When EPA assesses the risk of a pesticide to human health or the environment, it considers the toxicity of the pesticide as well as the amount of pesticide to which a person or the environments may be exposed. In assessing exposure, scientists frequently use mathematical models to predict pesticide concentrations in food, water, residential, and occupational environments.
On this page:
OPP uses aquatic models to estimate pesticide concentrations in food, water, non-target organisms, residential and occupational environments. These estimated concentrations are used to assess exposure to aquatic organisms, humans, and the environment.
SWCC (Surface Water Concentration Calculator)
The Surface Water Concentration Calculator (SWCC) estimates pesticide concentrations in water bodies that result from pesticide applications to land. The SWCC is designed to simulate the environmental concentration of a pesticide in the water column and sediment and is used for regulatory purposes by the USEPA Office of Pesticide Programs (OPP). The SWCC uses PRZM version 5.0+ (PRZM5) and the Variable Volume Water Body Model (VVWM), replacing the older PE5 shell (last updated November 2006), which used PRZM3 (Carousel et al., 2005) and EXAMS (Burns, 2003). This updated model will improve users' interactions with the program and facilitate maintenance and operation of the software.
PFAM is an aquatic model used to estimate surface water exposure from the use of pesticides in flooded fields. In comparison to the current Tier 1 rice model, PFAM allows for more advanced evaluation of pesticide use on flooded agricultural areas such as rice paddies and cranberry bogs. The advanced capabilities of PFAM include accounting for water and pest management practices and for degradation in soil and aquatic environments, as well as for post processing of discharged paddy waters to a stream, index reservoir, farm pond, or other user-defined receiving water.
FIRST (FQPA Index Reservoir Screening Tool)
FIRST is a surface water model that is used to assess exposure to pesticides in drinking water.
KABAM is used to estimate potential bioaccumulation of hydrophobic organic pesticides in freshwater aquatic food webs and subsequent risks to mammals and birds via consumption of contaminated aquatic prey.
EXPRESS (EXAMS - PRZM Exposure Simulation Shell)
EXPRESS is designed to facilitate a rapid and consistent assessment of aquatic pesticide exposure on a variety of crops. EXPRESS is a joint project of the USEPA Office of Pesticide Programs' Environmental Fate and Effects Division (OPP/EFED) and the USEPA Office of Research and Development (ORD).
SWAMP is a probabilistic model that estimates the probability, magnitude, and certainty of the risk to aquatic organisms from exposure to pesticides.
SCIGROW (Screening Concentration In GROund Water)
SCIGROW is an aquatic model used to estimate pesticide concentrations in ground water.
SWIMODEL (Swimmer Exposure Assessment Model)
SWIMODEL is a screenting tool for conducting exposure assessment of pesticides found in indoor swimming pools and spas.
Tier I Rice Model is an aquatic model used to estimate surface water exposure from the use of pesticides in rice paddies.
OPP uses terrestrial models to estimate pesticide concentrations on avian and mammalian food items and exposure and risk to terrestrial organisms from pesticide use.
SIP (Screening Imbibition Program)
SIP is used by OPP to provide an upper bound estimate of exposure of birds and mammals to pesticides through drinking water alone.
STIR (Screening Tool for Inhalation Risk)
STIR is used by OPP to estimate inhalation-type exposure based on pesticide-specific information.
T-REX (Terrestrial Residue Exposure)
T-REX is used by OPP to estimate pesticide concentration on avian and mammalian food items.
TIM (Terrestrial Investigation Model)
TIM is a probabilistic model that estimates the probability, magnitude, and certainty of risk to terrestrial organisms from exposure to pesticides.
TerrPlant is a Tier 1 model providing screening-level estimates of exposure to terrestrial plants from single pesticide applications.
T-HERPS is a simulation model that estimates exposure to terrestrial reptiles and amphibians from pesticide use.
OPP uses atmospheric models to predict the deposition patterns of pesticides released into the atmosphere.
AgDRIFT® (version 2.1.1), a modified version of the AGricultural DISPersal (AGDISP®) model developed by the US Forest Service, was created under a Cooperative Research and Development Agreement between the EPA, the US Department of Agriculture's Forest Service, and the Spray Drift Task Force. The AgDRIFT® model has the capability to assess a variety of spray drift conditions from agricultural applications and off-site deposition of liquid formulation of pesticides. This model can be used in estimating downwind deposition of spray drift from aerial, ground boom and orchard/vineyard airblast applications.
AGDISP® (version 8.26) is a "first-principles" science-based model that predicts spray drift from application sites. The model was developed by the USDA Forest Service. AGDISP® was designed to optimize agricultural spraying operations and has detailed algorithms for characterizing the release, dispersion, and deposition over and downwind of the application area. This model can be used in estimating downwind deposition of spray drift from aerial and ground boom applications. In addition, it can be used in estimating downwind deposition of spray drift from forestry and adulticide/mosquitocide applications. The research version of AGDISP model can be obtained from Dr. Harold W. Thistle, USDA Forest Service.
PERFUM (Probabilistic Exposure and Risk Model for FUMigants)
PERFUM is used to calculate distributional exposure to soil fumigants emitted from treated agricultural fields.
SOFEA (SOil Fumigant Exposure Assessment)
SOFEA system is used to calculate exposure to bystanders who are in proximity to fileds treated with soil fumigants.
FEMS (Fumigant Exposure Modeling System)
FEMS is used to calculate exposure to bystanders who are in proximity to fields treated with soil fumigants.
Health Effects Models
OPP uses health effects models to predict effects to humans from exposure to pesticides.
DEEM (Dietary Exposure Evaluation Model)
DEEM provides dietary probabilistic assessments of dietary pesticide exposure.
CALENDEXTM - FCID evaluates aggregated exposure that appropriately incorporates the probability of simultaneous exposures across multiple pathways.
CARES (Cumulative and Aggregate Risk Evaluation System)
LifeLine Version 4.3 is used to assess dietary, aggregate and cululative risks of pesticides. Version 4.3 is 50% faster than the prior version of LifeLine and includes new features in virtually every portion of the model.
OPHED (Occupational Pesticide Handler Exposure Data)
Describes data sources used in exposure and risk assessment of occupational pesticide handlers (i.e., mixer/loaders and applicators). Includes the "Occupational Pesticide Handler Unit Exposure Surrogate Reference Table".
OPPED (Occupational Pesticide Post-application Exposure Data)
Describes data sources used in assessment of occupational post-application exposures (e.g., harvesting, weeding, etc.). Includes "Science Advisory Council for Exposure, Policy 3".
REx (Residential Exposure Assessment)
SHEDS (Stochastic Human Exposure and Dose Simulation Model)
SHEDS is a physically-based stochastic model developed to quantify exposure and dose of humans to multimedia, multipathway pollutants.
PBPK/PD (Physiologically-Based Pharmacokinetic/Pharmacodynamic)