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New Corporate Logo on Forest Service Risk Assessments

Syracuse Environmental Research Associates, Inc. –

51 Highbridge St., 42C, Syracuse, NY 13066-0950

Reality Check

SERA = Patrick & Patricia Durkin plus contractors and reviewers as needed

Risk Assessment Basics

Risk Assessment Basics

A Fuller View

A Fuller View

Five Characteristics of Good Risk Assessment

  • Transparency
  • Rationale
  • Objectivity
  • Judgment
  • Coverage

Five Characteristics of Good Risk Assessment - #1

  • Transparency – State the methods and assumptions clearly enough so that the risk assessment could be duplicated; no numbers out of thin air

Five Characteristics of Good Risk Assessment - #2

  • Rationale – State why you do what you do

Five Characteristics of Good Risk Assessment - #3

  • Objectivity – Do not care what the results are. Care only for the integrity of the analysis

Five Characteristics of Good Risk Assessment - #4

  • Judgment – Ensure that the choices of models and data makes sense

Five Characteristics of Good Risk Assessment - #5

  • Coverage – Include everything that should influence the risk assessment

Hazard Identification

  • What can the chemical do?
    • Consistency of the studies
    • Quality of the data
    • Statistical Significance
    • Biological Significance
    • Weight-of-evidence
  • Qualitative conclusions but often developed using quantitative methods

Exposure Assessment

Who gets what and how much?

  • Modeling vs monitoring
  • Quality of the data and models
  • Consistency of the estimates
  • Variability of the estimates
  • Can range from trivial to very complicated models

Dose-Response Assessment

  • How much is too much?
    • Relationship of known exposures (dose) to effects (response)
    • Incidence, severity, and durations
      • Acute, subchronic, and chronic
    • Consistency of the estimates
    • Variability of the estimates
  • Math can range from trivial (divide by 10) to very complicated

Risk Characterization

Is there any reason to worry?

  • Just add the dose-response to the exposure assessments and mix
  • Risk = Toxicity * Exposure
  • Simple compared to everything else

Risk Assessment Limitations and Scope

  • Risk Assessment is a form of analysis and NOT a science
  • It is NOT comprehensive
    • only contains a summary of studies that impact the assessment
  • Cannot prove safety, however
  • Can indicate whether or not there is a plausible basis for concern

Welcome the HQ

  • (Not the DQ, GQ, IQ, or the PDQ)
  • The Hazard Quotient


  • Similar in intent to the MOS
    • MOS is a measure of the relative safety of
      • Of a proposed action
      • Within a defined scenario
      • Numeric value should be 100.0 or greater for F.S. O.K.
    • HQ is a measure of the relative hazard
      • Of a proposed action
      • Within a defined scenario
      • Numeric value should be 1.0 or less for F.S. O.K.

HQ = Dose / (NOAEL / UF)

  • Where
    • NOAEL = the No Observed Adverse Effect Level accepted by the EPA for the pesticide being assessed
    • UF = an uncertainty factor established by the EPA which rates their interpretation of the reliability of the scientific studies used to support the assessment of risk (generally between 1 and 10)

Relating the Familiar to the New

  • MOS versus HQ


  • MOS = NOAEL/Dose
  • HQ = Dose/(NOAEL/UF)


  • Move some stuff around
    • NOAEL = MOS * Dose
    • NOAEL = MOS * Dose
  • MOS * Dose = Dose / (HQ / UF)


  • MOS = UF / HQ
  • HQ = UF / MOS


  • Basically we have inverted our thinking
  • To conform more closely with current EPA thinking
  • And make communication among those assessing risk easier

Why Use SERA’s RAs

  • SERA brings more current data
    • Not strictly a fair comparison since time has passed since the LAI assessments were done
    • However, more recent SERA documents include a review of EPA’s CBI
      • Far more comprehensive than previous F.S. RAs
      • Including significant data not available on the street
  • SERA’s modeling is mathematically more sophisticated and in-line with EPA’s

