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HUMAN HEALTH RISK ASSESSMENT Lavarack Barracks - PFAS investigation

EEC16094.040 Human Health Risk

Assessment Rev 3

03 December 2019

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EXECUTIVE SUMMARY

Introduction RPS Australia West Propriety Limited (Pty Ltd) (RPS) in partnership with Wood Public Limited Company (Wood) (RPS/Wood) was engaged by the Department of Defence (Defence) to undertake a quantitative Human Health Risk Assessment (HHRA) for per- and poly-fluoroalkyl substances (collectively known as PFAS) exposure related to Lavarack Barracks (the “Base”), located in Townsville, Queensland. Lavarack Barracks (Figure 1) is a large working, training, and accommodation facility, which houses the Royal Australian Army (RAA) (Department of Defence 2017).

In the 1970s, Defence began using Aqueous Film Forming Foams (AFFF) for firefighting. AFFF products contain PFAS including Perfluorooctane sulfonic acid (PFOS), Perfluorohexane sulfonic acid (PFHxS), and Perfluorooctanoic acid (PFOA). Defence commenced phasing out legacy firefighting foam containing specific types of PFAS in 2004. Defence now uses a more environmentally safe product (http://www.defence.gov.au/ Environment/PFAS/). Defence has subsequently identified sites across Australia as potentially contaminated by PFAS. A National Program is on-going to investigate and manage these sites.

The primary project objective of the HHRA is to quantitatively assess potential risks to human health from media that may be impacted by PFAS, the active ingredient in AFFF which was historically used at the Base. This report assesses the potential human health risks associated with exposure to PFAS in soil, sediment, surface water and groundwater within the Investigation Area (IA) in addition to potential human health risks from the consumption of home-grown fruit, vegetables, chicken eggs, and seafood within the Ross River and associated tributaries. This report provides a comprehensive understanding of the potential risks to human health and the environment as a result of historic AFFF usage at the Base.

This report is the latest step in an iterative process, following a Detailed Site Investigation (DSI) (RPS/Wood 2019a) and previous stages of investigation. The DSI focused on the IA, which includes the Base and the surrounding off-Base area as per Figure 1. This report has been prepared in accordance with the National Environmental Protection Measure (Assessment of Site Contamination) Measure 1999, As Amended 2013 (ASC NEPM) (NEPC 2013), and the approved HHRA Sampling and Analysis Quality Plan (SAQP) and Methodology Report (RPS/Wood 2019b).

This report has been prepared in consultation with the Defence appointed accredited auditor, Brad May of Beca Consultants Pty Ltd, who was engaged as the technical advisor (TA) and third-party reviewer of technical deliverables for the project. The scope of work presented in this report as described in the HHRA SAQP has also been reviewed by the Queensland Technical Working Group, which was established by the Queensland Government Interdepartmental Committee for Fluorinated Fire Fighting Foam.

Objectives The overall objectives of the HHRA are to:

• Use representative, high quality data to quantitatively assess the potential health risks to current human health receptors within the IA associated with exposure to PFAS.

• Provide stakeholders with advice regarding potential risks associated with exposure to PFAS.

• Provide information to guide potential remediation and/or risk management measures to address PFAS contamination within the IA from historical PFAS releases.

To achieve the stated objectives, the scope of work includes running a quantitative human health risk assessment for all relevant exposure pathways to current receptors within the IA.

PFAS investigation This report follows the DSI, and early sampling efforts, as well as an initial water use survey. During this program a large amount of PFAS analytical data has been collected on-Base and off-Base. The analysis

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included over 200 soil samples, over 100 groundwater samples, over 70 surface water samples, over 40 sediment samples, and a comprehensive seafood investigation.

PFAS were assessed in soil, groundwater and other media (if present) at 12 primary potential source contaminant (PSC) areas on-Base. The PSCs are generally open mown lawn areas, which are understood to be limited to military use (adult exposure only). In addition to the primary source areas, secondary sources (translocation of PFAS through irrigation, storm runoff, construction etc.) were also identified. Secondary sources include the golf course and athletic fields along the northern base boundary that have been irrigated with water known to contain PFAS, as well as the upper and lower dams which are receptors as well as secondary sources.

