Nobody likes cockroaches. They’re the uninvited guests that scatter when the kitchen light flicks on, and somehow, no matter how clean you keep your place, one always finds a way in.
But according to new research from North Carolina State University, getting rid of them isn’t just about comfort or hygiene. It might actually make your indoor air healthier to breathe.
Researchers found a clear link between the size of cockroach infestations and the amount of allergens and endotoxins in homes. And when pest control measures reduced roach numbers, both allergens and endotoxins dropped significantly.
That’s a big deal.
Because endotoxins, tiny fragments released when bacteria die, can mess with your immune system and even trigger allergic responses.
And cockroaches? They’re walking factories for the stuff. Their guts are teeming with bacteria, and as they go about their business (yes, literally), they shed those endotoxins into your environment, mostly through their feces.
In this study, scientists tracked infestation levels across multi-unit apartment complexes in Raleigh, North Carolina. They collected dust samples from floors and the air, and measured both allergen and endotoxin levels. Unsurprisingly, the homes crawling with roaches had much higher concentrations of both.
And here’s an interesting twist:
Female cockroaches produced about twice as much endotoxin as males. Why? Simple, they eat more, which also explains why kitchens, where food is abundant, had higher levels of contamination than bedrooms.
When exterminators stepped in and successfully eliminated the infestations, something remarkable happened. Not only did allergen levels plummet, but endotoxins did too. Homes that didn’t get treatment, on the other hand, stayed just as toxic.
As Coby Schal, a distinguished entomology professor at NC State and one of the study’s authors, put it, “When you eliminate cockroaches, you eliminate their allergens. Small decreases don’t help because the remaining ones keep depositing more.”
In other words, it’s not enough to “reduce” the problem. You’ve got to get rid of them completely.
Cockroach milk is more nutritious than cow milk
The researchers also discovered that these allergens and endotoxins don’t just settle quietly into corners; they can become airborne. That means they’re not just contaminating surfaces; they’re floating in the air, waiting to be inhaled.
Why does that matter? Well, if you live with asthma or allergies, especially in low-income urban areas where infestations are more common, those airborne particles can worsen respiratory symptoms. Schal’s team is already planning the next step: testing how cockroach allergens and endotoxins interact in animal models of asthma.
“There exists the implication that asthma can be worse due to interactions between allergens and endotoxins,” Schal said. “We want to see if that’s the case.”
Global reinforces a simple but powerful idea. Cleaner homes start with healthier ecosystems, not just tidy counters. Eliminating cockroaches isn’t just about aesthetics or squeamishness.
It’s about breathing easier. Literally.
Journal Reference
- Madhavi L. Kakumanu, Richard G. Santangelo and Coby Schal, North Carolina State University: Zachary C. DeVries, University of Kentucky; Jeffrey Siegel, University of Toronto. Indoor Allergens and Endotoxins in Relation to Cockroach Infestations in Low-Income Urban Homes. Oct. 24, 2025 in The Journal of Allergy and Clinical Immunology: Global, Volume 5, Issue 1, 100571. DOI: 10.1016/j.jacig.2025.100571
