Agricultural Product Consumption Risk Assessment · 2020-04-14 · Agricultural Trends: Potential Future Activities in the Floodplain • Dairy farms on the decline • Commercial

Housatonic River Project

Agricultural Product Consumption Risk

Assessment

Agricultural Product Consumption Risk

Assessment

George Friesand

Donna J. Vorhees Menzie-Cura & Associates, Inc.

George Friesand

Donna J. Vorhees Menzie-Cura & Associates, Inc.

Housatonic River Project pg 2

OverviewOverview

• Identify current and possible future agricultural activities in the floodplain

• Estimate contaminant concentrations in animal products and home garden produce

• Select appropriate exposure assumptions

• Estimate human health risk associated with consuming food produced in the floodplain

• Identify current and possible future agricultural activities in the floodplain

• Estimate contaminant concentrations in animal products and home garden produce

• Select appropriate exposure assumptions

• Estimate human health risk associated with consuming food produced in the floodplain


Current Agricultural Activities in the FloodplainCurrent Agricultural Activities in the Floodplain

COMMERCIAL ACTIVITY Dairy

corn silage grass-based feed grazing (heifers/dry cows)

Fruits and vegetables Free-range poultry NON-COMMERCIAL ACTIVITY Beef

grazing Deer hunting Home gardening Wild crop harvesting (e.g., ferns)

COMMERCIAL ACTIVITY Dairy

corn silage grass-based feed grazing (heifers/dry cows)

Fruits and vegetables Free-range poultry NON-COMMERCIAL ACTIVITY Beef

grazing Deer hunting Home gardening Wild crop harvesting (e.g., ferns)


Agricultural Trends: Potential Future Activities in the FloodplainAgricultural Trends: Potential Future Activities in the Floodplain

• Dairy farms on the decline• Commercial dairy operations could be converted

to beef, goat, or sheep operations• Niche products (free-range poultry, organic beef

and dairy)• Backyard animal products (beef, dairy, poultry)

• Dairy farms on the decline• Commercial dairy operations could be converted

to beef, goat, or sheep operations• Niche products (free-range poultry, organic beef

and dairy)• Backyard animal products (beef, dairy, poultry)


Exposure Scenarios:consumption of PlantsExposure Scenarios:consumption of Plants

Source Pathway Receptor

Contaminated floodplain soil

below ground plants

above ground plants

Air(vapor

phase and particle phase)

People consuming edible wild plants

People consuming produce from home gardens


Exposure Scenarios: Consumption of Animal ProductsExposure Scenarios: Consumption of Animal Products

Source Pathway Receptor

grazing & ingestion of soil

commercial and backyard farm families consuming beef, milk, chicken and eggs

hunting families consuming venison

dairy cattlebeef cattlepoultrygoatssheep deer

Contaminated floodplain soil

corn silage and grass-based feeds

Air(vapor

phase and particle phase)


How were Farms and Gardens Assessed?How were Farms and Gardens Assessed?

• Non-parcel-specific approach

• Assumed that– 100% of cultivation area is in floodplain– 100% of grazing area is in floodplain

• Estimated risk associated with two hypothetical PCB concentrations in soil (0.5 mg/kg and 2 mg/kg)

• Non-parcel-specific approach

• Assumed that– 100% of cultivation area is in floodplain– 100% of grazing area is in floodplain

• Estimated risk associated with two hypothetical PCB concentrations in soil (0.5 mg/kg and 2 mg/kg)


Estimating Food Concentrations: Information from the FloodplainEstimating Food Concentrations: Information from the Floodplain

• Milk (MADFA 1993)

• Corn (USEPA 1998, 1999)

• Grass (USEPA 2001)

• Acorn squash (USEPA 1999)

• Beets, turnips, beans (Sawhney and Hankin 1984)

• Fiddlehead ferns (MADEP 1995 and USEPA 1999 & 2000)

• Milk (MADFA 1993)

• Corn (USEPA 1998, 1999)

• Grass (USEPA 2001)

• Acorn squash (USEPA 1999)

• Beets, turnips, beans (Sawhney and Hankin 1984)

• Fiddlehead ferns (MADEP 1995 and USEPA 1999 & 2000)

Note: PCBs were quantified as Aroclors in all samples except ferns

and grass


Milk DataMilk Data

• MADFA 1993 sampling program (n=7)

