They were not often near oil refineries, or other sources of industrial polution. At best, you could argue that they were more often closer to it than the districts marked as "best" or "still desirable", but in all, very few of redline neighborhoods were close to industrial pollution. Go look at the actual maps https://dsl.richmond.edu/panorama/redlining/ and see for yourself. Typically, the redlined neighborhoods are conveniently located close to downtown.
> Rural houses where a more sound investment when 40% of the USA employment was agricultural. As the this industry became more automated, the value shifted with employment opportunities. These changes can also be seen in towns and cities built around manufacturing today.
In the context of redlining, observe that agricultural employment was already at around 20% when redlining started, and 5% when it ended, and also the redlined neighborhood were the ones with best commutes and job availability. This is still true, by the way: the ghetto parts of the American cities almost universally are centrally located, close to jobs and facilities, and they are well served by transportation infrastructure (in fact, this is one of the activists biggest complaints: that they're too close to freeways).