The DSI concluded that there are identified source areas within the Base where the historical use of AFFF for fire-fighting purposes has contributed to PFAS impacts in soil, groundwater, sediment, and surface water. Based on a qualitative assessment of the source areas the following key source areas have been identified which will be further investigated as part of the PFAS Management Area Plan (PMAP) and future work within the Seasonal Monitoring Report; Former Fire Station (PSC-4), Monocell (PSC-5), Former Fire Training Area (PSC-6), Sporting Fields and Golf Course (Secondary Source) and Top, Middle and Lower dams (Secondary Source). It is noted that the seasonal sampling has been performed, and that the results are generally comparable to the previous (pre-flooding) data.

This report considers all PFAS data and information collected at the Base. Soil, groundwater, surface water, sediment, and pore water samples were analysed for the Defence list of 28 PFAS compounds consistent with the PFAS analysis presented in the DSI SAQP (RPS/Wood 2018a). Biota samples were analysed for the 22 PFAS compounds with available laboratory standards in biota. Twenty different PFAS were detected in soil, 17 in groundwater, 11 in surface water, 7 in sediment, 10 in aquatic biota, and 1 in home grown produce. Seafood samples include 72 fish fillet samples, and 9 shellfish samples.

Due to the potentially high bioaccumulation factors from surface water to fish tissue, collecting sufficient analytical data to evaluate potential risks to human health from recreational fishing within the Ross River has been a major focus of the PFAS investigation. The analytical results for finfish collected in January 2018 (ESP) (RPS/Wood 2017) from the freshwater reach of Aplin’s Weir were evaluated by Defence and Queensland Department of Health (DoH) within an initial human health evaluation of potential risks from consumption of seafood. The initial human health evaluation by Queensland DoH determined that PFAS in fish tissue was unlikely to cause a significant risk to health given the small contribution of Ross River fish tissue to the local population’s diet, and given the current mercury-driven fish advisory of 2 – 3 meals per week for most types of fish (Queensland DoH 2018). Defence prepared a work plan for additional biota sampling to confirm the results. The data collected in August 2018 was generally consistent with the previous findings, however interim precautionary fish consumption advice has been issued for the lakes in Idalia. Data from both rounds of biota sampling are included within the HHRA.

Home grown produce consumption was identified as a data gap following the DSI due to the spatial spread of the 15 backyard produce samples (not targeted to the off-Base areas with the highest concentrations) and also the type of tissue sampled (the majority of the samples were fruit, which has relatively lower uptake factors when compared to leafy green vegetables and animal products). A targeted sampling program to evaluate concentrations within backyard produce off-Base was developed, but due to the flooding in Townsville was not implemented. Therefore, the approach within this HHRA uses mathematical models to estimate potential concentrations in backyard produce rather than relying on directly measured produce concentrations.

Conceptual site model A Conceptual Site Model (CSM) has been developed that represents the characteristics of the source and exposure areas in a table, illustrating the possible relationships between contaminants, pathways and receptors (termed pollutant linkages). Source-pathway-receptor pollutant linkages have been identified.

Figure A and B from the DSI present graphical representations of the CSM illustrating key potential sources, pathways, and receptors for the two primary sub-catchments. The figures show the primary and secondary sources carried forward, incorporating the key findings of the DSI.

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Figure A: Conceptual Site Model A (Catchments F, G, R, S, T)

Figure B: Conceptual Site Model B (Catchments J, K, V, Z)

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Exposures were either evaluated by PSC (soil exposure) or evaluated by sub-catchment. The primary two sub-catchments evaluated are shown on Figure A and B. Surface water migration pathway is likely the dominant pathway for PFAS flux off the Base. Groundwater pathways exist, but due to the nature of the geology and the intermitting and disconnected groundwater flow paths, described in the DSI, surface water transport is the more dominant mechanism of PFAS flux from source areas on-Base into the off-Base IA. As indicated within the DSI, migration of PFAS is occurring by several mechanisms in the IA. Irrigation with surface water on-Base and bore water off-Base is moving PFAS into shallow soils and further infiltrating into groundwater. Stormwater and flood water are transporting PFAS from tributaries onto flood plains and upland soils. PFAS in irrigation water and stormwater is transported into gardens and backyard produce (including fruit, vegetables and poultry) where it may be accumulating in biota and potentially consumed by humans.

