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C. Restrepo, J. Simonoff, G. Thurston and R. Zimmerman 2012. Asthma Hospital Admissions and Ambient Air Pollutant Concentrations in New York City. Journal of Environmental Protection, Vol. 3 No. 29, 2012, pp. 1102-1116. doi: 10.4236/jep.2012.329129.
Air pollution is considered a risk factor for asthma. In this paper, we analyze the association between daily hospital admissions for asthma and ambient air pollution concentrations in four New York City counties. Negative binomial regression is used to model the association between daily asthma hospital admissions and ambient air pollution concentrations. Potential confounding factors such as heat index, day of week, holidays, yearly population changes, and seasonal and long-term trends are controlled for in the models. Nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) show the most consistent statistically significant associations with daily hospitalizations for asthma during the entire period (1996-2000). The associations are stronger for children (0 - 17 years) than for adults (18 - 64 years). Relative risks (RR) for the inter-quartile range (IQR) of same day 24-hour average pollutant concentration and asthma hospitalizations for children for the four county hospitalization totals were: NO2 (IQR = 0.011 ppm, RR = 1.017, 95% CI = 1.001, 1.034), SO2 (IQR = 0.008 ppm, RR = 1.023, 95% CI = 1.004, 1.042), CO (IQR = 0.232 ppm, RR = 1.014, 95% CI = 1.003, 1.025). In the case of ozone (O3) and particulate matter (PM2.5) statistically significant associations were found for daily one-hour maxima values and children’s asthma hospitalization in models that used lagged values for air pollution concentrations. Five-day weighted average lag models resulted in these estimates: O3 (one-hour maxima) (IQR = 0.025 ppm, RR = 1.049, 95% CI = 1.002, 1.098), PM2.5 (one-hour maxima) (IQR = 16.679 μg/m3, RR = 1.055, 95% CI = 1.008, 1.103). In addition, seasonal variations were also explored for PM2.5 and statistically significant associations with daily hospital admissions for asthma were found during the colder months (November-March) of the year. Important differences in pollution effects were found across pollutants, counties, and age groups. The results for PM2.5 suggest that the composition of PM is important to this health outcome, since the major sources of NYC PM differ between winter and summer months.
J. S. Simonoff, C. E. Restrepo, R. Zimmerman, Z. S. Naphtali, and H. H. Willis. 2011. Resource Allocation, Emergency Response Capability and Infrastructure Concentration Around Vulnerable Sites. First published on: 14 April 2011, forthcoming 2011, Journal of Risk Research, 18pp. doi:10.1080/13669877.2010.547257.
Public and private decision-makers continue to seek risk-based approaches to allocate funds to help communities respond to disasters, accidents, and terrorist attacks involving critical infrastructure facilities. The requirements for emergency response capability depend both upon risks within a region's jurisdiction and mutual aid agreements that have been made with other regions. In general, regions in close proximity to infrastructure would benefit more from resources to improve preparedness because there is a greater potential for an event requiring emergency response to occur if there are more facilities at which such events could occur. Thus, a potentially important input into decisions about allocating funds for security is the proximity of a community to high concentrations of infrastructure systems that potentially could be at risk to an industrial accident, natural disaster, or terrorist attack. In this paper, we describe a methodology for measuring a region's exposure to infrastructure-related risks that captures both a community's concentration of facilities or sites considered to be vulnerable and of the proximity of these facilities to surrounding infrastructure systems. These measures are based on smoothing-based nonparametric probability density estimators, which are then used to estimate the probability of the entire infrastructure occurring within any specified distance of facilities in a county. The set of facilities used in the paper to illustrate the use of this methodology consists of facilities identified as vulnerable through the California Buffer Zone Protection Program. For infrastructure in surrounding areas we use dams judged to be high hazards, and BART tracks. The results show that the methodology provides information about patterns of critical infrastructure in regions that is relevant for decisions about how to allocate terrorism security and emergency preparedness resources.
R. Zimmerman, C. Restrepo, A. Culpen, W. Remington, A. Kling, I.
Portelli and G. Foltin
2010. Risk communication for catastrophic events:
Results from focus groups. Journal of Risk Research Vol. 13 No. 7, 2010, pp. 913-35.
Extreme events of all kinds have been increasing in number, severity, and consequencesand have come to the attention of the public to an increasing extent. This necessitatesimproving mechanisms to communicate the risks of these events for many reasons, suchas understanding attitudes and behavior to encourage actions that reduce the conse-quences of such events. Focus groups are a common mechanism to begin to probe the foundations for risk communication. Focus groups are used here to develop approachesto and content for risk communication based on hypothetical scenarios involving sarin and smallpox releases in a confined space exemplified by a transit center.
