Why is my PDF export appearing with vector path lines on my image?

[Friscodobe]

Hi there, 

I'm fairly new to illustrator and need to export a vector image to print onto a billboard. For some reason, the image/photograph, which I've manipulated and vectorised seems to export with all the path lines in it. Can you help me rectify this? I've tried rasterising the image, which removes the lines but then it doesnt look vectorised. Attached are two images: one is the working file in illustrator and the other is the exported pdf. Looking for solutions if possible. Thanks, EJ 

[Monika Gause · Accepted solution]

Those are anti-aliasing artefacts.

What you could try: Rasterizing it while you still have not expanded the Live Trace

Or: use the Tracing method "Overlapping" instead of "Abutting"