Since the Sept. 11 disaster that saw the total destruction of the World Trade Center in New York and several surrounding buildings, the U.S. Environmental Protection Agency and the Occupational Safety and Health Administration (OSHA), along with other city, state and federal agencies, have been conducting monitoring for a number of potentially hazardous materials, such as asbestos, lead, dioxin, and polychlorinated biphenyls (PCBs). The two agencies recently released their sampling data.
In total, EPA and OSHA have taken 835 ambient air samples in the New York City metropolitan area. EPA is currently collecting data from 16 fixed air monitors at Ground Zero and in the residential and business districts around the site, and both EPA and OSHA are using portable sampling equipment to collect data from a range of locations throughout the area.
Out of a total of 442 air samples EPA took at Ground Zero and in the immediate area, only 27 had levels of asbestos above the standard EPA uses to determine if children can re-enter a school after asbestos has been removed. EPA uses a stringent standard based upon assumptions of long-term exposure. OSHA has analyzed 67 air samples from the same area, and all were below the OSHA workplace standard for asbestos.
All 54 air samples from EPA's four monitors in New Jersey found no levels above EPA's standard. Another 162 samples were taken from EPA's monitors at the Fresh Kills landfill in Staten Island, where debris from the World Trade Center is being taken and only two exceeded EPA's standard.
Of 177 bulk dust and debris samples collected by EPA and OSHA and analyzed for asbestos, 48 had levels over one percent, the level EPA and OSHA use to define asbestos-containing material. Although early samples from water runoff into the Hudson and East Rivers showed some elevated levels of polychlorinated biphenyls (PCBs), dioxin, asbestos and metals, recent results find non-detectable levels of asbestos, and PCBs and polycyclic aromatic hydrocarbons (PAHs) and metals below the level of concern.
EPA and OSHA have also conducted sampling for the presence of metals (lead, iron oxide, zinc oxide, copper and beryllium) at Ground Zero and in surrounding areas. None of the levels of these metals have exceeded OSHA limits.
Although EPA has measured dioxin levels in and around the World Trade Center site that were at or above EPA's level for taking action, the risk from dioxin is based on long-term exposure. EPA and OSHA expect levels to diminish as soon as the remaining fires on the site are extinguished.
Of the 36 samples of volatile organic compounds (VOCs) taken around Ground Zero to assist response workers in determining the appropriate level of respiratory protection, several samples have been above the OSHA standard for workers. None presented an immediate risk to workers, and the levels are expected to decline when the fires are out.
Edited by Sandy Smith