Health & Environmental Risk Assessment

Peter W. Woodman Ph.D.

Risk Management IncorporatedEnvironmental Services Division

Acton, MA 01720-5676(978) 266-2878

Copyright 1998-2007 ©

Fifth Annual Environmental Career Night

“Environmental Careers in a Perilous World”

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Role of Risk Assessors:Assessment & Communication

Put your hand over your mouth when you sneeze; internal organs will be scarce in the post-nuclear age.

Try to be neat; fall only in designated piles.

Drive carefully in "Heavy Fallout" areas; people could be staggering illegally.

Safety Tips for a Post-Nuclear Existence!!

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Unforeseen RisksA woman was killed from chlorine gas poisoning when she mixed Harpic™ and Domestos™ together in a confined space.

She had inadvertently created the same conditions as experienced by the soldiers during a gas attack in the trenches of the First World War

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Health & Environmental Risks

• Hazardous Chemicals:Heavy Metals, PCBs, Petroleum Products,Chlorinated Solvents

• Radionuclides: U, Th, Pu, Rn, Po

• Biological Agents: Molds, Bacteria, Viruses

• Genetically Modified Materials: Animals, Plants, Microorganisms, Pathogens

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Risk-Impacted Media

• Indoor and Outdoor Air: Inhalation of vapors, particulates, spores

• Soil and Groundwater: Incidental/Intentional Ingestion; Dermal Contact; Inhalation of vapors, particulates, spores• Surface Water/Environmental Habitats: Incidental/Intentional Ingestion; Dermal Contact

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Receptors at Risk• Human Health:

General Public; Industrial or Commercial Employees; Residents, Site Trespassers; Site Workers

• Environmental: Wildlife, Terrestrial, Aquatic and Benthic Organisms Habitats of Threatened or Endangered Species

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Risk Assessment:Acute, Subchronic, Chronic and Lifetime Exposures

• Human Health: Non-Cancer Endpoints of Toxicity – Hazard Indices Cancer Endpoints of Toxicity – Excess Lifetime Cancer Risks Comparison of EPCs to Standards & Criteria - Air; Drinking Water; Consumption of Fish

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• Environmental: Ecological Screening - Comparison of EPCs to NAWQC, Sediment Criteria, Toxicity Thresholds Field Studies - Habitat Assessments, Toxicity Studies

in Indicator Species

Risk Assessment:Acute, Subchronic, Chronic and Lifetime Exposures

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Risk Assessment Findings• Human Health:

Do Cumulative Non-Cancer Hazard Indices for Total Site Risk for Each Receptor Exceed Unity (i.e., HI ≥ 1)? Do Cumulative Excess Lifetime Cancer Risks for Total Site Risk for Each Receptor Exceed One in a Hundred Thousand (i.e., 1 x 10-5)? Do EPCs Exceed Applicable Standards or Criteria?

NO = “NO SIGNIFCANT RISKS”

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Risk Assessment Findings• Environmental :

Any Visible Signs of Apparent Harm? Any Impacted Critical Habitats, Vernal Pools,

Threatened or Endangered Species? Do EPCs Exceed Applicable Standards or

Criteria for Each Receptor? Do Individual Toxicity Quotients for Each Hazardous Material Exceed Unity? Any Positive Toxicity Tests for Indicator

Species?

NO = “NO SIGNIFCANT RISKS”

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Risk Assessment Challenges

• Assessment : Be observant, ask questions, record details Work closely with environmental engineers and

hydro geologists to understand and characterize the nature and extent of the hazardous contamination

Identify impacted media and potential receptors

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Risk Assessment Challenges

• Assessment cont. : Determine if exposure pathways either exist or could potentially exist between the hazard and the receptor Assess risk using site-specific exposure assumptions and the most current toxicity information and standards available Work closely with your client, state and federal officials to ensure “No Surprises”

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Risk Assessment Challenges

• Communication : Clearly describe the Conceptual Site Exposure Model and assumptions you use to assess the risks Discuss what the risk findings mean for both current and future foreseeable uses and activities of the release site

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Risk Assessment Challenges

• Communication cont. : Ensure that you discuss the uncertainty and conservative exposure assumptions associated with the risk findings - nothing is necessarily black or white!

Finally, become part of the multidisciplinary team of environmental specialists that assess these risks and enjoy a common goal – to protect human health and the environment.