1.   He claimed his research had shown links between high-voltage overhead cables and cancer clusters.

2.   But the scientific establishment has largely dismissed the notion that such cancer clusters can be traceable to environmental causes.

3.   Cases of the often-curable cancer have been grouped by geography as a cancer cluster before, while what may have triggered them remains either hidden or unrelated.

4.   Clinton, for instance, came to Fallon on Thursday because of unexplained cancer clusters in New York state.

5.   Despite the concerns of some residents, in most cases researchers have yet to show any definitive link between cancer clusters and environmental factors.

6.   Experts note that pinpointing the cause of cancer clusters can be impossible.

7.   In most cases of alleged cancer clusters, scientists are wary of identifying an absolute cause of illness.

8.   Many believe that there is no such thing as a residential cancer cluster, that neighborhood variations are essentially random.

9.   Paul Brodeur, a New Yorker magazine writer who reported on apparent cancer clusters in Connecticut and California, is their main transmitter Tuesday night.