ABSTRACT
Data sets concerning components of environmental toxicity are available in a number of data bases; however, their quality and extent of coverage is highly variable. With any data set (presented in electronic or paper format), it is important first to examine the set for interesting or unusual patterns in the display. These patterns often influence decisions in choosing subsets of data and tools to analyze subsets. This chapter focuses on the problem of limiting data selection by choosing comparable regions from different parts of the world: what is true for both regions on one variable may not be true for both on another variable. Another toxicity variable with an extensive time series in the data base involves industrial CO2 emissions. The chapter views the Danube region within the larger context of the entire set of countries for which there is data on SO2 emissions.
