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The Standard
June 2010 - Page 1

Relative Potency Factor Approach For Polycyclic Aromatic Hydrocarbon Mixtures
The US Environmental Protection Agency’s (US EPA’s) Integrated Risk Information System (IRIS) Program has released a relative potency factor (RPF) approach document to assess cancer risk from exposure to polycyclic aromatic hydrocarbon (PAH) mixtures (one approach) for scientific review. The published draft document is not a reassessment of individual PAH carcinogenicity, but rather, a cancer risk estimate for PAH mixtures determined by summing doses of component PAHs after scaling the doses (with RPFs) relative to the potency of an index PAH such as benzo[a]pyrene. The cancer risk is then estimated using the dose-response curve for the index PAH. RPFs for seven individual PAHs were developed in the US EPA Provisional Guidance for Quantitative Risk Assessment of PAHs (Provisional Guidance, 1993) and are utilized extensively within US EPA program offices and other regulatory agencies. The Provisional Guidance, however, does not reflect the most recent research, nor does it consider additional PAHs with carcinogenic potential (such as fjord-region PAHs).

Geoscientists install a groundwater monitoring well at an unpermitted landfill containing a large volume of crushed asphalt (a common source of PAHs).
Environmental Standards has reviewed the RPF document and has many concerns - most specifically regarding the precision and accuracy of the data used. US EPA has made no attempt to validate the chemical data used as the basis of its study and the data are invariably of inherent questionable quality. Data from historical studies dating to as far back as 1959 have been reviewed for the study; the apparent requirement for inclusion, based on US EPA’s own report, is that the information was not judiciously screened relative to analytical data quality.

The Supplemental Guidance for Conducting Health Risk Assessment of Chemical Mixtures (US EPA, 2000) emphasizes that approaches based on whole mixtures are preferred to component approaches, such as the RPF approach. Risk assessment based on toxicity evaluations of whole mixtures inherently address specific interactions among PAHs and account for the toxicity of unidentified components of PAH mixtures. These approaches do not require assumptions regarding the toxicity of individual components (e.g., dose or response additivity).

US EPA noted in its announcement that although whole-mixture assessment is preferred, there are associated challenges. Very limited toxicity data are available for whole PAH mixtures and, in most cases, chemical analyses of the composition of mixtures are limited. In addition, PAH-containing mixtures tend to be very complex; the composition of these mixtures appears to vary across sources releasing these mixtures to the environment and in different environmental media in which the mixtures occur. For these reasons, a whole-mixture approach may not always be practicable for risk assessment purposes.

There is a large PAH database on carcinogenicity in animal bioassays, genotoxicity in various test systems, and bioactivation to tumorigenic and/or genotoxic metabolic intermediates. The RPF analysis presented in the draft document includes only unsubstituted PAHs with three or more fused aromatic rings containing only carbon and hydrogen atoms - these are the most widely studied members of the PAH chemical class. A database of primary literature relevant to the RPF approach for PAHs was developed by performing a comprehensive review of the scientific literature dating from the 1950s through 2009 on the carcinogenicity and genotoxicity of PAHs. The search identified over 900 individual publications for a target list of 74 PAHs that have been identified in environmental media or for which toxicological data are available. These publications identified more than 600 papers that included carcinogenicity or cancer-related endpoint data on at least one PAH and benzo[a]pyrene tested at the same time.

US EPA notes in the draft report that studies were included in the analysis if the following selection criteria were met:

Benzo[a]pyrene was tested simultaneously with another PAH.
A statistically increased incidence of tumors was observed with benzo[a]pyrene administration, compared with control incidence.
Benzo[a]pyrene produced a statistically significant change in a cancer-related endpoint finding.
Quantitative results were presented.
The carcinogenic response observed in either the benzo[a]pyrene- or other PAH-treated animals at the lowest dose level was not saturated (i.e., tumor incidence at the lowest dose was < 90%), with the exception of tumor multiplicity findings.
There were no study quality concerns or potential confounding factors that precluded use (e.g., no concurrent control, different and co-carcinogenic vehicles used, strains used for the tested PAH and benzo[a]pyrene; use of PAHs of questionable purity; unexplained mortality in treated or control animals).

Environmental Standards observes that no specific study screening relative to analytical data reliability was undertaken as part of this reassessment. In fact, only a cursory treatment of such laboratory data quality issues is provided at all. Even in the uncertainty analysis of the document, there is only limited discussion of analytical detection limits, laboratory testing methodologies, reporting limits, and other critical components upon which US EPA relied.

The new draft document represents a major revision to the manner in which PAH toxicity is evaluated at hazardous waste sites and introduces analytical obstacles. In many instances, commercial environmental analytical laboratories do not currently have the standards necessary to analyze qualitatively and quantitatively for the listed PAHs. In addition, most laboratories do not have the precision, accuracy, and sensitivity required to analyze for many of the listed PAHs to make the proposed RPFs realistic for implementation at this point in time. Furthermore, in more than a dozen cases, there are no reliable published methods for the analysis of the individual PAHs for which US EPA has proposed regulation.

