World Trade Center Buildings Research Articles

PBDE Exposure, Placental Transfer, and Birth Outcomes

ISEE-664 Objective: Animal studies have suggested that prenatal exposure to polybrominated diphenyl ethers (PBDEs) may result in alterations in growth and development. A cohort study was initiated by the Columbia Center for Children's Environmental Health to examine the impact of prenatal exposures to toxicants, including PBDEs, that may have been emitted from the World Trade Center (WTC) buildings in New York City following the 9/11 terrorist attack. This report focuses on the transfer of PBDE congeners across the placenta to the fetus and the effect these exposures have on birth outcomes, including birth weight, length, head circumference and ponderal index. Materials and Methods: Between December 2001 and June 2002, maternal and/or cord blood samples were collected from 329 women delivering singletons at 3 hospitals located near the WTC site, of which 210 cord and 161 maternal plasma samples were analyzed for selected PBDE congeners. Demographic, health, and exposure information was abstracted from medical records and from a questionnaire administered after delivery. Spearman's correlation coefficients, Wilcoxon signed-rank tests, and linear regression analyses were used to evaluate these data. Results: Cord and maternal levels of BDE-47, BDE-99, and BDE-100 were highly correlated (r = 0.95, r = 0.83, and r = 0.91, respectively). However, maternal concentrations of BDE-100 and BDE-153 were, on average, significantly higher than corresponding cord levels (P = 0.02 and P = 0.05, respectively). In separate univariate and multivariate analyses, birth weight, length, head circumference, and ponderal index were not related to cord PBDE concentrations. Conclusions: Although maternal and cord concentrations are highly correlated for BDE-47, BDE-99, and BDE-100, differences between cord and maternal concentrations of BDE-153 are more apparent, indicating that this congener may not move as easily from mother to fetus. Contrary to what has been observed in toxicologic animal models, our birth outcomes appear to be unrelated to PBDE exposure. Children are being followed to assess neurodevelopmental outcomes.

Geography of asbestos contamination near the World Trade Center site

Despite the dust cleanup and indoor air testing program led by the U.S. Environmental Protection Agency (EPA) and offered to all residents of Lower Manhattan (south of Canal Street), concern remains about local chemical residues from the collapse of the World Trade Center (WTC) buildings. Data on post-cleanup indoor airborne asbestos concentration, available from EPA Region 2, were analyzed to assess the possibility that the WTC site is the source of geographically concentrated rare post-cleanup exceedances of the health-based standard for asbestos. Recognizing that these rare exceedances may be attributable to sources other than the WTC disaster, and that these sources are very likely to exhibit geographic patterns, the data were analyzed using a spatial filter specification of the auto-Poisson probability model. Our analysis shows that ignoring geographic patterns latent in these exceedances affects the empirical probability of exceeding the health-based standards for airborne asbestos. We did not find any statistically-significant geographic pattern in the exceedance events that would indicate the WTC site as the source of the post-cleanup exceedances. Apparent geographic patterns may be due to the geographic variability in sampling intensity. Our analysis indicates the Residential Dust Cleanup Program lead by EPA Region 2 has been effective at reducing the concentration of air-borne asbestos in indoor air to below the health-based benchmark.

