Human Health Risk Assessment - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 223

5.3.3.5 Other Exposure Pathways

Other exposure pathways that are often included in existing exposure models are
(Carlon and Swartjes 2007 ):
Oral exposure:

•

exposure through ingestion of deposited house dust (which partly originates from
soil);

• exposure through consumption of drinking water;

• exposure through consumption of animal products, that is, meat, milk and eggs.

Inhalation exposure:

• exposure through inhalation of outdoor air (excluding airborne dust particles);

• exposure through inhalation of indoor airborne dust particles;

• exposure through inhalation of outdoor airborne dust particles;

• exposure through inhalation of vapours during showering.

Dermal exposure:

• exposure through dermal uptake via contact of the skin with soil and dust;

• exposure through dermal uptake via contact of the skin with water during bathing

or showering.

Note that no contact medium is concerned with regard to the pathway exposure
via dermal uptake via contact of the skin with soil. Just as for the soil ingestion
pathway, soil material could be regarded as a contact medium in and of itself.
For some immobile contaminants, exposure through ingestion of deposited house
dust can be an important pathway, for example, Lanphear et al. ( 2003 ), who showed
that exposure through ingestion of settled house dust is a principal source of excess
lead among children. For the calculation of the relevant concentration in dust par-
ticles, analogous to the calculation of the relevant concentration in vegetables and
indoor air, only contaminants that originate from the soil are of importance. Outdoor
(airborne) and indoor (deposited and airborne) dust consists partly of local soil
material and partly of other materials from other places. The concentration in the
dust often is enriched compared to the concentration in the original soil. Again,
analogous to exposure through vegetable consumption and indoor air inhalation,
contaminants in dust particles originating from indoor sources or places outside the
contaminated site contribute to the background exposure.
For the pathways mentioned above the intercompartmental relationships between
the contaminant concentrations in soil and in the following contact media must be
derived:

• deposited dust particles indoors;

• groundwater, used as drinking water;

• drinking water, after permeation through water pipes;