• 3-qt agitated, raw milk samples from bulk tanskon 7 farms

• No PCBs detected – LOQ ≤ 10 µg/L, whole milk basis (estimated)– LOD ≤ 4-5 µ g/L, whole milk basis (estimated)

• MADFA 1993 sampling program (n=7)

• 3-qt agitated, raw milk samples from bulk tanskon 7 farms

• No PCBs detected – LOQ ≤ 10 µg/L, whole milk basis (estimated)– LOD ≤ 4-5 µ g/L, whole milk basis (estimated)


Factors Influencing Transfer of Persistent Organochlorine Contaminants to PlantsFactors Influencing Transfer of Persistent Organochlorine Contaminants to Plants

• Plant characteristics– lipid content– surface area – height of edible portions

• Soil characteristics• Chemical characteristics

– Lipophilicity– vapor pressure– solubility

• Farming practices– planting density

• Plant characteristics– lipid content– surface area – height of edible portions

• Soil characteristics• Chemical characteristics

– Lipophilicity– vapor pressure– solubility

• Farming practices– planting density


Corn Data (unwashed)Corn Data (unwashed)

Corn collected in October 1998 (n=10)• all samples were “nd” (dl: 230-300 µg/kg, semi-dry) • corresponding soil samples were “nd”

(dl: 0.55-0.64 mg/kg)

Corn collected in September 1999 (n=10)• from 4 areas with PCB-contaminated soils and 1

reference/background area• Stalks: 5 hits (10.3-23.7 µg/kg, ww)

(Aroclor 1260, “J” qualified)• Ears: all samples were “nd”

Corn collected in October 1998 (n=10)• all samples were “nd” (dl: 230-300 µg/kg, semi-dry) • corresponding soil samples were “nd”

(dl: 0.55-0.64 mg/kg)

Corn collected in September 1999 (n=10)• from 4 areas with PCB-contaminated soils and 1

reference/background area• Stalks: 5 hits (10.3-23.7 µg/kg, ww)

(Aroclor 1260, “J” qualified)• Ears: all samples were “nd”


Grass (unwashed)Grass (unwashed)

• Collected from former dairy farm in Reach 5 in July 2001 (n=10)

• Soil samples also collected (n=10)

• All samples analyzed for 100+ PCB congeners, dioxins, and furans

• tPCB concentrations in grass: 51-136 µg/kg, ww

• Collected from former dairy farm in Reach 5 in July 2001 (n=10)

• Soil samples also collected (n=10)

• All samples analyzed for 100+ PCB congeners, dioxins, and furans

• tPCB concentrations in grass: 51-136 µg/kg, ww


PCB Congener Pattern in Grass and Soil Sample PairsPCB Congener Pattern in Grass and Soil Sample Pairs

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

PCB Congeners in order of increasing retention time

Wei

ght F

ract

ion

Grass

Soil


Grass-to-soil Concentration Ratios for PCB CongenersGrass-to-soil Concentration Ratios for PCB Congeners

Grass-to-Soil Uptake vs Vapor PressureLog Mean Uptake = -0.9028+0.3179*x

r2 = 0.3034; r = 0.5508, p < 0.001

-5.0 -4.5 -4.0 -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5

Log Vapor Pressure

-2.8

-2.6

-2.4

-2.2

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

Log

Aver

age

Upt

ake

([gr

ass]

/ [s

oil])


Squash Data (unwashed)Squash Data (unwashed)

Samples collected in September 1999 (n=4), mg/kg, dw

flesh pulp/seed whole

Reference 0.17 UJ - - 0.12 R

Sample 2 1.4 R - - 1.1 J

Sample 3 0.74 J 0.74 J 0.98 J

Sample 4 0.55 J - - 1.2 J

flesh pulp/seed whole

Reference 0.17 UJ - - 0.12 R

Sample 2 1.4 R - - 1.1 J

Sample 3 0.74 J 0.74 J 0.98 J

Sample 4 0.55 J - - 1.2 J


Fiddlehead Fern DataFiddlehead Fern Data

• May 1999– n=3 in contaminated areas– unwashed– all data were rejected due to low %

solids

• May 2000– n=3 in contaminated areas– n=1 in reference area– unwashed/washed– nd in two samples; 16 µg/kg, ww in

