| Report number: LBNL-59303 |
Year: 2007 |
| Title: Sorption of organic gases in residential rooms |
Published in: Atmospheric Environment, Volume 41, Pages 3251-3265. |
| Authors: Singer, B.C., Hodgson, A.T., Hotchi, T., Ming, K.Y., Sextro, R.G., Wood, E. E., Brown, N.J. |
Type: Journal Article |
| Report number: LBNL-57946 |
Year: 2006 |
| Title: Systems approach to evaluating sensor characteristics for real-time monitoring of high-risk indoor contaminant releases |
Published in: Atmospheric Environment, Volume 40, Pages 3490-3502. |
| Authors: Sreedharan, P., Sohn, M.D., Gadgil, A., Nazaroff, W. |
Type: Journal Article |
| Abstract: Rapid detection of toxic agents in the indoor environment is essential to protecting building occupants from accidental or intentional releases. While there is much research dedicated to designing sensors to detect airborne toxic contaminants, little research has addressed how to incorporate such sensors into a monitoring system designed to protect building occupants. To design sensor systems, sensor designers must quantify design tradeoffs, such as response time and accuracy, to optimize the performance of an overall system. We illustrate the importance of a systems approach for properly evaluating such tradeoffs, using data from tracer gas experiments conducted in a three-floor unit at the Dugway Proving Grounds, Utah. We apply Bayesian statistics to assess the effects of various sensor characteristics, such as response time, threshold level and accuracy, on overall system performance. We evaluated the system performance by the time (and thus amount of data) needed to characterize the release (location, amount released, and duration). We demonstrate that a systems perspective is necessary to understand the potential benefits of selecting values of specific sensor characteristics to optimize sensor system performance. |
| Report number: LBNL-56780 |
Year: 2005 |
| Title: Simplifying the assessment of building vulnerability to chemical, biological and radiological releases |
Published in: |
| Authors: Thatcher, T. L., Wood, E. E., Edelsohn, E.C., Sextro, R. |
Type: Report |
| Abstract: The intentional or accidental release of airborne chemical, biological, or radiological materials can pose a significant threat to the health of building occupants. Pre-planning and emergency response measures, such as HVAC system manipulation and sheltering during an event, can significantly reduce the exposure of building occupants. A straightforward and comprehensive vulnerability assessment methodology is an essential tool for assisting building managers and operators in preparing for airborne hazards. |
| Report number: LBNL-57078 |
Year: 2005 |
| Title: Assessing Sheltering-In-Place Responses to Outdoor Toxic Releases |
Published in: 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 2(6), Pages 1792-1796. |
| Authors: Sohn, M.D., Sextro, R., Lorenzetti, D. |
Type: Conference Proceedings |
| Abstract: An accidental or intentional outdoor release of pollutants can produce a hazardous plume, potentially contaminating large portions of a metropolitan area as it disperses downwind. To minimize health consequences on the populace, government and research organizations often recommend sheltering in place when evacuation is impractical. Some reports also recommend "hardening" an indoor shelter, for example by applying duct tape to prevent leakage into a bathroom. However, few studies have quantified the perceived beneficial effects of sheltering and hardening, or examined the limits of their applicability. In this paper, we examine how sheltering and hardening might reduce exposure levels under different building and meteorological conditions (e.g., wind direction). We predict concentrations and exposure levels for several conditions, and discuss the net benefits from several sheltering and hardening options. |
| Report number: LBNL-54992 |
Year: 2005 |
| Title: Indoor sorption of surrogates for sarin and related nerve agents |
Published in: Environmental Science & Technology, Volume 39, Pages 3203-3214. |
| Authors: Singer, B.C., Hodgson, A.T., Destaillats, H., Hotchi, T., Revzan, K., Sextro, R.G. |
Type: Journal Article |
| Report number: LBNL-56787 |
Year: 2005 |
| Title: Sorption of organic gases in residential bedrooms and bathrooms |
Published in: 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 2(9), Pages 2314-2319. |
| Authors: Singer, B.C., Hodgson, A., Hotchi, T., Ming, K.Y., Sextro, R., Wood, E. E., Brown, N.J. |
Type: Conference Proceedings |
| Report number: LBNL-57037 |
Year: 2005 |
| Title: Distribution Of Residential Air Leakage: Implications For Health Consequences Of An Outdoor Toxic Release |
