Sundström is a Swedish surname, a compound of the Swedish words sund (sound; passage of water) ström (stream and/or stream in water) Geographical distribution. As of 2014, 79.2% of all known bearers of the surname Sundström were residents of Sweden (frequency 1:1,192) and 19.5% of Finland (1:2,697). In Sweden, the frequency of the surname was higher than national average (1:1,192) in the following counties: 1. Norrbotten County (1:244) 2. Västernorrland County (1:356) 3. Västerbotten County (1:424) 4. Jämtland County (1:654) 5. Gävleborg County (1:761) 6. Dalarna County (1:784) 7.
https://en.wikipedia.org/wiki/Sundstr%C3%B6m