chapter  2
- Environmental Factors
Pages 10

Researchers are looking for aspects of lifestyle that can interact

with genes to cause or contribute to ALS. The notion that ALS could

be linked to viral infection is a concept that reappears periodically

when researchers focus on the issue. Exposure to toxins and the

influence of intense exertion are ideas researchers consider as

possible reasons for the finding that some veterans and some

athletes have increased incidence of ALS.