If you would like a copy of the proposed draft document, please contact Environmental Standards.

Environmental Standards Opens New Office In Kingston, Tennessee
Environmental Standards, Inc. is pleased to announce the company’s expansion and the opening of our newest office in Kingston, Tennessee. The Tennessee office, which opened its doors on April 1, 2010, acts as a cornerstone for Environmental Standards’ projects throughout the southeast United States. The office was initially founded to cost-effectively service an important regional client. The Tennessee office is currently managed by Senior Technical Chemist David I. Thal and will maintain a staff of experienced chemistry, geology, and information technologies professionals.

The new office is located at 1013 Brentwood Way, Kingston, TN 37763 and can be reached at 865.376.7590.

Environmental Standards Invited To Join API
The American Petroleum Institute (API) is the US oil and natural gas industry’s primary trade association. The API develops and supports policies, standards, and collaborative programs to help the US oil and natural gas industry meet the energy needs of consumers in an efficient, environmentally responsible manner. Environmental Standards is proud that the membership committee has extended an invitation, and we are very happy to announce that we are joining the API.

A key function of the API is to provide federal and state legislative and regulatory advocacy that is based on scientific research; we look forward to this opportunity to further advance our understanding of the industry’s scientific needs. The institute also develops measurement and operational standards for its member-practitioners. The more we can contribute to (and track) the development of these standards, the better we can serve the industry.

Membership in the API is by no means a given for anyone willing to join. Environmental Standards’ value to the industry in very specific terms was recognized by API’s leadership to gain the invitation. Membership promises to afford us the opportunity to work in support of the US oil and natural gas industry. Environmental Standards will have access to API’s well-respected research capabilities and will be able to contribute to the industry’s reputation through participation in widely recognized standards development and certification programs. We will also have access to API conferences, symposia, and training programs where our clients can further benefit from the experiences of our industry professionals. Other benefits include access to the members-only annual meeting, increased access to API publications and training, and leadership opportunities on API standards committees.

We look forward to sharing these special opportunities and insights with our clients, colleagues, and associates.

Brownfields Program Produces Widespread Economic And Environmental Benefits
Environmental Standards has a long tradition of assisting developers and communities with brownfields redevelopment programs. Even now, in the current economic downturn, Environmental Standards is acting as the prime environmental consultant on several brownfields redevelopment projects. These projects, valued at more than $300 million (and future tax revenues to host communities projected to be in the billions of dollars), continue to provide a key source of project work for the firm.

According to the latest studies, US EPA’s Brownfields Program alone (excluding economic development authority and local, county, and state initiatives) empowers states, communities, and other stakeholders to work together to prevent, assess, safely clean up, and sustainably reuse brownfields. Revitalizing brownfield sites creates benefits at a site and throughout the community.

The Phoenixville Foundry in Phoenixville, Pennsylvania, is a redeveloped brownfield site that is now a special event space.
Based on data from US EPA grantee reporting and through the program’s ACRES database, through fiscal year 2008, on average, $18.68 has been leveraged for each US EPA Brownfields dollar expended at a brownfield from Assessment, Cleanup, and Revolving Loan Fund cooperative agreements since program inception.

US EPA’s data also indicate that through fiscal year 2008, on average, 7.75 jobs have been leveraged per $100,000 of US EPA Brownfields funding expended on Assessment, Cleanup and Revolving Loan Fund cooperative agreements, also since program inception. As of January 2010, 61,023 jobs have reportedly been leveraged through the Brownfields Program.

The US EPA Brownfields Program has conducted five pilot studies, all of which concluded that redeveloped brownfield sites tend to have greater location efficiency than alternative development scenarios at greenfield sites; location efficiency has resulted in a 33% to 58% reduction in associated vehicle miles traveled and a reduction in air pollution emissions, including greenhouse gases. These same site comparisons show an estimated 44% to 88% reduction in storm water runoff. The US EPA studies suggest a range of positive impacts due to regional variation in development and travel patterns.

The US EPA Brownfields Program has also funded a study to assess the impact, or economic benefit, of Brownfields grants on residential property values. The study concluded that residential property values increased between 2% and 3% when a nearby brownfield was assessed or cleaned up. The study further concluded that cleaning up a brownfield can increase overall property values within a one-mile radius by $0.5 to $1.5 million. Additionally, initial anecdotal surveys indicate a reduction in crime in recently revitalized brownfield areas.

As is apparent from the numbers, there is a huge demand for site assessment work. The US EPA Program can expand upon recent policy clarifications to use site assessment dollars for environmental site assessments in conjunction with efforts to promote area-wide planning among areas and corridors of brownfield sites. The use of funds for these purposes enables the identification of infrastructure capacity along with potential end uses and is particularly important for economically distressed areas. Also, in certain instances when environmental site assessments reveal immediate threats to the environment or human health, a more programmatic use of US EPA funds to address these threats could be implemented.

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