Now if a shopkeeper may not sell in his store, nor may a craftsman labor in his workplace because of noise and disturbance, how can they earn their livelihood? Halakhah permits them to teach Jewish children in their residence. Their neighbors may not protest and say to them:“We cannot sleep because of the loud noise of the school children!” And so it is with every matter of mitzvah that one may not protest about noise.’
Now do not school children produce cacophony as great as or greater than a store or workshop? Why is the classroom permitted while other work spaces are forbidden? Nahmanides said that a school class would not be considered a disturbance unless it exceeds fifty children.”
Notwithstanding the Ramban’s ruling, anyone who has taught or attended a class room of forty to fifty children would certainly be aware of the loud commotion. Would the noise be greater than that of a store or a craftsman’s shop? Indeed, it might exceed them by many decibels. The answer is that in such a matter, where a great mitzvah is involved, the children may learn and the neighbors may not protest.
Furthermore, we may ask how these storekeepers and craftsmen became Torah teachers for little children. Every Jew is required to study Torah all of his life, so what would be a more natural vocation for an unemployed person?
Pollution
Many regulations were made by the halakhah to prevent pollution and contamination. It was forbidden to make a permanent threshing floor less than 50 cubits(28 meters or 30.6 yards) from the border of a town, so that the wind would not carry the chaff when the owner winnows, that is, clears away the chaff from the grain. Graveyards, carcasses and tanneries must be kept 50 cubits from the town. A tannery may be set up only on the east side of a town, because the east wind is mild and reduces the unpleasantness of odors produced by tanning the hides."
If someone does construction work on a threshing floor or a privy on his property that raises dust or particles of earth or causes a stench, one must do so at a distance so that the dust and the stench will not reach his neighbors, even if an ordinary wind is carrying these damaging elements."