had been contaminating

• past perfect progressive

  past perfect progressive

  Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.

  of contaminate.
  contaminate

  verb (used with object)

  to make impure or unsuitable by contact or mixture with something unclean, bad, etc..

Related Words

• corrupt
• harm
• infect
• injure
• poison
• pollute
• stain
• taint
• tarnish