by Yussel Gonzalez MEXICO CITY, Mexico (AFP) — A major construction project in wetlands seen as one of the “green lungs” of smog-choked Mexico City has raised concerns for the future of the UNESCO World Heritage Site. A more than 1.7-kilometer (one mile) long reinforced concrete bridge is being built on a freshwater lake system that helps to regulate the temperature and prevent flooding in the city of nine million people. Hundreds of trees have […]