From libertarian Michael A. LaFerrara:
To my knowledge, Rand didn’t spend much time specifically on the issue of pollution. But given that her political philosophy is grounded in the principle of individual rights, it logically follows that she would believe that anti-pollution laws have their place in a free, industrial society.
And she did have a few things to say explicitly on pollution and the government’s role:
As far as the issue of actual pollution is concerned, it is primarily a scientific, not a political, problem. In regard to the political principle involved: if a man creates a physical danger or harm to others, which extends beyond the line of his own property, such as unsanitary conditions or even loud noise, and if this is proved, the law can and does hold him responsible.