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Liu X, Guo Z, Krebs KA, Greenwell DJ, Roache NF, Stinson RA, Nardin JA, Pope RH. Laboratory study of PCB transport from primary sources to settled dust. Chemosphere 2016; 149:62-69. [PMID: 26849196 DOI: 10.1016/j.chemosphere.2016.01.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 01/13/2016] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
Dust is an important sink for indoor air pollutants, such as polychlorinated biphenyls (PCBs) that were used in building materials and products. In this study, two types of dust, house dust and Arizona Test Dust, were tested in a 30-m(3) stainless steel chamber with two types of panels. The PCB-containing panels were aluminum sheets coated with a PCB-spiked primer or caulk. The PCB-free panels were coated with the same materials but without PCBs. The dust evenly spread on each panel was collected at different times to determine its PCB content. The data from the PCB panels were used to evaluate the PCB migration from the source to the dust through direct contact, and the data from the PCB-free panels were used to evaluate the sorption of PCBs through the dust/air partition. Settled dust can adsorb PCBs from air. The sorption concentration was dependent on the congener concentration in the air and favored less volatile congeners. When the house dust was in direct contact with the PCB-containing panel, PCBs migrated into the dust at a much faster rate than the PCB transfer rate due to the dust/air partition. The dust/source partition was not significantly affected by the congener's volatility. For a given congener, the ratio between its concentration in the dust and in the source was used to estimate the dust/source partition coefficient. The estimated values ranged from 0.04 to 0.16. These values are indicative of the sink strength of the tested house dust being in the middle or lower-middle range.
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Affiliation(s)
- Xiaoyu Liu
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division Research Triangle Park, NC 27711, United States.
| | - Zhishi Guo
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division Research Triangle Park, NC 27711, United States
| | - Kenneth A Krebs
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division Research Triangle Park, NC 27711, United States
| | - Dale J Greenwell
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division Research Triangle Park, NC 27711, United States
| | - Nancy F Roache
- ARCADIS, US Inc., 4915 Prospectus Dr., Suite F, Durham, NC 27709, United States
| | - Rayford A Stinson
- ARCADIS, US Inc., 4915 Prospectus Dr., Suite F, Durham, NC 27709, United States
| | - Joshua A Nardin
- ARCADIS, US Inc., 4915 Prospectus Dr., Suite F, Durham, NC 27709, United States
| | - Robert H Pope
- ARCADIS, US Inc., 4915 Prospectus Dr., Suite F, Durham, NC 27709, United States
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Liu X, Guo Z, Krebs KA, Stinson RA, Nardin JA, Pope RH, Roache NF. Chamber study of PCB emissions from caulking materials and light ballasts. Chemosphere 2015; 137:115-121. [PMID: 26092318 DOI: 10.1016/j.chemosphere.2015.05.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/29/2015] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
The emissions of polychlorinated biphenyl (PCB) congeners from thirteen caulk samples were tested in a micro-chamber system. Twelve samples were from PCB-contaminated buildings and one was prepared in the laboratory. Nineteen light ballasts collected from buildings that represent 13 different models from five manufacturers were tested in 53-L environmental chambers. The rates of PCB congener emissions from caulking materials and light ballasts were determined. Several factors that may have affected the emission rates were evaluated. The experimentally determined emission factors showed that, for a given PCB congener, there is a linear correlation between the emission factor and the concentration of the PCB congener in the source. Furthermore, the test results showed that an excellent log-linear correlation exists between the normalized emission factor and the vapor pressure (coefficient of determination, r(2)⩾0.8846). The PCB congener emissions from ballasts at or near room temperature were relatively low with or without electrical load. However, the PCB congener emission rates increased significantly as the temperature increased. The results of this research provide new data and models for ranking the primary sources of PCBs and supports the development and refinement of exposure assessment models for PCBs.
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Affiliation(s)
- Xiaoyu Liu
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States.
