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George A Weymouth - One of the best experts on this subject based on the ideXlab platform.
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Soil Contamination from PCB-Containing Buildings
2013Co-Authors: Robert F Herrick, Daniel J. Lefkowitz, George A WeymouthAbstract:BACKGROUND: Polychlorinated biphenyls (PCBs) in construction materials, such as Caulking used around windows and expansion joints, may constitute a source of PCB contamination in the building interiors and in surrounding soil. Several studies of soil contamination have been conducted around buildings where the Caulking has been removed by grinding or scraping. The PCBs in soil may have been generated in the process of removing the Caulking, but natural weathering and deterioration of the Caulking may have also been a source. OBJECTIVES: The objectives of this study were to measure PCB levels in soil surrounding buildings where PCB-containing caulk was still in place, and to evaluate the mobility of the PCBs from Caulking using the Toxicity Characteristic Leaching Procedure (U.S. Environmental Protection Agency Method 1311). DISCUSSION: We found soil PCB contamination ranging from 3.3 to 34 mg/kg around buildings with undisturbed Caulking that contained 10,000–36,200 mg/kg PCBs. The results of the Toxicity Characteristic Leaching Procedure (leachate concentrations of 76–288 mg PCB/L) suggest that PCBs in Caulking can be mobilized, apparently as complexes with dissolved organic matter that also leach off the Caulking material. CONCLUSIONS AND RECOMMENDATIONS: Although these new findings are based on a small sample size, they demonstrate the need for a national survey of PCBs in building materials and in soil surrounding these buildings. Because the buildings constructed during the time the PCB Caulking was in use (1960s and 1970s) include schools, hospitals, and apartment buildings, the potential for exposure of children is a particular concern. It is necessary to reconsider the practice of disposing of old PCB Caulking removed during building renovations in conventional landfills, given the apparent mobility of PCBs from the Caulking material. Disposal of some Caulking material in nonhazardous landfills might lead to high PCB levels in landfill leachate
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An unrecognized source of PCB contamination in schools and other buildings. Environmental Health Perspectives
2013Co-Authors: Robert F Herrick, Lisa K Baxter, John D Meeker, Michael D Mcclean, George A WeymouthAbstract:Caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, which is the U.S. Environmental Protection Agency (U.S. EPA) specified limit above which this material is considered to be PCB bulk product waste. These buildings included schools and other public buildings. In a university building where similar levels of PCB were found in Caulking material, PCB levels in indoor air ranged from 111 to 393 ng/m 3; and in dust taken from the building ventilation system, < 1 ppm to 81 ppm. In this building, the U.S. EPA mandated requirements for the removal and disposal of the PCB bulk product waste as well as for confirmatory sampling to ensure that the interior and exterior of the building were decontaminated. Although U.S. EPA regulations under the Toxic Substances Control Act stipulate procedures by which PCB-contaminated materials must be handled and disposed, the regulations apparently do not require that materials such as Caulking be tested to determine its PCB content. This limited investigation strongly suggests that were this testing done, many buildings would be found to contain high levels of PCBs in the building materials and potentially in the building environment. The presence of PCBs in schools is of particular concern given evidence suggesting that PCBs are developmental toxins. Key words: carcinogen, developmental toxin, environmental exposure, PCB, public buildings, remediation, schools. Environ Health Perspect 112:1051–1053 (2004). doi:10.1289/ehp.6912 available vi
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serum pcb levels and congener profiles among us construction workers
Environmental Health, 2007Co-Authors: Robert F Herrick, John D Meeker, Russ Hauser, Larisa M Altshul, George A WeymouthAbstract:Background: The presence of PCB in Caulking (sealant) material found in masonry buildings has been well-documented in several countries. A recent investigation of 24 buildings in the greater Boston area found that 8 buildings had high PCB levels in Caulking materials used around window frames and in joints between masonry blocks. Workers removing Caulking material have been shown to have elevated serum PCB levels. Methods: This project compared serum PCB levels among male workers who installed and/or removed PCB-containing Caulking material from buildings in the greater Boston area with reference serum PCB levels from 358 men from the same area. Serum PCB levels were measured in the same laboratory by liquid-liquid extraction, column chromatography clean-up and dual capillary column GC/microECD analysis. Results: When the congener profiles were compared between the reference population and the construction workers, the serum levels of the more volatile, lighter PCBs (di-, tri-and tetrachloro, sum of IUPAC# 6–74) were substantially higher among the construction workers. One of the youngest workers had the lowest total serum PCB levels (sum of 57 congeners) of all 6 workers, but the contribution of more volatile (less chlorinated) PCB congeners (#16, 26,28,33,74,66, and 60) was markedly higher than in other 5 workers and reference men. Only this worker was working on a job that involved removing PCB Caulking at the time of the blood sampling. Conclusion: While the results of this pilot study are based upon small numbers (6 construction workers who handled PCB Caulking), the serum PCB levels among the construction workers exceed the referents. Comparison of the congener profiles suggests that there are substantial differences between the construction workers and the general population samples. These differences, and the similarities of profiles among the construction workers strongly suggest that occupational contact with Caulking material can be a major source of PCB exposure for construction workers.
