A modern redrawing of the 1807 version of the Commissioner's Grid plan for Manhattan, a few years before it was adopted in 1811. Central Park is absent.
One neighborhood of New York County is contiguous with The Bronx. Marble Hill at one time was part of Manhattan Island, but the Harlem River Ship Canal, dug in 1895 to improve navigation on the Harlem River, separated it from the remainder of Manhattan as an island between the Bronx and the remainder of Manhattan. Before World War I, the section of the original Harlem River channel separating Marble Hill from The Bronx was filled in, and Marble Hill became part of the mainland.
There are cracks in the foundation. Nothing structural. Nothing that’s going to threaten the stability of the home, salve but they’re there. Nooks, medications crannies and holes through which seeps an invisible threat. Colorless, odorless and undetectable by your average human, it is nonetheless the second leading cause of lung cancer in the United States.
Radon gas – even the name sounds ominous, evoking images of radiation and nuclear devastation. Radon gas is created when uranium in the soil decays. The gas then seeps through any access point into a home. Common entry points are cracks in the foundation, poorly sealed pipes, drainage or any other loose point. Once in the home, the gas can collect in certain areas – especially basements and other low-lying, closed areas – and build up over time to dangerous levels. The Environmental Protection Agency of the US Government has set a threshold of 4 pico curies per liter as the safe level. As humans are exposed to the gas over a period of years, it can have a significant and detrimental effect.