PFAS may enter the human food chain by several pathways. It can be taken up into plants and can bioaccumulate within animal tissue. The two main dietary exposure pathways identified within the IA are recreational fishing and ingestion of home-grown produce. Uptake from dermal contact is generally considered negligible for PFAS (HEPA, 2018). Uptake from inhalation is considered; however, it is generally a minimal contributor to the overall risk (HEPA, 2018). Due to the unique attributes of PFAS, they bioaccumulate and may biomagnify within the food chain. As a result, after the drinking water pathway, the dietary exposure pathway has the highest potential to drive health risk management decisions.

Potentially complete exposure pathways considered in the HHRA are summarized below:

• Groundwater: Although PFAS have been detected in groundwater on-Base, there is no potable use of groundwater and therefore no complete exposure pathway. There is no gardening/growing of produce on the base; however, some off-base residents do use irrigation bores. Incidental ingestion of groundwater (used as irrigation water) during recreational activity within irrigated areas is considered a potentially complete pathway. Construction workers may encounter shallow groundwater during excavation works, but groundwater on-Base is all greater than 3 m below ground surface (bgs), therefore this pathway is considered incomplete on-Base.

• Soil: Access to on-base PSCs is limited to military personnel, who may contact soil through incidental ingestion, dermal contact, and ingestion of particulates. Due to the surface application of AFFF, the majority of impact is typically within surface soils. Deeper soils may be contacted by intrusive construction workers through the same pathways. PFAS contamination in soils off-base is minimal, though PFAS may be transferred to soil through irrigation using PFAS-impacted groundwater or surface water and may in turn be taken up by biota on private residential properties. PFAS may also leach out of soil into groundwater.

• Sediment/Pore Water: PFAS have been detected in sediments and associated pore water in the tributaries discharging from Lavarack Barracks. As a conservative measure, pore water has been considered equivalent to surface water and has therefore been assessed as surface water. Recreational receptors could contact sediments through incidental ingestion and dermal contact. No PFAS was detected in Ross River sediment.

• Surface Water/Pore Water: PFAS have been detected in surface water and pore water within the Ross River and tributaries discharging into the Ross River. Recreational receptors may contact surface water/pore water along the tributaries, or by use of surface water for irrigation purposes through incidental ingestion.

• Home grown produce and poultry: PFAS have been detected in one sample of backyard leafy green vegetables (parsley), as well as the only poultry egg sample collected. Sample collection was not targeted, and therefore it is unknown if these results represent the highest concentrations within the investigation area. The produce was grown for consumption; therefore, the dietary exposure pathway for ingestion of home grown produce and poultry is considered potentially complete.

• Fish and Shellfish: Initial biota sampling within the Ross River detected concentrations of PFOS above conservative FSANZ “trigger values” for fish consumption investigation. PFHxS was below the trigger value and detected in seven milk fish samples only, and PFOA was not detected in any finfish tissue samples. Both PFOA and PFHxS were detected within shellfish samples. Since recreational fishing takes place in the Ross River, the dietary ingestion exposure pathway for fish tissue is considered complete.

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PFAS human health risk assessment The HHRA has been conducted in five key sections. The content and key findings of each section is summarised below.

Issues identification The HHRA focuses only on evaluating potential risks to current receptors from potentially complete exposure pathways identified within the CSM. These include incidental ingestion and dermal contact with soil, groundwater, sediment, and surface water, as well as inhalation of fugitive dust, and ingestion of produce from irrigated crops. Seafood ingestion is also considered, specifically ingestion of recreationally caught fish and shellfish from the Ross River, Northview Lake, and Fairfield Lake. This evaluation has been performed to guide risk management decisions related to exposure to media potentially impacted by legacy AFFF use at the Base.

