Rapid Methods to Estimate Potential Exposure to Semivolatile Organic Compounds in the Indoor Environment

A systematic and efficient strategy is needed to assess
and manage
potential risks to human health that arise from the manufacture and
use of thousands of chemicals. Among available tools for rapid assessment
of large numbers of chemicals, significant gaps are associated with
the capability to evaluate exposures that occur indoors. For semivolatile
organic compounds (SVOCs), exposure is strongly influenced by the
types of products in which these SVOCs occur. We propose methods for
obtaining screening-level estimates for two primary SVOC source classes:
additives in products used indoors and ingredients in products sprayed
or applied to interior surfaces. Accounting for product use, emission
characteristics, and the properties of the SVOCs, we estimate exposure
via inhalation of SVOCs in the gas-phase, inhalation of SVOCs sorbed
to airborne particles, ingestion of SVOCs sorbed to dust, and dermal
sorption of SVOCs from the air into the blood. We also evaluate how
exposure to the general public will change if chemical substitutions
are made. Further development of a comprehensive set of models including
the other SVOC-containing products and the other SVOC exposure pathways,
together with appropriate methods for estimating or measuring the
key parameters (in particular, the gas-phase concentration in equilibrium
with the material-phase concentration of the SVOC in the product,
or y0), is needed. When combined with
rapid toxicity estimates, screening-level exposure estimates can contribute
to health-risk-based prioritization of a wide range of chemicals of
concern.