was a clinical fellow at harvard in the mid-1990's, i learned about a cancer cluster in nearby and wooburn, massachusetts. 12 children got leukemia over a period of a few years. most of them lived on just one street in a certain section of town. that cluster, like many, was not discovered by a state or federal agency or scientist but was discovered by community members who recognized each other when they were sitting waiting and waiting room at the cancer institute. ultimately, this cluster was confirmed by scientists and it provided a very key clue. it was the first time that the chemical tce was linked with cancer in humans. an abundance of science since that time has multiply confirmed that link. the cluster provided a clue that helped science move forward. this senate committee held a field hearing in april, 2001, in the town of fallon, nev., where many children were diagnosed with leukemia. scientists published a paper calculations at a cluster of this magnitude would occur in the united states by pure chance about once every 22,000 years. that cluster in nevada provided clues. testin