Yeah, safety is a big issue.
Even on our field down here, we have old metal pieces, and some fencing, along with other things scattered around. We generally try to avoid these spots for the most part... as it's been a slow process, and unfortunately, when it comes time for us to ask everyone that plays down here for a bit of help and clean up... we usually don't get a very great response from players.
Our field is very big though, and there's just alot to do, especially with a little bit done at a time.