Clean technology will be expensive, and a country facing a demographic time bomb in a decade or so cannot afford to waste a single percentage point in GDP growth to clean up its environment.
Though North Korea openly admits making nuclear weapons using plutonium, it has still not come clean about its pursuit of the uranium route to the bomb, even though Pakistan's former chief nuclear scientist, Abdul Qadeer Khan, has reportedly said he sold Mr Kim's regime some uranium-linked nuclear secrets.
But the blocks around the bomb sites remain closed to the public while Boston officials clean up the area and make sure the buildings are safe to occupy.