Data collection and data evaluation The current dataset is considered adequate to conduct a HHRA. The Tier 1 screen was performed by comparing maximum detected concentrations within each identified exposure area separately. The Tier 1 screen is conducted to identify which PFAS compounds in which media, and for seafood in which species/areas are likely to pose more than negligible risk and therefore should be evaluated in the Tier 2 evaluation. The results of the Tier 1 screen that is presented in Section 4.8 indicated that concentrations in surface water on-Base in two catchments were above the recreational screening criteria, however only surface water from sub-catchment G is used for non-potable purposes on-Base (to irrigate the golf course). Additionally, fish tissue was above the Food Standards Australia New Zealand (FSANZ) trigger values for specific species and areas, which were carried into the Tier 2 evaluation. All other species and areas were considered negligible risk including the recreational shellfish harvesting ingestion pathway. There are no applicable Tier 1 standards to evaluate produce consumption following irrigation, therefore this pathway was also carried into the Tier 2, as well as calculated uptake from soil in order to evaluate cumulative risks from this pathway.

Exposure assessment Based on the Tier 1 screen, one exposure area in surface water and sediment was carried into the Tier 2 for quantitative assessment (sub-catchment G on-Base). Calculations were performed for recreational exposure to surface water and sediment from ingestion and dermal contact. The remainder of the Tier 2 calculations were for ingestion of seafood or produce. Tier 2 evaluation of seafood included 19 exposure scenarios, which are presented in Figure C below. Exposure Point Concentrations (EPCs) were calculated for PFAS within surface water, sediment, and seafood exposure areas based on measured concentrations as both the 95% Upper Confidence Limit (95% UCL) and mean for each exposure area. For the seafood assessment, several iterations were considered based on assumed recreational angler preferences for location or species.

No Tier 1 evaluation was performed for the home grown produce pathway as there are no screening values available to evaluate potential risks from irrigation of produce. A specific targeted home grown produce area was identified based on consideration of the maximum detected concentrations off-Base and along the northern site boundary. Concentrations within produce were estimated from soil, groundwater, and surface water data within this area for uptake into backyard produce. Modelling was performed for the selected areas using standard equations and current best practice literature values to estimate uptake from soil and water media. Concentrations were estimated for fruit, vegetables, and poultry eggs. EPCs were calculated for Tier 2 evaluation based on modelled concentrations of fruit, vegetables, and poultry eggs within the identified exposure areas.

The Tier 2 evaluation considers both a “typical” exposure estimate and an “upper limit” exposure estimate for both child and adult receptors at each of the selected exposure scenarios. The upper limit estimate of exposures includes the more conservative (higher) estimate of potential concentrations, as well as the more conservative (higher) estimate for potential exposure/ingestion. Combining these two upper estimates provides an evaluation of a ‘worst-case’ exposure intake.

• For the seafood evaluation the consumption rates equate to two meals per week under the typical scenario, and seven meals per week under the upper limit scenario. Including seven meals per week is a highly conservative assumption for a population that evidence suggests mainly practices catch and

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release fishing. The upper limit calculations assume 100% of all fish meals come from the contaminated source. The upper limit scenario is considered close to a subsistence level evaluation (subsistence level ingestion assumes that most of the protein within an individual’s diet comes from this source).

• For the produce evaluation the uptake rates assume either 10% or 50% ingestion of total vegetables from home grown sources. This is likely an overly conservative estimate for the IA as there were very limited vegetables collected for analysis during the field program. Only parsley and mint were collected, which are within the vegetable or herb category, suggesting that vegetables may not be grown within the IA in large quantities. Fruits were more frequently collected, and only a single poultry egg sample.

Figure C: Tier 2 fish consumption species/areas

Toxicity assessment Final health-based threshold (non-cancer) toxicity reference values (TRVs) were published in April 2017 by the Department of Health for three PFAS compounds: PFOS/PFHxS and PFOA. These were developed by Food Standards Australia New Zealand’s (FSANZ) and published in their report on Perfluorinated Chemicals in Food. Tolerable Daily Intakes (TDIs) indicate the daily amount of a substance that a receptor can be exposed to over a lifetime with no significant risk to health. These values are expressed in units of mg or µg of contaminant, per kg of bodyweight, per day.

