Question

Define exposure, potential dose, and internal dose Using a specific pollutant for each exposure route (dermal, ingestion, inhalation), explain at least two different factors that may affect each dose as it sequentially moves through each exposure pathway.

Answer requirements:

1. Define: potential dose, internal dose, exposure

2. Specific pollutant for ingestion

1. Factor 1 that affects potential dose, internal dose, exposure

2.Factor 2 that affects potential dose, internal dose, exposure

3. Specific pollutant for inhalation

1.Factor 1 that affects potential dose, internal dose, exposure

2.Factor 2 that affects potential dose, internal dose, exposure

4. Specific pollutant for dermal

1. Factor 1 that affects potential dose, internal dose, exposure

2.Factor 2 that affects potential dose, internal dose, exposure

Answer 1

1.Exposure definition :Exposure is defined as the state of being in contact with something or is defined as a condition that can develop from being subject to bad weather. exposure to polluted air can have permanent health effects such as accelerated aging of the lungs,loss of lung capacity and decreased lung function. Development of diseases such as asthma, bronchitis, emphysema, and possibly cancer.

Potential dose :A calculated dose based on a postulated set of exposure conditions that have a reasonable probability of occurrence.

Internal dose :The amount of a compound that is absorbed by the body by penetrating an epithelial barrier such as the skin, eyes, respiratory tract, or gastrointestinal tract.

2.ingestion pollutant :food, water, or soil or dust containing the pollutant that an individual ingests during a specific period of time.

Example is pesticides of food, extra minerals in water etc.

Factor 1:type of food and water

Factor 2:receptor - Intake rates might differ across different populations. Where intake rates for different age groups, races, and ethnic groups are different.

3.Inhalation pollutant :it results from breathing air that is polluted with particulate matter, vapors , or aerosols. Individuals can be exposed via the inhalation route during a variety of activities outdoors and indoors. Indoor receptors could also be exposed to outdoor air contaminants that infiltrate the indoor environment.

Examples are dust, volatile or semivolatile contaminants

Factor 1:inhalational rate effects the potential dose, internal dose, exposure.

Factor 2:location of the individual - certain location population exposes to specific type of pollutent.

4.Dermal pollutant :it results from skin contact with contaminated environmental media.

Examples are water during swimming, bathing and outdoor soil or dust during gardening or construction sites.

Factor 1:amount of skin that is exposed to pollutant(skin surface area).

Factor 2:adherence factor - quantity of soil or solids that can adhere to the skin surface after contact.