Instructions for Using VRP Calculation Spreadsheets
Gwcalcs.xls
The purpose of this spreadsheet is to calculate risk due to exposure to contaminated groundwater for a residential adult, a residential child, a construction/utility worker, and a commercial/industrial worker. The file contains a separate worksheet for each of these receptors. For each receptor the spreadsheet will calculate risk for three exposure routes-dermal absorption, ingestion, and inhalation.
Choose the receptor for which you want to calculate risk by clicking on the appropriate tab at the bottom of the worksheet.
Resident Adult and Resident Child
The oral and dermal sections of these worksheets assume use of groundwater for drinking and other domestic activities. Use these sections for sites where there will not be any restrictions on the use of the groundwater. The inhalation section of the worksheet may be used for either a showering scenario for an unrestricted site or for vapor intrusion from groundwater at sites where groundwater use will be restricted.
Enter the exposure point concentration (EPC) for groundwater in ug/L in the column labeled “groundwater concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.10, 3.11, and 3.12 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. For the residential scenario, the VRP default exposure factors should not be changed.
Dermal Exposure
The spreadsheet will convert the concentration from ug/L to mg/cm3 for use in the dermal absorption equation. The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, Kp, tau, t*, B, and FA have already been entered and should not be changed. See Section 3.3.1.1.1 of the VRP RAG for explanation of the dermal exposure equations and factors.
Oral Exposure (Ingestion)
The groundwater concentration will automatically be converted from ug/L to mg/L for use in the ingestion equation. The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
If the site will not have any restrictions on the use of groundwater, enter “y” for yes in Table 3.12 at the top of the worksheet thereby indicating that groundwater use will be occurring at the site. The exposure time (ET) will automatically be adjusted to the appropriate length of time for a shower for a resident adult. Note that a shower model is not incorporated into the gwcalcs spreadsheet. Therefore the EPC must be calculated for the shower air concentration via means external to the spreadsheet. The Foster and Chrostowski model is recommended. The EPC must be entered manually into the gwcalcs spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed. Note that since children are assumed to bathe instead of shower, the shower scenario is not calculated for the child resident.
If groundwater at the site will be restricted to prohibit potable use, enter “n” for no in the box in Table 3.12 found at the top of the worksheet. The ET will automatically be adjusted to 24 hours for the vapor intrusion scenario. Again, the EPC must be calculated via means external to the spreadsheet. The J&E model may be used to model indoor air concentrations from either groundwater or soil gas concentrations. Soil gas samples are highly recommended when VOCs are COPCs. Indoor samples may also be used for the EPC. Indoor air samples are generally only recommended when the weight of evidence for vapor intrusion is strong. We recommend that you consult the VRP project manager before collecting indoor air samples.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes. Since adult and child risks are calculated separately, the risks must be manually added to obtain lifetime cancer risks.
Construction/Utility Worker
The oral and dermal sections of this worksheet assume that a construction or utility worker will have direct contact with groundwater. The default assumption is that if the depth to groundwater is 15 feet or less, the worker will contact the groundwater directly. The inhalation section of the worksheet may be used for either a direct contact or inhalation-only scenario. See Section 3.2.2 of the VRP RAG for a description of these two scenarios.
Enter the EPC for groundwater in ug/L in the column labeled “groundwater concentration”. See Section 3.2 of the VRP RAG for information on calculating the EPC.
VRP Tables 3.10, 3.11, and 3.12 are found at the top section of the worksheet and contain the VRP default exposure factors. For the construction/utility worker scenario, some of the VRP default exposure factors may be changed to a site specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will convert the concentration from ug/L to mg/cm3 for use in the dermal absorption equation. The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, Kp, tau, t*, B, and FA have already been entered and should not be changed. See Section 3.3.1.1.1 of the VRP RAG for explanation of the dermal exposure equations and factors.
Oral Exposure (Incidental Ingestion)
The groundwater concentration will automatically be converted from ug/L to mg/L for use in the ingestion equation. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
Because the spreadsheet does not calculate air concentrations from groundwater concentrations, the construction trench air concentration or EPC must be calculated by methods external to the spreadsheet. For a direct contact scenario use VRP Table 3.8 to calculate the trench air concentration. For the inhalation-only scenario use VRP Table 3.7 to calculate the trench air concentration. The modeled concentration from Table 3.7 or 3.8 must be entered manually into the gwcalcs spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes.
Commercial/Industrial Worker
The oral and dermal sections of these worksheets assume use of groundwater for an industrial process. Use these sections if potable use of the groundwater will be restricted but industrial use will not be restricted. The inhalation section of the worksheet should be used for vapor intrusion.
Enter the EPC for groundwater in ug/L in the column labeled “groundwater concentration”. See Section 3.2 of the VRP RAG for information on calculating the EPC.
VRP Tables 3.10, 3.11, and 3.12 are found at the top section of the worksheet and contain the VRP default exposure factors. For the industrial scenario, some of the VRP default exposure factors may be changed to a site-specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will convert the concentration from ug/L to mg/cm3 for use in the dermal absorption equation. The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, Kp, tau, t*, B, and FA have already been entered and should not be changed. See Section 3.3.1.1.1 of the VRP RAG for explanation of the dermal exposure equations and factors.
