New research from North Carolina State University (NCSU) links residential cockroach infestations to high levels of indoor contaminants. The findings, set to be published in the January 2026 issue of the Journal of Allergy and Clinical Immunology: Global, highlight that targeted pest control can significantly improve environmental health.
Key Takeaways
- Direct Correlation: The size of a cockroach infestation directly correlates with the concentration of endotoxins in both settled and airborne dust.
- Kitchens are Hotspots: Endotoxin levels were found to be significantly higher in kitchens than in bedrooms.
- Elimination is Essential: Small decreases in cockroach populations are not enough to lower allergen levels; removing the source entirely is paramount.
The link between infestation and air quality
Conducted in multi-unit apartment complexes in Raleigh, N.C., the research found that the size of an infestation directly correlated with the concentration of endotoxins in settled and airborne dust.
Many of these endotoxins — bacterial components released when bacteria die — were associated with the fecal matter of German cockroaches (Blattella germanica).
Researchers discovered that endotoxin levels were significantly higher in kitchens than in bedrooms. This aligns with the observation that cockroaches are most active where food is abundant. Furthermore, the study noted a physiological difference in contamination contribution: because they eat more, female cockroaches excreted about twice the amount of endotoxins as males.
Targeted treatment proven effective
To measure the impact of professional intervention, infested homes were divided into two groups: those that received pest management treatments and those that did not.
Samples were taken over a six-month period, and the results were conclusive. The homes that received treatment were mostly cockroach-, allergen-, and endotoxin-free.
Expert insight: Why total Control Matters
“This paper shows that the cockroach is the most important depositor of endotoxin in infested homes,” said Dr. Coby Schal, the NCSU Blanton J. Whitmire Distinguished Professor of Entomology and study co-author.
Dr. Schal noted that because these contaminants can be airborne, removing the source is paramount. Crucially, the study found that small decreases in cockroach numbers were not enough to lower allergen levels — total reduction is necessary.
The next step for researchers involves examining whether the co-exposure to both allergens and endotoxins makes asthma worse. For more on this study, visit JACI-global.org.
About the Author
Heather Gooch is the editor-in-chief for PMP magazine. She can be reached at hgooch@northcoastmedia.net or 330-321-9754.
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