And One More Reason

In the United States District Court for the District of Oregon

Blue Mountains Biodiversity      )
Project, A Project of League of  )
Wilderness Defenders, a non-   )
profit corporation;                     ) Civil No. 01-703-HA
Opinion and Order

The Plaintiffs Contended

...defendants erred by relying upon the 1988 EIS instead of preparing a Supplemental EIS for this project. Plaintiff asserts the 1988 EIS cannot account for the impact of the planned herbicide applications, and the mitigation measures provided in the 1988 EIS should have been reviewed and updated with current information about herbicides and their effects

The Court (9th Circuit) Agreed

In view of this purpose, an agency that has prepared an EIS cannot simply rest on the original document. The agency must be alert to new information that may alter the results of its original environmental analysis, and continue to take a "hard look at the environmental effects of [its] planned action, even after a proposal has received initial approval

The SERA Risk Assessments

Are clearly

‘ information that may alter the results of its original environmental analysis...’

Except Forthe Following Herbicides
(EAs for about the next year and today’s test)

  • 2,4-DP
  • Fosamine
  • Tebuthiuron

Labat-Anderson’s RA Tools Will Shortly Be Superceded

Labat-Anderson’s RA Tools Will Shortly Be Superceded

SERA Risk Assessments Available on the F.S. – W.O. FHP website

SERA Risk Assessments Available on the F.S. – W.O. FHP website

Herbicides in the LAI RAs That have Been Reevaluated

Herbicides in the LAI RAs That have Been Reevaluated

Herbicides Which Remain Dependant on MOS and Conclusions Derived from the Labat Anderson RAs

  • 2,4-DP
  • Fosamine
  • Tebuthiuron

In Addition - New Herbicides Assessed by SERA

  • Clopyralid (Transline)
  • Imazapic (Plateau)
  • Metsulfuron methyl (Escort)
  • Sethoxydim (Poast)
  • (Isoxaben [Gallery])

And Insecticide RAs by SERA

  • MHC
  • Verbenone
  • TM Biocontrol - (Tussock Moth Biocontrol)
  • plus a couple supporting the Gypsy Moth EIS

Additional Support Documents (not RAs) Prepared by SERA

  • Marker Dyes
  • Neurotoxicity, Immunotoxicity, and Endocrine Disruptors
  • Surfactant Effects on Glyphosate Toxicity

Understand That None of These Are Easy Reading

  • Hard copies make good doorstops (thick)
  • Reading at night has cured insomnia (very technical)
  • BUT
  • These documents are critical to understanding and documenting the potential effects of our program

How to Use the SERA Risk Assessments

  • A Farewell to MOS

Two Versions: Bipolar Disorder?


Some History

  • 1998
    • Worksheets originally developed (internally at SERA) in WordPerfect in response to need for further transparency in risk assessments
  • 2000
    • SERA/Paul Mistretta (FS) explore development of EXCEL worksheets/VBA programs for doing worksheets
  • 2001
    • The USDA Forest Service adopted Microsoft Office (MS Word/EXCEL/…)
    • Forest Service tasks SERA with developing Worksheets in EXCEL

Characteristics of Two Versions

  • Both
    • The bottom-line math is the same
    • Used as a quality assurance check on each other
  • WordPerfect
    • More fully developed and easier to follow
    • Delicate/error prone when changing
    • Can be used by Forest Service personnel
    • Relatively easy to work with if you read the documentation

Worksheet Structure

Worksheet Structure

Sample from Series A

Sample from Series A

As much fine print as necessary to document where the numbers come from

How to Learn to Use Them

How to Learn to Use Them
How to Learn to Use Them
How to Learn to Use Them
How to Learn to Use Them

