A Geographic Information System (GIS) is a computer software solution that enables managers to store, retrieve, and analyze data which are related to a particular location. Locational or "spatially referenced" data can be found in nearly all databases, yet this spatial component may be hidden or overlooked when data are viewed in a spreadsheet. A GIS combines the unique aspect of location with other information by integrating relational database technology with mapping, computer aided design, and graphics capabilities.

Why are Managers Using GIS?
Prior to the availability of the GIS, managers have had to rely solely on paper documents or multiple databases to keep track of, and access data. Mapping is typically in the form of hard copy maps created with manual cartography, or possibly a mix of hard copy and digital maps generated by CAD software. Not only is the information segregated by the different computer formats, it is also segmented on a project-by-project basis.

This segmentation of the data has often led to the duplication of labor-intensive data entry. Furthermore, once the data is compiled, it may be equally labor-intensive to retrieve, produce reports of, or compare with other historical data or related information provided on other projects. One solution to these problems is to integrate the multiple data formats and projects using GIS software as a management tool.

Asbestos Management at the U.S. Navy
One example of using GIS as a management tool is the Asbestos Operations and Maintenance (O&M) Management Application created for the Naval Air Engineering Station (NAES) in Lakehurst, New Jersey. The goal of the project was to create a customized GIS application which would integrate all the asbestos survey data from the O&M program that would allow safety managers, tradespersons, and maintenance personnel crews to quickly locate, analyze, and update the appropriate information.

The setting for the project was a common one. Three separate asbestos surveys had been completed on the base by two different companies. As expected, some of the data were in digital form, while other data existed only in hard copy. Information about the asbestos sampling points was available in several database files, but the maps and building floor plans were not linked to these files. Thus, managers had to consult several sources to find the asbestos data, but there was no easy way to manage it.

Choosing Software
One of the first challenges of implementing a GIS is selecting the proper software for the application (EM, a magazine published by the Air & Waste Management Association, recently listed 1,900 software products designed to help environmental managers, of which well over one hundred claimed to have a GIS component.) For the NAES asbestos management application, the choice was ArcView GIS developed by Environmental Systems Research Institute (ESRI) based in Redlands, California. Not only was ArcView software a good fit for the application, it was also cost-effective since the Navy currently uses ESRI software for other applications.

Getting the Data Into the GIS
The first task was to import the available digital data into ArcView GIS. The Navy's digital base map files included roads, runways, hydrography, and buildings. These map layers were brought into ArcView to create a base map which would serve as the reference point for the asbestos management tasks. Next, the asbestos survey information was normalized and combined into a single database file. This "complete" database was then linked to the buildings on the map. If a manager selected a building on the map, all the asbestos database records relating to that building would be highlighted in the asbestos database table.

While the ability to do this simple selection was helpful, the Navy wanted to take the management a step further by locating the asbestos sampling locations on the floor plans. This involved bringing AutoCAD drawings into ArcView and creating a map layer or "theme" for the asbestos sample points. Each sample point was given a unique identification number which corresponded to the sample number in the asbestos database file. Now the database file could be linked to points indicated on the floor plans, giving managers a better idea of exactly where asbestos had been found in the building. In addition, the asbestos sample points could be color coded to indicate presence of asbestos, its condition, accessibility to employees/public and other characteristics provided by the database.

Creating a Customized Application
Because the Navy wanted some additional functionality in the GIS, plans were developed to create a customized application using both Visual Basic programming and Avenue Scripts, the programming language used by ArcView. The plans specified that the application had to provide quick access to the data, be easy to use, and still provide all the analytical capabilities managers would require.

In order to make the application user-friendly, basic menu options were created which allowed the managers to specify which building, floor plan, homogeneous area, or sample point they wished to access. When a selection is made, the application automatically loads the proper map layers, CAD drawings, or database files and allows the user to review or manipulate the data. Managers can even view a photograph of the building as a reference check.

Although the visual display of the asbestos information is useful, the true value of the customized application is that it automatically summarizes the sampling data. For example, the manager may summarize all the data on a particular type of asbestos on the base to find out the total quantity of the material and generate cost estimates for remediation or removal. A manager may also summarize the data by selecting a building, a particular floor of that building, or a specified homogeneous area. Finally, when the analysis is complete, the manager has the option to print the maps, floor plans, or database files for use in the field or for training purposes.

Other GIS Applications for Safety and Health
The uses for GIS are too numerous and diverse to list. A few examples include

• monitoring indoor air quality through management of survey data
• managing hazardous materials such as lead used in paint or from aging water systems
• tracking acid rain and other air pollution problems
• monitoring ground water quality around landfills or industrial sites