Block · one region of the page, as the scanner read it. It may hold a whole story, part of one, several, or an advertisement; stitching blocks into articles is the next step. Text is supplied OCR.
Page 3 · column 4 of 7 · from the scan, no model involved
cracks in foundations, crawlspaces, sewer vent pipes and buried conduits.
As with any radiation source, lengthy exposure is believed to cause cancer in humans. In homes, it creates a problem when it is breathed into the lungs, where it causes damage to the nuclei of the cells which line the lungs, eventually causing lung cancer.
The presence of radon gas is measured in picocuries per liter of air (pCi/1). The Environmental Protection Agency has established 4 pCi/1 as the safe limit. That is roughly equivalent to the radiation
92.1%