The published PFOS+PFHxS (sum) TDI has been adjusted to consider the potential contribution from background (approximately 7% of the PFOS TDI). PFOA background contribution is considered negligible (<1 %). The adopted TDIs are shown below:

• PFOS+PFHxS (sum): 1.86 x 10-5 mg/kg/day

• PFOA: 1.6 x 10-4 mg/kg/day

Non-threshold effects (cancer) are not evaluated.

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Risk characterisation Overall the potential risks from exposure to PFAS in media potentially impacted by the base is low and acceptable. Specific source-pathway-receptor linkages are summarized along with the results of the Tier 1 and Tier 2 evaluation in table S1 below.

Table S1: Summary of risks per exposure scenario

Receptor and Setting

Exposure Media

Transport Pathway from PSCs

Exposure Pathway

Tier 1 Results

Tier 2 Results

Assessed Health Risk Outcome

On-Base Defence personnel and other workers

Soil Surficial release of PFAS on-Base

Ingestion, dermal contact, and inhalation of dust

Below Tier 1 criteria

NA Low and acceptable

Groundwater Leaching of PFAS from soil to groundwater

No exposure pathway

Above Tier 1 criteria for drinking water and recreational use at several PSCs

NA No current exposure risk

Surface water

Overland flow and stormwater discharge

Ingestion and dermal contact

Above Tier 1 criteria for recreational use in sub-catchment G

Results below HI of 1 for recreational use

Low and acceptable

Sediment No criteria On-Base recreators within the golf course

Surface water

Overland flow and stormwater discharge

Ingestion and dermal contact

Above Tier 1 criteria in sub-catchment G

Results below HI of 1 for recreational use

Low and acceptable

Sediment No criteria Off-Base residents

Soil Transport of PFAS to off-Base soils from water either by flooding or irrigation

Ingestion, dermal contact, and inhalation of dust

Below Tier 1 Criteria

NA Low and acceptable

Groundwater PFAS movement in groundwater aquifer off-Base

Ingestion and dermal contact with extracted groundwater for irrigation or other non-potable uses

Below Tier 1 criteria for recreational use

NA Low and acceptable

Surface water

Overland flow and stormwater discharge, and PFAS movement from groundwater to surface water and sediments

Ingestion and dermal contact

Below Tier 1 criteria for recreational use

NA Low and acceptable

Sediment No criteria, however below conservative soil criteria

Home Grown Produce

Bioaccumulation from water used for irrigation or PFAS impacted soils

Ingestion of home grown produce

Measured produce results below Tier 1 criteria. No criteria for water media.

Results below HI of 1 for ingestion of 10% fruits, vegetables, and poultry eggs from home

Low and acceptable for current scenario*

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Receptor and Setting

Exposure Media

Transport Pathway from PSCs

Exposure Pathway

Tier 1 Results

Tier 2 Results

Assessed Health Risk Outcome

Off-Base recreators within tributaries and the Ross River

Surface water

Overland flow and stormwater discharge

Ingestion and dermal contact

Below Tier 1 criteria for recreational use

Results below HI of 1 for recreational use

Low and acceptable

Sediment No criteria Recreational Anglers

Finfish Bioaccumulation from surface water and sediment carrying PFAS

Ingestion of locally caught seafood

Above Tier 1 criteria

Results below HI of 1 for ingestion of 50% of fish from local sources

Low and acceptable

Recreational Shellfish Harvesters

Shellfish Below Tier 1 criteria

NA Low and acceptable

HI - Hazard Index *Concentrations within groundwater in boundary wells and at some locations within the IA may be associated with unacceptable risks during an irrigation scenario in the future, depending on the quantity and rate of vegetable and poultry egg consumption, should it be greater than the assumptions during this assessment, or should the boundary wells be used for irrigation. Therefore, precautionary advice is recommended within a limited area that will be identified based on concentrations in soil and groundwater associated with potentially unacceptable risks.

All Hazard Quotients (HQs) and Hazard Indices (HIs) calculated for the typical scenario for both produce ingestion and seafood consumption were below one. Precautionary advice for produce ingestion within the IA is likely to be recommended for vegetable and poultry ingestion, as some HQs were above 1 for the upper limit scenario. Specific details are summarised below:

• Based on the limited produce sampling conducted, fruits were the most frequently collected crop. HQs were below 1 for all fruit ingestion calculations, and all fruit collected were below Tier 1 screening criteria, suggesting that no precautionary advice is necessary to manage potential risks from fruit ingestion.