The Security and Prosperity Partnership

The tragic events of 11 September 2001 marked a watershed in the lives of most of the world, but they affected most especially those in the United States and its two land neighbours, Canada and Mexico. For the first time in history, America was gravely threatened from within by terrorists who managed to assimilate into its open society and attack buildings in its most symbolic cities. Not since Pearl Harbor-which was geographically, if not emotionally, distant from the North American mainland-had there been an attack on the United States by enemies from abroad. Unlike World War II, the wilful destruction of iconic buildings and the loss of innocent lives in New York and the nation's capital brought home the very real threat posed by individuals and groups bent on challenging the economic and political might of the world's only remaining superpower. After several centuries of fighting many battles far from its borders, the United States found itself in a war in the very kitchen of the American home.One of the first decisions taken by the US administration in the hours following the destruction of the World Trade Center buildings and the attack on the Pentagon was to seal off the country's land, air, and seaports, which are the lifeline of billions of dollars in commerce and the route of millions of people who enter and leave the US on any given day. The result was total chaos, particularly along the two land borders that formally divide the US from its North American neighbours. Individual lives were disrupted to an unimaginable degree, while the flow of goods and services, on which most of North American industry depends, came to a virtual standstill. All of a sudden the open border that characterized the boundary between the US and Canada slammed shut, while the border with Mexico-already much more controlled-became a logistical nightmare for the millions of bona fide travelers, importers, and exporters who rely on a smooth and efficient border for their economic and social intercourse.Who can forget the images of miles and miles of tractor-trailers backed up on the Canadian side of the Ambassador Bridge, or of the lonely, unmanned crossing that only had a traffic cone to signal that it was closed for the day? Traffic jams at Otay Mesa or Nuevo Laredo stretched as far as the eye could see, while hapless immigration and customs officials struggled with implementing the emergency closure order that came from Washington. For at least 72 hours, the entire machinery of commerce set up under the North American free trade agreement came to a screeching halt. Factories in all three countries that relied on just-in-time deliveries for their production were forced to suspend activities, while trucks, trains, and cars spent hours and sometimes days waiting to clear the border and resume their itineraries. In short, the terrorists, whose primary objective was to destroy landmarks in New York and Washington, ended up devastating the very nervous system of North America.A few weeks after 9/11, the foreign ministers of Mexico and Canada met at the Mexican embassy in Washington to discuss the crisis that had so severely affected the economies of their countries. This was the first occasion since the entry into force of NAFTA that prompted the US's two neighbours to schedule an urgent political consultation to decide what individual and joint steps could be taken to mitigate the impact of the actions at the borders. They also wanted to ensure that the basic lifelines among the three trade partners be kept open until a negotiated agreement with the US was reached on measures that would significantly improve border security and give the authorities in Washington the necessary confidence to gradually resume operations at the dozens of land and bridge crossings on their northern and southern borders. Unfortunately, it wasn't possible at the time to come up with a bilateral strategy between Canada and Mexico on this issue. Then-Foreign Minister John Manley told his Mexican counterpart that Canada's relationship with the US was different from Mexico's, and that security and intelligence cooperation under NATO and other military and law enforcement agreements made it necessary for Ottawa to negotiate separately with its American ally. …

Picture-Driven Stories

THIS WEEK'S COVER STORY IS A DEPARture for C&EN. The Gorgeous Inside Stories of Metal by Senior Editor Ivan Amato is, as its title implies, a scientific photo essay (see page 14). In traditional C&EN stories, graphical elements such as photographs, chemical structures, and molecular graphics function to support the text, which generally dominates each page. In this essay, the images are the story, the text provides the reader with information and context to better appreciate the images. Metallographers are anatomists of metal, Amato writes. Whether it's the bronze of an 1,800-year-old arrowhead or a steel I-beam from World Trade Center Building 7, metallographers use a family of techniques for revealing metallic microstructures that tell stories. Those stories reveal the extraterrestrial origin of alloys in a meteorite, the stress a high-velocity projectile imparts to a sheet of nickel steel alloy, or the microstructure imparted by cold work to a sheet of ...

THE GORGEOUS INSIDE STORIES OF METAL

METALLOGRAPHERS ARE ANATOMISTS of metal. Whether it's the bronze of a 1,800 year-old arrowhead or a steel I-beam from World Trade Center Building 7, metallographers use a family of techniques for revealing metallic microstructures that tell stories. ALIEN PATTERNS Remains of the Gibeon nickel-iron meteorite were first found in 1836 in what is now Namibia, but some of its tens of thousands of pounds of fragments found their way to Dave's Down to Earth Rock Shop in Evanston, Ill., and one of those ended up in the possession of metallographer Alan Stone. After slicing and polishing his piece of the meteorite, Stone etched it with a reagent that revealed several of the space rock's more notable traits. The central triangular feature on the left is part of an eight-faced motif, known as a Widmanstatten structure, which occurs naturally only in extraterrestrial alloys, Stone says. It takes extremely slow cooling rates—temperature drops ...

