Human Health & Aquatic Life Criteria Cara Cowan Watts Graduate Student Biosystems Engineering

Source of Class Materials Presentations and Handouts adapted from The U.S. EPA’s Water Quality Standards Academy November 27-December 1, 2006 Washington, DC

Human Health Criteria Expressed as a Pollutant Concentration Based on: Toxicological Assessment Exposure Scenario Calculated for Ingestion of Aquatic Organisms Only and for Ingestion of Water and Organisms http://www.ca.uky.edu/enri/clipart/waterdrop.jpg

Data Needed for HHC Toxicity Exposure Bioaccumulation factors (BAFs) Toxic effects and dose-response properties Risk Specific Doses for linear carcinogens Point of Departure (POD) & Uncertainty Factor (UF) for nonlinear carcinogens Reference dose (RfD) for noncarcinogens Exposure Site-specific BAFs or National BAFs Trophic level data on accumulation of chemical in fish or shellfish Bioaccumulation factors (BAFs) Relative Source Contribution (RSC) Exposure parameters: body weight (BW) drinking water intake (DI) and Fish Intake (FI)

Non-threshold Effects All Levels of exposure pose some probability of an adverse response Incremental risk levels can be calculated EPA targets a risk level of one in one million (10-6)

Threshold Effects Exposures to some finite value are expected to be without adverse effect on human health

Non-Cancer Dose Response Values Reference Dose (RfD) Estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to humans (including sensitive subgroups) that is likely to be without an appreciable risk of adverse effects during a lifetime EPA’s Integrated Risk Information System (IRIS) www.epa.gov/iris

Non-Cancer Effects RfD Derivation Point of Departure Point of Departure divided by Uncertainty Factor (UF) Point of Departure No Observed Adverse Effect Level (NOAEL) Lowest Observed Adverse Effect Level (LOAEL) Benchmark Dose (BMD)

Benchmark Dose Model

Uncertainty Factors Five areas of consideration Intraspecies variation (UFH) Interspecies variation (UFA) Uncertainty due to the duration of study (UFS) Uncertainty due to use of LOAEL (UFL) Uncertainty due an inadequate database (UFD) Invoked as integers of 1, 3, 10 3 is a half log10 Value selected determined by the data available Usually ≤ 3,000

Non-Cancerous Effects AWQC = RfD x RSC x [ ] BW DI + (FI x BAF) AWQC = Ambient Water Quality Criterion (mg/L) RfD = Reference Dose (mg/kg-day) RSC = Relative Source Contribution (%, to account for other sources of exposure) BW = Human Body Weight (kg, 70 for average adult) DI = Drinking Water Intake (L/day, 2 for average adult) FI = Fish Intake (kg/day) BAF = Bioaccumulation Factor (L/kg)

Carcinogen Dose-Response Values Risk Specific Dose (RSD) for linear carcinogens RSD is the acceptable risk Level divided by the Cancer Slope Factor EPA recommends 10-6 (one in a million chance of cancer) but accepts the 10-5 risk level as long as highly exposed populations do not exceed 10-4 risk level POD/UF approach for nonlinear carcinogens

Carcinogens Dose-Response

Linear Cancerous Effects AWQC = RSD x [ ] BW DI + (FI x BAF) AWQC = Ambient Water Quality Criterion (mg/L) RSD = Risk Specific Dose (mg/kg-day) BW = Human Body Weight (kg, 70 for average adult) DI = Drinking Water Intake (L/day, 2 for average adult) FI = Fish Intake (kg/day) BAF = Bioaccumulation Factor (L/kg)

Dose Response for Nonlinear Carcinogens

Nonlinear Cancer Effects AWQC = POD/UF x RSC x [ ] BW DI + (FI x BAF) AWQC = Ambient Water Quality Criterion (mg/L) POD/UF = Point of Departure/Uncertainty Factor (mg/kg-day) RSC = Relative Source Contribution (to account for other sources of exposure) BW = Human Body Weight (kg, 70 for average adult) DI = Drinking Water Intake (L/day, 2 for average adult) FI = Fish Intake (kg/day) = Bioaccumulation Factor (L/kg) BAF = Bioaccumulation factor (L/kg)

Exposure Parameters Assumes daily exposure over the course of a lifetime Assigns mix of average values and high end values (e.g., 90th percentile) for exposure parameters such as ingestion rates and body weight Derived to protect the majority of the general population

Default Exposure Parameters Average adult body weight BW = 70 kg 90th percentile estimate DI = 2 L/day FI = 17.5 g/day Used by EPA for the national recommended water quality criteria when chronic health effects are of concern http://www.alsa.org/images/cms/atsdr_logo(2).gif

Developmental Exposure Parameters Women of childbearing age (ages 15-44), when fetal developmental effects are the most sensitive health endpoint BW = 67 Kg DI = 2 L/day Children BW = 30 Kg; ages 1-14 = 13 Kg; toddlers (ages 1-3) = 7 Kg; infants DI = 1 L/day for all sub-categories http://www.nesc.wvu.edu/images/netc_links/go3.jpg