Oral Exposure (Incidental Ingestion)
The groundwater concentration will automatically be converted from ug/L to mg/L for use in the ingestion equation. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
Because the spreadsheet does not calculate indoor air concentrations from groundwater concentrations the indoor air EPC must be calculated by methods external to the spreadsheet. The J&E model may be used to model indoor air concentrations from either groundwater or soil gas concentrations. Soil gas samples are highly recommended when VOCs are COPCs. Indoor samples may also be used for the EPC. Indoor air samples are generally only recommended when the weight of evidence for vapor intrusion is strong. We recommend that you consult the VRP project manager before collecting indoor air samples.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes.
Soilcalcs.xls
The purpose of this spreadsheet is to calculate risk due to exposure to contaminated soil for a residential adult, a residential child, a construction/utility worker, and a commercial/industrial worker. The file contains a separate worksheet for each of these receptors. For each receptor the spreadsheet will calculate risk for three exposure routes-dermal absorption, ingestion, and inhalation.
Choose the receptor for which you want to calculate risk by clicking on the appropriate tab at the bottom of the worksheet.
Resident Adult and Resident Child
Use these spreadsheets for sites where there will not be any land-use restrictions.
Enter the exposure point concentration (EPC) for soil in mg/kg in the column labeled “soil concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.13, 3.14, and 3.15 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. For the residential scenario, the VRP default exposure factors should not be changed.
Dermal Exposure
The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, and absorption factor (ABS) have already been entered and should not be changed.
Oral Exposure (Inadvertent Ingestion)
The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
For ambient (outside) air, CA may be calculated by dividing the soil concentration by either the particulate emission factor (PEF) for inorganics or the volatilization factor (VF) for organics and mercury. Default PEFs and VFs are provided in the spreadsheet. For indoor air, CA may be calculated by inputting a representative soil vapor concentration into the Johnson and Ettinger (J&E) model. Direct measurement of indoor air may also be used as the EPC. However, we recommend consulting the VRP project manager before collecting indoor air samples. The EPC must be entered manually into the soilcalcs spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes. Since adult and child risks are calculated separately, the risks must be manually added to obtain lifetime cancer risks.
Construction/Utility Worker
Use these spreadsheets for sites where there will not be any restrictions on intrusive activities such as construction or utility work.
Enter the exposure point concentration (EPC) for soil in mg/kg in the column labeled “soil concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.13, 3.14, and 3.15 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. For the construction/utility worker scenario, some of the VRP default exposure factors may be changed to a site specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor and ABS have already been entered and should not be changed. See the footnotes on Table 3.13 for options for the soil-to-skin adherence factor (AF).
Oral Exposure (Inadvertent Ingestion)
The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
The air concentration (CA) may be calculated by dividing the soil concentration by either the particulate emission factor (PEF) for inorganics or the volatilization factor (VF) for organics and mercury. Default PEFs and VFs are provided in the spreadsheet. The EPC must be entered manually into the soilcalcs spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes.
Commercial/Industrial Worker
Use these spreadsheets for sites where there will be land use restrictions on residential use of the property.
Enter the exposure point concentration (EPC) for soil in mg/kg in the column labeled “soil concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.13, 3.14, and 3.15 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. In general, the exposure factors for the commercial/industrial worker scenario should not be changed. However, in a few cases some of the VRP default exposure factors may be changed to a site- specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor and ABS have already been entered and should not be changed.
Oral Exposure (Inadvertent Ingestion)
The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
For ambient (outside) air, the air concentration (CA) may be calculated by dividing the soil concentration by either the particulate emission factor (PEF) for inorganics or the volatilization factor (VF) for organics and mercury. Default PEFs and VFs are provided in the spreadsheet. For indoor air, CA may be calculated by inputting a representative soil vapor concentration into the Johnson and Ettinger (J&E) model. Direct measurement of indoor air may also be used as the EPC. However, we recommend consulting the VRP project manager before collecting indoor air samples. The EPC must be entered manually into the soilcalcs spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes.
Swcalcs.xls
The purpose of this spreadsheet is to calculate risk due to exposure to contaminated surface water for a recreational adult and child and a trespasser adult and child. If the surface water is a drinking water source, use gwcalcs to calculate risk for potable use. The file contains a separate worksheet for each of these receptors. The main difference between the receptors is the exposure frequency. For sites that have impacted surface water either on or off site that is in an area used for recreation, the recreational scenario should be used. For all other sites with impacted surface water the trespasser scenario should be used. For each receptor the spreadsheet will calculate risk for three exposure routes-dermal absorption, inadvertent ingestion, and ingestion of aquatic organisms.
Choose the receptor for which you want to calculate risk by clicking on the appropriate tab at the bottom of the worksheet.
Recreational Adult and Recreational Child
Enter the exposure point concentration (EPC) for surface water in ug/L in the column labeled “surface water concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.16, 3.17, and 3.18 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. The VRP default exposure factors may be changed to a site-specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors. If the impacted surface water can support swimming, enter “y” for yes in Table 3.16 and 3.17 at the top of the worksheet. The skin surface area and ingestion rate will be adjusted accordingly. If “n” is entered, a wading scenario is assumed.