Let’s Tour the EXCEL Workbook for Glyphosate

FHP WO – Home Page

FHP WO – Home Page

Health & Safety Screen

Health & Safety Screen

Bottom Half of the Risk Worksheet Screen

Bottom Half of the Risk Worksheet Screen

Glyphosate – Worksheet Cover Sheet

Glyphosate – Worksheet Cover Sheet

Version 2.03

  • Title Page
    • Read the instructions!
      • Below the header on the title page
  • TOC
      • Table of Contents
      • Title and brief description of all of the sheets in the Workbook
  • A Series
      • Listing of Constants
  • B Series
    • Listing of some of the variables used in the sheets
  • C Series
    • Worker health analysis
  • D Series
    • Visitor and general public health analysis
  • E Series
    • Human health exposure and risk assessment summaries
  • F Series
    • Wildlife health effects analysis
  • G Series
    • Wildlife exposure and risk assessment summaries

Version 2.03

  • Designed by Pat Durkin to check his WordPerfect worksheets
  • A basic tool without bells & whistles
  • Allows changes to be made for rate of application (‘B Series’ page)
  • And for other parameters (throughout)
  • My opinion – format is slightly unwieldy
    • Data input generally (but not always) in ‘B Series’
    • Then need only E and G Series tables
      • Way off screen if working in B Series
  • One change changes all – but only for some

To Overcome These Perceived Problems

  • Version 2.03b
  • Not yet on the web

Version 2.03b

  • Title Page
    • Read the instructions!
      • Below the header on the title page – to the right of the original instructions
      • Basically => if a number is in boldface red type you can change it
      • If not => DON’T
  • TOC
    • Table of Contents
      • Title and brief description of all of the sheets in the Workbook
  • Former ‘A Series’
    • Const
      • Listing of Constants
  • Former ‘B Series’
    • A&CSVs (assumptions and chemical specific values)
    • Gen A&CSVs – general values
      • affect both HH & WL values below
    • HH A&CSVs – human health
    • WL A&CSVs – wildlife
  • Former ‘E Series’
    • Human health exposure and risk assessment summaries
      • HH Ex1 – Worker exposure
      • HH HQ1 – Worker HQs
      • HH Ex2 – Visitor & public exposure
      • HH HQ2 – Visitor & public HQs
  • Former ‘G Series’
    • Wildlife exposure and risk assessment summaries
      • WL Ex1 –Wildlife exposure
      • WL HQ1 – HQs for terrestrial animal scenarios
      • WL HQ2 – HQs for aquatic species
      • Some only:
      • (G04 – Offsite plant risk from runoff)
      • (G05 – Offsite plant risk from drift)
  • C Series
    • Worker health analyses
  • D Series
    • Visitor and general public health analyses
  • F Series
    • Wildlife health effects analyses
  • Allows changes to be made for several different parameters up front
    • One change changes all occurrences of a variable in the workbook
  • Output tables pulled forward
    • Next to input tables
    • Locates (computational) worksheets behind output tables – available but out of sight

Using Version 2.03b

  • Entering the workbook
    • Title page
    • Instructions for use
  • TOC
  • Const
    • Very few constants
    • No bold red values
  • Gen A&CSVs
    • Some Bold Red variables
      • Application rate (only 1 allowed)
      • Concentration in field solution
      • Size of pond
      • Length of time = chronic exposure
  • HH A&CSVs
    • Some Bold Red variables
      • Hours of application per day
      • Acres treated per hour (3 diff)
      • Body weight
  • WL A&CSVs
    • Some Bold Red variables
      • Body weight
      • Proportion of diet contaminated
  • Reports
    • HH Ex1
    • HH HQ1
    • HH EX2
    • HH HQ2
    • WL Ex1
    • WL HQ1
    • WL HQ2
    • (G04 & G05)
  • The Black Box
    • C Series
    • D Series
    • F Series

Using This Tool You Can Generate a Project Specific Risk Assessment

Project Specific EA

  • HQs of 1.0 or less indicate scenarios with acceptably low risk to the evaluated non-target entity
  • If all HQs are 1.0 or less then the project poses an acceptably low risk profile and may be implemented

Project Specific EA - An Example

  • Enter the workbook for glyphosate
    • Check the default rate per acre (in Gen A&CSVs sheet)
    • Check some of the HQ values in the summary sheets (HH HQ1, HH HQ2, WL HQ1 or WL HQ2)
  • Return to Gen A&CSVs and change the ‘1’ in cell D4 to ‘2’
    • Check the effect on the HQ values you reviewed above