• During the limited sampling round only two leafy vegetables/herbs, and a single poultry egg sample were collected. No roots or tubers were collected. Since vegetables and poultry do not appear to be widely grown within the IA, risks from ingestion of vegetables and poultry eggs are currently considered low. The calculated risks for vegetable uptake are likely conservative for current residents within the IA.

• In order to ensure that risks from ingestion of vegetables and poultry are acceptable for all residents within the IA currently and in the future, precautionary advice may recommend specific limitations for ingesting home-grown vegetables and poultry. Advice may also include best practice methods be adopted within a portion of the IA, such as using raised beds and using town water rather than private bore water to irrigate vegetables and water poultry.

• In addition to assumptions about exposure within the IA off-Base, PFAS concentrations in groundwater are generally higher at the Northern Base boundary locations than they are within the home-grown produce area. Based on currently available information there is limited use of water to irrigate vegetables or water poultry. However, additional restrictions may be placed on groundwater from this area to ensure no groundwater is extracted, or that any irrigation use at these locations is appropriately managed.

Risk management measures as required will be addressed in the PFAS Management Area Plan (PMAP), and monitoring requirements to confirm the level of risk identified by sampling completed to date will be presented in the Ongoing Monitoring Plan (OMP).

Although some HQs were above 1 for the upper limit scenario for seafood consumption, based on the advice from the Department of Agriculture and Fisheries suggesting that the majority of fishing above Aplin’s Weir is catch and release, even the “typical” exposure calculations are likely to provide a conservative estimate of potential risks. This is consistent with Department of Health advice, suggesting that consumption of fish from

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Upstream of Aplin’s Weir is unlikely to form a significant portion of an individual’s total diet or seafood intake (Queensland Department of Health 2018, Appendix C).

Each exposure scenario (recreator, home grown produce consumer ingesting fruit, vegetables, and eggs, and recreational angler) has been run independently, which does not consider cumulative risks for a potential receptor recreating at the golf course, growing produce within the IA, and recreationally fishing within the IA. Community derived data would be required to identify whether combining exposure is appropriate.

Table S2: Meals per week before reaching the TDI

Species Area Typical Upper limit Adult Child Adult Child

All Species Combined Areas 10 5 7 4 All Species Upstream of Aplin’s Weir 8 4 4 2 Downstream of Aplin’s Weir 19 10 12 7 Northview Lake 13 7 9 5 Northview Lake + Fairfield Lake 6 3 4 2 Barramundi Combined Areas 8 4 6 3 Ross River 7 4 6 3 Upstream of Aplin’s Weir 6 3 5 3 Downstream of Aplin’s Weir 9 5 9 5 Northview Lake 9 5 9 5 Longfin Eel Upstream of Aplin’s Weir 3 2 2 1 Sleepy Cod Combined Areas 17 9 9 5 Upstream of Aplin’s Weir 10 5 9 5 Blackspot Longtom Downstream of Aplin's Weir 10 5 10 5 Milk Fish Combined Areas 6 3 4 2 Downstream of Aplin’s Weir 9 5 7 4 Northview Lake 10 5 9 5 Fairfield Lake 3 2 3 2 Northview Lake + Fairfield Lake 5 3 4 2

Another way to look at the potential risk from eating fish is to calculate how many meals are safe to eat per week. The Queensland Department of Health advice issued in May 2018 for the Ross River was based on three meals per week. Table S.2 shows, based on the calculated EPCs for the typical and upper limit exposure estimates, the number of meals that are safe for an adult to eat assuming a 150 g meal size, and the number of meals a child can eat assuming a 75g meal size (i.e. how much fish can be eaten before reaching the TDI). In all exposure scenarios at least one locally sourced meal is safe to consume per week, and for the majority of exposure scenarios more than one locally sourced meal per week is safe to consume. This is also shown in Figure D below.

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Figure D: Summary of risk results and meals per week