I don't think it's a security issue. possible causes are:
- you responded to something online- maybe a survey- and your email address was then passed on to spammers who in turn pass it on
-your email address has been printedon a forum
- your email addrss is easily guessable or one that be geneerated easily -eg
[email protected]
- one of your friends has had a virus that has harvested email addresses from his/her address book
One thing you could do is change your email address or use a disposable email address for anyone you don't know well. But once you get on spammers' lists you'll continue to get more and more spam