Project Specific EA

  • If some of the HQs projected are 1.0 or greater then risk management must be considered or the project may not go forward
  • Simple risk management includes
    • Reduced amount of herbicide per acre
    • Reduced time of exposure (if HH problem)
    • Use of different herbicide
    • Additional PPE (Personnel Protective Equipment)

Note a Glitch

  • In the current system
    • Excel Version 2.03 or 2.03b
  • In the report HH HQ1
    • Worker scenarios
    • You will get three scenarios rated
      • Ground backpack sprayer
      • ground mechanical sprayer
      • aerial application
  • Select only the appropriate data
    • Others will probably be incorrect due to factors such as application rate, tank dilution, exposure math , etc.

How To

  • Incorporate the new SERA RA information in an EA
  • Use of these new risk assessments may require a supplement to the VMFEIS
    • Clear decision still pending on this
    • Change may be made as a “standard” in the Forest Plans currently being revised
    • Not yet sure how this will be handled in the other 10+ Plans out there (Kisatchie included)
  • Depends somewhat on language in your current Forest Plan
    • How was the VMFEIS analysis included in your current Forest Plan
  • Also depends, somewhat, on established Forest level NEPA/NFMA protocols
  • Begging the question since the answer will vary
  • Physically include in the EA
    • As part of the EA itself with the HQ summary sheets included
    • As a summary of the findings in the EA with the project specific RA stuck away in the project file
    • ???

Why Prepare RAs?


40 CFR Parts 1500-1508

  • National Environmental Policy Act/ Council of Environmental Quality regulations
    • At 1502.22 deals with incomplete or unavailable information
    • More commonly known as ‘data gaps’
    • Places where we just don’t have enough information about the subject to state a conclusion from the scientific record alone

40 CFR Part 1502.22

  • Deals with reasonable foreseeable significant adverse effects
  • If development of the data is affordable
    • It must be developed and provided
    • Within the body of generally available science
  • Prohibitively expensive missing data
    • Document the lack of availability
    • Document the relevance of the data gap to the current document
    • Summarize existing credible data which relates to the gap
    • Present an Agency evaluation of the potential impacts of the missing or unavailable data (generally developed through modeling)
  • Methods
    • May be theoretical, but
    • Must be ‘...generally accepted by the scientific community...’
    • Must ‘...not based on pure conjecture...’
    • Must be ‘...within the rule of reason...’
  • ‘Reasonably foreseeable’ includes potential catastrophic effects with low probability of occurrence
  • Risk Assessments present
    • The results of analysis of
    • Known information about
      • Hazard
      • Pattern of use (exposure)
      • Dose-response relationships
    • Projections of information addressing data gaps in all three of these areas
    • An integrated characterization of potential risk

Where we were...

Volume II

Appendix A

Risk Assessment for the Use of Herbicides In the Southern Region USDA Forest Service

Herbicides Evaluated

2,4-D Imazapyr
2,4-DP Picloram
Dicamba Sulfometuron methyl
Fosamine Tebuthiuron
Glyphosate Triclopyr

Additives Evaluated

  • Light Fuel Oils
    • Diesel Oil
    • Kerosene
  • Mineral Oil
  • Limonene
  • (Later: Vegetable Oil)

Used Margin of Safety as the Measure of Risk

  • MOS = NOEL / Dose

For Forest Service Projects.MOS Must Be Greater Than 100

  • 10 = Inter-species protection factor
  • 10 = Intra-species protection factor
  • 10 X 10 = 100

MOSs Presented in Tables


  • Since 1994 many of these risk assessments have been redone in an ongoing effort to keep them current
  • With the reawarding of the contract a new Assessor was brought onboard
  • And with the new Assessor came new methods of analysis
  • Significantly more methodologically current than prior RAs
  • Far more in line with EPA thinking

[  Contents  ]

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Last updated on Wednesday, March 05, 2003 at 10:02 AM
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