The WTC disaster: Landrigan's response.My colleagues and I thank Lange for his letter confirming our finding that asbestos was present in settled dust as well as in airborne samples obtained at Ground Zero, the site of the World Trade Center, and for his having agreed with us that this asbestos almost certainly represented an exposure hazard for workers. The asbestos that was detected in the dust at Ground Zero originated from asbestos that had been sprayed onto the steel skeleton of the Twin Towers as fireproofing fireproofing, method of making normally combustible materials as nearly noncombustible as possible. Fireproofing generally applies to textiles and construction materials that are treated with a solution or coating of some substance that will tend to retard their when the structure was being built. It was well known that asbestos was applied in the North Tower up to about the 40th story and at other locations throughout the structure before the practice of spraying on asbestos was banned in New York City New York City: see New York, city. New York City City (pop., 2000: 8,008,278), southeastern New York, at the mouth of the Hudson River. The largest city in the U.S. in the early 1970s (Nicholson et al. 1971; Reitze et al. 1972). Concentrations of asbestos in the dust at Ground Zero were highly variable, and the level in any particular sample reflects the location of sampling and the composition of the dust that happened to be in that area. We agree with Lange's view that workers likely had intermittent exposures to asbestos that would have arisen unpredictably when, for example, they picked up a steel beam or turned over rubble and liberated asbestos fibers into the air. The asbestos hazard to workers was magnified by the fact that the U.S. Occupational Safety and Health Administration Occupational Safety and Health Administration (OSHA), U.S. agency established (1970) in the Dept. of Labor (see Labor, United States Department of) to develop and enforce regulations for the safety and health of workers in businesses that are engaged in interstate (OSHA OSHA n. Occupational Safety and Health Administration, a branch of the US Department of Labor responsible for establishing and enforcing safety and health standards in the workplace. ) failed to require constant use of respirators at Ground Zero. We disagree strongly with Lange's statement that "it is unlikely that exposure to asbestos itself will result in any actual health effects." Lange appears to base his assertion, first, on the fact that most of the asbestos at the World Trade Center was chrysotile chrysotile: see serpentine. chrysotile Fibrous variety of the magnesium silicate mineral serpentine; it is the most important asbestos mineral. Individual fibres are white and silky, but the aggregate in veins is usually green or yellowish. asbestos, and second, that duration of exposure for most workers was brief. Unfortunately neither of those factors conveys protection. We remain concerned that there now exists a risk for mesothelioma Mesothelioma Definition Mesothelioma is an uncommon disease that causes malignant cancer cells to form within the lining of the chest, abdomen, or around the heart. Its primary cause is believed to be exposure to asbestos. caused by occupational exposure to asbestos for the brave men and women who worked and volunteered at Ground Zero. All types of asbestos fibers, chrysotile included, have been shown in laboratory as well as clinical studies to be capable of causing malignant mesothelioma malignant mesothelioma Mesothelioma, see there (Nicholson and Landrigan 1996). All types of asbestos fibers, chrysotile included, have been declared proven human carcinogens Carcinogens Substances in the environment that cause cancer, presumably by inducing mutations, with prolonged exposure. Mentioned in: Colon Cancer, Rectal Cancer by OSHA, the U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and , and the International Agency for Research on Cancer The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations. Its main offices are in Lyon, France. . Pathologic studies have found short chrysotile fibers, the predominant type of fiber in World Trade Center dust, to be the predominant fiber in mesothelioma tissue (Dodson et al. 1991; LeBouffant et al. 1973; Suzuki and Yuen 2002). Moreover, mesothelioma has been reported in persons with relatively low-dose, nonoccupational exposure to asbestos of brief duration (Anderson 1982; Camus et al. 1998; Magnani et al. 2001). The greatest future risk of mesothelioma would appear to exist among first responders who were covered by the cloud of dust on 11 September 2001 as well as in other workers employed directly at Ground Zero and workers employed in cleaning asbestos-laden dust from contaminated buildings. Although we agree with Lange that the number of mesothelioma cases will probably not be great, we think it quite misleading to state that no risk exists. The author declares he has no competing financial interests. Philip J. Landrigan Mount Sinai School of Medicine
Mount Sinai School of Medicine is a medical school found in the borough of Manhattan in New York City. New York, New York E-mail: phil.landrigan@mssm.edu REFERENCES Anderson HA 1982. Family contact exposure. In: Proceedings of the World Symposium on Asbestos, 25-27 May 1982, Montreal, Quebec, Canada. Montreal, Quebec, Canada:Canadian Asbestos Information Centre, 349-362. Camus M, Siemiatycki J, Meek B. 1998. Nonoccupational exposure to chrysotile asbestos and the risk of lung cancer. N Engl J Med 338:1865-1571. Dodson RF, Williams MG, Corn CJ, Brollo A, Bianchi C. 1991. A comparison of asbestos burden in lung parenchma, lymph nodes and plaques. Ann NY Acad Sci 643:53-60. LeBouffant L, Martin JC, Durif W, Daniel H. 1973. Structure and composition of pleural Pleural Pleural refers to the pleura or membrane that enfolds the lungs. Mentioned in: Pneumothorax pleural emanating from or pertaining to the pleura. plaque. In: Biological Effects of Asbestos. (Bogovski P, Gilson JC, Timbrell V, Wagner JC, eds). IARC Sci Publ 8:246-257. Magnani C, Dalmasso P, Biggeri A, Ivaldi C, Mirabelli D, Terracini B. 2001. Increased risk of malignant mesothelioma of the pleura pleura (pl  r`ə), membranous lining of the upper body cavity and covering for the lungs. after residential or domestic exposure to asbestos: a case-control study in Casale Monferrato, Italy. Environ Health Perspect 109:915-919. Nicholson WJ, Rohl AN, Ferrand EF. 1971. Asbestos air pollution in New York City. In: Proceedings of the Second International Clean Air Congress (Englund HM, Beer WT, eds). New York:Academic Press, 36-139. Nicholson WJ, Landrigan PJ. 1996. Asbestos: a status report. Curr Issues Public Health 2:116-123. Reitze WB, Nicholson WJ, Holaday BA, Selikoff IJ. 1972. Application of sprayed inorganic fiber containing asbestos: occupational health hazards. Am Ind Hyg Assoc J 33:178-191. Suzuki Y, Yuen SR. 2002. Asbestos fibers contributing to the induction of human malignant mesothelioma. Annals NY Acad Sci 982:160-176. |
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