It was with great interest that my colleagues and I read the article "IH In the Wake of Terror," January 2002, The Synergist. In particular, Christine Umbrell touched on several key points in which we shared experiences with Aaron Ondo at the World Trade Center. When NIOSH personnel began arriving at the WTC on Sept. 12, issues relating to respirator use and communication were paramount on many people's minds and quickly became apparent to us. NIOSH became involved at the WTC at the request of the NYC Department of Health. Because of the large number of groups collecting environmental and worker exposure data at the WTC, daily conference calls among involved parties (NYC DOH, NIOSH, ConEdison, EPA, OSHA, etc., as well as private companies) became a vital means for sharing information in the days following Sept. 11. Without identifying and 'plugging into' those parties who were centralizing exposure information as it became available, anyone arriving on the scene could easily feel overwhelmed by the scope of work required to adequately characterize worker exposures at Ground Zero, and could be unaware of work being done by fellow OEHS professionals. It may be months before a complete picture of all the EHS-related activities at the WTC develops. After reading this article, one may have the (false) impression that only asbestos was sampled at WTC until Ondo began sampling for other contaminants ten days after the disaster, on Sept. 21. By Sept. 21, more comprehensive site characterization was well underway. NIOSH, for example, had literally hundreds of man-hours invested in sampling (heavy equipment operators, rescue personnel, security forces, and others) not only asbestos, but various VOCs, metals, crystalline silica, freons, CO, respirable and total PNOR and mercury. After the 21st, NIOSH also collected data on exhaled-breath CO levels, diesel exhaust, acid gases, PAHs and H2S exposures. While results from most of this sampling were not immediately available for interpretation, their collection was discussed at least daily with NYC DOH and the other groups involved with the evening conference calls. The rest of the sampling results were given to these same parties as soon as NIOSH received laboratory results; a comprehensive NIOSH WTC report is currently in development. We bring these Issues to the attention of the editors not to detract from the timely and Informative writing of Umbrell or from the fine work done by Ondo and his colleagues at the IOUE, but to emphasize the challenges to effective communication and seamless IH work presented by tragic events like the WTC.