Question from Magda

Dear Debra,

Originally I thought that chlordane would not be a problem in and around houses any more. Until I came upon the study, article, and description of practices excerpted below.

Sorry to bring up such a long, unpleasant litany, now that spring is here and the daffodils are blooming!
But I live in Iowa and love gardening. It is very hard not to weed close to house walls, where a potential contmination would be worst, and has possibly been spread around through the building of porches, digging near foundations etc.

Do you know of any chlordane test except the one offered by Dr. Richard A. Cassidy of Toxfree, who also put the mentioned practices described below on the internet?

Thank you very much in advance. Thank you also for helping us ordinary people (who do not know science) live healthier lives.



Health Dangers of Chlordane
by Dr. Edward Group DC, NP, DACBN, DCBCN, DABFM
[schema] published + updated Published on March 14, 2013, Last Updated on May 28, 2013

The University of Iowa examined soil samples and discovered that Cedar Rapids Iowa had chlordane soil contamination almost as severe as urban areas of China.


Hedley AJ,   Hui LL,   Kypke K,   Malisch R,   van Leeuwen FX,   Moy G,   Wong TW,   Nelson EA.   Residues of persistent organic pollutants (POPs) in human milk in Hong Kong.   Chemosphere. 2010 Apr;79(3):259-65. doi: 10.1016/j.chemosphere.2010.01.047. Epub 2010 Mar 2.
Bao LJ,   Maruya KA,   Snyder SA,    Zeng EY. China’s water pollution by persistent organic pollutants. Environ Pollut. 2012 Apr;163:100-8. doi: 10.1016/j.envpol.2011.12.022. Epub 2012 Jan 11. Review.
Martinez A,   Erdman NR,   Rodenburg ZL,   Eastling PM,   Hornbuckle KC.   Spatial distribution of chlordanes and PCB congeners in soil in Cedar Rapids,   Iowa,   USA.   Environ Pollut. 2012 Feb;161:222-8. doi: 10.1016/j.envpol.2011.10.028. Epub 2011 Nov 26.
Mast MA,   Alvarez DA,   Zaugg SD.   Deposition and accumulation of airborne organic contaminants in Yosemite National Park, California.   Environ Toxicol Chem. 2012 Mar;31(3):524-33. doi: 10.1002/etc.1727. Epub 2012 Feb 6.
Morrissey CA,   Pollet IL,   Ormerod SJ,   Elliott JE.   American dippers indicate contaminant biotransport by Pacific salmon.   Environ Sci Technol. 2012 Jan 17;46(2):1153-62. doi: 10.1021/es2028058. Epub 2011 Dec 23.
Lopez J,   Boyd D,   Ylitalo GM,   Littnan C,   Pearce R.   Persistent organic pollutants in the endangered Hawaiian monk seal (Monachus schauinslandi) from the main Hawaiian Islands. Mar Pollut Bull. 2012 Nov;64(11):2588-98. doi: 10.1016/j.marpolbul.2012.07.012. Epub 2012 Aug 9.
Everett CJ,   Matheson EM.   Biomarkers of pesticide exposure and diabetes in the 1999-2004 national health and nutrition examination survey.   Environ Int. 2010 May;36(4):398-401. doi: 10.1016/j.envint.2010.02.010. Epub 2010 Mar 17.
Goldner WS,   Sandler DP,   Yu F,   Hoppin JA,   Kamel F,   Levan TD.   Pesticide use and thyroid disease among women in the Agricultural Health Study.   Am J Epidemiol. 2010 Feb 15;171(4):455-64. doi: 10.1093/aje/kwp404. Epub 2010 Jan 8.
Vogt R,   Bennett D,   Cassady D,   Frost J,   Ritz B,   Hertz-Picciotto I.   Cancer and non-cancer health effects from food contaminant exposures for children and adults in California: a risk assessment. Environ Health. 2012 Nov 9;11:83. doi: 10.1186/1476-069X-11-83.
Sakamoto K,   Nishizawa H,   Manabe N.   Behavior of pesticides in coffee beans during the roasting process.   Shokuhin Eiseigaku Zasshi. 2012;53(5):233-6.


Environ Pollut. 2012 Feb;161:222-8. doi: 10.1016/j.envpol.2011.10.028. Epub 2011 Nov 26.
Spatial distribution of chlordanes and PCB congeners in soil in Cedar Rapids, Iowa, USA.

Martinez A1, Erdman NR, Rodenburg ZL, Eastling PM, Hornbuckle KC.
Author information

Department of Civil & Environmental Engineering, IIHR-Hydroscience and Engineering, The University of Iowa, 4105 SC, Iowa City, IA 52242, USA.