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an unrecognized source of pcb contamination in schools and other buildings
Environmental Health Perspectives, 2004Co-Authors: Robert F Herrick, Lisa K Baxter, John D Meeker, Michael D Mcclean, George A WeymouthAbstract:An investigation of 24 buildings in the Greater Boston Area revealed that one-third (8 of 24) contained Caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, which is the U.S. Environmental Protection Agency (U.S. EPA) specified limit above which this material is considered to be PCB bulk product waste. These buildings included schools and other public buildings. In a university building where similar levels of PCB were found in Caulking material, PCB levels in indoor air ranged from 111 to 393 ng/m3; and in dust taken from the building ventilation system, < 1 ppm to 81 ppm. In this building, the U.S. EPA mandated requirements for the removal and disposal of the PCB bulk product waste as well as for confirmatory sampling to ensure that the interior and exterior of the building were decontaminated. Although U.S. EPA regulations under the Toxic Substances Control Act stipulate procedures by which PCB-contaminated materials must be handled and disposed, the regulations apparently do not require that materials such as Caulking be tested to determine its PCB content. This limited investigation strongly suggests that were this testing done, many buildings would be found to contain high levels of PCBs in the building materials and potentially in the building environment. The presence of PCBs in schools is of particular concern given evidence suggesting that PCBs are developmental toxins.
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an unrecognized source of pcb contamination in schools and other buildings
Environmental Health Perspectives, 2004Co-Authors: Robert F Herrick, Lisa K Baxter, John D Meeker, Michael D Mcclean, George A WeymouthAbstract:An investigation of 24 buildings in the Greater Boston Area revealed that one-third (8 of 24) contained Caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, wh...
Franck Cochoy - One of the best experts on this subject based on the ideXlab platform.
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managing leaks shoplifting in us grocery retailing 1922 1969
European Management Journal, 2017Co-Authors: Johan Hagberg, Hans Kjellberg, Franck CochoyAbstract:The purpose of this paper is to further develop the general program of managing overflows by attending to the managing of leaks. Specifically, the paper explores efforts to manage the problem of shoplifting in US grocery retailing during the period 1922–1969. The study identifies three different yet interrelated ways of managing leaks: identifying, preventing, and Caulking leaks. Each of these rests on a combination of skills and devices as well as on efforts to align with the other ways of managing leaks and routinize them as part of ordinary retail operations. By providing an analysis of leaks management the paper proposes a theoretical and empirical complement to the research program on managing overflows, which has previously primarily focused on overflows in the sense of excess, surplus and abundance.
Robert F Herrick - One of the best experts on this subject based on the ideXlab platform.
