The pollution of waterways is one of the most serious problems
facing environmental researchers (and the rest of us) today. 
Billions of dollars are being spent on cleaning efforts, 
antipollution laws have been passed, technological innovations 
have tried to prevent pollution, and the public is becoming 
more and more aware of the problems. Accurate prediction of 
future levels of pollution based on current levels would be a 
great boon to those determining antipollution strategies. The 
data we will study is based on 1984 and 1985 concentrations of 
PCBs (polychlorinated biphenyls), measured in parts per billion, 
found in 37 U.S. bays and estuaries. The first column contains 
the bay names, the second the 1984 data, and the third the 1985 data.

These data come from the publication "Environmental Quality 1987-1988"
by the U.S. Council on Environmental Quality.