Fish Intake Values For chronic health effects when targeting: Recreational fishers = 17.5 g/day Estimate of average consumption of freshwater/estuarine fish/shellfish; Subsistence fishers = 142.4 g/day Estimate of average consumption of freshwater/estuarine fish/shellfish. For developmental health effects when targeting: Women of childbearing age (re: fetal effects) = 165.5 g/day Estimate of 90th percentile meal size of freshwater/estuarine fish/shellfish; Children (ages 1-14) = 156.3 g/day Estimate of 90th percentile meal size of freshwater/estuarine fish/shellfish. www.juliangibson.com/images/cartoon/fish01.jpg

Relative Source Contribution Accounts for exposures from sources other than water and freshwater/estuarine fish and shellfish ingestion Inhalation for airborne sources Consumption of food Consumption of marine aquatic organisms Not applied to linear carcinogens (i.e., those associated with a risk level) Expressed as a percentage or subtracted, depending on the circumstances, from the RfD or nonlinear carcinogen

Bioaccumulation Concentration in Tissue Concentration in Water BAF =

Aquatic Life Criteria Concentration of Exposure Magnitude Time Period of Exposure Duration Frequency of Exposure How often (http://www.epa.gov/owow/monitoring/rbp/)

Aquatic Life Criteria Types

CMC and CCC CMC Highest instream concentration of a toxicant to which organisms can be exposed for a brief period of time without causing an unacceptable adverse acute effect CCC Highest instream concentration of a toxicant to which organisms can be exposed for longer time periods without causing an unacceptable adverse effect Final Chronic Value Final Plant Value Final Residue Value

Acute Toxicity Test 96-hour LC50 Concentration: 0.0 μg/L 13 μg/L 25 μg/L 50 μg/L 100 μg/L 200 μg/L Control 1 2 3 4 5 96-hr LC50 = 50 μg/L

Fathead Minnow Early Life Stage Test Growth Measured as Length Chronic Toxicity Test Fathead Minnow Early Life Stage Test Growth Measured as Length Concentration: Control 0.0 μg/L 3.8 μg/L 7.5 μg/L 15 μg/L 30 μg/L 60 μg/L Length: 40 mm 41 mm 38 mm 37 mm 25 mm 5 mm

Minimum Data Set: Freshwater Criteria Development SALMONID SECOND FISH FAMILY CHORDATA PLANKTONIC CRUSTACEAN BENTHIC INSECT ROTIFERA, ANNELIDA, MOLLUSCA OTHER INSECT OR

Sensitive Life Stages Most Sensitive Egg Larva Adult

Aquatic WQC Determination Rank Genus Mean Acute Values (GMAV) and Calculate the Percentile of Each Rank (100 R/(N+1)) GMAV Chronic Endpoints Using the 4 Most Sensitive Genera, Perform a Least Squares Regression of the GMAV2 (log values) on the Percentile Ranks (square roots)

Final Chronic Value Perform Acute and Chronic testing using same species in same dilution water 2. Use Results to Calculate Acute-Chronic Ratios (ACR) Acute Value Chronic Value ACR = 3. Develop final Acute-Chronic Ratio (FACR) by taking Geometric Mean of the appropriate Acute-Chronic Ratios 4. Calculate the Final Chronic Value (FCV) using the final Acute-Chronic Ratio Final Acute Value FACR FCV =

Final Chronic Value Process Are Data Available from 8 Families? Is Toxicity Related to a WQ Characteristic? Calculate Final Chronic Equation Yes Yes No No Use Calculation of FAV Procedures To Calculate Final Chronic Value Calculate Species Mean Acute-Chronic Ratios Yes Do Ratios Fit Any of the 4 Specified Cases in Guidelines? Calculate Final Chronic Value: Final Acute Value Final Acute-Chronic Ratio No A Final Chronic Value Cannot Be Calculated

Final Residue Value FRV = CCC CMC 4-Day Average 1-Hour Average Maximum Permissable Tissue Concentration BCF or BAF FRV = Default Averaging Period for Freshwater and Saltwater CCC CMC 4-Day Average 1-Hour Average

Site Specific Criteria Sensitivities of the site-species differ from the National Data Base and/or Physical/Chemical characteristics of the site alter the bioavailability or toxicity of the pollutant

Site Specific Criteria Procedures Use Recalculation Procedure in Conjunction with Water- Effect Ratio Procedure or Use Resident Species Procedure If Physical or Chemical Properties at Site Affect Bioavailability If Species at Site Are More or Less Sensitive If Both of These Conditions Exist Use Water-Effect Ratio Procedure or a Streamlined WER Use Recalculation Procedure

Water Effect Ratios Site Water Toxicity Concentration WER = Lab Water Toxicity Concentration WER = Site-Specific Criteria = WER x National Criteria

Questions?