Virtual Pollution; January 1996; Scientific American Magazine; by Nemecek; 1 Page(s)

Checking water quality was once a simple matter of sample jars and chemical tests. But these days many researchers no longer pull out the litmus paper--instead they just turn on their computers. Simulations of air, soil and water contamination are increasingly being hailed as cheap and efficient ways of studying the environment. And as recent findings regarding the Chesapeake Bay indicate, computers can demonstrate complex interactions that simply cannot be determined using other methods.

Computer modeling has revealed that approximately 25 percent of the nitrogen in the Chesapeake comes from air pollution wafting in from as far away as western Pennsylvania, Ohio and Kentucky. This finding alters the current perception that the bay's greatest problems stem from more local waterborne pollution, such as sewage and runoff from agriculture--which conservation efforts now seek to lessen.