The two hijacked jets that crashed into the World Trade Center on September 11, 2001 covered New York City (NYC) in asbestos-laden smoke for weeks. Everyone in outdoors Lower Manhattan was covered in dust, soot and smoke, including firefighters, emergency response and rescue crews, police officers, surviving workers and building dwellers, and pedestrians. (See Editorial on page 4, Industry News on page 5 and Cover Story on page 6.)The smoldering rubble at "ground zero" was a vast combination of more than 200,000 tonnes of steel and 400,000 tonnes of pulverized concrete along with glass, paints, plastics, solvents, office furniture, vehicles and decomposing bodies.
The average daily population at the World Trade Centre included approximately 50,000 workers and another 70,000 business and leisure visitors. Prior to its destruction, the World Trade Center survived an explosion set off in the basement of a twin tower on February 26, 1993. The centre opened for its first tenants in December 1970.
When the towers were built in the late 1960s, they became among the first high-rises to use spray-on ceramic fireproofing instead of asbestos as insulating material. However, asbestos was used in flooring materials, and may have been used as a fire-retardant and as an insulator in some adjacent buildings. Also, the buildings were also constructed in an era when lead-based paints were used, and lead can be hazardous when burned.
Many rescue workers and journalists on the scene immediately following the incident wore various types of masks. Pedestrians were also provided with masks, but many did not use them. Those who just wore paper masks -- which merely provide protection from larger harmless dust particles and not the more hazardous chemical particles -- are expected to have problems.
Environmental consultant John Brdar of C.D. Sonter Management Inc. in Toronto, Ontario estimates, "Everyone who was not properly protected within a one-mile radius of the World Trade Center will have major breathing problems."
At the request of the NYC Department of Health, the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) were on the scene as soon as possible to monitor exposure to hazardous dust and debris, including asbestos.
Monitoring and sampling of ambient air quality conducted on September 11 and 12 found low levels of the airborne carcinogen. The levels of asbestos, lead and volatile organic compounds in air samples from Brooklyn, downwind from the World Trade Center site, were not detectable or not of concern.
But as rescue workers searched for the dead, they stirred up and were exposed to the asbestos lurking in the bulk debris and airborne particles. And to make matters worse, the urgent nature of the situation meant that safety protocols for handling asbestos and other hazardous contaminants were too often disregarded.
Statements from EPA Administrator Christine Whitman assured that the agency would work closely with rescue crews to ensure that all appropriate precautions were taken and that continual monitoring was performed.
In the aftermath, the EPA coordinated efforts with several agencies to provide personal protective equipment: 3,000 asbestos respirators, 60 self-contained breathing apparatuses, 10,000 suits, respiratory and eye equipment, health and safety training, design and implementation of a site monitoring plan; and, technical assistance for site control and decontamination.
On September 13, EPA and OSHA staff walked through the site to collect data on asbestos exposure levels. Air samples taken inside the buildings were negative. Debris samples collected outside buildings on cars and other surfaces contained small percentages, ranging from 2.1 to 3.3 -- above the permitted one per cent level for asbestos.
Health effects
Optimists such as Beta Montemayor of GlobalTox speculate that the high temperatures caused by the estimated burning jet fuel -- estimated at more than 555 degrees Celsius -- may have burned off some of the hazardous materials, including asbestos, and rendered some of it harmless. (It is estimated that each 220-tonne jet was flying at least 300 miles per hour and carrying 60,000 pounds of jet fuel.) Also, the dust problem decreased somewhat by the second week after heavy rains.
However, around the same time, many of the rescue workers were already reporting breathing difficulties. It's estimated that anyone with pre-existing respiratory problems, such as asthma, emphysema or chronic obstructive pulmonary disorder was also at risk from the fires and demolition work. The constant coming and going of construction vehicles and the relentless cleanup -- which resulted in the shuffle of tens of thousands of tonnes of material -- created clouds of dust and further disturbed the asbestos.
As of September 21, the EPA had taken a total of 97 samples from 11 sites in lower Manhattan and four in New Jersey. Ms. Whitman confirmed that seven samples at or near ground zero had marginally higher levels of asbestos that exceeded the level of concern for long-term exposure.
Vacuum trucks and street sweepers were used to clean up the asbestos-laced debris and dust. However, not all precautions were taken, as some vehicles covered in the dust were driven or towed out of the city on major streets. In one reported instance, a fire truck covered in dust drove down 6th Avenue and cast off dust on unprotected pedestrians and patrons at outdoor cafes.
Experts believe that the asbestos may emerge as a threat to returning workers and residents. U.S. Labor Secretary Elaine Chao announced that OSHA is providing advice and technical assistance to employers and federal agencies to help protect workers from toxic exposure at the disaster sites.
Health concerns about asbestos contamination are primarily related to long-term exposure, which has been linked to cancer of the chest cavity. Typically, malignancy takes about 20 years to develop. Miners and asbestos-factory workers can develop asbestosis, a lung disease that causes coughing, breathlessness, disability, and even death.
Connie Vitello is editor of this magazine.