This Italian surname Baruta is indeed most concentrated in Sondrio, Lombardy, a rare surname. The surname Baruta is also concentrated in the region of Padova. A variant surname I found is Barutta, also most concentrated in Padova and in the area of province Como, Lecco, and Varese. The province Sondrio borders Como and Lecco, perhaps meaning that Barutta is a variant of Baruta. Variants of the Baruttas of Padova include the more common surname Barutto and Baratto. Perhaps the surname Baratto is a variant of the much more common surname Baratta. The meaning of the surname Baratto/Baratta is "exchange". More of the origin and meaning of Baratta can be found here (http://www.ancestry.com/facts/Baratta-family-history.ashx
). All of the variants above are most concentrated in Northern Italy, except for Baratta, which the surname is also established in Southern Italy. So, perhaps the Baruta of Sondrio, Lombardy is a variant of the more common surname Baratta, the surname Baratta being most concentrated (Northern only) in the province Asti, and in the area of province Massa-Carrara, La Spezia, and Parma. This surname Baratta is also found in province Sondrio.
Now, the Polish surname Baruta is quite rare, but perhaps a variant of the much more common Polish surname Boruta. Variants include Boroda, and the surname Boruta/Boroda is derived from Broda, a personal name. Broda also means "beard", perhaps a nickname for someone with a "beard". More information can be found here (http://boruta.ca/history.htm