Is This Really A Cluster, Or Are The Italians Just Paying Attention?

http://www.earthtimes.org/articles/show/259620,lou-gehrigs-disease-hits-another-retired-footballer.html

Rome - A retired Serie B footballer has said he contracted amyotrophic lateral sclerosis (ALS), a nervous-system disease with an unusually high incidence among former Italian players. Italian media reported Thursday that Stefano Turchi, 40, a forward with Ancona between 1990 and 1992 has suffered from ALS since 2005.
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Researchers studying ALS have found that the incidence of the disease among footballers is about 18 times higher than among the general Italian population. Some 40 former footballers have been diagnosed with ALS in recent years, although it remains unclear what may have caused their illness.