By Maria C. Powell, PhD
Note: All citations have been removed for ease of reading. If you are interested in sources for specific points, please contact Maria Powell at mariapowell@mejo.us
Oscar Mayer’s insecticide experiments and manufacturing
Oscar Mayer did much more than raise and slaughter animals and produce processed meat products. From the beginning, the company prided itself on scientific innovations. In 1929, it started its own “research bureau” at the plant. Dr. D. H Nelson from the University of Wisconsin, who specialized in chemistry and bacteriology, was hired to direct it. According to the Wisconsin State Journal, the bureau included “a laboratory for experimentation in new food and medicinal products, package product research, utilization of wastes, and chemical control, including analysis of ingredients used in the processing of meats.”
Most meat manufacturers at that time made insecticides to deal with cockroaches and other insect pests in their animal stockyards, as well as inside their factories—and Oscar Mayer was no different.[1] As the company expanded, several laboratories were built onsite, where scientists developed new types of processed meats, pharmaceuticals and insecticides for animal and factory diseases and/or pests, and spices for meat products. It isn’t clear exactly when Oscar Mayer began producing pesticides in their labs, but it was likely right at the start. (Photo: Oscar Mayer in 1931, Wisconsin State Journal)
Earlier pesticide formulations were probably simple (e.g., arsenic and copper compounds), but during and after World War II, increasingly sophisticated petroleum and halogen (chlorine, fluorine, bromine) science developed for war purposes created a whole new toolbox for chemists to devise innovative, more toxic and non-biodegradable pesticides. The use of chlorinated pesticides, especially DDT and organophosphates (developed as nerve agents in the war) exploded. Oscar Mayer scientists also used these new tools to produce pesticides during and after the war, as well as using pesticides created by others, such as DDT, Malathion, and more.
Oscar Mayer-UW-City of Madison Burke insecticide experiments
Oscar Mayer began insecticide experiments at the Burke plant and surrounding lands some time during or after World War II; it isn’t clear exactly when. The military began using DDT (in kerosene) at Truax Field for flies and other pests in 1945; some of these applications likely overlapped with Burke land, part of Truax Field.
In 1952, after fishermen complained that bluegills from Starkweather Creek tasted like oil, the city biochemist in charge of “stream pollution studies” for the rivers and lakes commission investigated and traced an “‘oil slick’ upstream to Truax field” where he said, “mosquito control work had been underway.”
In 1959, with the cooperation of the City of Madison Health Department and the University of Wisconsin Entomology Department, Oscar Mayer initiated insecticide studies at the Burke sewage lagoons. The studies, led by Oscar Mayer project engineer Roger P. Scovill, piggy-backed on the irrigation experiments they had been doing at Burke since 1950, in which wastewater from the Burke plant was used to irrigate fields of reed canary grass and other vegetation planted in the areas around the sewage plant. The main purpose of these projects was to find ways to reduce costs to Oscar Mayer for sewage disposal—by disposing of the sewage in the neighborhood.
Oscar Mayer’s 1959-1962 insecticide studies had similar goals—to reduce sewage disposal costs. According to a 1963 paper Scovill published on the experiments in the journal of the “Water Pollution Control Federation,” the studies had two purposes. The first was “to enable disposal of wastewater in a manner devoid of nuisance conditions resulting from insect propagation or due to objectionable odors,” and the second was “to reduce the sewage service costs of the company by reduction of the volume of wastewater discharged to city sewers.”