Dermal Exposure
The spreadsheet will convert the concentration from ug/L to mg/cm3 for use in the dermal absorption equation. The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, Kp, tau, t*, B, and FA have already been entered and should not be changed. See Section 3.3.1.1.1 of the VRP RAG for explanation of the dermal exposure equations and factors.
Oral Exposure (Ingestion)
The surface water concentration will automatically be converted from ug/L to mg/L for use in the ingestion equation. The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Ingestion of Aquatic Organisms
If the impacted surface water can support edible aquatic organisms (e.g. fish, crabs, shellfish) risk due to injection of aquatic organisms should be calculated. The EPC in tissue may be estimated by entering the surface water concentration and a bioconcentration factor. The reference for the bioconcentration factor should be provided. The spreadsheet will calculate an estimated tissue concentration. A measured concentration for tissue should be used if available. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the three exposure routes. Since adult and child risks are calculated separately, the risks must be manually added to obtain lifetime cancer risks.
Trespasser Adult and Trespasser Child
Enter the exposure point concentration (EPC) for surface water in ug/L in the column labeled “surface water concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.16, 3.17, and 3.18 from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. The VRP default exposure factors may be changed to a site-specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors. If the impacted surface water can support swimming, enter “y” for yes in Table 3.16 and 3.17 at the top of the worksheet. The skin surface area and ingestion rate will be adjusted accordingly. If “n” is entered, a wading scenario is assumed.
Dermal Exposure
The spreadsheet will convert the concentration from ug/L to mg/cm3 for use in the dermal absorption equation. The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, Kp, tau, t*, B, and FA have already been entered and should not be changed. See Section 3.3.1.1.1 of the VRP RAG for explanation of the dermal exposure equations and factors.
Oral Exposure (Ingestion)
The surface water concentration will automatically be converted from ug/L to mg/L for use in the ingestion equation. The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Soilsedrectrescalcs.xls
The purpose of this spreadsheet is to calculate risk due to exposure to contaminated soil and sediment for a recreational adult and child and a trespasser adult and child. The file contains a separate worksheet for each of these receptors. For soil, the spreadsheet will calculate risk for three exposure routes-dermal absorption, ingestion, and inhalation. For sediment, inhalation risk is generally minimal and is not included.
Choose the receptor for which you want to calculate risk by clicking on the appropriate tab at the bottom of the worksheet.
Recreational Adult and Recreational Child
Use these spreadsheets for sites where there will be land-use restrictions prohibiting residential use but recreational use is possible.
Enter the exposure point concentration (EPC) for soil or sediment in mg/kg in the column labeled “soil concentration” or “sediment concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.19, 3.20, and 3.21 (soil only) from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. The VRP default exposure factors may be changed to a site-specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, and absorption factor (ABS) have already been entered and should not be changed.
Oral Exposure (Inadvertent Ingestion)
The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
The air concentration (CA) may be calculated by dividing the soil concentration by either the particulate emission factor (PEF) for inorganics or the volatilization factor (VF) for organics and mercury. Default PEFs and VFs are provided in the spreadsheet. The EPC must be entered manually into the spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the exposure routes. Since adult and child risks are calculated separately, the risks must be manually added to obtain lifetime cancer risks.
Trespasser Adult and Trespasser Child
Use these spreadsheets for sites where there will be land-use restrictions prohibiting residential and recreational use is not likely.
Enter the exposure point concentration (EPC) for soil or sediment in mg/kg in the column labeled “soil concentration” or “sediment concentration”. See Section 3.2 of the VRP Risk Assessment Guidance (RAG) for information on calculating the EPC.
The top section of each worksheet contains VRP Table 3.19, 3.20, and 3.21 (soil only) from the VRP RAG. These tables contain the VRP default exposure factors for each of the three exposure routes for each receptor. The VRP default exposure factors may be changed to a site-specific scenario if appropriate rationale and documentation are provided. We recommend that you consult with the VRP project manager or risk assessment staff prior to changing the default exposure factors.
Dermal Exposure
The spreadsheet will calculate the dermally absorbed dose, cancer risk and hazard quotient. VRP default values for cancer slope factor, reference dose, and absorption factor (ABS) have already been entered and should not be changed.
Oral Exposure (Inadvertent Ingestion)
The spreadsheet will calculate the chronic daily intake (CDI), cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
Inhalation
The air concentration (CA) may be calculated by dividing the soil concentration by either the particulate emission factor (PEF) for inorganics or the volatilization factor (VF) for organics and mercury. Default PEFs and VFs are provided in the spreadsheet. The EPC must be entered manually into the spreadsheet in mg/m3. The spreadsheet will calculate the CDI, cancer risk and hazard quotient. The VRP default values for cancer slope factor and reference dose have already been entered and should not be changed.
The spreadsheet will then sum the risks and hazard quotients for the exposure routes. Since adult and child risks are calculated separately, the risks must be manually added to obtain lifetime cancer risks.