Residential Exposure

What is the residential module in CARES NG?

The CARES NG residential module estimates exposure to pesticides from products used in and around houses, such as insect repellents and indoor/outdoor foggers. This will include products used by the homeowner as well as products applied by pest control and lawn care professionals. The word “residential” will refer to all exposures due to the application of pesticidal products by consumers and to the post-application exposure of consumer-applied and/or professionally applied products. Occupational exposure (application by and post-application exposure to professional workers) is excluded from the CARES NG software. The exposure calculations follow the algorithms described in the EPA’s standard operating procedures for residential pesticide exposure assessment published in 2012. All three routes of exposure (incidental oral, dermal and inhalation) are considered in this model as appropriate.

What data is used in the residential module?

The residential module will be based on two databases:

  • WWEIA/NHANES database (please refer to the dietary module page for more information): this database provides the demographic data of the subject that will be analyzed in the residential exposure assessments.
  • CHAD database: this database contains detailed data about the activities performed by the U.S. population together with geographic and demographic information. The CHAD database will be combined with the WWEIA/NHANES database to create a 365-day activity profile for each subject under analysis.

A third proprietary database, called Residential Exposure Joint Venture (REJV), will be installed into the CARES NG platform but can only be accessed by members of the REJV Task Force.  The REJV database is a national consumer pesticide use survey from 2012 to 2013 providing information on scenario, product, monthly, and co-occurrence probability but it will not be directly used in the Residential Module.

What is CHAD?

The Consolidated Human Activity Database (CHAD) contains detailed data about the activities performed by the U.S. population together with geographic and demographic information. The data were collected in 12 studies performed in the cities of Baltimore, Cincinnati, Denver, Los Angeles, Valdez (Alaska), and Washington, DC; in the state of California; and nationwide by the University of Michigan and by NHAPS (National Human Activity Pattern Study). Due to the fact that the majority of the study was carried out on a local basis, not all groups of the American population would be represented and certain groups are oversampled.

The demographic data recorded in the database include age, gender, race, employment, and education level; hence, they allow researchers to examine specific groups within the general population to understand how their unique behavior patterns influence their exposures to chemicals.

The activity diary of each subject in the database is broken down into individual hours and activity type. Together with the start and ending times of the recorded activity, the location where the activity has been performed is recorded. Further, the database provides data about whether the subject had heavy breathing and a high/low metabolic rate while performing the activity. All of these pieces of information will be used in the residential module to provide more realistic exposure analyses.

What is REJV?

The Residential Exposure Joint Venture (REJV) collects, organizes, and analyzes label and use information for pesticide products used in and around the home. The REJV created a survey for consumers with an overall objective of developing a comprehensive database of residential use and exposure data on consumer pesticides to provide EPA with “real world” use information for assessments. Survey objectives included the following:

  • Providing key label related information such as registration number, formulation type, % active ingredient, application method and rate, area treated, use instructions and precautionary statements
  • Survey-based use information such as EPA registration number, product name, application method, date of application, frequency and timing of use, and site of application

The REJV database is a proprietary data set; it will be installed into the CARES NG platform but the access will be granted to the REJV members only.

What type of analyses can I run in the CARES NG platform?

The current version of the residential module developed in the CARES NG platform allows only deterministic analyses based on conservative assumptions such as it assumes that whenever there is a product application, the exposure to the pesticide under analysis occurs.
The next release of the CARES NG program will contain a more refined version of the residential module that will allow the user to run statistical calendar-based analyses.

Which residential scenarios are implemented in the residential module?

The CARES NG software will provide the following list of default residential scenarios that are defined in the 2012 EPA SOPs Residential Guidelines:

  1. Lawn/Turf Care
  2. Gardens and Trees
  3. Outdoor Fogging/Misting Systems
    1. Outdoor Aerosol Space Sprays (OASS)
    2. Candles, Coils, Torches and Mats (CCTM)
    3. Outdoor Residential Misting Systems (ORMS)
    4. Animal Barn Misting Systems
  4. Insect Repellents
  5. Indoor Environments
  6. Treated Pets
  7. Impregnated Materials
  8. Treated Paints and Preservatives

The majority of the exposure scenarios are divided in two main parts:

  1. Handler exposure: this refers to an individual who mixes, loads, and/or applies a pesticide. The pesticide handler can be exposed to the chemical through the dermal and the inhalation routes depending on the product type. The handler exposure happens only for products that are applied by consumers. It is usually assumed that only adults apply these products.
  2. Post-application exposure: this refers to exposure as a result of contact with pesticide residues in previously treated areas. All gender/age groups of the population can be affected by the pesticide post-application exposure. Routes of post-application exposure typically are dermal for adults and both dermal and incidental oral ingestion for children. There are also some inhalation scenarios.

A few residential scenarios, such as Impregnated Materials or CCTM scenarios, contain only the post-application exposure part because the pesticide(s) was already applied to the products and materials used in these scenarios; thus, the subject has no active role in the pesticide application.

In the CARES NG software, each scenario will be linked to the set of algorithms described in the 2012 EPA SOPs Residential Guidelines. Once the user has chosen the scenario(s), the algorithm(s) relating to that/those scenario(s) will be utilized. Each algorithm represents one activity that can be performed in the scenario of interest by the populations under analysis and is linked to a specific route of exposure (dermal, incidental oral or inhalation).

Which parameters can I use to run the residential scenarios?

Each residential scenario needs a set of variables and exposure durations to be run. Moreover, parameters describing the product(s) applied, such as the product’s formulation and the application method, are required. The CARES NG program will provide default point-estimate values for these parameters, specific to both scenarios and products, to give the user the ability to run an assessment even if he/she does not have scenario- and product-specific information. The default values are provided by the 2012 EPA Residential Guidelines. The user will have the capability to replace any parameter with custom values.