In 1988, my father died of amyotrophic lateral sclerosis [ALS], also known as Lou Gehrig's Disease. It is a degenerative disease of the nerves, destroying motor control; it is nearly always fatal (although Stephen Hawking's atypical ALS is one of the exceptions). My father was 54 at the time of his death -- four years older than I am now.

No one knows what causes ALS. In something like 8% of the cases, heredity appears to play a part. And there are some indications that environmental factors make a big difference.

If the situation in Middleboro, Massachusetts reported by the New York Times is any indication, environmental factors may play a more important role than we knew.

Dozens of cases of ALS have shown up in this Massachusetts town. Industrial pollutants were a common problem in Middleboro, and now the town is being studied as a "disease cluster."

How unusual is it to have dozens of cases show up in one area? Each year, roughly 5,600 cases of ALS are diagnosed in the U.S., according to the ALS Association. That there should be a large cluster in Middleboro (unless they're all originally from Guam) is so unlikely that very little except environmental toxins could account for the numbers.

I think...I will not buy a summer house in Middleboro. Or visit one, either.

[Corrected...to change the town name back to Middleboro...from Mashpee, which I had typed in error.]