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Scientific Solutions PCBS IN SCHOOL—PERSISTENT CHEMICALS, PERSISTENT PROBLEMS
2015Co-Authors: Robert F HerrickAbstract:The issue of polychlorinated biphenyls (PCB) exposures resulting from occu-pancy of PCB-contaminated buildings is not new, but the contribution of building materials to that contamination is largely unrecognized. A rapidly emerging base of evidence shows that PCBs can be widely found in Caulking and paint in masonry buildings constructed or renovated from about 1950 to the late 1970s. These materials can cause extensive PCB contamination of the building interiors and surrounding soil, and people who teach, live, or attend school in these buildings can have elevated serum PCB levels. The potential risk associated with this source of PCB exposure is not known; however, it is worth noting that the specific PCB congeners found at high levels in the building environments, and in biological samples from the occupants, include some that are suspected of being potent neurotoxins. The U.S. Environmental Protection Agency (EPA) is moving to address this issue in schools; however, the costs of remediating contaminated buildings will pose a formidable obstacle to most school districts. The story of PCB contamination in schools is unfinished. We know that PCBs got into schools in building materials such as window Caulking and paints. Given the time that has passed since these buildings were constructed, and the number of buildings that have already been renovated and had the PCB materials removed, the precise significance of the risk that PCBs from these sources pose to children, teachers, and other occupants of the schools may never be known. Although the presence of PCB caulk and paint in these buildings causes PC
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Soil Contamination from PCB-Containing Buildings
2013Co-Authors: Robert F Herrick, Daniel J. Lefkowitz, George A WeymouthAbstract:BACKGROUND: Polychlorinated biphenyls (PCBs) in construction materials, such as Caulking used around windows and expansion joints, may constitute a source of PCB contamination in the building interiors and in surrounding soil. Several studies of soil contamination have been conducted around buildings where the Caulking has been removed by grinding or scraping. The PCBs in soil may have been generated in the process of removing the Caulking, but natural weathering and deterioration of the Caulking may have also been a source. OBJECTIVES: The objectives of this study were to measure PCB levels in soil surrounding buildings where PCB-containing caulk was still in place, and to evaluate the mobility of the PCBs from Caulking using the Toxicity Characteristic Leaching Procedure (U.S. Environmental Protection Agency Method 1311). DISCUSSION: We found soil PCB contamination ranging from 3.3 to 34 mg/kg around buildings with undisturbed Caulking that contained 10,000–36,200 mg/kg PCBs. The results of the Toxicity Characteristic Leaching Procedure (leachate concentrations of 76–288 mg PCB/L) suggest that PCBs in Caulking can be mobilized, apparently as complexes with dissolved organic matter that also leach off the Caulking material. CONCLUSIONS AND RECOMMENDATIONS: Although these new findings are based on a small sample size, they demonstrate the need for a national survey of PCBs in building materials and in soil surrounding these buildings. Because the buildings constructed during the time the PCB Caulking was in use (1960s and 1970s) include schools, hospitals, and apartment buildings, the potential for exposure of children is a particular concern. It is necessary to reconsider the practice of disposing of old PCB Caulking removed during building renovations in conventional landfills, given the apparent mobility of PCBs from the Caulking material. Disposal of some Caulking material in nonhazardous landfills might lead to high PCB levels in landfill leachate
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An unrecognized source of PCB contamination in schools and other buildings. Environmental Health Perspectives
2013Co-Authors: Robert F Herrick, Lisa K Baxter, John D Meeker, Michael D Mcclean, George A WeymouthAbstract:Caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, which is the U.S. Environmental Protection Agency (U.S. EPA) specified limit above which this material is considered to be PCB bulk product waste. These buildings included schools and other public buildings. In a university building where similar levels of PCB were found in Caulking material, PCB levels in indoor air ranged from 111 to 393 ng/m 3; and in dust taken from the building ventilation system, < 1 ppm to 81 ppm. In this building, the U.S. EPA mandated requirements for the removal and disposal of the PCB bulk product waste as well as for confirmatory sampling to ensure that the interior and