Cockroaches in the home environment are a health hazard not only because of the risks posed by cockroach antigens to asthma sufferers, but also because they can carry disease-causing germs and because some of the methods traditionally used to eliminate them cause additional health hazards.
Traditionally, cockroaches were controlled because they are offensive, leave behind an awful smell, and cause gastrointestinal and respiratory illness. However, research shows that cockroach debris (old shells, saliva, body parts, and droppings) triggers asthma attacks in people who are sensitized to cockroach antigen (proteins found in the debris). In homes where several allergens are present, including dust mites, mold, furry pets, tobacco smoke, and certain chemicals, children may experience severe and frequent asthma attacks from high airborne concentrations of these allergens.
Because young children spend more time indoors, allergens found in homes and other buildings pose a significant health risk for asthma sufferers. With asthma rates growing at a startling rate, the hazard posed by the presence of any cockroaches must be addressed.
Any home with food or moisture can have cockroaches. Kitchens and bathrooms typically have the highest number of cockroaches due to the presence of food products and moisture from plumbing fixtures.
Apartment buildings often have the worst infestations. The goal is to keep cockroaches out of the home and to eliminate existing pests. Reaching this goal is not always easy, especially in multi-unit housing that is already infested. For most apartment buildings, the landlord must take a building-wide approach to controlling these pests. Moreover, a coordinated effort by the landlord and all tenants is required to eliminate cockroaches.
Testing for Cockroaches
Generally, determining whether a home has a cockroach problem and the extent of the infestation involves the use of glue traps, which can be purchased at most hardware or grocery stores. The traps are laid out in target areas, where they are left for at least one night. Upon either filling the trap with cockroaches or waiting a predetermined length of time, the number of cockroaches caught on the glue trap is counted to provide an estimate of the extent of the cockroach problem in the home environment.
If an apartment building is to be sampled, it is best to test more than one unit. If only one unit is tested, the landlord may claim that only that unit is infested and put the blame for the problem solely on that tenant. Most housing codes put responsibility for cockroach control on the landlord if two or more units are infested.
Any home can have cockroaches. However, there are steps you can take to prevent cockroaches from becoming a problem in your home; identify the extent of and solutions to any potential cockroach problem; and reduce or eliminate cockroach problems.
General maintenance and cleaning are important because they remove the food, water, and shelter on which cockroaches depend, and block the entrances cockroaches use to get into housing. There are many steps tenants, landlords, and homeowners can take individually and jointly to prevent cockroach infestation of the home environment.
- Wipe off counters, tables, and stovetops after all meals, snacks, and food preparations.
- Keep food confined to specific areas of the house and clean any spills immediately.
- Keep all food and garbage in tightly sealed containers, and do not allow trash to accumulate too much.
- Do not leave dirty dishes in the sink, on the counter, or in the dishwasher overnight.
- Fix leaky pipes, faucets, toilets, and other plumbing problems, as well as leaky roofs.
- Use a bathroom fan that vents to the outside after all baths and showers to reduce humidity. Dry any damp areas in the kitchen or bathroom to keep moisture down.
- Remove all piles of boxes, cardboard, newspapers, etc. from both inside and around the home. Cockroaches can both live in and eat these materials.
- Remove other clutter as well to eliminate shelter and hiding places for cockroaches.
- Caulk all cracks and crevices throughout the home around systems such as plumbing, electrical, and gas lines, as well as in places like cupboards and walls.
As an added bonus, integrated pest management techniques that control cockroaches can also help to minimize exposure to other environmental hazards. For example, controlling moisture by fixing leaks and drying up spills can also help prevent exposure to lead and mold. Safe and effective pest management techniques must be utilized, because some chemicals used to treat pests are toxic, may exacerbate asthma symptoms, and are not successful at ridding homes of cockroaches.
The ultimate goal is to keep cockroaches out of a home and when necessary, to eliminate those that are there, while keeping residents safe. Reaching this goal can be difficult, especially in multi-unit housing that is heavily infested. For most apartment buildings, the landlord must take a building-wide approach to controlling cockroaches. Normally, it will take a coordinated effort from the landlords and tenants to eliminate cockroaches. Getting their support takes compelling evidence, such as a trap full of cockroaches coupled with a count of the number of cockroaches.
The initial actions residents and landlords can take are regular cleaning and maintenance to remove the food, water, and shelter for the cockroaches. Not only will this help to prevent a cockroach problem in the first place, it is also crucial to controlling an existing infestation and maintaining a cockroach-free environment.
