Parameters for temperature influence study.

<p>Parameters for temperature influence study.</p

Predicting Dermal Exposure to Gas-Phase Semivolatile Organic Compounds (SVOCs): A Further Study of SVOC Mass Transfer between Clothing and Skin Surface Lipids

Dermal exposure to indoor gas-phase semivolatile organic compounds (SVOCs) has recently received a great deal of attention, and this has included evaluating the role of clothing in this process. Several models have been developed to assess dermal exposure to SVOCs, based on the transient mass transfer of SVOCs from air to dermal capillaries. Assumptions of these models are either that clothing completely retards SVOC transport, or that there is an air gap of constant thickness between the clothing and the surface of the skin, which may lead to errors in the model calculations. To solve this problem, we tried to describe SVOC transport between clothing and epidermis by considering two parallel processes: partitioning of SVOCs by direct contact (ignored in existing models), and Fickian diffusion through the air gap. Predictions from the present model agree well with the experimental data found in the literature (dermal uptake of diethyl phthalate (DEP) and di-<i>n</i>-butyl phthalate (DnBP) of a clothed participant). This study provides a useful tool to accurately assess dermal exposure to indoor SVOCs, especially for evaluating the effects of clothing on dermal exposure

Temperature influence on model prediction of emissions.

<p>Temperature influence on model prediction of emissions.</p

Schematic of formaldehyde and VOC sorption of building material in an airtight chamber.

<p>Schematic of formaldehyde and VOC sorption of building material in an airtight chamber.</p

Inter-laboratory studies for measuring VOC/formaldehyde concentrations in chamber air.

<p>Inter-laboratory studies for measuring VOC/formaldehyde concentrations in chamber air.</p

Impact of Temperature on the Ratio of Initial Emittable Concentration to Total Concentration for Formaldehyde in Building Materials: Theoretical Correlation and Validation

The initial emittable concentration (<i>C</i>_m,0) is a key parameter characterizing the emission behaviors of formaldehyde from building materials, which is highly dependent on temperature but has seldom been studied. Our previous study found that <i>C</i>_m,0 is much less than the total concentration (<i>C</i>_0,total, used for labeling material in many standards) of formaldehyde. Because <i>C</i>_m,0 and not <i>C</i>_0,total directly determines the actual emission behaviors, we need to determine the relationship between <i>C</i>_m,0 and <i>C</i>_0,total so as to use <i>C</i>_m,0 as a more appropriate labeling index. By applying statistical physics theory, this paper derives a novel correlation between the emittable ratio (<i>C</i>_m,0/<i>C</i>_0,total) and temperature. This correlation shows that the logarithm of the emittable ratio multiplied by power of 0.5 of temperature is linearly related to the reciprocal of temperature. Emissions tests for formaldehyde from a type of medium density fiberboard over the temperature range of 25.0–80.0 °C were performed to validate the correlation. Experimental results indicated that <i>C</i>_m,0 (or emittable ratio) increased significantly with increasing temperature, this increase being 14-fold from 25.0 to 80.0 °C. The correlation prediction agreed well with experiments, demonstrating its effectiveness in characterizing physical emissions. This study will be helpful for predicting/controlling the emission characteristics of pollutants at various temperatures

Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (multi variables).

<p>Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (multi variables).</p

Comparison of simulated results with experimental data for different processes of pollutants in environmental chambers.

<p>(a) Toluene; (b) TMB; (c) TVOC.</p

Parameters of the building material and chamber.

<p>Parameters of the building material and chamber.</p

Measurement data and model prediction of formaldehyde concentrations in a ventilated chamber.

<p>Measurement data and model prediction of formaldehyde concentrations in a ventilated chamber.</p