exterior of the building were decontaminated. Although U.S. EPA regulations under the Toxic Substances Control Act stipulate procedures by which PCB-contaminated materials must be handled and disposed, the regulations apparently do not require that materials such as Caulking be tested to determine its PCB content. This limited investigation strongly suggests that were this testing done, many buildings would be found to contain high levels of PCBs in the building materials and potentially in the building environment. The presence of PCBs in schools is of particular concern given evidence suggesting that PCBs are developmental toxins. Key words: carcinogen, developmental toxin, environmental exposure, PCB, public buildings, remediation, schools. Environ Health Perspect 112:1051–1053 (2004). doi:10.1289/ehp.6912 available vi
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serum pcb levels and congener profiles among us construction workers
Environmental Health, 2007Co-Authors: Robert F Herrick, John D Meeker, Russ Hauser, Larisa M Altshul, George A WeymouthAbstract:Background: The presence of PCB in Caulking (sealant) material found in masonry buildings has been well-documented in several countries. A recent investigation of 24 buildings in the greater Boston area found that 8 buildings had high PCB levels in Caulking materials used around window frames and in joints between masonry blocks. Workers removing Caulking material have been shown to have elevated serum PCB levels. Methods: This project compared serum PCB levels among male workers who installed and/or removed PCB-containing Caulking material from buildings in the greater Boston area with reference serum PCB levels from 358 men from the same area. Serum PCB levels were measured in the same laboratory by liquid-liquid extraction, column chromatography clean-up and dual capillary column GC/microECD analysis. Results: When the congener profiles were compared between the reference population and the construction workers, the serum levels of the more volatile, lighter PCBs (di-, tri-and tetrachloro, sum of IUPAC# 6–74) were substantially higher among the construction workers. One of the youngest workers had the lowest total serum PCB levels (sum of 57 congeners) of all 6 workers, but the contribution of more volatile (less chlorinated) PCB congeners (#16, 26,28,33,74,66, and 60) was markedly higher than in other 5 workers and reference men. Only this worker was working on a job that involved removing PCB Caulking at the time of the blood sampling. Conclusion: While the results of this pilot study are based upon small numbers (6 construction workers who handled PCB Caulking), the serum PCB levels among the construction workers exceed the referents. Comparison of the congener profiles suggests that there are substantial differences between the construction workers and the general population samples. These differences, and the similarities of profiles among the construction workers strongly suggest that occupational contact with Caulking material can be a major source of PCB exposure for construction workers.
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an unrecognized source of pcb contamination in schools and other buildings
Environmental Health Perspectives, 2004Co-Authors: Robert F Herrick, Lisa K Baxter, John D Meeker, Michael D Mcclean, George A WeymouthAbstract:An investigation of 24 buildings in the Greater Boston Area revealed that one-third (8 of 24) contained Caulking materials with polychlorinated biphenyl (PCB) content exceeding 50 ppm by weight, which is the U.S. Environmental Protection Agency (U.S. EPA) specified limit above which this material is considered to be PCB bulk product waste. These buildings included schools and other public buildings. In a university building where similar levels of PCB were found in Caulking material, PCB levels in indoor air ranged from 111 to 393 ng/m3; and in dust taken from the building ventilation system, < 1 ppm to 81 ppm. In this building, the U.S. EPA mandated requirements for the removal and disposal of the PCB bulk product waste as well as for confirmatory sampling to ensure that the interior and exterior of the building were decontaminated. Although U.S. EPA regulations under the Toxic Substances Control Act stipulate procedures by which PCB-contaminated materials must be handled and disposed, the regulations apparently do not require that materials such as Caulking be tested to determine its PCB content. This limited investigation strongly suggests that were this testing done, many buildings would be found to contain high levels of PCBs in the building materials and potentially in the building environment. The presence of PCBs in schools is of particular concern given evidence suggesting that PCBs are developmental toxins.
Wang Wei - One of the best experts on this subject based on the ideXlab platform.
