The Collaborative International Dictionary of English v.0.48:

contaminating \contaminating\ adj.
   spreading contamination; especially radioactive
   contamination. clean

   Syn: dirty.
        [WordNet 1.5]

   2. causing moral or behavioral degredation. the contaminating
      influence of violent movies

   Syn: corrupting.
        [WordNet 1.5 +PJC]

The Collaborative International Dictionary of English v.0.48:

Contaminate \Con*tam"i*nate\ (k[o^]n*t[a^]m"[i^]*n[=a]t), v. t.
   [imp. & p. p. Contaminated; p. pr. & vb. n.
   Contaminating.] [L. contaminatus, p. p. of contaminare to
   bring into contact, to contaminate, fr. contamen contagion,
   for contagmen; con- + root of tangere to touch. See
   Contact.]
   To soil, stain, or corrupt by contact; to tarnish; to sully;
   to taint; to pollute; to defile.
   [1913 Webster]

         Shall we now
         Contaminate our figures with base bribes? --Shak.
   [1913 Webster]

         I would neither have simplicity imposed upon, nor
         virtue contaminated.                     --Goldsmith.

   Syn: To pollute; defile; sully; taint; tarnish; soil; stain;
        corrupt.
        [1913 Webster]

WordNet (r) 3.0 (2006):

contaminating
    adj 1: spreading pollution or contamination; especially
           radioactive contamination; "the air near the foundry was
           always dirty"; "a dirty bomb releases enormous amounts of
           long-lived radioactive fallout" [syn: dirty,
           contaminating] [ant: clean, uncontaminating]
    2: that infects or taints [syn: corrupting, contaminating]