one sample – co-located soil samples

• May 1999– n=3 in contaminated areas– unwashed– all data were rejected due to low %

solids

• May 2000– n=3 in contaminated areas– n=1 in reference area– unwashed/washed– nd in two samples; 16 µg/kg, ww in

one sample – co-located soil samples


Sawhney and HankinSawhney and Hankin

• Field study

• Plants grown in soil amended with Woods Pond sediment

• Plants washed with warm, soapy water prior to laboratory analysis

• Field study

• Plants grown in soil amended with Woods Pond sediment

• Plants washed with warm, soapy water prior to laboratory analysis


Average Plant-to-soil Ratios for Various Plant SpeciesAverage Plant-to-soil Ratios for Various Plant Species

Plant-to-Soil Ratio(ww/dw) (dw/dw)

USEPA Samples, collected between 1999-2001 Corn, unwashed 7.2E-04 2.4E-03 Squash (flesh), unwashed 1.2E-02 1.6E-01 Squash (who le), unwashed 2.1E-02 2.8E-01 Fiddlehead Ferns, washed 6.9E-04 5.7E-03 Grass, unwashed 1.1E-02 3.6E-02MADEP 1995 Study Fiddlehead Ferns, washed? 7.3E-05 5.6E-04Sawhney and Hankin, 1984 Beet Roots, washed 3.0E-04 2.4E-03 Beet Leaves, washed 2.8E-04 3.6E-03 Turnip Roots, washed 1.1E-04 1.4E-03 Turnip Leaves, washed 1.7E-04 1.9E-03


Site-specific Data used to Estimate Soil-to-plant Transfer FactorsSite-specific Data used to Estimate Soil-to-plant Transfer Factors

Human consumption of plants:

Farm animal consumption of plant-based feeds:

• Exposed fruit• Exposed vegetables• Root vegetables

• Exposed fruit• Exposed vegetables• Root vegetables

• Grass-based feed• Corn silage• Grass-based feed• Corn silage

Soil-to-Plant Transfer Factor = Chemical concentration in plantChemical concentration in soil


Animal Management Commercial Dairy

Animal Management Commercial Dairy

• Lactating dairy cows are confined in areas out of the floodplain

• No animals graze in the Reach 5 floodplain, but non-lactating animals have in the past

• Non-lactating animals were observed grazing in floodplain of Reach 9

• Production practices could vary

• Lactating dairy cows are confined in areas out of the floodplain

• No animals graze in the Reach 5 floodplain, but non-lactating animals have in the past

• Non-lactating animals were observed grazing in floodplain of Reach 9

• Production practices could vary


Animal ManagementDairy Feeding

Animal ManagementDairy Feeding

• Roughages– Corn silage– Grass silage– Hay – Hay – Pasture– Pasture

• Concentrates– Mainly grains– Mainly imported

• Roughages– Corn silage– Grass silage

• Concentrates– Mainly grains– Mainly imported


Animal ManagementBeef

Animal ManagementBeef

• One commercial herd in the area. Does not have access to the floodplain or use feeds from the floodplain.

• Small non-commercial herd on a residential parcel on Reach 7

• Potential for conversion of dairy to beef.• Cull and surplus dairy could be used for beef.• Residue exposure and uptake would be similar to

that for growing dairy animals.

• One commercial herd in the area. Does not have access to the floodplain or use feeds from the floodplain.

• Small non-commercial herd on a residential parcel on Reach 7

• Potential for conversion of dairy to beef.• Cull and surplus dairy could be used for beef.• Residue exposure and uptake would be similar to

that for growing dairy animals.


Animal ManagementFree-Range Poultry

Animal ManagementFree-Range Poultry

• One farm in Reach 9• Confined to portable pens moved among

areas that could include the floodplain• Birds raised for meat only from April to

October• Commercial free-range egg production is

unlikely, but “backyard flocks” are possible

• One farm in Reach 9• Confined to portable pens moved among

areas that could include the floodplain• Birds raised for meat only from April to

October• Commercial free-range egg production is

unlikely, but “backyard flocks” are possible


Animal Products Considered(Present and Potential)

Animal Products Considered(Present and Potential)

• Dairy Cattle (milk and meat)• Beef Cattle (meat)• Goats (milk)• Sheep (lamb meat)• Free-range poultry (eggs and meat)• Deer (meat)

• Dairy Cattle (milk and meat)• Beef Cattle (meat)• Goats (milk)• Sheep (lamb meat)• Free-range poultry (eggs and meat)• Deer (meat)


Basic AssumptionsBasic Assumptions

• The amount of contaminant transferred is proportional to concentration

• Long-term exposures are evaluated –temporal variations are not considered

• The amount of contaminant transferred is proportional to concentration

• Long-term exposures are evaluated –temporal variations are not considered


Steady StateAssumptions and Limitations

Steady StateAssumptions and Limitations

• True steady state does not occur because of normal variations in diet or physiological state.

