LINZER historically developed within sealed domes of the type common to marginally-habitable planets.  The hereditary oligarchy that owns all of the domes brought with them a population of indentured servants who were promised newly-constructed domes of their own in return for a lengthy period of labor.  So new domes are constantly being constructed, and no one ever declines the opportunity to move into a new one.  The older domes, in addition to being overpopulated, are also intentionally polluted by the oligarchs, who pump in waste products and genetically-engineered vermin on a regular basis.  They do this as part of "experiments" to find out how people deal with such inconveniences, and perhaps to eventually develop a society that is immune to them.  Such is the depth of their commitment to future generations that they are willing to supervise such experiments for as long as is necessary.