One of the key problems with DDT is its persistence. That was a selling point early on — one application would last for six months to a year. In the wild or in a city, DDT can breakdown in about a year, but it breaks down into DDE which is pretty deadly itself and can cause a raft of other trouble while it hangs around. While DDT will kill young birds and even adult songbirds outright, its most pernicious workings come in the breakdowns. DDE insinuates itself in the reproductive organs of animals, causing birds to be unable to lay eggs with properly calcified eggshells. Even if the DDT doesn’t kill the chicks, the DDE gets next year’s generation, making sure the egg cannot protect the chick to hatching.
A treaty adhered to by most of the world’s nations targets DDT specifically, you can tell by the name if you don’t know the content: The Persistent Organic Pollutants Treaty (POPs), also known as the Stockholm Convention after the city where it was finally negotiated under the direction of the United Nations’ health care arm, the World Health Organization (WHO).
40 years after DDT use essentially ended in the U.S., traces of it still show up in the tissues of creatures in the wild, in plants, in crops, and in human tissue.
Where does it come from?
Most of what shows up is just circulating in the air, soil, water and living things. There could be other sources.
I doubt this is a significant source, but a lot of DDT remains stored in barns and sheds on farms and in gardens across North America. Over at a blog operated by an exterminator in Charlotte, North Carolina, we get a glimpse of history and potential disaster all at once.
Today, I traveled up to a Lincolnton, North Carolina Farm house to give a gentleman a price on Termite Protection for his home. After I performed an inspection, he took me out to his barn to show off a couple of old tractors. Immediately catching my eye on an old work bench was anachronistic blast from the past.
There it was, an unopened bottle of DDT. (See images below) DDT was Banned in the United States more than 30 years ago, and it remains America’s best known toxic substance. Like some sort of rap star, it’s known just by its initials; it’s the Notorious B.I.G. of pesticides. And much like the Notorious B.I.G., it has been put to rest.
Electrolux Insecticide featuring DDT in the formulation, on a barn workbench in 2012, near Charlotte North Carolina – Charlotte Pest Control image
Did it really have DDT? Look at the next photo. It’s badly focused, but you can probably make it out, that line at the bottom of the can.
Label of Electrolux Insecticide can, showing DDT as the contents. Charlottepestcontrol.me image
DDT put to rest? If only it were that easy. Not only is the stuff in that can still deadly, it’ll hang around for decades if released from the can.
You’re wondering, of course, just what in the world was Electrolux doing selling DDT? Look at the label: See that woman using the vacuum rather like a spray device?
Cannister vacuums of the 1950s and 1960s were advertised as universal tools. Not only would they suck up dirt from a floor, but they could also be used as blowers, simply by reversing the hole into which the hose was plugged. Manufacturers provided attachments to make vacuums into paint blowers, powdered plant fertilizer spreaders, and liquid or powder pesticide sprayers. See for example this page from a 1960s-era Universal canister vacuum:
Instruction booklet for a Universal-brand cannister vacuum, showing the attachments used to turn it into a sprayer — and on page 28, a sprayer of DDT insecticide. Image courtesy of VacuumLand (go to that site to see the entire instruction manual).
The greatest dangers of DDT came from broadcast use outdoors. These pictures show indoor use, but in application by an untrained, poorly-equipped amateur. If your exterminator shows up in heels and pearls, fire that company and hire someone else!
In any case, vacuum manufacturers and resellers would often provide virtually every product that could be added to or used with a machine, often at very high markup. In this case, Electrolux had some other company package DDT in a can with the Electrolux label. That can must have been sold before 1972 when over-the-counter sales of DDT ended; it probably was before 1970, when most in-home uses of DDT were ordered to stop. In the photos I have not detected anything to date it, but it must be at least 42 years old.
What a different time it was, when housewives used their vacuums to thoroughly spray their own homes with DDT!