Bed bugs were a common pest in North America in the 1930s. The use of DDT after world war 2 put a large dent in the bed bug populations until it was banned (for good reasons) in 1972. With the banning of DDT, organophosphate and carbamate class chemicals became the replacement of choice for residential use. Unfortunately, though these chemicals functioned excellently in the killing of bed bugs, both these classes of chemicals were cholinesterase inhibitors which means that they interfere with nerve function in both humans and insects. The organophosphates were banned for residential use in 2001 because of safety concerns. The carbamates, which were slightly safer than then organophosphates, were banned for residential use shortly thereafter.
So we see that North America had a 60 year window (1940 to 2001) where bed bugs were almost made extinct via the successive use of three different classes of chemicals which were later banned when it was determined that they were also harmful to humans. That left only the pyrethroid class of insecticide. And of course bed bugs rapidly became resistant when only a single class of chemical was used for their control. Farmers experience similar problems when they spray weeds on their fields with a single class of chemical – resistance develops.
So we see the current bed bug epidemic has its beginning with the banning of the organochlorine (DDT), organophosphate, and carbamate classes of chemicals. It is not a coincidence that the bed bug epidemic started shortly after these chemicals were banned.
Pesticides always contain label directions which state how and where the product can be used. The label is a legal document and any deviation from the instructions is “off label” or illegal. The exterminators, of course, do not want to be held liable for any “off label” use so they follow the label directions. The result for bed bugs is that they are now much more difficult to control with simple chemical methods. Therefore there has been a rise in the amount of heating, vacuuming, cleaning, prevention, etc required to get rid of bed bugs.
The landlords have, of course, taken a dim view to the increasing costs of bed bug control. Some landlords have taken to experimenting with any chemical they find. Unfortunately all the chemicals they find are either in the organophosphate or carbamate categories which were banned earlier because of the health effects on humans. For example, I was contracted to take the belongings out of a single room in a rooming house and kill the bed bugs with heat sterilization before they were taken to a new home. I asked the caretaker what they did for bed bug control and he pulled out a massive jug of clear liquid called “Propoxur.” Propoxur is in the carbamate class mentioned earlier so I asked the caretaker if he had experienced any blurred vision, slurred speech, or irregular heart beats. The caretaker immediately stated that he did have those problems and I informed him that the chemical he was using was the likely cause. The tenant was also interviewed and it turned out that he had been going to the hospital regularly with the same symptoms but the doctors had been unable to find what was wrong. In another case I noted a caretaker who had been tasked with bed bug control using propoxur was hospitalized due to poisoning. The doctor wrote a letter to the building owner demanding that the abuse of these chemicals stop.
Of course propoxur is only one of many possible chemicals that kill bed bugs. There are are other chemicals, especially in the organophosphate family, that are much more dangerous. And the combination of inexperienced applicators, ignorance of the chemical properties, lack of safety practices, and previously banned pesticides is a very dangerous combination.
The landlords should reconsider some of their actions with off label use of pesticides. They need to remember that any damages that result from the off label use of these chemicals will come out of their own pockets with lawsuits. If a tenant, or caretaker, is injured due to deliberate negligence the insurance company may not cover the costs. Perhaps the landlord will get away with illegal use for years but it only takes one case that “goes wrong” and the landlord could lose millions. Even if the landlord cares nothing for the health of his/her tenants he/she should care about the risk to the bottom line.