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Caulking polydimethylsiloxane molecular networks by thermal chemical vapor deposition of Parylene-C
LAB ON A CHIP, 2016Co-Authors: Liu Yaoping, Zhang Lingqian, Mo Chi, Cao Yanping, Wu Wengang, Wang WeiAbstract:Surface functionalization of polydimethylsiloxane (PDMS) is important in developing high-performance microfluidic devices. This work applied the thermal chemical vapor deposition (t-CVD) of Parylene-C onto PDMS to caulk the molecular network while retaining the original surface properties for the oxygen plasma bonding. The very low deposition rates (for example, a nominal rate of 0.12 angstrom min(-1) at 135 degrees C) of Parylene-C at elevated substrate temperatures enabled the reactive Parylene-C monomers to penetrate into the PDMS matrix up to 4.6 +/- 0.1 mu m (135 degrees C), which was verified for the first time by a scanning electron microscope with an energy dispersive X-ray analysis (SEM-EDAX). The Parylene-C caulked in the molecular network of PDMS matrix guaranteed an excellent resistance to small molecule permeations. Meanwhile, only discrete nucleation islands were formed on the top surface rather than a continuous Parylene-C layer as observed under the AFM scan, which made the processed PDMS surface ready for device assembly. This surface functionalization method has better long-term stability than the other wet-type rivals. The barrier for oxygen plasma bonding in previously reported dry surface treatments was also avoided, thereby, facilitating the device assembly. The present work successfully developed a novel pcPDMS (Parylene-C caulked PDMS) technique, which overcame the bonding difficulty in the previous works but retained the low small molecule permeability as before. Caulking a molecular network through the t-CVD of Parylene-C also demonstrated a new strategy of functionalizing polymer surfaces and preparing new hybrid materials for wide lab-on-a-chip applications.Chinese Major State Basic Research Development Program (973 Program) [2015CB352100]; National Natural Science Foundation of China (NSFC) [81471750, 91323304]; Seed Grant for Medicine and Information Sciences of Peking University [2016-MI-04]SCI(E)PubMedARTICLEw.wang@pku.edu.cn214220-42291
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Restraining non-specific adsorption of protein using Parylene C-caulked polydimethylsiloxane
BIOMICROFLUIDICS, 2016Co-Authors: Liu Yaoping, Zhang Lingqian, Wu Wengang, Zhao Meiping, Wang WeiAbstract:Non-specific adsorption (NSA) of proteins on surface is a critical issue in polydimethylsiloxane (PDMS)-based microfluidics, which may either considerably decrease the efficiency of a continuous flow reaction or cause a large background noise in a heterogeneous sensing. This work introduced a new method to restrain NSA of protein by Caulking PDMS with Parylene C, i.e., forming a Parylene C-caulked PDMS (pcPDMS) surface. The Caulking depth of Parylene C inside PDMS matrix was characterized by laser scanning confocal microscopy based on a detectable autofluorescence intensity difference between Parylene C and PDMS after being annealed at 270 degrees C for 2 h in nitrogen. NSA of bovine serum albumin (BSA) on the inner surfaces of PDMS and pcPDMS microchannels was experimentally compared. The results indicated that the adsorbed BSA on the pcPDMS surface were 35.2% of that on the pristine PDMS surface after the BSA solution flowing through the microchannels at a flow rate of 2000 nL/min, a typical scenario of the continuous flow reaction. In a case mimicking the heterogeneous sensing, after a 60 min washing of phosphate buffered saline flow on a pre-saturated BSA adsorbed surface, the residual BSA on the pcPDMS surface was only 4.5% of that on the pristine PDMS surface. Adsorption/desorption coefficients of BSA on the PDMS and the pcPDMS surfaces were extracted from the experimental results based on the first-order Langmuir model, which indicated that the pcPDMS has a lower adsorption coefficient (K-a) and a higher desorption coefficient (K-d), compared to those of the pristine PDMS. A preliminary experiment also indicated that Taq polymerase kept 93.0% activity after flowing through a pcPDMS microchannel, while only 28.9% activity was left after passing a pristine PDMS microchannel under the same operation condition. Published by AIP Publishing.National Natural Science Foundation of China [81471750, 91023045]; Major State Basic Research Development Program (973 Program) [2015CB352100]SCI(E)EIPubMedARTICLEw.wang@pku.edu.cn20241261
Johan Hagberg - One of the best experts on this subject based on the ideXlab platform.
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managing leaks shoplifting in us grocery retailing 1922 1969
European Management Journal, 2017Co-Authors: Johan Hagberg, Hans Kjellberg, Franck CochoyAbstract:The purpose of this paper is to further develop the general program of managing overflows by attending to the managing of leaks. Specifically, the paper explores efforts to manage the problem of shoplifting in US grocery retailing during the period 1922–1969. The study identifies three different yet interrelated ways of managing leaks: identifying, preventing, and Caulking leaks. Each of these rests on a combination of skills and devices as well as on efforts to align with the other ways of managing leaks and routinize them as part of ordinary retail operations. By providing an analysis of leaks management the paper proposes a theoretical and empirical complement to the research program on managing overflows, which has previously primarily focused on overflows in the sense of excess, surplus and abundance.