O&G Toxicology Issues O&G Toxicology Issues Michael - - PowerPoint PPT Presentation

O&G Toxicology Issues O&G Toxicology Issues

Michael Honeycutt, Ph.D. Michael Honeycutt, Ph.D.

Effects Screening Levels Effects Screening Levels

• Chemical

Chemical-

• specific level in air set to

specific level in air set to prevent short prevent short-

• term and long

term and long-

• term health

term health effects and nuisance odor conditions effects and nuisance odor conditions

• New guidelines November 2006

New guidelines November 2006

– – External scientific peer review External scientific peer review – – 2 rounds public comment 2 rounds public comment

• Used in air permitting and for evaluating

Used in air permitting and for evaluating air monitoring data air monitoring data

ESL Averaging Time ESL Averaging Time

• Short

Short-

• Term

Term

– – 1 hour 1 hour – – Health, odors, Health, odors, vegetation vegetation – – Compare 1 hour air Compare 1 hour air monitoring samples; monitoring samples; instantaneous & 24 instantaneous & 24 hour air monitoring hour air monitoring samples with caution samples with caution – – Ethanol = CNS effects Ethanol = CNS effects

• Long

Long-

• Term

Term

– – Lifetime Lifetime – – Health, vegetation Health, vegetation – – Cancer, Non Cancer, Non-

• cancer

cancer – – Compare at least Compare at least annual averages of air annual averages of air monitoring data; longer monitoring data; longer time periods more time periods more appropriate appropriate – – Ethanol = Liver, Ethanol = Liver, reproductive, cancer reproductive, cancer

Monitoring vs. Permitting Monitoring vs. Permitting

• Health

Health-

• based value (

based value (ReV ReV) = AMCV ) = AMCV

• Health

Health-

• based value x 0.3 = Permitting

based value x 0.3 = Permitting ESL ESL

• Noncarcinogens

Noncarcinogens adjusted for adjusted for cumulative (aggregate) exposure cumulative (aggregate) exposure

Carcinogens Carcinogens

• No cumulative adjustment

No cumulative adjustment

• Rarely permit more than 1 known human

Rarely permit more than 1 known human carcinogen carcinogen

• Set at 1 in 100,000 theoretical cancer risk

Set at 1 in 100,000 theoretical cancer risk level level

• 1 in 10,000 is upper bound of acceptable

1 in 10,000 is upper bound of acceptable range range

TCEQ Target

Meteor

Carcinogens Carcinogens

• “

“Acceptable Acceptable” ” = = 1 in 10,000 to 1 in 10,000 to 1 in 1 million 1 in 1 million

• Set at 1 in

Set at 1 in 100,000 cancer 100,000 cancer risk level risk level

• In toxicology, an

In toxicology, an

• rder of
• rder of

magnitude is a magnitude is a big jump big jump

Benzene Benzene annual annual ESL ESL 14 ppb 14 ppb 1.4 ppb 1.4 ppb 0.14 ppb 0.14 ppb Risk Level Risk Level 10 10-

• 4

4

10 10-

• 5

5

10 10-

• 6

6

What is Benzene?

C C C C C C H H H H H H

• Clear, sweet

Clear, sweet-

• smelling

smelling liquid at room temperature liquid at room temperature

• Highly flammable

Highly flammable

• Evaporates into the air

Evaporates into the air very quickly very quickly

• Very common

Very common -

• in the top

in the top 20 of chemicals produced 20 of chemicals produced in the United States in the United States

• Rapidly degraded in the

Rapidly degraded in the atmosphere atmosphere

• Known human carcinogen

Known human carcinogen

Benzene Exposure

• Benzene is ubiquitous

Benzene is ubiquitous

• Stricter air regulations have led to

Stricter air regulations have led to significant decreases in benzene levels significant decreases in benzene levels

• ver the last several decades
• ver the last several decades
• Major sources are

Major sources are

– – Petrochemical industry Petrochemical industry – – Motor vehicles Motor vehicles – – Cigarettes Cigarettes

• Indoor concentrations are around twice as

Indoor concentrations are around twice as high as outdoor concentrations high as outdoor concentrations

Table 4. Derivation of the Acute ReV and acuteESL

Study Rozen et al. (1984), supported by Dempster and Snyder (1991) and Corti and Snyder (1996) Study population C57BL/6J mice (male) Study quality medium-high Exposure Methods 6 h per day for 6 days via inhalation from 0 to 301 ppm LOAEL 10.2 ppm (average analytical concentration) NOAEL None Critical Effects depressed peripheral lymphocytes and depressed mitogen-induced blastogenesis