Physical Characteristics and Health Effects of Aerosols from Collapsed Buildings

Airborne pollutants can rise to extreme levels when large buildings fall down. The terrorist attack on New York's World Trade Center (WTC) towers caused the release of an enormous quantity of pulverized building materials and combustion products into the local environment. Particulate matter (PM) from crushed WTC building materials is primarily non-respirable (>96% larger than 10 microm mass median aerodynamic diameter [MMAD]) and composed of fibrous and nonfibrous components such as gypsum, calcite, silica, glass fibers, cellulose, and asbestos. Respirable fine WTC PM (PM(2.5)) may include finely crushed building materials as well as combustion products such as dioxins and polycyclic aromatic hydrocarbons (PAHs). Rescue workers at the WTC site had exposure-related increases in the incidences of nasal congestion, bronchial hyperreactivity to aerosolized methacholine, gastroesophageal reflux disease, and persistent cough. Toxicological studies in mice indicate that WTC PM(2.5) causes airflow obstruction above a critical dose. The review of physical characteristics and health effects of major pollutants derived from the collapse of the WTC towers has assisted in risk assessment efforts related to the collapse of large buildings.

Are Post-9/11 Resilience Data Good or Troubling News?

Are Post-9/11 Resilience Data Good or Troubling News?

The aesthetics of absence: Rebuilding Ground Zero

ABSTRACTIn this article, I examine the narratives and meanings that have been projected onto the space of Ground Zero in New York City since September 11, 2001, how they have been deployed for various political agendas, and how they have informed the ways in which the site will be rebuilt and memorialized. I investigate the changing meanings attributed to the dust and the footprints of the World Trade Center buildings and the debates over architectural designs and the proposed memorial.

Analysis of Aerosols from the World Trade Center Collapse Site, New York, October 2 to October 30, 2001

The collapse of the World Trade Center (WTC) buildings #2 (South Tower), #1 (North Tower), and #7 created an enormous collapse pile which emitted intense plumes of acrid smoke and dust until roughly mid-December, when the last spontaneous surface fire occurred. We collected particles by size (8 modes, ≈12 to 0.09 micrometers diameter) and time (typical resolution of 1 to 3 h) from October 2 until late December at the EML 201 Varick Street site roughly 1.8 km NNE of the collapse site and 50 m above ground level. Here we show some of the 70,000 mass and elemental data from the time period October 2 through October 30. Identification of a WTC collapse pile source for aerosols seen at the receptor site were based upon the simultaneous presence of finely powdered concrete, gypsum, and glass with intense very fine combustion mode mass episodes concurrent with winds from the southwest quadrant. The results, derived from seven independent beam-based analytical techniques, showed that while PM10 and PM2.5 24 h val...

New York City Department of Buildings World Trade Center Building Code Task Force Findings and Recommendations

New York City Department of Buildings World Trade Center Building Code Task Force Findings and Recommendations

Building and Evaluating Models to Estimate Ambient Population Density

The concept of human population density is quite simple: the number of persons occupying a given area. Nonetheless, practical representations of population density must use appropriate spatial and temporal scales of measurement to be useful. The 11 September 2001 attack on the World Trade Center in New York is a poignant example: “How many people were in the two World Trade Center buildings at 0830 local time?” Population density data derived from mostnational censuses is a residential measure of population density and consequently does not capture non-residential population density. Human mobility suggests that a nonresidential or ambient measure of population density may be a more useful representation for some applications. Ambient population density in this sense is a temporally averaged measure of population density that takes into account where people work, sleep, eat, drive, shop, etc. Short of implanting a GPS reciever into everyone’s skull and tracking their spatio-temporal behavior, it is extremely difficult to make direct measurements of ambient population density. This paper explores some theoretical and empirical efforts at estimating ambient population density and proposes a quantitative means for evaluating their validity. The three models of population density examined are LandScan, Gridded Population of the World (GPW), and a simple empirical model derived from nighttime satellite imagery provided by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP OLS). These measures are compared to both residential and employment-based measures of population density in the Los Angeles metropolitan area. The GPW, LandScan, and DMSP OLS models of ambient population density described here all make foundational contributions to future efforts at filling the gap in social, economic, and demographic information for parts of the world where such data are unavailable. The proxy measures of population density described here show promise for many applications, including improved mapping of population distribution and as a supplement to census enumerations in many parts of the world.

