A high prevalence of animal hair in primary school classrooms may be triggering children's asthma attacks and other respiratory distress, a study has found.

The He Kura Asthma study, published in the New Zealand Medical Journal, involved collecting floor dust samples from 136 classrooms in 12 primary schools around the country.

Findings showed cat allergens, which are commonly found in hair and saliva, were detected in a quarter classrooms. Cow and horse allergens were also common.

The study's lead author, associate professor Rob Siebers, said these levels of cat allergen were most likely due to passive transfer from children's clothing, as there are generally no cats on school premises.


Researchers suggested the high levels of cat and other animal hair could be linked to respiratory symptoms.

They recommended better cleaning practices and smoother flooring options, as opposed to carpet, in all schools to help reduce allergic reactions or asthma attacks in a school environment.

Allergy New Zealand chief executive Mark Dixon endorsed the removal of carpets in schools, saying it was "common sense" given the amount of dirt and smells that stay buried in carpet.

"The only downside to this is noise, but I think that's a small price to pay for children's health," Dixon said.

He said it was surprising the study found a low level of dust mites and peanuts in classrooms, given how common those allergies were in New Zealand.

"This is pleasing to hear," Dixon said.

Only one of the classrooms had measurable levels of peanut allergen, but these were also at such a low level as to be barely detectable.

However, intervention studies were needed to show the benefits of replacing carpet with smooth flooring in terms of health outcomes.