Pulmonary edema occurs when the alveoli fill up with excess fluid seeped out of the blood vessels in the lung instead of air. This can cause problems with the exchange of gas (oxygen and carbon dioxide), resulting in breathing difficulty and poor oxygenation of blood.
Currently buildings are limited to a height of 200 meters and are subject to not contrasting the view of Mount Royal, the city's central green space, with the only exception being antennas and communication towers, that are allowed to reach 223 metres (732 ft) above mean sea level.
List of all cities by number of completed or topped out skyscrapers[edit] This is a list of cities by number of completed or topped out skyscrapers. The majority of international organizations, such as the CTBUH and Emporis, define a skyscraper as a building that reaches or exceeds the height of 150 metres. Some skyscraper definitions draw the lower limit at 150 metres (492 ft).