DDT and several other insecticides were applied to Burke lagoons and fields
Experiments involved adding one or a combination of several insecticides (DDT, Phosdrin, Baytex, Malathion) to “lagoon influents” coming from the Burke plant to see what doses and combinations would prevent mosquito larvae from hatching. The pesticide-infused water was also used to irrigate the “south field,” which “drained by percolation through the soil to Starkweather Creek.” (The garden plots just south of this field were presumably the public health “sludge gardens” set up in the 1930s for homeless and poor people to help sustain their families (see previous Oscar Mayer story)[2]
Map of Burke lagoons, pesticide treatment areas, creek and garden plots (1963 Scovill paper)
In 1959, Phosdrin (also called Mevinphos and other trade names) was used because it is “completely miscible in water.” This proved not to be fully effective for several reasons. Mosquitoes continued to emerging in irrigated areas, so “in small ponds and ditch sections, emergence was controlled by hand distribution of five percent DDT in Number 2 fuel oil.” In 1959, 91 pounds of Phosdrin were applied, and when that didn’t work well, in 1960 the amount was increased to 116 pounds, which also proved less effective than hoped. Consequently, the next year they tried a combination of 6 pounds of Phosdrin, 155 pounds of DDT, and 3.2 pounds of Baytex (also called Fenthion). In 1962, 30 pounds of Baytex plus 30 gallons of 25 percent DDT solution were applied. Scovill also noted that “Irrigation of the south field was conducted at a rate which would allow all water to be disposed of within 7 to 11 days. Whenever small ponds of standing water existed, the water was treated with DDT and Malathion sprayed onto the surface.”
Effects on workers, aquatic life, fish, birds? No worries…
Scovill’s paper on the insecticide experiments was published one year after Rachel Carson wrote her seminal and highly popular book Silent Spring, which eloquently described the long term toxic effects of DDT as well as other chlorinated and organophosphate pesticides on birds, wildlife—and, over the long term, humans.
When the paper was published in 1963, Scovill was an Associate Public Health Engineer with the Wisconsin State Board of Health. By this time, he and his university and city collaborators would have been well aware of Carson’s highly publicized book and the science showing that DDT and the organophosphates are very toxic to life. Scientists and citizens began raising concerns about the toxicity of DDT as early as 1945, if not earlier–years before Carson’s book was published. A Wisconsin bill to regulate DDT and the related chlorinated organic insecticide 2, 4-D because of their “possible ill effects” was proposed by 1948. It’s not clear what happened with this bill, but scientific studies documenting how toxic DDT, other chlorinated insecticides and organophosphates were to birds, wildlife, and humans piled up in the years between then and his 1959-1962 studies at Burke.
Yet Scovill’s paper did not mention any toxicity concerns about DDT, and he only minimally mentioned concerns about the organophosphate insecticides used in the experiments. Deflecting concerns about workers’ exposures, he noted that Phosdrin “is very highly toxic…and must be handled with extreme care to avoid ingestion, absorption, or inhalation…” but assured that the chemical is “not accumulatively toxic” and workers responsible for applying it would not have much contact with its distribution would be automated. [3] He later noted that Baytex, made by Chemagro Corporation, “is in the intermediate class of organic phosphate pesticides as far as mammalian toxicity is concerned,” but did not elaborate further. No mention was made of the hand-distribution of DDT and Malathion-spraying, presumably by Oscar Mayer workers.
As for effects on wildlife and the creek, the paper was laughably non-scientific—it implied that the presence of much wildlife in the testing areas meant that the insecticides were not harming them. A section titled “Effects on Wildlife” said: “Throughout the experimentation with both Phosdrin and Baytex the lagoons were heavily populated with ducks of several species and with pheasants. Numerous woodchucks and some muskrats and skunks lived in the lagoon embankments. Other small birds, mostly red-wing blackbirds and sandpipers were very numerous. The environment was ideal for propagation of wildlife and no deleterious effects were observed at any time.” This was the entirety of the analysis of the “effects on wildlife.”[4]
A section called “Effects on Streams Receiving Percolating Water” said nothing whatsoever about actual or potential toxic effects on aquatic life of the insecticides in Starkweather Creek: “Sampling stations previously established in investigations for irrigation of wastewater in the lagoons were upstream of the lagoon area in Starkweather Creek and approximately 1,500 ft downstream from the area. Samples of the creek water are collected weekly and analyzed for 5-day BOD, total nitrogen, and chlorides. Chlorides ordinarily increased approximately 114 ppm, increases in BOD and total nitrogen were small and within the range of normal sampling and analyses errors. Rough fish spawned in ditch areas upstream from the lagoons and numerous turtles were present in the creek.” Levels of pesticides in the creek weren’t monitored at all.
