Over 700 schools in Washington state have been rated for having poor ventilation systems

Data from the Washington Office of Superintendent of Public Instruction show that 787 school buildings across the state have “poor” ratings for their heating, ventilation and air conditioning (HVAC) systems.

The state requires school districts that receive state money for building upgrades to file inspection reports on HVAC systems for all their buildings, reports King 5 News.

Officials say most of the problem buildings were constructed before 1991 when new building codes that required improved ventilation went into effect.

One of the lowest-rated school complexes on he state's list is Tyee Park Elementary School in the Clover Park (Wash.) district in Pierce County.

It was constructed in 1958 building and additions were built in 1961 and 1991.

Test results from February show seven of the school’s buildings, including its classrooms, gym, and administration building, are in the lowest range of a “poor” rating.