| | - Zhishi Guo
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Kenneth A Krebs
- U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Rayford A Stinson
- ARCADIS U.S., Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
| | - Joshua A Nardin
- ARCADIS U.S., Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
| | - Robert H Pope
- ARCADIS U.S., Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
| | - Nancy F Roache
- ARCADIS U.S., Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
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Liu X, Guo Z, Krebs KA, Pope RH, Roache NF. Concentrations and trends of perfluorinated chemicals in potential indoor sources from 2007 through 2011 in the US. Chemosphere 2014; 98:51-7. [PMID: 24268172 DOI: 10.1016/j.chemosphere.2013.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 09/19/2013] [Accepted: 10/01/2013] [Indexed: 05/22/2023]
Abstract
Certain perfluorinated chemicals (PFCs) in consumer products used indoors are potential indoor PFCs sources and have been associated with developmental toxicity and other adverse health effects in laboratory animals (Lao et al., 2007). The concentrations of selected PFCs including perfluorooctanoic acid (PFOA) and other perfluorocarboxylic acids (PFCAs), in 35 selected consumer products that are commonly used in indoors were measured from the year of 2007 through 2011. The products collected included carpet, commercial carpet-care liquids, household carpet/fabric-care liquids, treated apparel, treated home textiles, treated non-woven medical garments, floor waxes, food-contact paper, membranes for apparel, and thread-sealant tapes. They were purchased from retail outlets in the United States between March 2007 and September 2011. The perfluorocarboxylic acid (PFCA) contents in the products have shown an overall downward trend. However, PFOA (C8) could still be detected in many products that we analyzed. Reductions of PFCAs were shown in both short-chain PFCAs (sum of C4 to C7) and long-chain PFCAs (sum of C8 to C12) over the study period. There were no significant changes observed between short-chain PFCAs and long-chain PFCAs. Fourteen products were analyzed to determine the amounts of perfluoroalkyl sulfonates (PFASs) they contained. These limited data show the pronounced increase of perfluoro-butane sulfonate (PFBS), an alternative to perfluorooctanoic sulfonate (PFOS), in the samples. A longer and wider range of study will be required to confirm this observed trend.
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Affiliation(s)
- Xiaoyu Liu
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States.
| | - Zhishi Guo
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Kenneth A Krebs
- US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Robert H Pope
- Arcadis US Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
| | - Nancy F Roache
- Arcadis US Inc., 4915 Prospectus Drive, Suite F, Durham, NC 27713, United States
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Krebs KA, Clem DS. A report from the American Academy of Periodontology. Guidelines for the management of patients with periodontal diseases. Compend Contin Educ Dent 2006; 27:654-8. [PMID: 17191646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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Krebs KA. Response from the AAP. J Am Dent Assoc 2006; 137:296, 298; author reply 298, 300. [PMID: 16570462 DOI: 10.14219/jada.archive.2006.0167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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McCrillis RC, Howard EM, Guo Z, Krebs KA, Fortmann R, Lao HC. Characterization of Curing Emissions from Conversion Varnishes. J Air Waste Manag Assoc 1999; 49:70-75. [PMID: 28060611 DOI: 10.1080/10473289.1999.10463777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Three commercially available conversion varnish coating "systems" (stain, sealer, and topcoat) were selected for an initial scoping study. The total volatile content of the catalyzed varnishes, as determined by U.S. Environmental Protection Agency (EPA) Method 24, ranged from 64 to 73 weight%. Uncombined (free) formaldehyde concentrations, determined by a sodium sulfite titration method, ranged from 0.15 to 0.58 weight% of the uncatalyzed varnishes. Each sealer and topcoat was also analyzed by gas chromatography (EPA Method 311). The primary volatile organic constituents included methyl ethyl ketone (MEK), isobutanol, n-butanol, methyl isobutyl ketone (MIBK), toluene, ethylbenzene, the xylenes, and 1,2,4-trimethylbenzene.
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Affiliation(s)
- Robert C McCrillis
- a U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division , Research Triangle Park , North Carolina , USA
| | - Elizabeth M Howard
- a U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division , Research Triangle Park , North Carolina , USA
| | - Zhishi Guo
- a U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division , Research Triangle Park , North Carolina , USA
| | - Kenneth A Krebs
- a U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Air Pollution Prevention and Control Division , Research Triangle Park , North Carolina , USA
| | - Roy Fortmann
- b ARCADIS Geraghty & Miller, Inc. , Durham , North Carolina , USA
| | - Huei-Chen Lao
- b ARCADIS Geraghty & Miller, Inc. , Durham , North Carolina , USA
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Abstract
Conversion varnishes are two-component, acid-catalyzed varnishes that are commonly used to finish cabinets. They are valued for their water and stain resistance, as well as their appearance. They have been found, however, to contribute to indoor emissions of organic compounds. For this project, three commercially available conversion varnish systems were selected. A U.S. Environmental Protection Agency (EPA) Method 24 analysis was performed to determine total volatile content, and a sodium sulfite titration method was used to determine uncombined (free) formaldehyde content of the varnish components. The resin component was also analyzed by gas chromatography/mass spectroscopy (GC/MS) (EPA Method 311 with an MS detector) to identify individual organic compounds. Dynamic small chamber tests were then performed to identify and quantify emissions following application to coupons of typical kitchen cabinet wood substrates, during both curing and aging. Because conversion varnishes cure by chemical reaction, the compounds emitted during curing and aging are not necessarily the same as those in the formulation. Results of small chamber tests showed that the amount of formaldehyde emitted from these coatings was 2.3-8.1 times the amount of free formaldehyde applied in the coatings. A long-term test showed a formaldehyde emission rate of 0.17 mg/m2/hr after 115 days.
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Affiliation(s)
- E M Howard
- U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, North Carolina, USA
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