Published in: Proceedings of The 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 2(6), Pages 1729-1733. |
| Authors: Chan, W.R., Price, P. N., Nazaroff, W.W., Gadgil, A.J. |
Type: Conference Proceedings |
| Abstract: Reasonably airtight buildings can protect occupants from large-scale outdoor airborne releases. However, some houses are leaky, as air tightness tends to vary greatly in a housing stock. We modeled the health consequences if a single-family residential community were to "shelter-in-place," for two different models of a toxic release: (I) a simple Gaussian puff, and (II) a realistic simulation of outdoor transport and dispersion generated by the National Atmospheric Release Advisory Center. We predicted the health effects under two different assumptions: (1) every house has the same indoor-outdoor air-exchange rate, or (2) the houses have a lognormal distribution of air-exchange rates. The assumption that every house has the same air-exchange rate (at the median of the actual distribution) can lead to an under-prediction of the community area adversely affected by the release by a factor of 3 or more. The difference is largest if the dose-response relationship of the chemical is highly nonlinear. |
| Report number: LBNL-53367 |
Year: 2005 |
| Title: Analyzing a database of residential air leakage in the United States |
Published in: Atmospheric Environment, Volume 39, Pages 3445-3455. |
| Authors: Chan, W.R., Nazaroff, W., Price, P. N., Sohn, M.D., Gadgil, A. |
Type: Journal Article |
| Abstract: We analyzed more than 70,000 air leakage measurements in houses across the United States to relate leakage area—the effective size of all penetrations of the building shell—to readily available building characteristics such as building size, year built, geographic region, and various construction characteristics. After adjusting for the lackof statistical
representativeness of the data, we found that the distribution of leakage area normalized by floor area is approximately lognormal. Based on a classification tree analysis, year built and floor area are the two most significant predictors of leakage area: older and smaller houses tend to have higher normalized leakage areas than newer and larger ones.
Multivariate regressions of normalized leakage are presented with respect to these two factors for three house classifications: low-income households, energy program houses, and conventional houses. We demonstrate a method of applying the regression model to housing characteristics from the American Housing Survey to derive a leakage-area distribution for all single-family houses in the US. The air exchange rates implied by these estimates agree reasonably well with published measurements. |
| Report number: LBNL-55575 |
Year: 2004 |
| Title: Sheltering in buildings from large-scale outdoor releases |
Published in: |
| Authors: Chan, W.R., Price, P. N., Gadgil, A.J. |
Type: Report |
| Abstract: Intentional or accidental large-scale airborne toxic release (e.g. terrorist attacks or industrial accidents) can cause severe harm to nearby communities. Under these circumstances, taking shelter in buildings can be an effective emergency response strategy. Some examples where shelter-in-place was successful at preventing injuries and casualties have been documented [1, 2]. As public education and preparedness are vital to ensure the success of an emergency response, many agencies have prepared documents advising the public on what to do during and after sheltering [3, 4, 5]. In this document, we will focus on the role buildings play in providing protection to occupants. |
| Report number: LBNL-53987 |
Year: 2004 |
| Title: Modeling shelter-in-place including sorption on indoor surfaces |
Published in: 84th American Meteorological Society Annual Meeting, Volume PNFUZ Session 6.5. |
| Authors: Chan, W.R., Price, P. N., Gadgil, A., Nazaroff, W., Loosmore, G., Sugiyama, G. |
Type: Conference Proceedings |
| Abstract: Intentional or accidental large-scale airborne toxic releases (e.g. terrorist attacks or industrial accidents) can cause severe harm to nearby communities. As part of an emergency response plan, shelter-in-place (SIP) can be an effective response option, especially in situations when evacuation is infeasible. Reasonably tight building envelopes provide protection against exposure to peak concentrations when toxic release passes over an area. However, this protection is temporary because some toxic materials will be carried into buildings by the exchange of air between outdoors and indoors. Prompt termination of shelter-in-place after the outdoor plume has passed is also required to minimize the exposure of the