An expert system platform supporting multiple and customizable taxonomies is useable in a number of applications. In one embodiment, the expert system platform includes a plurality of libraries and a plurality of study tables with each being related to a corresponding library. Each of the plurality of libraries corresponds to one of the number of applications and has a question table having a plurality of questions and an answer table having a plurality of answers, each of the plurality of answers is related to one of the plurality of questions, wherein a user of the expert system qualifies for one or more studies or clinical trials based on responses provided by the user. In another embodiment, the expert platform system is useable to identify an individual's potential exposure to chemical, biological, and/or nuclear contamination in a rapidly changing environment.