• Can only be applied to averages for a cropping year or production cycle

• High production and weight loss in early lactation is balanced by low production and weight gain in late lactation

• Timing of intake by meat-producing animals is not important because half-lives of contaminants are long compared to age at slaughter

• True steady state does not occur because of normal variations in diet or physiological state.

• Can only be applied to averages for a cropping year or production cycle

• High production and weight loss in early lactation is balanced by low production and weight gain in late lactation

• Timing of intake by meat-producing animals is not important because half-lives of contaminants are long compared to age at slaughter


Concentration in ProductConcentration in Product

Function of:1. Concentration in environmental matrix2. Animal access3. Characteristics of the chemical4. Physiological status of the animal

Function of:1. Concentration in environmental matrix2. Animal access3. Characteristics of the chemical4. Physiological status of the animal


Pathways of Animal ExposurePathways of Animal Exposure

(1) Soil — Air — Plant — Animal — Product

(2) Soil — Animal — Product

(1) Soil — Air — Plant — Animal — Product

(2) Soil — Animal — Product


Transfer Coefficients - MilkTransfer Coefficients - MilkBioconcentration Factor (BCF)

BCF = CMilkFat/CDiet

Biotransfer Factor (BTF)

BTF = CMilk/Intake

Carryover (COR)

COR = 100*QMilk/Intake

Bioconcentration Factor (BCF)

BCF = CMilkFat/CDiet

Biotransfer Factor (BTF)

BTF = CMilk/Intake

Carryover (COR)

COR = 100*QMilk/Intake


Prediction of Residue Concentrations in ProductsPrediction of Residue Concentrations in Products

Basic equation

Cprod = BCF*Cdiet(dw)

Expanded Equation

Cprod = (BCF*R*Dsoil*Csoil) + (BCF*DSil*CSil) + (BCF*DGrass*CGrass) + (BCF*DCon*CCon)

Cprod = Concentration in productCdiet(dw) = Concentration in diet (dry weight)R = bioavailability reduction factorDsoil = fraction of soil in the dietCsoil = Concentration in soilDSil = fraction of corn silage in the dietCSil = concentration in corn silageDGrass = fraction of grass-based feed in the dietCGrass = concentration in grass-based feedDcon = fraction of concentrate in the dietCcon = concentration in concentrate

Basic equation

Cprod = BCF*Cdiet(dw)

Expanded Equation

Cprod = (BCF*R*Dsoil*Csoil) + (BCF*DSil*CSil) + (BCF*DGrass*CGrass) + (BCF*DCon*CCon)

Cprod = Concentration in productCdiet(dw) = Concentration in diet (dry weight)R = bioavailability reduction factorDsoil = fraction of soil in the dietCsoil = Concentration in soilDSil = fraction of corn silage in the dietCSil = concentration in corn silageDGrass = fraction of grass-based feed in the dietCGrass = concentration in grass-based feedDcon = fraction of concentrate in the dietCcon = concentration in concentrate


Intake Factors - GeneralIntake Factors - General• Percentages of dry matter intake from roughages,

concentrates and soil are required (annual averages assuming 6 months of pasturing)

• Values based on knowledge of local conditions, literature, and generally accepted good management practices

• Values consist of a best estimate and a range consistent with good management practices

• Percentages of dry matter intake from roughages, concentrates and soil are required (annual averages assuming 6 months of pasturing)

• Values based on knowledge of local conditions, literature, and generally accepted good management practices

• Values consist of a best estimate and a range consistent with good management practices