• f femoral B-

lymphocytes POD 10.2 ppm (LOAEL) Exposure Duration 6 h Extrapolation to 1 h TCEQ (2006) default procedures with n=3 PODADJ (extrapolated 1 h concentration) 18.5 ppm PODHEC 18.5 ppm (RGDR = 1) Total Uncertainty Factors (UFs) 100 Interspecies UF 3 Intraspecies UF 10 LOAEL UF 3 Incomplete Database UF Database Quality 1 high acute ReV [1 h] (HQ = 1) 580 μg/m3 (180 ppb)

acuteESL [1 h] (HQ = 0.3)

170 μg/m3 (54 ppb)

Carcinogenic Evaluation Carcinogenic Evaluation

• Pliofilm

Pliofilm Cohort (3 factories in Ohio) from Cohort (3 factories in Ohio) from Rinsky Rinsky, et al. (1981, 1987) with Crump (1994) , et al. (1981, 1987) with Crump (1994) exposure estimates exposure estimates

• Acute

Acute myelogenous myelogenous and and monocytic monocytic leukemia leukemia (AMML) (AMML)

• Linear multiplicative risk model and life

Linear multiplicative risk model and life-

• table

table analyses using the BEIR IV approach (NRC analyses using the BEIR IV approach (NRC 1988) 1988)

• Weighted cumulative exposure metric with US

Weighted cumulative exposure metric with US background mortality rates (95% UCL on background mortality rates (95% UCL on β β) )

• 1.4 ppb at 10

1.4 ppb at 10-

• 5

5 risk

risk

Benzene Concentrations at Different Samplers at the Lynchburg Ferry Monitoring Site, 2008

100 200 300 400 500 600 700 800 900 1 / 1 / 2 8 1 / 1 5 / 2 8 1 / 2 9 / 2 8 2 / 1 2 / 2 8 2 / 2 6 / 2 8 3 / 1 1 / 2 8 3 / 2 5 / 2 8 4 / 8 / 2 8 4 / 2 2 / 2 8 5 / 6 / 2 8 5 / 2 / 2 8 6 / 3 / 2 8 6 / 1 7 / 2 8 7 / 1 / 2 8 7 / 1 5 / 2 8 7 / 2 9 / 2 8 8 / 1 2 / 2 8 8 / 2 6 / 2 8 9 / 9 / 2 8 9 / 2 3 / 2 8 1 / 7 / 2 8 1 / 2 1 / 2 8 1 1 / 4 / 2 8 1 1 / 1 8 / 2 8 1 2 / 2 / 2 8 1 2 / 1 6 / 2 8 1 2 / 3 / 2 8 Benzene Concentration (ppbv) 1 Hr (AutoGC) 24-Hr Average (AutoGC) Every 6th Day Average (AutoGC) Every 6th Day Average (Canister)

Auto Auto-

• GC vs. Canister Data

GC vs. Canister Data

Calculated Annual Average Benzene Concentration Data Type Benzene Concentration (ppbv) 1 Hr AutoGC 1.10 24 Hr Average (AutoGC) 1.09 Every 6th Day Average (AutoGC) 0.815 Every 6th Day Average (Canister) 0.934

Value of Auto Value of Auto-

• GC Data

GC Data

Median Benzene Concentration by 5-min Wind Direction URS Huisache St. Site June 18 through July 28, 2003

1.8 3.3 3.6 5.0 5.6 8.2 5.9 3.9 2.0 1.4 0.5 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.3 0.2 0.7 0.2 0.8 1.4 2.9 1.3 0.5 1.0 1.6 3.9 1.3 1.2

2 4 6 8 10 12 14 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 Wind Direction (degrees) Median Benzene Concentration

10th and 90th percentile values given by distribution b

Concentration N W E S N

Lynchburg Ferry

Back Trajectory Lynchburg Monitor, Back Trajectory Lynchburg Monitor, February 04, 2007, 110 ppb February 04, 2007, 110 ppb-

• v

v

Back Trajectory Lynchburg Monitor, Back Trajectory Lynchburg Monitor, April 30, 2007, 213 ppb April 30, 2007, 213 ppb-

• v

v

Back Trajectory Lynchburg Monitor, Back Trajectory Lynchburg Monitor, April 30, 2007, 213 ppb April 30, 2007, 213 ppb-

• v

v

Back Trajectory Lynchburg Monitor, Back Trajectory Lynchburg Monitor, February 06, 2007, 184 ppb February 06, 2007, 184 ppb-

• v

v

Carbon Disulfide Comparison Carbon Disulfide Comparison Values (ppb) Values (ppb)

Agency Short-Term Long-Term TCEQ 10 1 USEPA 13,000 (2,240)* 224 ATSDR

• 300

Cal EPA 2,325 300 Canada

• 32

*EPA School Monitoring Program