No dust mites, lots of cat dander in New Zealand classrooms - study

New Zealand classrooms are a minefield for allergens, especially cat dander, a study has found.

Dust samples collected from 136 classroom floors at 12 primary schools across New Zealand found cat, horse and cow allergens.

Cat allergens were found in every single classroom studied, while horse allergens were in 82 percent of classrooms, and cow allergens in 37 percent.

Three classrooms had low levels of cockroach allergens and one had traces of peanuts. The study found few instances of dust mites.

University of Otago researcher, associate professor Rob Siebers, told Newshub traces of cat was the most common.

"About a quarter of the classrooms had levels high enough that could potentially cause respiratory symptoms in asthmatic children."

Dr Siebers said vacuuming would be the best solution, or replacing carpet with smooth flooring to prevent allergens getting stuck.

"The other thing that you could possibly suggest is for parents who send their children to school in newly washed clothing."

It's believed the allergens appeared in schools due to passive transfer from students clothes, as there are generally no cats inside schools.