If a cockroach problem requires remedial action, there are numerous paths of control and products available. Once a cockroach problem has been identified, the landlord or homeowner should call an integrated pest management (IPM) professional to conduct a formal inspection. Care should be taken to avoid residential exposure to pesticides, as these chemicals can be a carcinogenic health hazard in the home. Many pesticides can also trigger asthma attacks and cause developmental disabilities.
Pesticide sprays and fogs should not be used to control the problem. Not only will sprays and fogs leave a residue that is hazardous to human health, they also must be applied periodically and are not effective against cockroaches. Baits and boric acid are safer, more preferable forms of treatment that limit the level of human exposure to pesticides. Using IPM practices such as these to control cockroaches are a healthier way to eliminate the problem than spraying pesticides in your home.
Integrated Pest Management (IPM)
- IPM uses a combination of common-sense practices, information on the life cycles of the pests in question and their interaction with the environment, and available pest control methods.
- In general, practicers of IPM use modes of pest control that are less harmful to people and the environment (such as traps) before considering more drastic measures (such as spraying conventional pesticides).
- IPM presents the least possible hazard to people, property, and the environment.
- IPM is effective, economical, and environmentally sensitive.
Beyond Pesticides – Integrated pest management to control cockroaches
Canada Mortgage and Housing Corporation – Farewell to Cockroaches Guide
Environmental Health Watch – Cockroach Control Guide
Gumm, Brian, Home Energy, “Integrated Pest Management in the Home,” Vol. 21 Iss. 6 pp. 36-39 (Nov-Dec 2004)
US Environmental Protection Agency – Asthma: Cockroaches and Other Pests
Asthma No Attacks Hotline: 1-866-NO-ATTACKS (1-866-662-8822)
Su Familia (Your Family) Helpline: 1-866-SU FAMILIA or 1-866-783-2645
The National Alliance for Hispanic Health sponsors this helpline to offer Hispanic consumers free, reliable, and confidential health information in Spanish and English and help navigate callers through the health system.
Health Impacts Exposure to rodents can trigger asthma attacks. Studies have shown a linkage between rodent allergy and asthma symptoms. Exposure to rodents (mice and rats) has been linked to increased asthma symptoms among laboratory workers who handle rodents and are sensitized to them. Other studies have established links between rodent allergies and asthmatic symptoms in lab workers. Research published in 2004 found similar linkages in residential settings. Rodent allergens are likely from rodent urine, saliva, or skin.
It is clear that many inner-city residents are exposed to and allergic to rodents. A major study on asthma among inner-city children found that nearly 20 percent of asthmatic children had been sensitized to rats and 15 percent were sensitized to mice. This is important to note, as research has found mouse allergen in 82 percent of U.S. homes.
Rodents can also expose humans to diseases such as hantavirus. Exposure to such disease vectors is rare but can cause severe health problems.
Integrated pest management (IPM) approaches offer effective means of eliminating rodents from the home. IPM methods focus on preventing infestations, trapping rodents, and limited use of lower-toxicity pesticides. However, even after a rodent population is controlled, rodent hair, urine, and fecal allergens may remain and can trigger allergic reactions in some people.
Designing, maintaining, and renovating buildings to minimize rodents is an effective prevention-based approach.
- Seal holes and cracks in building foundations, utility openings, and joints between materials. Use corrosion-proof materials such as copper or stainless steel mesh. Rodents can chew through many other materials and squeeze through tiny openings.
- Add rodent barriers to foundation walls to make it more difficult for them to enter a building. For example, heavy-duty wire mesh along the outside of a foundation is an effective barrier.
- Seal passages through interior floors, walls, ceilings, and kick spaces. If possible, keep kick spaces open to limit places rodents can hide. (Kick spaces are the gaps between the bottom of cabinetry or built-in furniture and the floor.)
- Keep bushes and trees at least three feet from homes. Bushes and trees near a home provide food, a living place, and sheltered passage for rats and rodents.
- Ensure trash is stored in secure containers (covered garbage cans and dumpsters).
- Store food in rodent-proof containers.
Cohn R, Arbes S, Yin M, Jaramillo R and Zeldin D. Journal of Allergy and Clinical Immunology, National prevalence and exposure risk for mouse allergen in US households, June 2004.
Gumm, Brian, Home Energy, “Integrated Pest Management in the Home,” Vol. 21 Iss. 6 pp. 36-39 (Nov-Dec 2004)
Kattan M, Mitchell H, Eggleston P, Gergen P, Crain E, Redline S, et al. Pediatr. Pulmonol, Characteristics of Inner-City Children with Asthma: The National Cooperative Inner-City Asthma Study, 24:253-262, 1997
National Academy of Science, Institute of Medicine – Clearing the Air: Asthma and Indoor Air Exposures 2000.
U.S. Centers for Disease Control and Prevention