Bonnie, I get headaches from xylene the first few days I return from being 
gone from the lab for 3 weeks or more.   And all the aches and pains most of 
seem to have is due to the repetitive motion involved in our jobs and lack of 
knowledge of ergonomic postures, furniture and instrumentation.  And age also 
plays an important role in all these repetitive motion induced problems.  
pearl