Thursday, December 13, 2007

Taming termite terrors, plus some concerns over chlordane contamination

I recently bought my first home - yay! As many of you homeowners know, a pest inspection is one of the first and most important conditions on home financing. My new home's pest inspection came back clean at present, but with signs of past infestation by both termites and powder post beetles. Eek!

A pest to fill every homeowner with dread - termite!!
Then, at my closing, the attorney (who had no idea what I do for a living) said, "your home showed signs of past termite infestation. I strongly recommend you get a contract for semi-annual termite treatments..." Oh gosh! Holding off on the chemicals was an easy choice when I was just dealing with the occasional cockroach at my old apartment, but it's quite a different matter when thinking about bugs that could literally EAT my house, by far the most expensive thing I have ever owned in my life!

So, one big question I have is this: Since the buggers were in my house before, it must have been prone to infestation in some way, and may still be. How can I prevent future problems, without resorting to pesticide treatments?

So, I checked out Beyond Pesticides' factsheets on alternatives to pesticides for termite control, and particularly liked this article - Taking the Terror Out of Termites (link downloads 152 kb PDF file). You can check it out for their recommendations. In a nutshell, termites like moist wood, so moisture reduction is a major component of preventing termites. And, there are several least-toxic and non-toxic treatment methods available, so a chemical arsenal really shouldn't be necessary.

Another big question on my mind has to do with the past infestations in my house, and how they were treated. This house was built in 1950, and I have no idea when termites were an issue in that nearly sixty-year history. From 1948 to 1988, a common method of treating termites in the US was a chemical called chlordane, an organochlorine pesticide related in structure to the likes of DDT, aldrin, lindane and endosulfan. Chlordane was applied to the soil around and under the house to act as a chemical barrier to wood-boring insects. It was banned for use on food crops in the US in 1978, and for use as a termite treatment in 1988, due to rising concern over health and environmental impacts. Exposure has been linked to increased risk for a host of health problems, including some types of cancer, neurological problems, and fertility disorders. A really worrisome finding from an article in today's Vancouver Sun:

"(...) Researchers found people with the highest levels of a certain type of insecticide in their blood had 2.7 times the risk of developing non-Hodgkin lymphoma as those with the lowest amounts.
That strong link involved a metabolite of the insecticide chlordane. (...)"

Some highlights (or lowlights, in this case) from the ATSDR public health statement for chlordane (emphasis is all mine):
"Chlordane is known to remain in some soils for over 20 years. Persistence is greater in heavy, clayey or organic soil than in sandy soil."
"Today, people receive the highest exposure to chlordane from living in homes that were treated with chlordane for termites. Chlordane may be found in the air in these homes for many years after treatment. Houses in the deep south and southwest were most commonly treated."
"You may come into contact with chlordane while digging in soil around the foundation of homes where it was applied to protect the homes against termites."
Oh no! So along with all the fumes from the glues, finishes, paints, and carpet in my house, I may also be breathing fumes from pre-1988 chlordane treatments that are seeping up through my floorboards! I'm trying not to panic - after all, stress is bad for your health, too, and every house I've ever lived in (and that most Americans have lived in!) was built before 1988 and probably carries some level of chlordane. It's a common, though no less unfortunate contaminant of the home environment.

Based on what I've read about chlordane and other similar chemicals, I have a few ideas for ways to reduce my risk of exposure at home, and to improve my indoor air quality overall:
- Ventilation. I've got window screens and ceiling fans, so I'm ready for lots of fresh air in the spring, summer and fall...and also on freak 80-degree days in the winter, like today!
- Cleaning - especially dusting. This could be more of a challenge - I'm not exactly a neat freak, but I understand that chemical contaminants in indoor air settle with the dust in a room onto the floor and surfaces. So, mopping and dusting regularly with natural cleaners like borax, baking soda, and Dr. Bronners soap will be helpful to get rid of any chemical residues, and to prevent cockroaches, dust mites, and a bunch of other pests and allergens too.
- Mulch. While having mulch in direct contact with the side of my home is a bad idea, since it can harbor pests and trap moisture along the foundation, laying mulch over some of the possibly-contaminated soil around the perimeter of my house is sounding like a better and better idea. I have a dog who will be spending a lot of time digging around in the dirt in my yard, and she can't exactly take off her shoes before entering the house to avoid tracking in contaminated soil! Mulching over the soil that's most likely to be contaminated could be a good way to prevent her from digging in it and tracking it in, and will also help to keep down weeds.
- Soil mitigation. I'm planning for a little herb and vegetable garden in the backyard, not too far from the back wall of the house. I might need to get a soil test to check for chlordane contamination before planting edible plants, or at least put in some relatively "clean" compost or topsoil to reduce contaminant levels in the soil.

I'm going to keep looking into both questions over the next couple months, and will report back with my findings and keep you all posted on what I end up doing. In the mean time, I'd love to hear your thoughts on the matter, and any tips you have for either preventing termites without toxic chemicals, or for getting chlordane and other chemical contaminants out of my home and garden. Please leave me a comment with your suggestions. Thanks!


bijan said...

we are considering buying a house in Massachusetts that was treated with chlordane in an effort to kill termites.

they did it in the early 1990's by drilling holes in the basement and a few around the house and then applied the chlordane and then sealed it up.

how worried should I be about this. I have 3 young kids.

many thanks. pls email me at if you have any info to share.

anajz said...

Our soil has a "chemical" odor throughout our backyard. Recently, I was informed that it could be chlordane. We do not use chemicals to treat our yard and our garden is as organic as we can make it...mostly grown in containers due to the unknown odor.
I would be very interested in information regarding the decontamination of the soil if you come across a solution. Thanks.

pest contol said...

Thanks for taking the time to discuss this, I feel strongly about it and love learning more on this topic. If possible, as you gain expertise, would you mind updating your blog with more information? It is extremely helpful for me.

asciiman said...

Hi! I didn't see any follow-up of your chlordane investigation in your home. I had the same issue with a home I just bought here in Pittsburgh. I learned right near closing that it had this thing called Chlordane in it. Long story short, I'm doing a major renovation and taking out all the wood that it was injected into in the house and replacing it. I'm blogging about my experience as I go: