Gradient CORPORATION Corrales Environmental Air Quality Health Evaluation Prepared for New Mexico Environment Department By Chris Long, ScD; Mara Seeley, Ph.D., DABT; Peter Valberg, Ph.D. Presented by Mara Seeley, Ph.D., DABT Senior Toxicologist Gradient Corporation April 1, 2004

Gradient CORPORATION Purpose of Health Evaluation Determine whether chemicals in outdoor air in the vicinity of Corrales, New Mexico are likely to cause adverse health effects

Gradient CORPORATION Overview of Health Evaluation Comprehensive analysis Evaluated 81 chemicals Monitoring data – for both ambient chemicals and chemicals in Intel emissions Modeling data – for chemicals in Intel emissions Maximum air concentrations compared to health- protective toxicity criteria (i.e. air concentrations at which adverse health effects are unlikely to occur) Both monitored and modeled maximum air concentrations are below health-protective toxicity criteria

Gradient CORPORATION Outline Background on Toxicology and Risk Assessment Corrales Environmental Air Quality Health Evaluation Chemicals of Concern Air Concentrations Acute (Short-term) Exposures Chronic (Long-term) Exposures Chemical Interactions Uncertainties

Toxicology Guiding Principle: The dose makes the poison “All substances are poisons: there is none which is not a poison. The right dose differentiates a poison from a remedy.” Paracelsus ( ) Gradient CORPORATION

The Dose Response Relationship The larger the dose, the greater the effect Gradient CORPORATION

The Dose Response Relationship (cont.) Liver Effects Dose Lowest Observed Adverse Effect Level (LOAEL) No Observed Adverse Effect Level (NOAEL) Example: Aspirin Therapeutic Effect Level

Risk Assessment Determine whether a specified level of exposure to a chemical may cause adverse health effects Gradient CORPORATION

 Identify potential toxic effects The Four Components of Risk Assessment Hazard Identification  How much of each chemical causes what effects?  Identify levels of concern  Identify chemicals of concern  Who is exposed and how?  Estimate exposure level  Compare exposure levels with levels of concern Dose- Response Exposure Assessment Risk Characterization Gradient CORPORATION

Hazard Identification – Typical Health Endpoints Cancer Any site Non-cancer effects: Nervous system Development of offspring Reproduction Respiratory system Immune system Specific organs Gradient CORPORATION

The Reference Concentration (RfC) Concentration of a chemical in air at which adverse health effects are not likely to occur in humans, including susceptible individuals RfC = NOAEL or LOAEL Uncertainty Factors Gradient CORPORATION No-Observed Adverse Effect Level Lowest-Observed Adverse Effect Level

Dealing with Uncertainty Make health-protective assumptions about toxicity Reduce allowable exposure by factors of 10 to account for: Inter-species variation (animal human) Intra-species variation (human human) Use of lowest-observed adverse effect level (LOAEL) instead of no-observed adverse effect level (NOAEL) Can result in a reference concentration (RfC) 10 – 1,000-fold lower than the NOAEL Gradient CORPORATION

Evaluation of Non-Cancer Inhalation Hazards Calculate a hazard quotient Gradient CORPORATION If hazard quotient  1, then adverse health effects not likely Hazard Quotient = Exposure Concentration Reference Concentration (RfC)

Evaluation of Inhalation Cancer Risks Gradient CORPORATION Excess Lifetime Cancer Risk = EC x UR Exposure Concentration Unit Risk = Cancer risk per unit concentration of chemical in air Acceptable Target Range for Excess Risk: < 1 in a million to 1 in 10,000 Background Lifetime Cancer Risk in General Population: 1 in 3

Effects of Combined Exposures Independence = 3 Additivity = 5 Synergism = 15 e.g., lung cancer due to smoking and asbestos Potentiation = 6 e.g., isopropyl alcohol and carbon tetrachloride Antagonism = 1 e.g., ethanol and ethylene glycol Gradient CORPORATION

Key Elements of Corrales Health Evaluation Identify chemicals of concern based on available air monitoring and modeling data Estimate air exposure concentrations based on available air monitoring and modeling data Identify reference concentrations (RfCs) for chemicals of concern Evaluate potential for adverse health outcomes based on estimated exposure concentrations and toxicity

