Before going too far with this hypothesis, its worth considering that general conscription doesn't mean that everyone has combat experience in Gaza - there are a lot of people whose military service involves office work, or patrolling quiet borders, etc. It may be that this sperm bank has a high proportion of combat veterans because getting into a top combat unit is something that many of the best male Israeli high school students aspire to, but in general, a lot of people serve in the IDF in positions that wouldn't expose them to DU.
This is especially true of older people doing their mandatory reserve service. My understanding is that if you have a particular skill, the IDF will find a way to use that. Actors get reserve duty entertaining soldiers, professors get reserve duty in the IDF education department, etc.
They aren't in the business of transporting human beings, but they are in the business of transporting and storing things that are really, really important to human beings. Their financial information. Their family photos, records of who they talked to and what they said, etc. Real human beings got hurt when Yahoo handed over information about who they were talking to to the Chinese government. If you spend 99 cents on an MP3 from Amazon and something goes wrong you'll almost certainly get a really good customer service experience. There's no reason that a company you're trusting with all of your communications can't have the same level of service.
In the last ten years Connecticut Light & Power made major cut backs on trimming the trees near its power lines. The state got slammed by a huge snowstorm last Holloween and a huge portion of the state lost power - for as long as 10 days. Not only did CL&P suffer a financial and public relations disaster in the aftermath of the storm, they decided to double their tree-trimming budget for the next year. But this just led to further problems - people who weren't used to the power company coming in with chainsaws created a fuss at town meetings about CL&P removing or damaging their trees, leading to more ongoing PR problems.
This is especially true of older people doing their mandatory reserve service. My understanding is that if you have a particular skill, the IDF will find a way to use that. Actors get reserve duty entertaining soldiers, professors get reserve duty in the IDF education department, etc.