C. Restrepo, J. Simonoff, and Rae Zimmerman 2009. Causes, Cost Consequences, and Risk Implications of Accidents in U.S. Hazardous Liquid Pipeline Infrastructure. International Journal of Critical Infrastructure Protection Vol. 2 No. 1+2, 2009, pp.: 38-50.
In this paper the causes and consequences of accidents in US hazardous liquid pipelines that result in the unplanned release of hazardous liquids are examined. Understanding how different causes of accidents are associated with consequence measures can provide important inputs into risk management for this (and other) critical infrastructure systems. Data on 1582 accidents related to hazardous liquid pipelines for the period 2002–2005 are analyzed. The data were obtained from the US Department of Transportation’s Office of Pipeline Safety (OPS). Of the 25 different causes of accidents included in the data the most common ones are equipment malfunction, corrosion, material and weld failures, and incorrect operation. This paper focuses on one type of consequence–various costs associated with these pipeline accidents–and causes associated with them. The following economic consequence measures related to accident cost are examined: the value of the product lost; public, private, and operator property damage; and cleanup, recovery, and other costs. Logistic regression modeling is used to determine what factors are associated with nonzero product loss cost, nonzero property damage cost and nonzero cleanup and recovery costs. The factors examined include the system part involved in the accident, location characteristics (offshore versus onshore location, occurrence in a high consequence area), and whether there was liquid ignition, an explosion, and/or a liquid spill. For the accidents associated with nonzero values for these consequence measures (weighted) least squares regression is used to understand the factors related to them, as well as how the different initiating causes of the accidents are associated with the consequence measures. The results of these models are then used to construct illustrative scenarios for hazardous liquid pipeline accidents. These scenarios suggest that the magnitude of consequence measures such as value of product lost, property damage and cleanup and recovery costs are highly dependent on accident cause and other accident characteristics. The regression models used to construct these scenarios constitute an analytical tool that industry decision-makers can use to estimate the possible consequences of accidents in these pipeline systems by cause (and other characteristics) and to allocate resources for maintenance and to reduce risk factors in these systems.
Restrepo, C. & Zimmerman, R. 2008. Environmental Justice. Encyclopedia of Quantitative Risk Assessment. Edited by B. Everitt and E. Melnick. John Wiley Publishers. New York, NY.
Quantitative risk assessment is a growing, important component of the larger field of risk assessment. The need to understand the risks of an activity, be it economic, environmental, public health/biomedical, or even based on terrorist or other hazardous impacts, has led to a number of methods of analysis for many different application scenarios. Indeed, all major areas of the larger endeavor - hazard identification, dose-response assessment, exposure assessment, and risk characterization - rely on and benefit from quantitative operations. Within these contexts, enhanced understanding of both the variability and the uncertainty inherent in the risk identification process is critically dependent upon proper implementation of appropriate statistical methodologies.
Naphtali, Z.S. & Restrepo, C., Zimmerman, R. 2007. Using GIS to Examine Environmental Injustice in the South Bronx. The Case of Waste Transfer Stations. Connect, Spring/Summer 2007, pp. 23-28.
The U.S. Environmental Protection Agency defines environmental justice as "...the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies."2 Environmental injustice has been defined as the disproportionate exposure of communities of color and poor people, or other vulnerable groups, such as children and the elderly, to environmental risks.3
In the analyses described in this article, Geographic Information Systems (GIS)4 techniques and models were used extensively to facilitate and streamline the analysis of demographic and socioeconomic data about people living in close proximity to waste transfer stations and major highways, and to determine whether a disproportionate number of people in communities of color and poor people live in proximity to these sites. The area of application for this analysis was a portion of the South Bronx, New York.
Zimmerman, R. & Restrepo, C.. 2006. The Next Step: Quantifying Infrastructure Interdependencies to Improve Security. International Journal of Critical Infrastructures. UK: Inderscience Enterprices, Ltd. 2005.
In International Journal of Critical Infrastructures, Vol. 2, (2/3), pp. 215-230, UK: Inderscience Enterprises, Ltd.: "Understanding cascading effects among interdependent infrastructure systems can have an important effect on public policies that aim to address vulnerabilities in critical infrastructures, especially those policies pertaining to infrastructure security. Efforts to quantify these cascading effects and illustrative examples of such metrics are presented. The first set of examples is based upon various impacts that the 14th August, 2003 blackout in the USA had on other sectors. A second set of examples is based on various electric power outages and their impact on other infrastructure systems collected from the authors' research. Although efforts to quantify cascading effects are challenging, given the nature of the data and its limited availability, research in this area can provide useful metrics."
Zimmerman, R., Restrepo, C.E., Dooskin, N.J., Hartwell, R.V., Miller, J.I., Remington, W.E…. & Schuler, R.E.. 2005. Electricity Case: Main Report: Risk, Consequences, and Economic Accounting. Center for Risk and Economic Analysis of Terrorism Events, May 2005 (Updated June 2005).
