A Harvard author is challenging the wisdom of one long-held EPA standard. “One in a million” is a phrase often used by the EPA in describing a risk of exposing humans to a chemical, referencing the standard applied to cleaning up spills and discharges. The agency seeks to clean up a problem such that if a person were exposed at that location for decades, that he or she would have a one-in-one-million chance to die or contract a disease from that exposure.

But in their recent book, Risk-Benefit Analysis, 2nd edition, Richard Wilson, a professor of Physics at Harvard University, and Edmund Crouch of Cambridge Environmental Inc, compares the EPA's one-in-a-million exposure concept with a number of common risk factors. According to the book, a person practicing the following activities have a one in a million chance of contracting cancer.

• Eating four tablespoons of peanut butter every 10 days.
  
  
• Eating one hundred 1 gram servings of brown mustard.
  
  
• Eating 35 slices of fresh bread.
  
  
• Eating 350 slices of stale bread.
  
  
• Drinking 70 pints of beer a year.
  
  
• Drinking water with EPA's former limit of arsenic (50 ppb) for three days.
  
  
• A non-smoker living in a home with a smoker for two weeks.
  
  
• Smoking two cigarettes.