Brodno (doesn't mean "dirty", maybe "brudno" does),
Exactly. It is not Brudno, but Brodno. It has the same root as Brodnica, both place names stemming from a word "bród" - "a river ford".
wola, in latin "libera villa" or "libertas" - a settlement established under a foundation of "wolnizna", which means that its settlers could use the land for some number of years free of charge. Depending on the conditions in the area being settled "wolnizna" could take up to 20 years. During that time the settlers had to be built cottages, often the church, and - above all - clear the assigned area, or dry it up, so it will be suitable for agriculture.
There are 10 villages "Wola" in Poland. But there are also about 100 place names or so, with an adjective preceding or following the name "wola", such as "Żelazowa Wola" - a birthplace of Frederic Chopin. The adjective usually indicates an owner of the settlement, or a name of original village where the settlers came from - such as "Zduńska Wola" (from Zduny) - but it may also mean something else.
Among many interesting "wola" names there are:
Boża Wola
Kotowa Wola
Kozia Wola
Wola Węgierska
Żabia Wola
Check the wikipedia: pl.wikipedia.org/wiki/Wola