Residential soils from Cedar Rapids, Iowa, USA were collected and analyzed for chlordanes and polychlorinated biphenyls (PCBs). This study is one of the very few urban soil investigations in the USA. The chlordanes concentrations ranged from 0 to 7500 ng g(-1) dry weight (d.w.), with a mean and standard deviation of 130 ± 920 ng g(-1) d.w., which is about 1000 times larger than background levels. ΣPCB concentrations ranged from 3 to 1200 ng g(-1) d.w., with a mean and standard deviation of 56 ± 160 ng g(-1) d.w. and are about 10 times higher than world-wide background levels. Both groups exhibit considerable variability in chemical patterns and site-to-site concentrations. Although no measurements of dioxins were carried out, the potential toxicity due to the 12 dioxin-like PCBs found in the soil is in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation.
Copyright © 2011 Elsevier Ltd. All rights reserved.


Information provided by
Richard W. Pressinger (M.Ed.), Wayne Sinclair, M.D.

How to Correct Chlordane Home Contamination

Application to Outside Wood Surfaces
Chlordane was frequently applied to the outside wood surfaces of many homes built before 1988. This would have been done because of an actual termite problem or as a preventive safeguard from a worried homeowner. Under first consideration, the application to the outside of the home would not appear as a problem, however, as described in research on the chlordane web site, conducted by Dr. Kaye Kilburn of the the University of California, even outdoor applications of the chemical can find their way indoors to contaminate the interior to a level that can cause a variety of health problems from increased infections to increases in many neurological disorders including – anger, migraine headaches and depression.

Correction Procedure
The least expensive way to correct contamination of the exterior wood surfaces of a home is to seal the wood with a hard, enamel based paint. The most efficient method for correcting this problem is to identify which side of the home the problem exists and to then replace the contaminated wood pieces. If the home is constructed of 4×8 sheets of plywood siding, these sheets can be easily replaced for a materials cost of about $25.00 per sheet. Check with the pest control company who applied the chlordane and ask if their records show where chlordane was applied.

Infiltration up through the Foundation of the Home
This is the same route that radon has been found to contaminate homes throughout the U.S. When a home was built before 1988, standard procedure was to literally saturate 100 gallons of chlordane into the soil per 1000 square feet of home area just before the concrete foundation was poured. Therefore, a 2000 square foot home would have 200 gallons of chlordane saturated into the soil. After several years of “settling,” cracks form in the foundation and basement walls or around plumbing pipes which has been found to allow for entry of the chemical into the home.

Correction Procedure
Success has been shown with underground infiltration problems by simply identifying where the cracks in the foundation are located and sealing these with an acrylic caulking or similar compound. It is also recommended to caulk around all plumbing pipe entry points through the foundation. As chlordane was often concentrated in the outer one or two foot perimeter just underneath the foundation, there needs to be a good caulking seal at the point where the wall meets the floor

Attic Contamination
As the attic of a home is comprised of wooden 2×4 support beams, these were often sprayed with chlordane by a pesticide company to ward off future termite problems. Unfortunately, when the applicator is spraying the beams, the chemical can easily drip onto the ceiling drywall sheets that were nailed to the 2×4’s. Drywall is made of rock powders that act like a sponge, quickly absorbing the chemical and then outgas the chlordane into the living area below. Contamination would then occur to the area below which could be either the kitchen, living room or bedroom.

Correction Procedure
Ceiling drywall that has soaked up chlordane due to an attic application of chlordane can be widespread. Ceiling drywall can be purchased inexpensively in 3/8 inch thicknesses for around $5.00 for a 4×8 foot sheet. It is recommended that these be placed over existing ceiling drywall or to completely remove the existing drywall and to then apply new drywall.

Accidental Spills
The research has documented spills of chlordane containers occurring during testing research and has certainly happened to an unknown percentage of homes built before 1988. The spills could range from a few ounces to one gallon or 55 gallon containers. If one room registers a much higher chlordane level than another room – the possibility of a chlordane spill should be considered.

Correction Procedure
If a significant amount of chlordane has been spilled onto any inside flooring the two correction procedures in order of effectiveness include – painting the floor with an enamel based paint or laying ceramic or hard vinyl tile over the contaminated area.

Normal Application Residue
Although chlordane was routinely used outside the home up through March of 1988, it was often used for the indoor control of roaches and ants up until 1981. Chlordane was easily purchased by homeowners from department stores before this date as an effective roach and ant pesticide. Indoor areas routinely treated with chlordane include underneath the kitchen sink, behind the refrigerator, behind the dishwasher and along baseboards throughout the bedrooms. Sometimes the chemical odor of chlordane underneath a kitchen sink is “overwhelming” due to this area receiving repeated chlordane applications. Chlordane contamination still occurs today as many “garden/tool sheds” still have bottles of outdated chlordane on the shelves.

Correction Procedure
If contamination under the kitchen sink is suspected, perform a chlordane air test underneath the sink. High levels found here can be “sealed in” using new plywood or if air chlordane contamination is exceptionally high, the homeowner may be better off replacing the old counter top with a new one. Baseboards along the floor can be sealed with an enamel paint or can be replaced at a cost of 30 cents to $1.00 per foot.

Debra’s Answer

Thank you for all this information Magda. Chlordane is a very toxic pesticide and it’s important to know it’s still a hazard to watch out for.

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