Fugitive Dust Exposure Sources Exposure Environments Effects Industry modeling data Agriculture Heating & Combustion Traffic Ambient (Outdoor) Air Monitoring data Potential Health Response Indoor Air at Home School/ Workplace Indoor Air Hobbies, Pets, and Lifestyle Activities Personal Exposure Air

Gradient CORPORATION Identify Chemicals of Concern Air Monitoring Data (NMED, TRC-Intel) Short-term ambient air concentrations Chemicals frequently detected: Common criteria pollutants (e.g., carbon monoxide, nitrogen dioxide, ozone), ammonia, methanol, tetrafluoromethane, hexafluoroethane Air Modeling Data (Desert Research Institute) Short-term and chronic exposure concentrations Chemicals present in Intel emissions: Isopropyl alcohol (rubbing alcohol), methanol, hydrogen fluoride, hexafluoroethane, hydrogen chloride, propylene glycol monoethyl ether acetate (PGMEA)

Gradient CORPORATION Identify Chemicals of Concern (cont.) Included: All positively identified chemicals detected at least once in 1- hour and 24-hour canister samples Both frequently and occasionally detected chemicals from OP-FTIR sampling All chemicals, including tentatively identified chemicals, detected in 15-second citizen canister samples Chemicals present in Intel emissions Did not include: Tentatively identified chemicals detected only once in 1-hour and 24-hour canister samples (consistent with USEPA guidance)

Summary of Chemicals of Concern (COCs) in the Risk Evaluation AcetaldehydeChloroformHydrogen chloridePhosphine AcetoneChloromethaneHydrogen cyanidePropane AcetyleneTotal CresolsHydrogen fluoride2-Propanol (isopropyl alcohol) AcrylonitrileCyclohexanoneMethanolPropionaldehyde AmmoniaDecanal2-Methyl ButanePropylyene glycol monomethyl ether acetate Ammonium chloride1,2-DichloroetheneMethyl methacrylateSilicon tetrahydride ArsineDicholorodifluoromethane (Freon 12)Methyl n-amyl ketoneStyrene Benzaldehyde1,1-DifluoroethaneMethylene ChlorideSulfur dioxide BenzeneEthanol2-MethylpentaneSulfur hexafluoride BromoformEthyl silicate2-Methylpropane (isobutane)Sulfuric acid Butane3-Ethyl-2,2-dimethylpentaneNitric acidTetrachloroethene 2-ButanoneEthylbenzeneNitric oxide1,1,1,2 Tetrafluoroethane n-Butyl acetateEthylcyclobutaneNitrogen dioxideTetrafluoromethane n-Butyl alcoholEthyleneNitrogen trifluorideToluene n-ButyraldehydeEthylene glycolNitrous oxideTrichlorofluoromethane (Freon 11) Carbon MonoxideFormaldehydeNonanal1,2,4-Trimethylbenzene Carbon TetrachlorideHeptanalOctafluorocyclobutane3,6,6-Trimethylbicyclo hetp-2-ene Carbonyl fluorideHexafluoroethaneOctanalUndecane Carbonyl SulfideHexanalOzoneTotal Xylenes Chlorinen-HexanePentane ChlorodifluoromethaneHydrogen bromidePhosgene

Gradient CORPORATION Estimate Air Exposure Concentrations Short-term Exposures Assume individuals present at all times and locations coinciding with short-term peak air concentrations (monitored or modeled) Use maximum 1-hour data wherever possible Chronic Exposures Assume individuals present at all times and locations coinciding with maximum modeled air concentrations 24 hours/day 350 days/year 30 years

Gradient CORPORATION Reference Concentrations (RfCs) for Evaluating Short-term Inhalation Hazards 1-hour exposure period Non-cancer and cancer effects Protective of susceptible populations (e.g., infants, the elderly) Level 1 – lowest, most protective values Group 1 (most preferred) ERPG-1 (Emergency Response Planning Guidelines)  American Industrial Hygiene Association AEGL-1 (Acute Exposure Guideline Level)  National Academy of Sciences

Gradient CORPORATION Reference Concentrations (RfCs) for Evaluating Short-term Inhalation Hazards (cont.) Non-cancer effects Protective of sensitive subgroups Group 2 Acute Inhalation MRL (Minimal Risk Level)  Agency for Toxic Substances and Disease Registry  1-14 day exposure period Acute REL (Reference Exposure Level)  California EPA Office of Environmental Health Hazard Assessment  1 – several hours, intermittent exposure

