Computing Impacts to Receptors

The impact to a receptor A group (usually of people) that could potentially receive impacts from contaminants in the environment. In GoldSim, a Receptor is an element that converts contaminant concentrations in the environment to impacts to a receptor group. (e.g., a farmer) from being exposed to contaminants via a particular exposure pathway (e.g., by ingesting contaminated water) is typically computed by multiplying contaminant concentrations in an environmental medium (e.g., water, soil, blood) to which the receptor is exposed by user-defined impact conversion factors Species- and receptor-specific factors that convert concentrations in environmental media to impacts to receptors. They have dimensions of impact per unit concentration, and are vectors in GoldSim (by species)..

Impacts are quantified either as an incremental cancer risk per individual per unit time, a radiation dose per unit time, or a Hazard Index (the concentration in a medium divided by a reference concentration).

The total impact to a receptor is computed as the sum of the impacts associated with each exposure pathway (e.g., drinking water from a well, breathing dust in the atmosphere, ingesting soil).

Impact conversion factors are species The chemical (or non-chemical, such as bacterial or viral) constituents that are stored and transported through an environmental system in a contaminant transport model. In GoldSim, the Species element defines all of the contaminant species being simulated (and their properties).- and receptor-specific and have dimensions An output attribute for an element that defines the dimensionality (in terms of Length, Time and other fundamental dimensions) of the output. of impact per unit concentration.

Within GoldSim, you usually compute an impact by using a Receptor element to carry out a term-by-term multiplication of the species concentration vectors from media Materials (such as water, sand, clay, air) that constitute (are contained within) transport pathways. GoldSim provides two types of elements for defining media: Fluids and Solids. in pathways by vectors of impact conversion factors. The result would be an impact vector A one-dimensional array.. It is a vector because it contains an item for each species.

You can carry out a term-by-term multiplication of two vectors using the multiplication (*) operator:

Impact = Concentration_Vector * Impact_Conversion_Factor_Vector

Typically, the impact to a receptor will be a sum of several term-by-term vector multiplications, since the receptor is likely to interact with multiple contaminated media (e.g., water in a well, soil, dust).

Note: Once you have an impact vector, you could compute a total impact (summed over all species) by using the Sumv function. The Sumv function sums the components of a vector (producing a scalar An output consisting of a single value or condition.).