Medical Surveillance of Search Dogs Deployed to the World Trade Center and Pentagon: 2001-2006

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The September 11, 2001, terrorist attacks on the World Trade Center (WTC) resulted in over one million tons of debris covering 16 acres and massive clouds of particulates and toxins. Numerous environmental hazards including particulate matter, asbestos, polycyclic aromatic hydrocarbons, metal compounds, dioxins, and volatile organic compounds were identified at the WTC site (Banauch, Dhala, & Prezant, 2005). Acute and delayed respiratory symptoms have afflicted the WTC emergency responders (Moline, Herbert, & Nguyen, 2006; Moscato & Yacoub, 2007; Reissman & Howard, 2008).

The Pentagon attack site was smaller and lacked the hazards associated with the massive crushing and combustion of the WTC but still posed a potential risk for responders. A U.S. Environmental Protection Agency (U.S. EPA) air monitoring summary from October 9, 2001, reported only trace levels of asbestos, volatile organic compounds, and other chemicals. U.S. EPA did, however, identify high concentrations of arsenic and antimony in the soot and ash (Lyman, 2003).

In addition to the estimated 40,000 emergency response personnel at the WTC site and over 8,000 responders at the Pentagon, an estimated 250-300 canines responded, including more than 55 dogs at the Pentagon (Otto, Downend, Serpell, Ziemer, & Saunders, 2004; Slensky, Drobatz, Downend, & Otto, 2004). These dogs served three main purposes: detection (e.g., live victims by search and rescue [S&R] dogs, human remains by cadaver dogs, and explosive devices by bomb dogs), patrol (e.g., site security by police dogs), and mental health support (e.g., therapy dogs). At the Fresh Kills Landfill on Staten Island, dogs were used to assist in locating human remains during the sifting and sorting of WTC debris.

Search dog teams started arriving at the WTC on September 11. None of the dogs from outside of the New York City Police Department or the New York-New Jersey Port Authority were present during the tower collapse. The plume of dust, smoke, and toxic components generated by the collapse of the WTC was a major risk factor for human pulmonary complications. The second-highest risk period for both acute and chronic respiratory symptoms in humans occurred during the first two days following the collapse (Herbert et al., 2006; Prezant et al., 2002). Approximately half of the dogs responding to the WTC arrived within the first two days (Otto et al., 2004). The rain on September 14, 2001, likely helped to at least temporarily reduce the overall airborne level of pollutants in lower Manhattan; however, the rain also may have altered the composition of the dusts to which the responders were exposed. In the immediate work zone (Ground Zero), the unrelenting digging and moving of rubble and the uncontained fires resulted in persistent exposure to airborne toxins and particulates.

Although working dogs arrived at the Fresh Kills Landfill on and after September 17, the constant sifting and sorting of debris from both the WTC and pre-existing waste continuously aerosolized particulate matter and toxins. At the Pentagon, where about half of the dogs arrived on September 11, personal protective gear and respiratory protection requirements for the human responders were enforced. The use of respiratory protection at the WTC, particularly in the early days of the response, was variable. Regardless of the site, the S&R dogs were not equipped with respiratory protection and foot protection was only used for a limited number of dogs working the site perimeter.

The manifestation of pulmonary disease in workers responding to the WTC disaster has prompted great concern and speculation about long-term hazards from environmental exposure. The risks and long-term effects of response to the Pentagon (Lyman, 2003) have not had such an obvious manifestation. The S&R dogs shared the exposure risks with the human workers.

Companion animals, particularly dogs, may serve as sentinels of human disease due to several similarities between humans and dogs (van der Schalie et al. …