occupants. The purpose of this work is to quantify the level of protection offered by existing houses, and the importance of sorption/desorption to and from surfaces on the effectiveness of SIP. We examined a hypothetical chlorine gas release scenario simulated by the National Atmospheric Release Advisory Center (NARAC). We used a standard infiltration model to calculate the distribution of time dependent infiltration rates within each census tract. Large variation in the air tightness of dwellings means some houses are more protective than others. Considering only the median air tightness, model results showed that if sheltered indoors, the total population intake of non-sorbing toxic gas is only 50% of the outdoor level 4 hours from the start of the release. Based on a sorption/desorption model by Karlsson and Huber (1996), we calculated that the sorption process would further lower the total intake of the population by an additional 50%. The potential benefit of SIP can be considerably higher if the comparison is made in terms of health effects because of the non-linear acute effect dose-response curve of many chemical warfare agents and toxic industrial substances. |
| Report number: LBNL-51959 |
Year: 2003 |
| Title: Protecting Buildings From a Biological or Chemical Attack: actions to take before or during a release |
Published in: |
| Authors: Price, P.N., Sohn, M.D., Gadgil, A.J., Delp, W.W., Lorenzetti, D.M., Finlayson, E.U., Thatcher, T.L., Sextro, R.G., Derby, E.A., Jarvis, S.A. |
Type: Report |
| Abstract: This report presents advice on how to operate a building to reduce casualties from a biological or chemical attack, as well as potential changes to the building (e.g. the design of the ventilation system) that could make it more secure. It also documents the assumptions and reasoning behind the advice. The particular circumstances of any attack, such as the ventilation system design, building occupancy, agent type, source strength and location, and so on, may differ from the assumptions made here, in which case actions other than our recommendations may be required; we hope that by understanding the rationale behind the advice, building operators can modify it as required for their circumstances. The advice was prepared by members of the Airflow and Pollutant Transport Group, which is part of the Indoor Environment Department at the Lawrence Berkeley National Laboratory. The group's expertise in this area includes: 耢 tracer-gas measurements of airflows in buildings (Sextro, Thatcher); 耢 design and operation of commercial building ventilation systems (Delp); 耢 modeling and analysis of airflow and tracer gas transport in large indoor spaces (Finlayson, Gadgil, Price); 耢 modeling of gas releases in multi-zone buildings (Sohn, Lorenzetti, Finlayson, Sextro); 耢 and occupational health and safety experience related to building design and operation (Sextro, Delp). This report is concerned only with building design and operation; it is not a how-to manual for emergency response. Many important emergency response topics are not covered here, including crowd control, medical treatment, evidence gathering, decontamination methods, and rescue gear. |
| Report number: LBNL-49537 |
Year: 2002 |
| Title: Modeling the spread of anthrax in buildings |
Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 4, Pages 506-511. |
| Authors: Sextro, R.G., Lorenzetti, D.M., Sohn, M.D., Thatcher, T.L. |
Type: Conference Proceedings |
| Abstract: The recent contamination of several U.S. buildings by letters containing anthrax demonstrates the need to understand better the transport and fate of anthrax spores within buildings. We modeled the spread of anthrax for a hypothetical office suite and estimated the distribution of mass and resulting occupant exposures. Based on our modeling assumptions, more than 90% of the anthrax released remains in the building during the first 48 hours, with the largest fraction of the mass accumulating on floor surfaces where it is subject to tracking and resuspension. Although tracking and resuspension account for only a small amount of mass transfer, the model results suggests they can have an important effect on subsequent exposures. Additional research is necessary to understand and quantify these processes. |
| Report number: PUB-867 |
Year: 2002 |
| Title: Advice for first responders to a building during a chemical or biological attack |
Published in: |
| Authors: Price, Phillip N., Delp, W.W., Sohn, M.D., Thatcher, T.L. , Lorenzetti, D.M., Sextro, R.G., Gadgil, A.G. , Derby, E. , Jarvis, S.A. |
Type: Journal Article |
| Abstract: No Abstract available. |
Go back to Table of Contents
Go back to top of page