Not only did this section not mention the effects of insecticides on creek life, it ignored effects of the huge amounts of chloride, total nitrogen, suspended solids and increases in BOD in lagoon influents and irrigation water. Nitrogen levels, according to Scovill, averaged 72 mg/L (ppm) in the irrigated wastewater, with 16.4 tons discharged into the lagoons and 5.7 tons to the south field during the 1962 season.
These are astounding levels of nitrogen being emitted from the Burke plant effluents (from Oscar Mayer waste treatment) and then into Starkweather and Lake Monona–contributing greatly to the nutrient loads and algae problems. To put these levels in perspective, according to EPA, the “acceptable range” of total nitrogen in surface waters is 2-6 mg/L.[5] Chlorides in lagoon influents were from 1,702 to 1,926 mg/L. The DNR water quality standards for chloride, based on aquatic life toxicity, are 395 mg/L (chronic) and 757 mg/L (acute).[6]
Did the insecticides work? Did Oscar Mayer continue to treat Burke lagoons after 1963?
Complete mixing of the chemicals in the lagoon and irrigation water proved to be challenging, and the effectiveness of the treatments were limited beyond a certain distance away from the application points. Scovill concluded that “complete mixing would not take place under the existing field conditions without forced circulation of the water and that effective control could not be obtained over the entire lagoon at insecticide concentrations less than 0.5 ppm when a mosquito larvae infestation of standing water existed.”
After trying different concentrations of insecticides under various conditions, ultimately Scovill concluded that “For mosquito control in an industrial waste lagoon containing dense, emergent vegetation, and irrigated with water containing organic material, dissolved and suspended solids, the use of Baytex at 0.2 ppm…will prevent emergence of mosquitoes for up to 14 days over 6.7 acres of area with the insecticide added into the influent, total length of the lagoon being 1800 feet.” Scovill also calculated the cost savings to Oscar Mayer from continuing to irrigate the fields instead of sending wastes to the Nine Springs sewer plant: “On the basis of the 1961 experience for costs, which were estimated to result in a savings of $51.87/mil gal of water irrigated due to the reduction in the sewer service charges, a total savings of $4,160 will result from the irrigation of 80.2 mil gal in fiscal year 1962.”
The paper didn’t say what kinds of insecticide treatments Oscar Mayer and its collaborators planned at Burke for coming years based on these findings. Continuing to dispose of this wastewater at Burke to save on sewage disposal costs was dependent on the use of insecticides to keep the mosquitoes and other insects under control (the public health department likely required this). Given this, presumably Oscar Mayer continued to treat the lagoons with insecticides for years afterwards (though we found no further information on that).
Oscar Mayer insecticide manufacture and uses after 1963
Whether or not Oscar Mayer kept treating the Burke lagoons with insecticides, the company definitely manufactured them in their laboratories and used them both inside the factory and in their animal yards outside.
A May 2020 Environmental Site Assessment (ESA) by Sigma, a consulting firm contracted by the City of Madison (when it was planning to purchase the northern parcel of the Oscar Mayer site) said the following (highlights added):[7]
“Ramboll Environ reviewed online documentation available through the USEPA, which indicated that insecticides, including space spray, pyrethrum, and lethane, were manufactured on the Oscar Mayer property in the late 1960s. The Ramboll Environ report did not elaborate on the source of this information. Sigma conducted a search of the USEPA’s Pesticide Product Information System (PPIS) and determined that Oscar Mayer & Co., located at 910 Mayer Ave, was a registered (Company Number 8514) manufacturer of three insecticides:
- Space Spray (USDA/EPA Registration Number 8514-2, no stock item number listed), an insecticide which was first registered in 1964 and accepted by the USEPA in 1967. The product label for Space Spray kept by the USEPA is largely illegible. No legible ingredient information was included.
- Pyrethrum Insecticide for Fogging (USDA/EPA Reg. No. 8514-3, Stock Item 91-0034), an insecticide which was first registered in 1964 and accepted by the USEPA in 1967. The product label states that it contained 0.3% pyrethrins, 1%technical piperonyl butoxide, and 98.7 petroleum distillate.