As a critical infrastructure sector, electricity enables numerous other critical infrastructures to function, and in many cases is the critical path for their operation. This is underscored by the fact that historically, electric power outages have played a central role in disruptions of many other infrastructures. As a consequence of the centrality of its role, electricity is potentially a key target for terrorist attacks. This case sets forth risks in terms of hypothetical alternative attack scenarios in the form of various grid configurations that are vulnerable based on both natural events in the U.S. and terrorism internationally as well as in terms of the odds that outages will occur and other characteristics of outages will change. Consequences are then identified based on hundreds of events and other records that portray the effects that electric power outages have on key public services and businesses. Economic accounting is conducted in terms of human premature death and injury and business loss for some of the key consequence areas, using a wide range of economic factors.
Although direct terrorist attacks on the oil and gas sector have not occurred in the United States, there are many recorded attacks on the sector in a large number of countries around the world. The statistical analysis and other evaluations of these data provide an important foundation for identifying case events that can be selected for an in-depth evaluation of the role of Supervisory Control and Data Acquisition (SCADA) in the disabling and rate of recovery of the oil and gas system. This report analyzes international terrorist attacks using a database from the National Memorial Institute for the Prevention of Terrorism (MIPT) which includes information about terrorist attacks from all over the world affecting all sectors, including oil and gas. The report looks at annual data for the period 1990-2005 with a special emphasis on attacks occurring in countries with the highest number of attacks during this period. Section 1 provides an introduction to the report. Section 2 looks at the number of incidents, including total incidents over time, attacks on the oil and gas sector as a percentage of total terrorist attacks, and incidents over time by geographical region. In Section 3 the number of fatalities associated with the attacks is examined, along with the fatalities associated with attacks on the oil and gas sector as a percentage of all fatalities associated with terrorist attacks. Section 4 looks at injuries associated with the attacks, and the injuries associated with attacks on the oil and gas sector as a percentage of all injuries associated with terrorist attacks. Section 5 provides a brief discussion about the association between injuries and fatalities. Section 6 contains a discussion of the kinds of components attacked. Finally, Section 7 ends with some concluding remarks. Although the terrorist attacks on the oil and gas sector are a relatively small proportion of terrorist attacks overall, the data show that a significant number of attacks have occurred over the period 1990-2005, suggesting that the sector is vulnerable. If terrorist groups feel that carrying out a physical attack within the United States is too difficult they could turn their attention to other vulnerabilities such as SCADA systems.
C. Restrepo, R. Zimmerman, G. Thurston, J. Clemente, J. Gorczynski, M.
Zhong, M. Blaustein, L. Chen 2004. A comparison of ground-level air quality data with New York State Department of Environmental Conservation monitoring stations data in South Bronx, New York. Atmospheric Environment Vol. 38, 2004, pp. 5295-5304.
The South Bronx is a low-income, minority community in New York City. It has one of the highest asthma rates in the country, which community residents feel is related to poor air quality. Community residents also feel that the air quality data provided by the New York State Department of Environmental Conservation (DEC) through its network of monitoring stations do not reflect the poor quality of the air they breathe. This is due to the fact that these monitoring stations are located 15 m above ground. In the year 2001 this project collected air quality data at three locations in the study area. They were collected close to ground-level at a height of 4 m by a mobile laboratory placed in a van as part of the South Bronx Environmental Health and Policy Study. This paper compares data collected by the project with data from DEC's monitoring stations in Bronx County during the same periods. The goal of the comparison is to gain a better understanding of differences in measured air quality concentrations at these different heights. Although there is good agreement in the data among DEC stations there are some important differences between ground-level measurements and DEC data. For PM2.5 the measured concentrations by the van were similar to those recorded by DEC stations. In the case of ozone, the concentrations recorded at ground level were similar or lower than those recorded by DEC stations. For NO2, however, the concentrations recorded at ground level were over twice as high as those recorded by DEC. In the case of SO2, ground level measurements were substantially higher in August but very similar in the other two periods. CO concentrations measured at ground-level tend to be 60–90% higher than those recorded by DEC monitoring stations. Despite these differences, van measurements of SO2 and CO concentrations were well below EPA standards.
Zimmerman, R., Restrepo, C., Hirschstein, C., Holguín-Veras, J., Lara, J. & Klebenov, D.. 2002. South Bronx Environmental Health and Policy Study, Public Health and Environmental Policy Analysis: Final Report for Phase I. New York, NY: New York University, Wagner Graduate School of Public Service, Institute for Civil Infrastructure Systems.
The quality of the environment in communities with large minority populations has been a growing concern particularly with respect to public health given the potential for greater