Biomedical subjects

L E Sparks

Publications and source records attributed to L E Sparks.

4 recordsLinked to original sources

PubMed1999

Volatile organic compound emissions from latex paint--Part 1. Chamber experiments and source model development.

Latex paints are widely used in residential and commercial indoor environments. The surface areas covered by the paints in these environments are relatively large. Thus, latex paints have the potential for having a major impact on indoor air quality (IAQ). A study was undertaken to develop methods for evaluating the impact of latex paint emission on IAQ. Small chamber experiments using stainless steel and painted and unpainted gypsum board substrates were conducted to determine the emission characteristics of latex paint. The emissions from the stainless steel were relatively short lived (3 to 4 days), whereas the emissions from gypsum board lasted for over 200 days. Because gypsum board is a common substrate for latex paint, all emission models were developed for the gypsum board substrates. The data from the small chamber tests led to the development of two empirical and two mass-transfer-based source emission models. Approximately 100 to 200 days of data were required to estimate the parameters required for the empirical models. Only 8 days of data were required to estimate the parameters for the mass-transfer-based models. The final models use paint formulation and mass transfer correlations to predict the emissions of the major individual volatile organic compounds emitted by latex paint.

Air Pollution, Indoor↗

PubMed1999

Volatile organic compound emissions from latex paint--Part 2. Test house studies and indoor air quality (IAQ) modeling.

Emission models developed using small chamber data were combined with an Indoor Air Quality (IAQ) model to analyze the impact of volatile organic compound (VOC) emissions from latex paint on indoor environments. Test house experiments were conducted to verify the IAQ model's predictions. The agreement between model predictions and experimental measurements met the American Society for Testing and Materials criteria for model verification in the room with the source and met most of the requirements in other rooms. The major cause of disagreement between the model predictions and the experimental data in the test house appears to be an inadequate sink model.

Air Pollution, Indoor↗

PubMed1998

Evaluation of sink effects on VOCs from a latex paint.

The sink strength of two common indoor materials, a carpet and a gypsum board, was evaluated by environmental chamber tests with four volatile organic compounds (VOCs): propylene glycol, ethylene glycol, 2-(2-butoxyethoxy)ethanol (BEE), and Texanol. These oxygenated compounds represent the major VOCs emitted from a latex paint. Each chamber test included two phases. Phase 1 was the dosing/sorption period during which sink materials (pieces of carpet and gypsum board samples) were exposed to the four VOCs. The sink strength of each material tested was characterized by the amount of the VOCs adsorbed or absorbed. Phase 2 was the purging/desorption period during which the chambers with the dosed sink materials were flushed with purified air. The reemission rates of the adsorbed VOCs from the sinks were reflected by the amount of the VOCs being flushed. Phase 1 results indicated that the sink strength for the four target compounds is more than 1 order of magnitude higher than that for other VOCs previously tested by the U.S. Environmental Protection Agency (EPA). The high sink strength reflected the unusually high sorption capacity of common indoor materials for the four VOCs. Phase 2 results showed that reemission was an extremely slow process. If all the VOCs adsorbed were reemittable, it would take more than a year to completely flush out the VOCs from the sink materials tested. The long reemission process can result in chronic and low-level exposure to the VOCs after painting interior walls and surfaces.

Air Pollution, Indoor↗

PubMed1996

VOC removal at low contaminant concentrations using granular activated carbon.

Small-scale beds of granular activated carbon (GAC) have been tested in this research using challenges of volatile organic compounds (VOCs) in air at concentrations ranging from approximately 0.5 to 100 ppm. The research linked the performance of GAC from high-concentration quickly completed tests to performance at low concentrations near those encountered indoors. For all tests, the carbon bed was approximately 2.54 cm thick and operated with a residence time of 0.11 s. The tests were conducted at 25 degrees C and 50% relative humidity. The measured 10% breakthrough times ranged from about 0.5 hour to several hundred hours. For the individual compounds, the relationship between the logarithms of breakthrough time and concentration was approximately linear over the experimental range, with different compounds producing lines having different slopes. The measured breakthrough times compared favorably to published data and models. The results suggest that higher-concentration single-component breakthrough tests, which are short and easily obtained, may be cautiously extrapolated to indoor concentrations for these compounds.

Air Pollution↗