Gradient CORPORATION Corrales Environmental Air Quality Health Evaluation Prepared for New Mexico Environment Department By Chris Long, ScD; Mara Seeley,

Gradient CORPORATION

Corrales Environmental Air Quality Health

EvaluationPrepared for New Mexico Environment Department

By Chris Long, ScD; Mara Seeley, Ph.D., DABT; Peter Valberg, Ph.D.

Presented byMara Seeley, Ph.D., DABT

Senior ToxicologistGradient Corporation

April 1, 2004


Purpose of Health Evaluation Determine whether chemicals in

outdoor air in the vicinity of Corrales, New Mexico are likely to cause adverse health effects


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


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 (1493-1541)


The Dose Response Relationship

The larger the dose, the greater the effect


The Dose Response Relationship (cont.)

100

00

Liv

er

Eff

ects

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


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

ExposureAssessment

RiskCharacterization


Hazard Identification – Typical Health Endpoints Cancer

Any site Non-cancer effects:

Nervous system Development of offspring Reproduction Respiratory system Immune system Specific organs


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


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


Evaluation of Non-Cancer Inhalation Hazards

Calculate a hazard quotient


If hazard quotient 1, then adverse health effects not likely

Hazard Quotient =

Exposure Concentration

Reference Concentration (RfC)

Evaluation of Inhalation Cancer Risks


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

2 + 3 = 3 Additivity

2 + 3 = 5 Synergism

2 + 3 = 15 e.g., lung cancer due to smoking and asbestos

Potentiation 0 + 3 = 6 e.g., isopropyl alcohol and carbon tetrachloride

Antagonism 2 + 3 = 1 e.g., ethanol and ethylene glycol



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

ExposureSources

ExposureEnvironments

Effects

Industrymodeling data

Agriculture

Heating & Combustion

Traffic

Ambient(Outdoor) AirMonitoring data

PotentialHealth

Response

Indoor Airat Home

School/WorkplaceIndoor Air

Hobbies, Pets,and Lifestyle

Activities

PersonalExposure Air


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)


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 EvaluationAcetaldehyde Chloroform Hydrogen chloride Phosphine

Acetone Chloromethane Hydrogen cyanide Propane

Acetylene Total Cresols Hydrogen fluoride 2-Propanol (isopropyl alcohol)

Acrylonitrile Cyclohexanone Methanol Propionaldehyde

Ammonia Decanal 2-Methyl Butane Propylyene glycol monomethyl ether acetate

Ammonium chloride 1,2-Dichloroethene Methyl methacrylate Silicon tetrahydride

Arsine Dicholorodifluoromethane (Freon 12) Methyl n-amyl ketone Styrene

Benzaldehyde 1,1-Difluoroethane Methylene Chloride Sulfur dioxide

Benzene Ethanol 2-Methylpentane Sulfur hexafluoride

Bromoform Ethyl silicate 2-Methylpropane (isobutane) Sulfuric acid

Butane 3-Ethyl-2,2-dimethylpentane Nitric acid Tetrachloroethene

2-Butanone Ethylbenzene Nitric oxide 1,1,1,2 Tetrafluoroethane

n-Butyl acetate Ethylcyclobutane Nitrogen dioxide Tetrafluoromethane

n-Butyl alcohol Ethylene Nitrogen trifluoride Toluene

n-Butyraldehyde Ethylene glycol Nitrous oxide Trichlorofluoromethane (Freon 11)

Carbon Monoxide Formaldehyde Nonanal 1,2,4-Trimethylbenzene

Carbon Tetrachloride Heptanal Octafluorocyclobutane 3,6,6-Trimethylbicyclo 3.1.1 hetp-2-ene

Carbonyl fluoride Hexafluoroethane Octanal Undecane

Carbonyl Sulfide Hexanal Ozone Total Xylenes

Chlorine n-Hexane Pentane

Chlorodifluoromethane Hydrogen bromide Phosgene


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


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


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


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


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

RfCacute

CacuteHQacute

Acute hazard quotient (unitless)

Acute (i.e., 1-hour maximum) air concentration

Acute reference concentration


0

0.2

0.4

0.6

0.8

1

NMED OP-FTIR

Max. 1-Hour

Average Conc.

NMED 15-sCitizen

CanisterMeasurements

NMEDMaximum 1-hour and

24-hourCanister

Measurements

NMEDMaximum

1-hourAverageModelingResults

Sampling Datasets

Ove

rall

Su

mm

ed H

I

Summary of Hazard Indices – Sampling Locations Outside Intel Property

Ove

rall

Su

mm

ed H

I

Sampling Datasets Modeling Data

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

Benzaldehyde Nitric Acid Ozone

Compound

Haz

ard

Quo

tien

t (H

Q) f

or

Max

imum

1-H

our

Exp

osur

e

Summary of Hazard Indices – TRC-Intel Property Line Data

Haz

ard

Qu

otie

nt

(HQ

) fo

rM

axim

um

1-H

our

Exp

osu

re

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Benzaldehyde Nitrogen Dioxide Ozone 2-Propanol(isopropyl alcohol)

Propylene glycolmonomethyl ether

acetate

Compound

TRC 8/1 – 8/9/03 NW-S Intel Property Line TRC 8/12 – 8/21/03 NW-E Intel Property Line

Haz

ard

Qu

otie

nt

(HQ

) fo

rM

axim

um

1-H

our

Exp

osu

re

TRC 8/21 – 9/7/03 SE Intel Property Line

Haz

ard

Qu

otie

nt

(HQ

) fo

rM

axim

um

1-H

our

Exp

osu

re

00.05

0.10.15

0.2

0.250.3

0.350.4

0.45

Nitric Oxide Nitrogen Dioxide Ozone

Compound

Haz

ard

Quo

tien

t (H

Q) f

orM

axim

um 1

-Hou

r E

xpos

ure


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


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

RfCchronic

CHQchronicchronic

Chronic hazard

quotient

Average annual air concentration

Chronic reference concentration


Summary of Chronic Non-Cancer Health Hazards

Compound Hazard Quotient

Acetone 0.000 000 2

Ammonia 0.000 39

Chlorine 0.043

1,2-Dichloroethylene (mixed cis/trans) 0.000 005

Ethylene Glycol 0.000 000 11

Hydrogen chloride 0.000 005 5

Hydrogen cyanide 0.000 005 2

Methanol 0.000 000 61

Sulfuric Acid 0.000 004 5

Total Xylenes (mixed o,m,p) 0.000 000 43

Total Summed Hazard Index 0.043 411 55


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)


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


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


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)

Documents

Gradient CORPORATION Corrales Environmental Air Quality Health Evaluation Prepared for New Mexico Environment Department By Chris Long, ScD; Mara Seeley,