Can I get a virus from the list? No. It is absolutely impossible for a virus to be transmitted via a message sent through the Arlington list. This is because the Arlington list software delivers only plain text, and filters out attachments and scripts, which is how viruses are delivered.
However, you can get a virus from any individual with whom you correspond by e-mail. So if you correspond with an individual on the Arlington list, you may receive a virus from that person. And there are viruses which pretend to be from people who are in the address book of the infected person. So you may receive a virus which appears to be from someone you know from the Arlington list, but is really from someone whose address book contained that person. In the same way, other people can get a virus which appears to be from you but is really from someone with whom you've corresponded.
It is also possible to get a virus from a web site, so if you click on a link contained in an e-mail, and you visit the web site that the link points to, and that web site is malicious, you may get a virus that way.
The bottom line: if you subscribe to the Arlington list but never correspond with anyone on the list or post to the list, and you never click on any links in e-mails posted through the list, there is no way you can get a virus either from the list or from anyone on the list.
Everyone should take measures to prevent virus infection: running virus-scanning software is one good way to do this.