Ignorance is bliss. Contaminated soils abound across the industrialized world, it's just that most people have no idea.

Moreover, there's legitimate pressure to keep it that way as people irrationally freak out when they learn something is "contaminated". It turns out that often times the best way to promote soil remediation is to turn a blind eye (at least to some extent), as once contamination is identified costs sore through the roof as people begin demanding ever onerous mandates, which is why lead thresholds are set considerably lower than for other similarly problematic contaminants.

Just this past week we called up the city inspector to ask him to check out some painting work being done at a house whose yard abuts our own. We've done it before as we have two young children. The inspector is very nice and accommodating, and there's basically zero risk of anyone getting fined or handed any stop-work order. He simply nudges the painters to take the barest of safety measures, e.g. tarping, to prevent leaded paint flakes from dispersing. And what more can you ask? Turning every house scraping job into a super fund site would just be ridiculous, but if the law treated lead the same way it treated nuclear, that's exactly what would be demanded.