Gradient CORPORATION Reference Concentrations (RfCs) for Evaluating Short-term Inhalation Hazards (cont.) Group 3 TEEL-0 (Temporary Emergency Exposure Limit) U.S. Department of Energy 15 minute exposure Group 4 (when other sources not available) Short-term ESL (Effects Screening Level) Texas Commission on Environmental Quality 1-hour exposure Adverse health effects, odor, environmental, corrosion Gradient-derived values Based on acute toxicity criteria for structurally similar compounds

Gradient CORPORATION Evaluate Potential for Acute Health Effects Acute hazard quotients for individual chemicals summed for total acute hazard index Assumes exposures to maximum air concentrations occurred simultaneously and at the same location If acute hazard index  1, then adverse effects not expected If hazard index > 1, there may be concern for potential health effects RfC acute C acute HQ acute  Acute hazard quotient (unitless) Acute (i.e., 1-hour maximum) air concentration Acute reference concentration

Gradient CORPORATION Summary of Hazard Indices – Sampling Locations Outside Intel Property Overall Summed HI Sampling DatasetsModeling Data

Summary of Hazard Indices – TRC-Intel Property Line Data Hazard Quotient (HQ) for Maximum 1-Hour Exposure TRC 8/1 – 8/9/03 NW-S Intel Property LineTRC 8/12 – 8/21/03 NW-E Intel Property Line Hazard Quotient (HQ) for Maximum 1-Hour Exposure TRC 8/21 – 9/7/03 SE Intel Property Line Hazard Quotient (HQ) for Maximum 1-Hour Exposure

Gradient CORPORATION Criteria for Evaluating Chronic Inhalation Hazards Reference Concentrations (RfCs) – for non-cancer hazards USEPA values Derive from inhalation or oral reference dose (RfD) Inhalation Unit Risks (URs) – for cancer risks USEPA values

Gradient CORPORATION Evaluate Potential for Chronic Non-Cancer Health Effects Chronic hazard quotients (CHQ) for individual chemicals summed for total hazard index for all chemicals If chronic hazard index  1, then adverse effects not expected If hazard index > 1, there may be concern for potential health effects RfC chronic C HQ chronic chronic  Chronic hazard quotient Average annual air concentration Chronic reference concentration

Gradient CORPORATION Summary of Chronic Non-Cancer Health Hazards CompoundHazard Quotient Acetone Ammonia Chlorine ,2-Dichloroethylene (mixed cis/trans) Ethylene Glycol Hydrogen chloride Hydrogen cyanide Methanol Sulfuric Acid Total Xylenes (mixed o,m,p) Total Summed Hazard Index

Gradient CORPORATION Evaluate Potential for Cancer Risks Cancer Risk = Air Exposure Concentration x (Cancer Risk per Unit Concentration in Air) Cancer risk for carbon tetrachloride: = 8 in 10 billion (in addition to background cancer risk of 0.33)

Gradient CORPORATION Effects of Combined Exposures Synergistic effects are unlikely to occur Our analysis assumed effects are additive For concentrations at or below no- observed adverse effect level, effects of combined exposure are usually either independent or additive

Gradient CORPORATION Uncertainties in Health Evaluation Not Likely to Underestimate Health Effects Uncertainties in Data Collection and Analysis Utilized limited monitoring data to maximum extent possible Monitoring data confirmed by modeling results Included tentatively identified chemicals in health evaluation Exposure Assessment Used maximum concentrations detected for monitoring data Used maximum predicted concentrations from modeling results Toxicity Assessment Uncertainty factors account for potential differences in sensitivity between animals-humans and humans-humans Chronic reference concentrations (RfCs) not available for all chemicals evaluated for chronic exposure scenario Maximum modeled annual average concentrations without chronic RfCs all well-below TCEQ long-term ESLs

Gradient CORPORATION Conclusions Acute health effects are unlikely to occur due to Intel emissions Acute hazard indexes for exposures occurring simultaneously all < 1 Chronic health effects are unlikely to occur due to Intel emissions Total chronic hazard index < 1 Cancer Risk = 8 in 10 billion (compared to background cancer risk of 1 in 3)