A research team has uncovered a strong connection between cockroach infestations and harmful household substances, specifically allergens and bacterial endotoxins.
Scientists at North Carolina State University have discovered a clear relationship between the extent of cockroach infestations in homes and the concentration of allergens and endotoxins present in those environments.
When pest control measures successfully reduced cockroach numbers, the levels of both allergens and endotoxins dropped substantially. These results indicate that removing cockroach infestations may significantly enhance indoor environmental health by lowering exposure to these harmful substances.
Endotoxins are components of bacterial cell walls that are released when bacteria die. Because cockroaches are omnivorous and consume a wide variety of materials, they maintain a complex and diverse gut microbiome.
Earlier studies have shown that cockroaches release considerable amounts of endotoxins through their feces, although humans and household pets can also contribute to endotoxin levels. In this study, researchers determined that much of the endotoxin found in household dust originated from cockroach droppings.
“Endotoxins are important to human health, as inhalation of these components has been shown to provoke allergic responses,” said Coby Schal, the Blanton J. Whitmire Distinguished Professor of Entomology at NC State and co-corresponding author of a paper describing the research. “Past surveys in U.S. homes found endotoxin levels much higher in homes with self-reported evidence of cockroaches; that association is stronger in low-income homes than in single-family homes.”
How the Study Was Conducted
The study, held in multi-unit apartment complexes in Raleigh, N.C., compared estimated cockroach infestation sizes as well as allergen and endotoxin levels in homes infested by cockroaches. These baseline levels were tabulated by capturing settled and airborne dust in homes.
The researchers found significant amounts of endotoxins in infested homes, with female cockroaches excreting about twice the amount that males excreted.
“Female cockroaches eat more than males, so more endotoxins are shed from their fecal matter,” said Madhavi Kakumanu, an NC State research scholar in Schal’s lab and co-corresponding author of the paper. She added that more endotoxins were found in kitchens than in bedrooms, as more cockroaches live in kitchens, where they find more food.
Infested homes were then divided into untreated homes and homes receiving an extermination intervention to eliminate cockroaches. The researchers also included a control group of homes that had no cockroaches. Cockroach counts and floor and airborne dust samples were taken three months and six months into the study.
The results showed that infested homes without extermination had very large amounts of both endotoxins and allergens at all timepoints.
Meanwhile, in most cases, infested homes that received the extermination intervention were rid of both cockroaches and their allergens, and experienced significant declines in endotoxins.
Key Insights and Health Implications
“When you eliminate cockroaches, you eliminate their allergens. Small decreases in cockroaches don’t lower allergen levels because the remaining live cockroaches deposit more allergens,” Schal said. “Endotoxins significantly decreased in homes where cockroaches were eliminated. This paper shows that the cockroach is the most important depositor of endotoxin in infested homes.”
“We also saw that allergens and endotoxins can be airborne,” Kakumanu said.
Schal added that the next steps include further examining interactions between cockroach allergens and endotoxins in animal models of asthma, such as mice.
“There exists the implication that asthma can be worse due to interactions between allergens and endotoxins,” Schal said. “We want to see if that is the case in mice.”
Reference: “Indoor allergens and endotoxins in relation to cockroach infestations in low-income urban homes” by Madhavi L. Kakumanu, Zachary C. DeVries, Richard G. Santangelo, Jeffrey Siegel and Coby Schal, 26 September 2025, Journal of Allergy and Clinical Immunology: Global.
DOI: 10.1016/j.jacig.2025.100571
Funding for the work came from the U.S. Department of Housing and Urban Development Healthy Homes program (NCHHU0053-19, NCHHU0081-24); the Alfred P. Sloan Foundation (2013-5-35 MBE); a Pilot Project awarded by the Center for Human Health and the Environment under P30ES025128 from the National Institute of Environmental Health Sciences; the National Institute of Allergy and Infectious Diseases of the National Institutes of Health (award number 1R21AI187857-01); Research Capacity Fund (HATCH) (project NC02639) from the U.S. Department of Agriculture National Institute of Food and Agriculture; and the Blanton J. Whitmire Endowment at North Carolina State University.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
5 Comments
I live in apartment and these roaches I weren’t even sure what they were at first but I do know they’re infestation is so bad in my apartment in the whole house there’s three apartments here in this house and it’s infested so bad and the landlord will not take care of it I have been suffering with anxiety and depression from them being here and not being able to get rid of them I have been using a spray bottle with bleach and detergent to spray them so that it’s not so toxic because I have a kitty and because of myself and I have asthma and I have to use a machine so I can breathe I don’t know what to do if there’s any way I can get any help or if you can give me an advice could you please email me on something on what to do if I can if what I can do about the landlord to get something done about him not doing anything about it because I think that he should be doing something about it and he’s not doing anything about it and this is been going on for months for over 6 months now this stuff has been going on these bugs have been here for and they’re not going away and they’re just going to keep on coming out because I know there’s eggs and stuff in the walls they’re so gross they’re just nasty and they get in your food I keep my stuff in the refrigerator I was gone for a month and when I came home I had to throw everything away my cupboards were full of them they’re so gross I can’t stand it I’ve never seen anything so disgusting in my life my name is Stephanie and I live in Eau Claire Wisconsin I don’t know how they got here but I’m assuming they got here through somebody that either has dumpster diving or somebody that took a trip to Mexico or to Texas and they brought him back here last summer in the beginning of spring something needs to be done they’re just so bad they’re infested. I hope that you can help please help please help!!!!!!.
Go to Walmart or Target get a big bag of box of Boric acid, wouldn’t hurt to grab a box of 20 mule team Borax, a bag of powdered sugar and a large container of powdered coffee creamer mix them all together heavier on the last 2 ingredients that way they won’t detect the boric acid you can use something like peanut butter or maybe just a little water roll them in tiny balls as roaches seem to prefer crumbs place them everywhere you see roaches especially the areas you see they get inside, just don’t put them where the cat can get to them, they will eat this go back to their nest (because this will kill them slowly) after they die the other roaches will eat them it will eventually wipe out the entire nest. Use gloves it may take a month or two but should kill them all without going into the other apts. Good luck. This is a tried true method without using sprays or harmful poisons.
Add- You can purchase everything you need for less than 20.00 this does work roaches love powdered sugar & powdered coffee creamer. Good luck. I would also clean your apt with D-limonene this is made from citrus and it is a natural deterant I believe it’s toxic to roaches as well. If I was you I would research and learn all you can about it. You can also use honey to make the powders stick together. The entire building should be roach free within a few months, without using toxic chemicals which are also very harmful for you and your cats health. Hope this helps
Add- You can purchase everything you need for less than 20.00 this does work roaches love powdered sugar & powdered coffee creamer. Good luck. I would also clean your apt with D-limonene this is made from citrus and it is a natural deterant I believe it’s toxic to roaches as well. If I was you I would research and learn all you can about it. You can also use honey to make the powders stick together. The entire building should be roach free within a few months, without using toxic chemicals which are also very harmful for you and your cats health. Hope this helps
Hi there.i recommend you to buy adivvon from get rid of them.you ain’t see them again.try and see miracle.