Intake FactorsCommercial Dairy

Intake FactorsCommercial Dairy

00Soil, %

40-5045Concentrate, %

50-6055Total Roughage, %

00Grass Based, %

50-6055Corn Silage, %

RangeBest EstimateMatrix


Bioconcentration Factors -PCB MixturesBioconcentration Factors -PCB Mixtures

• Cattle – Milk– Data for PCB mixtures but none for Aroclor 1260– Values for Aroclor 1254 used as a conservative

estimate for Aroclor 1260

• Cattle – Tissue– Little data; body fat BCFs were assumed to the same

as milk BCFs

• Poultry – Eggs and Tissue– Data for PCB mixtures but none for Aroclor 1260– Used the mean of Aroclor 1254 and 1268

• Cattle – Milk– Data for PCB mixtures but none for Aroclor 1260– Values for Aroclor 1254 used as a conservative

estimate for Aroclor 1260

• Cattle – Tissue– Little data; body fat BCFs were assumed to the same

as milk BCFs

• Poultry – Eggs and Tissue– Data for PCB mixtures but none for Aroclor 1260– Used the mean of Aroclor 1254 and 1268


Bioconcentration Factors -Dioxin-like PCBsBioconcentration Factors -Dioxin-like PCBs

• Cattle – Milk– No generally accepted BCFs– No complete data set for dioxin-like congeners– Prediction equation derived using log KOW’s and absorption data

from the literature• Cattle – Tissue

– Little data; body fat BCFs were assumed to be the same as milk BCFs

• Poultry – Eggs and Tissue– No literature data PCB congeners– Prediction equations were derived for eggs and tissues– Assuming the relative values of congeners were the same in cattle

and poultry

• Cattle – Milk– No generally accepted BCFs– No complete data set for dioxin-like congeners– Prediction equation derived using log KOW’s and absorption data

from the literature• Cattle – Tissue

– Little data; body fat BCFs were assumed to be the same as milk BCFs

• Poultry – Eggs and Tissue– No literature data PCB congeners– Prediction equations were derived for eggs and tissues– Assuming the relative values of congeners were the same in cattle

and poultry


Bioconcentration Factors -PCDD/PCDFsBioconcentration Factors -PCDD/PCDFs

• Cattle – Milk– Used the mean values from three published studies

• Cattle – Tissue– Little data; Body fat BCFs were assumed to be the same as Milk

BCFs

• Poultry – Eggs and Tissue– Data from a study in laying hens fed a diet contain 10%

PCDD/PCDF-contaminated soil– Residue measurements were made in eggs and tissue

• Cattle – Milk– Used the mean values from three published studies

• Cattle – Tissue– Little data; Body fat BCFs were assumed to be the same as Milk

BCFs

• Poultry – Eggs and Tissue– Data from a study in laying hens fed a diet contain 10%

PCDD/PCDF-contaminated soil– Residue measurements were made in eggs and tissue


Estimating Human ExposureEstimating Human Exposure

ADD (mg/kg-d) = C x F x CR x (1-Loss) x EF x EDAT

ADD = average daily dose of contaminantC = food concentrationF = fraction of media that is contaminatedCR = consumption rateEF = exposure frequencyED = exposure durationAT = averaging time


Exposure AssumptionsExposure Assumptions

Food Consumption Rates• Dairy, beef, produce consumption rates

– Consumer only home-produced food consumption rates from EPA EF Handbook (1997)

– CTE = mean; RME = 75th%ile• Fiddlehead fern and venison consumption rates

– MADPH (1997, 2001)– CTE = mean; RME = 95th %ile

• Dairy, beef, produce consumption rates– Consumer only home-produced food consumption

rates from EPA EF Handbook (1997) – CTE = mean; RME = 75th%ile

• Fiddlehead fern and venison consumption rates– MADPH (1997, 2001)– CTE = mean; RME = 95th %ile

Exposure Duration• From MADPH (1997) and interviews

– CTE = mean; RME = 95th%ile or 70 year lifetime• From MADPH (1997) and interviews

– CTE = mean; RME = 95th%ile or 70 year lifetime

Preparation and Cooking Loss• From USEPA EF Handbook (1997)

– CTE = mean; RME = mean• From USEPA EF Handbook (1997)

– CTE = mean; RME = mean


Summary of Cancer Risk EstimatesSummary of Cancer Risk Estimates


Summary of Hazard IndicesSummary of Hazard Indices

Documents

Agricultural Product Consumption Risk Assessment · 2020-04-14 · Agricultural Trends: Potential Future Activities in the Floodplain • Dairy farms on the decline • Commercial