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- -term and long term and long- -term health term health prevent short 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 � Long Long- -Term Term � � – 1 hour – Lifetime – 1 hour – Lifetime – – Health, odors, Health, odors, – – Health, vegetation Health, vegetation vegetation vegetation – Cancer, Non- -cancer cancer – Cancer, Non – Compare 1 hour air – Compare 1 hour air – Compare at least – Compare at least monitoring samples; monitoring samples; annual averages of air annual averages of air instantaneous & 24 instantaneous & 24 monitoring data; longer monitoring data; longer hour air monitoring hour air monitoring time periods more time periods more samples with caution samples with caution appropriate appropriate – Ethanol = CNS effects – Ethanol = CNS effects – 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” ” = = � Benzene Benzene 1 in 10,000 to 1 in 10,000 to annual annual Risk Level Risk Level ESL ESL 1 in 1 million 1 in 1 million 14 ppb 10 - -4 4 14 ppb 10 � Set at 1 in Set at 1 in � 100,000 cancer 100,000 cancer 1.4 ppb 1.4 ppb 10 - -5 5 10 risk level risk level � In toxicology, an In toxicology, an � 0.14 ppb 0.14 ppb 10 - -6 6 10 order of order of magnitude is a magnitude is a big jump big jump

What is Benzene? H � Clear, sweet Clear, sweet- -smelling smelling � liquid at room temperature liquid at room temperature � Highly flammable Highly flammable � H C H � Evaporates into the air Evaporates into the air � C C very quickly very quickly � Very common Very common - - in the top in the top � 20 of chemicals produced 20 of chemicals produced C C in the United States in the United States H C H � Rapidly degraded in the Rapidly degraded in the � atmosphere atmosphere � Known human carcinogen Known human carcinogen � H

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 over the last several decades over 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

and acute ESL Table 4. Derivation of the Acute ReV Rozen et al. (1984), supported by Dempster and Study 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 of femoral B- lymphocytes POD 10.2 ppm (LOAEL) Exposure Duration 6 h Extrapolation to 1 h TCEQ (2006) default procedures with n=3 POD ADJ (extrapolated 1 h concentration) 18.5 ppm POD HEC 18.5 ppm (RGDR = 1) Total Uncertainty Factors (UFs) 100 Interspecies UF 3 Intraspecies UF 10 LOAEL UF 3 Incomplete Database UF 1 Database Quality high acute ReV [1 h] (HQ = 1) 580 μ g/m 3 (180 ppb) acute ESL [1 h] (HQ = 0.3) 170 μ g/m 3 (54 ppb)

Carcinogenic Evaluation Carcinogenic Evaluation � Pliofilm Pliofilm Cohort (3 factories in Ohio) from Cohort (3 factories in Ohio) from � Rinsky, et al. (1981, 1987) with Crump (1994) , et al. (1981, 1987) with Crump (1994) Rinsky 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 β β ) ) background mortality rates (95% UCL on 5 risk � 1.4 ppb at 10 1.4 ppb at 10 - -5 risk �

Auto- -GC vs. Canister Data GC vs. Canister Data Auto Benzene Concentrations at Different Samplers at the Lynchburg Ferry Monitoring Site, 2008 900 1 Hr (AutoGC) 24-Hr Average (AutoGC) 800 Every 6th Day Average (AutoGC) Every 6th Day Average (Canister) Calculated Annual Average Benzene 700 Concentration Benzene Data Type Concentration (ppbv) Benzene Concentration (ppbv) 600 1 Hr AutoGC 1.10 24 Hr Average (AutoGC) 1.09 Every 6th Day Average 0.815 (AutoGC) 500 Every 6th Day Average 0.934 (Canister) 400 300 200 100 0 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 / / / / / / / / / / / / / / / / / / / / / / / / / / / 1 5 9 2 6 1 5 8 2 6 0 3 7 1 5 9 2 6 9 3 7 1 4 8 2 6 0 / 1 2 1 2 1 2 / 2 / 2 / 1 / 1 2 1 2 / 2 / 2 / 1 / 1 3 1 4 5 6 7 9 0 1 2 / / / / / / / / / / / / / / / / / / 1 1 2 2 3 3 4 5 6 7 7 8 8 9 1 0 1 1 1 2 2 1 1 1 1

Value of Auto- -GC Data GC Data Value of Auto Median Benzene Concentration by 5-min Wind Direction URS Huisache St. Site June 18 through July 28, 2003 14 10th and 90th percentile values given by distribution b 12 10 Median Benzene Concentration Concentration 8.2 8 5.9 6 5.6 5.0 3.9 3.9 4 3.6 3.3 2.9 2.0 1.8 2 1.6 1.4 1.4 1.3 1.3 1.2 1.0 0.8 0.7 0.5 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 0.2 0 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) N E S W N

Lynchburg Ferry

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

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

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

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

Carbon Disulfide Comparison Carbon Disulfide Comparison Values (ppb) Values (ppb) Agency Short-Term Long-Term TCEQ 10 1 USEPA 13,000 224 (2,240)* ATSDR --- 300 Cal EPA 2,325 300 Canada --- 32 *EPA School Monitoring Program