Edit .bash_profile and add:
echo 'ALERT - Root Shell Access on:' `date` `who` | mail -s "Alert: Root Access from `who | awk '{print $6}'`" your@email.com
Edit .bash_profile and add:
echo 'ALERT - Root Shell Access on:' `date` `who` | mail -s "Alert: Root Access from `who | awk '{print $6}'`" your@email.com