentachlorophenol causes cancer in humans." On page five of the ATSDR Toxicological Profile for pentachlorophenol (both the draft document and the final September 2001 document) under the section titled, "How can pentachlorophenol affect my health," the following paragraph can be found:
"An increased risk of cancer has been shown in some laboratory animals given large amounts of pentachlorophenol orally for a long time. There is weak evidence that pentachlorophenol causes cancer in humans. The International Agency for Research on Cancer (IARC) has determined that pentachlorophenol is possibly carcinogenic to humans, and the EPA has classified pentachlorophenol as a probable human carcinogen."
The toxicological profile is a peer-reviewed profile that, as stated in the foreword, "identifies and reviews the key literature that describes a hazardous substance's toxicological properties." It also states that "this profile reflects ATSDR's assessment of all relevant toxicologic testing and information that has been peer-reviewed. Staff of the Centers for Disease Control and Prevention and other federal scientists have also reviewed the profile. In addition, this profile has been peer-reviewed by a nongovernmental panel and was made available for public review.' ATSDR, even after reviewing copious amounts of peer-reviewed literature, continues to use the same language. Additionally, after reviewing many animal studies and epidemiology studies, EPA classified pentachlorophenol as a "probable human carcinogen." The IARC classified it as "possibly carcinogenic to humans". Pentachlorophenol is not currently classified as a known "human carcinogen" because there are not enough human epidemiologic studies supporting the classification.
BEHS noted in one of the community meetings that IDEQ did not consider pentachlorophenol as a carcinogen when establishing Idaho's ambient air standard. That decision was a professional judgment made at that time. IDEQ is now considering revising Idaho's standard to err on the side of protection. However, decisions made by the State of Idaho do not influence the scientific data EPA or ATSDR utilizes.
BEHS is not in a position to ban the use and manufacture of pentachlorophenol. BEHS, like ATSDR, can only make recommendations. In Oldtown, BEHS has not seen evidence, to date, to support a position that pentachlorophenol use at Poles, Inc. is presenting a situation immediately dangerous to life and health. If that situation were found, BEHS could work with IDEQ and the Idaho Department of Agriculture to control the facility's use of the chemical. BEHS cannot ban the use and manufacture of a chemical.
EPA reevaluates all pesticides that were registered before November 1984. When EPA completes the review and risk management decision for a pesticide that is subject to reregistration, the Agency generally issues a Reregistration Eligibility Decision (RED) document. The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S. If pentachlorophenol is not eligible to be reregistered during its RED, IDEQ and BEHS will respond to that final decision accordingly.
BEHS anticipates that the public health assessment for the site will provide a comprehensive picture of the issues in Oldtown. No recommendations are indicated at this time. The public health assessment, due spring 2002, will evaluate the issues in Oldtown and provide public health recommendations.
BEHS, IDEQ, ATSDR, and EPA have conducted or are currently planning the following public health actions:
- BEHS formed the Oldtown CAG, sponsored multiple public meetings, and provided a public availability session. BEHS is currently the point of contact for the CAG and will routinely provide CAG with updates about Oldtown site activities from all involved agencies.
- IDEQ conducted a preliminary soil sampling at the facility and on the school playground to determine the possibility of soil contamination. BEHS will review the IDEQ sampling results as part of the development of a public health assessment for the site.
- Community members requested EPA conduct a preliminary assessment for the site. EPA conducted an IA of the site and has involved IDEQ, BEHS, ATSDR, and the site owner (Poles Inc.). The IA was competed in August and a final report was published in January 2002. BEHS is currently evaluating the environmental sampling results as part of the development of a public health assessment for the site.
- BEHS is currently drafting a public health assessment for the site. A draft will be available for technical comment by spring 2002. The public health assessment will make recommendations about the need for further actions at the site and within the community.
- BEHS is working cooperatively with the State of Idaho Cancer Analysis Working Group to evaluate cancer rates for the community and among Idaho Hill Elementary school teachers. The Cancer Analysis Working Group is comprised of the State of Idaho Epidemiologist, representatives of BEHS, representative of the Bureau of Vital Records and Health Statistics, and the Cancer Data Registry of Idaho.
ATSDR 2001. Toxicological Profile for Pentachlorophenol (update). U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. Atlanta, GA.
BEHS 2001a. Evaluation of Potential Pentachlorophenol Air Contamination Based on the Idaho Department of Environmental Quality April 2001 Air Modeling Results. Poles Inc. Wood Treating Facility Oldtown, Bonner County, Idaho. Bureau of Environmental Health and Safety, Division of Health, Idaho Department of Health and Welfare, Boise, ID and Agency for Toxic Substances and Disease Registry, Atlanta, GA. August.
BEHS 2001b. Evaluation of EPA's Integrated Assessment Sampling and Quality Assurance Plan for Poles, Inc., EPA Contract No. 68-SO-01-01, TDD No. 01-07-0007 Poles Inc. Wood Treating Facility Oldtown, Bonner County, Idaho. Bureau of Environmental Health and Safety, Division of Health, Idaho Department of Health and Welfare, Boise, ID and Agency for Toxic Substances and Disease Registry, Atlanta, GA. August.
IDEQ 2001. Summary of Analysis: Ambient Air Impact of Pentachlorophenol from Poles, Inc. Idaho Department of Environmental Quality. Boise, ID.
Preparers of Report
Mingyi Trimble, Sc.D.
Environmental Health Education and Assessment Program
Bureau of Environmental Health and Safety
Division of Health
Idaho Department of Health and Welfare
ATSDR Technical Project Officer
Gregory V. Ulirsch
Environmental Health Engineer
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
Any questions concerning this document should be directed to:
450 W. State St., 4th floor
P.O. Box 83720
Boise, ID 83720-0036
The Idaho Bureau of Environmental Health and Safety prepared this Health Consultation 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.
Gregory V. Ulirsch
Technical Project Officer, SPS, SSAB, DHAC
The Superfund Site Assessment Branch (SSAB), Division of Health Assessment and Consultation (DHAC), ATSDR has reviewed this health consultation and concurs with its findings.
Sven E. Rodenbeck
for Richard Gillig
Chief, SSAB, DHAC, ATSDR