Exterminators treated another 111 apartments in nearby buildings using standard chemical procedures, spraying pesticides around baseboards up to two times in the six-month period.
Twice during the study, after three months and six months, researchers trapped insects in glue traps scented with a cockroach attractant.
During both collection periods, 68 percent of the homes receiving IPM had reduced cockroach numbers by at least half, while 48 percent of the pesticide-treated apartments over three months, and 56 percent over six months, had similar reductions, according to the study, which was published in Environmental Health Perspectives in August.
“This was a very good study,” said Barbara Brenner, an associate professor of preventive medicine at Mount Sinai Medical Center in New York City. “I think this study is going to be relied on by those who want to advocate for integrated pest management.” Brenner was not involved with Kass’s research, but has conducted other IPM studies.
Karen Reardon, director of communication for RISE (Responsible Industry for a Sound Environment), a pesticide industry trade group, said the methods used in the new study “are extremely important and necessary parts of IPM.” But she adds that pesticides are also part of an integrated approach to controlling pests, and stresses that every infestation is different so chemical use should not be off-limits.
Also, it is not always cheap or easy to implement IPM. Initial costs in an apartment building can be two to three times higher than traditional treatments for the first year, according to the New York City study.
“It is more expensive to do what we did,” said Kass, “but we think [IPM] is cheaper in the long term.” Many IPM interventions are permanent. “Once you caulk something, it does not need to be reapplied,” he said. Pesticides however, move around with time, soaking into baseboards, so treatments must be repeated.
The Boston Housing Authority conducted a thorough cost analysis of IPM in an 85-unit apartment complex in 2003. First year costs were $18,000 compared to around $7,000 for traditional pest control. However, in the third year, IPM costs were $200 less than traditional pesticide applications. The savings were mostly made up by a dramatic drop in pest complaints, which saved the housing authority around 150 man-hours.
When you include the health costs of pesticides, said Kass, IPM becomes even cheaper. In 2003, around 1,000 cases of pesticide exposures or poisonings were reported to the New York City poison control center. Half were children under five, and 95 percent of the exposures happened in homes.
And there can be more catastrophic consequences to pesticide use.
“Every year several apartments blow up because of pesticide foggers,” said Kass. The products are highly flammable and can be ignited by pilot lights or electrical sparks. The U.S. Centers for Disease Control and Prevention reports there were 123 fogger related injuries in New York State between 2001 and 2006.
“People hear by word of mouth that something works, and they don’t stop to think that if it kills the bugs there’s got to be something in it that’s not safe,” said Steve Scholl-Buckwald, director of the Pesticide Action Network of North America based in San Francisco. Many of the chemicals used to kill bugs are nerve poisons that might cause long-term health problems, he said.
The chemical industry says that when used properly, pesticides are safe.
“They have been through a large battery of required tests and they all must be registered by the U.S. Environmental Protection Agency,” Reardon said. “They have been proven to be safe for use by professionals and consumers.” To use these products properly, Reardon said, “Always read and follow all the label directions about every aspect of product use. A lot of time goes into those labels to assure that the product is used safely and that it is going to take care of your pest.”
Many pesticides, however, have been taken off the market because of health effects, and some of them stick around long after they have been used in a home.