Schools out indefinitely for Codwell Elementary School students — at least until the district has cleared up the mold problem found behind the walls.

The students will instead be sent to another campus in August after the fungus was discovered, by renovation work crews, infesting the inner walls.

Molds are fungi that are found everywhere—indoors and out—and it is unknown how many species exist. Estimates range from thousands to 300,000 or more. They can enter a building through open doorways, windows, vents, and heating and AC units and thrive anywhere that provides it with plenty of moisture. Generally, mold is found around leaks in roofs, windows, pipes, or where there has been recent flooding.

Sheleah Reed, spokeswoman for the Houston Independent School District, said the elementary school will open Rhoads Elementary School to the students — located just two miles down the road.

“The mold was contained in sealed areas behind walls and only exposed as part of the construction work,” Reed said in an email statement.

Although the mold was supposedly contained, a few are still concerned about the underlying health risks associated with the fungus. In 2004, the Institute of Medicine found sufficient evidence linking indoor mold exposure with respiratory tract symptoms such as coughing and wheezing.

Other health issues from mold exposure include itchy eyes, serious allergic reactions, asthma, and permanent lung damage. Nearly $3.5 billion has been spent every year to treat mold-related asthma in the U.S., and the Codwell Elementary School assures that no students will be subject to these health issues.

Codwell Elementary School was built in 1970 and received $1.7 million in order to perform needed renovation work on the school. This money was approved under the district’s 2007 voter-approved bond issue.

There are three categories of mold that can be found in a building. Allergenic molds do not usually produce any life threatening symptoms and whatever symptoms they do cause they are generally mild. Pathogenic molds product some type of infections, usually respiratory. Toxigenic molds can affect almost everyone, causing short-term irritation to the immune system and have been linked to cause cancer.

Fortunately for Codwell, the mold issue is already being taken care of and the students will be returning to their old premises.