Less toxic methods work best to control New York City cockroaches.

Jun 22, 2009

Kass D, W McKelvey, E Carlton, M Hernandez, G Chew, S Nagle, R Garfinkel, B Clarke, J Tiven, C Espino and D Evans. 2009. Effectiveness of an Integrated Pest Management Intervention in Controlling Cockroaches, Mice and Allergens in New York City Public Housing. Environmental Health Perspectives doi:10.1289/ehp.0800149.

Sarah Camp, Flickr.


Management measures that keep unwanted pests out of buildings and apartments can control cockroaches and their associated allergens better than traditional pesticide sprayings. This is the first study to show how a one-time, low cost visit by professionals can effectively reduce the insects' populations for up to six months. Sealing cracks and using bait traps – rather than periodic pesticide applications – to control the pests lowers people's indoor exposures to unhealthy toxic chemicals and allergens that can lead to asthma.



Cockroach infestations are a serious problem in New York’s public housing projects. In city-owned housing developments in East Harlem and Brooklyn, 94 percent of residents reported seeing cockroaches in the past three months. Rodents were sighted in 48 percent of apartments.

Allergens from cockroaches and mice in the home can trigger asthma attacks. Asthma rates are increasing nationally, and low income, minority children are at higher risk.

However, there is a concern that as more parents become aware of the role of indoor pest allergens in asthma severity, their use of potentially toxic pesticides in the home will increase.

Integrated pest management is a technique that attempts to cut off pests’ access to food, water, and shelter. The main focus is to keep the pests out of homes instead of relying on heavy use of pesticides kill the pests once they are inside.

What did they do?

The authors compared the effectiveness of integrated pest management (IPM) to that of toxic pesticides in controlling cockroaches and mice in 13 buildings from five different public housing developments in New York City.

Some buildings received a single visit from a team of  IPM pest control technicians who cleaned kitchens and bathrooms, caulked cracks in walls and cabinets, and applied low toxicity cockroach baits. Other buildings were sprayed every three months with traditional use pesticides.

Cockroach and mice populations and their allergens (proteins in pest urine) were measured at the beginning of the study and again three and six months later. The researchers also interviewed the apartment dwellers.

What did they find?

IPM did a better job of controlling and reducing the pests than spraying pesticides. In IPM apartments, pesticide use dropped and residents were more positive about building maintenance.

In buildings where residents received a single integrated pest management visit, the number of cockroaches dropped by 75 percent after three months.

Six months later, they had reduced by 88 percent. The amount of cockroach allergen found in dust in both kitchens and bedrooms had also dropped by more than half compared to control apartments.

In contrast, the number of cockroaches in the buildings receiving professional exterminator visits every three to six months increased slightly.

The intervention did not appear to have any effect on mice.

What does it mean?

This study is the first to show that a single, short, low-cost visit by housing authority workers to address the underlying source of pests can be more effective at controlling cockroaches and their allergens in buildings than repeated professional pesticide applications.

Other studies have shown that integrated pest management is effective. But, these studies generally have been costly – involving labor-intensive follow-up visits and resident education.

IPM tehcniques can be used to control pests in buildings, according to the authors findings. Pest numbers dropped and their population growth slowed in the buildings in this study where IPM was used. Another recent study that examined using IPM for pest control in North Carolina schools found similar results and came to similar conclusions (Godfrey 2009).

The IPM technique used here was more effective and less expensive than either past IPM efforts tested or traditional pesticide programs. The method reduced allergen and pesticide exposure of children and adults living in the apartments, quite possibly improving their long-term health and reducing accidental poisoning.

The authors report that "traditional pest control had no independent impact over time on objectively determined cockroach levels, and minimal impact on resident sightings, suggesting that the use of pesticides alone is both ineffective and an unnecessary introduction of pesticides into the environment, even without an alternative pest control approach to replace it."

The New York City Housing Authority has since trained its entire workforce of pest control professionals in integrated pest management and suspended its use of pesticide sprays in residential units.


Cockroach fact sheet. Univeristy of Rhode Island Landscape Horticulture Program.

Cockroach allergens have greatest impact on childhood asthma in many US cities. NIH News. March 8, 2005.

Cockroach allergy. Asthma and Allergy Foundation of America. 

Godfrey, N, JC Gore, HM Linker and C Schal. 2009. German cockroach allergen levels in North Carolina schools: comparison of Integrated Pest Management and conventional cockroach control. Journal of Medical Entomology 46:420-427.

Integrated Pest Management Principles. US Environmental Protection Agency.



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