What are the health risks of asbestos?

Asbestos-related health concerns forced the closure Tuesday of  New York's Madison Square Garden and the postponement of a  Knicks' game.  During overnight maintenance at Madison Square that included cleaning asbestos-related materials in the attic, "some debris fell into the arena," according to a statement released by the team.

Microscopic asbestos  fibers can embed in lung tissue and  can cause serious lung diseases and respiratory problems.

The New York City's Department of Environmental Protection said the agency's inspectors determined no asbestos was released, according to CNN affiliate WPIX.   And Madison Square Garden told the station that crews were working to make the venue safe for reopening.

Asbestos, a natural mineral fiber, was used in the United States for building construction materials such as roofing shingles, fire-retardant fabrics, cement, and some vinyl floor tiles. In 1989, EPA issued a final rule banning most asbestos-containing products.

EPA recommends that asbestos-containing material that is  intact should be left alone as it generally does not pose a health risk.  But when the material is damaged or disturbed, this can release microscopic asbestos fibers.  The area would need to be isolated until asbestos professionals can assess the situation.

The greater the exposure to asbestos, the greater the risk of developing health effects, according to the EPA.  Here are some of the health risks:

Asbestosis is a non-cancer disease of the lungs, causing scarring that makes it harder for oxygen to get into the blood and causes a crackling sound in the lungs.

Lung cancer related to asbestos exposure has been known to affect people who have had exposure to the substance.

Mesothelioma is a rare form of cancer in the thin lining of the lung, chest, abdomen, and heart, and almost all cases are linked to exposure to asbestos.   Read more on asbestos here.