Crisis, Recovery, Innovation: Responsive Organization after September 11

After the attack on the World Trade Center on September 11, many firms, directly affected by the attack, resumed trading when markets reopened less than a week later. How were these companies able to respond, working under conditions of fear and grief, so quickly and effectively? Drawing on conversations with executives and employees in financial service firms with offices in the World Trade Center and adjacent buildings, this report documents the importance of strong personal ties, lateral self-organization, and nonhierarchical relations in the recovery process. As a response to uncertainty, organizational factors that explain recovery are similar to those that generate innovation.

Occupational Exposures to Air Contaminants at the World Trade Center Disaster Site—New York, September–October, 2001

Amid concerns about the fires and suspected presence of toxic materials in the rubble pile following the collapse of the World Trade Center (WTC) buildings on September 11, 2001, the New York City Department of Health (NYCDOH) asked CDC for assistance in evaluating occupational exposures at the site. CDC's National Institute for Occupational Safety and Health (NIOSH) collected general area (GA) and personal breathing zone (PBZ) air samples for numerous potential air contaminants. This report summarizes the results of the assessment, which indicate that most exposures, including asbestos, did not exceed NIOSH recommended exposure limits (RELs) or Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs). One torch cutter was overexposed to cadmium; another worker was overexposed to carbon monoxide (CO) while cutting metal beams with an oxyacetylene torch or a gasoline-powered saw, and two more were possibly overexposed to CO. NIOSH recommended that workers ensure adequate on-site ventilation when using gas-powered equipment and use rechargeable, battery-powered equipment when possible.

Use of viscoelastic dampers in reducing wind- and earthquake-induced motion of building structures

Viscoelastic (VE) dampers have been successfully incorporated in a number of tall buildings as a viable energy dissipating system to suppress wind- and earthquake-induced motion of building structures. This type of damper dissipates the building's mechanical energy by converting it into heat. Several factors such as ambient temperature and the loading frequency will affect the performance and hence the effectiveness of the damper system. VE dampers have been able to increase the overall damping of the structure significantly, hence improving the overall performance of dynamically sensitive structures. The effectiveness of VE dampers has been demonstrated both experimentally and analytically by many researchers over the past 25 years. The twin towers of the World Trade Center Buildings in New York City and the Columbia SeaFirst Building in Seattle, Washington, are among the first buildings which benefited from the installation of VE dampers. In seismic applications, the VE dampers can be incorporated either into new construction or as a viable candidate for the retrofit of existing buildings which adds to the versatility of VE dampers.

Illumination of World Trade Center Building

Illumination of World Trade Center Building

Prospects of BOT (Build-Operate-Transfer) Projects for Infrastructure Development in Nepal

Infrastructure development is one of the top priorities in a country's economic progress. Planned and well connected infrastructure services attract foreign direct investments and boost local investments. To meet the present and future demand for infrastructure development, developing and least developed countries like Nepal always face scarcity of their own resources. To mitigate the shortage of the Government's funds for infrastructure developments, the Build-Operate-Transfer (BOT) mode of financing has been a model in many countries. Considering the BOT project successes in Malaysia, Thailand, the Philippines and other countries, and following Khimti-I and the United World Trade Center building, Nepal must seriously consider having more BOT projects. Especially in its urgently needed infrastructure such as Hydropower generation, roads, bridges, telecommunications, water supply, waste disposal, etc.Key Words: Build Operate Transfer; BOT; Public Private PartnershipDOI: http://dx.doi.org/10.3126/jie.v8i1-2.5104Journal of the Institute of Engineering Vol. 8, No. 1&2, 2010/2011Page: 138-142Uploaded Date: 20 July, 2011