M-Zone Since the last major overhaul of New York City zoning ordinance in 1961, there have been many zoning map changes, especially affecting Manufacturing, or M-zones. These are primarily industrial and are the only zones in which waste-related facilities can legally be located. The South Bronx, where over 90 percent of residents are Latino or African American and almost 50 percent live below the poverty line, has been stuck in a sort of time warp. The disproportionate share of M-zones in the South Bronx has rendered it unable to develop along with other parts of the city. With current development proposals underway, it is only a matter of time before gentrification completely alters the landscape of one of the few places left in New York City that has for better or worse stayed left behind.