John, It did not work on the MAC so I modified it to the below and I get a compile error because it does not like the .Fill.PicturreEffects (says Method or Data member not found)

Sub Blur()
Dim oSl As Slide
For Each oSl In ActivePresentation.Slides
With oSl.Shapes(1)
With .PictureFormat
.Fill.PictureEffects = msoEffectBlur
.Fill.PictureEffects(1).EffectParamers(1) = 10
End With
End With
Next
End Sub

Anyone with MAC input please advise!!