A couple of links on CO:
http://www.eurekalert.org/pub_releases/2002-12/uot-nfm120302.php
http://www.eurekalert.org/pub_releases/2007-01/joci-cmp011807.php
http://www.eurekalert.org/pub_releases/2007-03/foas-hau031307.php
http://www.eurekalert.org/pub_releases/2006-09/bidm-trf091806.php
http://www.eurekalert.org/pub_releases/2006-09/ajop-wpp090106.php
http://www.eurekalert.org/pub_releases/2006-09/qu-cmm090506.php
http://www.newswise.com/articles/view/519262/
http://www.newscientist.com/article/dn11036-carbon-monoxide-may-protect-against-ms-symptoms.html
Regards,
Joachim