- Lethane Insecticide for Fogging (USDA/EPA Reg. No. 8514-4, Stock Item 91-036), an insecticide which was first registered in 1964 and accepted in 1968. The ingredient section of the product label is largely illegible. A product label for lethane produced by Rohm & Haas indicated that lethane contained 53% beta-butoxy beta-thiocyano diethyl ether and 47% petroleum distillate.
According to the ESA, “The manufacturing of all three insecticides was considered inactive as of May 1, 1987.” The chemical makeup of the “space spray” is unknown. Pyrethrum includes natural compounds (pyrethrins), but 99.7% of the insecticide is petroleum distillate and piperonyl butoxide.[8] The Dec. 11, 1968 EPA document on Oscar Mayer’s manufacture of Lethane, made up of about half “beta-butoxy beta-thiocyano diethyl ether” and half petroleum distillate says the insecticide “can be used in edible product production departments in the absence of food provided the area and the equipment located therein is thoroughly cleaned with detergent” and “can be used in inedible product areas, stockpens, yards, and out buildings.” Lethane was also intended for use in “thermal foggers” and “conventional spraying equipment.”
Sigma also stated that “[i]n addition to Space Spray, lethane and pyrethrum, the insecticide chlordane was authorized for use for Oscar Mayer.” Chlordane is an especially toxic chlorinated insecticide. According to Wikipedia, EPA banned chlordane in 1988. It is classified among the “dirty dozen” and was banned by the 2001 Stockholm Convention on Persistent Organic Pollutants. It builds up in the fatty tissues of animals and humans and is highly toxic to fish. Human exposures to chlordane and its breakdown products have been associated with type-2 diabetes, lymphoma, prostate cancer, obesity, testicular cancer, and breast cancer—as well as several non-cancer effects, including respiratory infections, immune-system activation, anxiety, depression, blurry vision, confusion, intractable seizures and permanent neurological damage.
What insecticidal compounds remain at Oscar Mayer now? At Burke? Has anyone tested?
The organophosphate insecticides are very toxic, but most tend to break down fairly quickly in the environment (one reason they have to be repeatedly applied). The chlorinated insecticides like DDT are another story. Chlordane is very persistent; it has an environmental half-life of 10 to 20 years. “Given the environmental persistence of chlordane,” the Sigma report noted, “releases related to the manufacturing and/or usage of insecticides may have impacted the subject property via soil or groundwater.”
We don’t know what other insecticides Oscar Mayer manufactured and used at the factory site (indoors and outdoors) or all the types of insecticidal chemicals they tested in their experiments at Burke. Some of these insecticides could have included PFAS, as the Sigma report noted.
Given the known and potential serious health and environmental effects of these chemicals, the fact that residential development is planned for the Oscar Mayer site, and runoff from this site and Burke goes into Starkweather Creek, Yahara River, and Lake Monona—DNR should ask the owners of Oscar Mayer and Burke sites to test for a range of insecticides–as well as herbicides, also likely used at both sites–as soon as possible.
[1] Chicago meat processor B. Heller and Company, for example, was also the proprietor of the Chicago Insecticide Laboratory. “The effects of insecticides on human consumers were not taken as seriously as they are now,” historical materials noted “From Sausage to Hot Dog,” B. Heller and Co.Collection 1896-2003, Special Collections, University of Chicago Library.
[2] It’s not clear who was using these plots by the 1950s and 1960s.
[3] Phosdrin is still used in the U.S. but is banned in the European Union
[4] From Wikipedia, March 31, 2021: “Amid concerns of harmful effects on environment, especially birds, Food and Drug Administration no longer approves uses of fenthion…After preliminary risk assessments on human health and environment in 1998 and its revision in 1999, USEPA issued an Interim Reregistration Eligibility Decision (IRED) for fenthion in January 2001. The EPA has classified fenthion as Restricted Use Pesticide (RUP), and warrants special handling because of its toxicity.”
[5] As of 2021, astoundingly, the Wisconsin DNR hasn’t set any surface water nitrogen standards, likely due to agriculture and industrial lobbying.
[6]Chronic toxicity (DNR): The ability of a substance to cause an adverse effect in an organism that results from exposure to the substance for a time period representing that substantial portion of the natural life expectance of that organism. Acute toxicity (DNR): The ability of a substance to cause mortality or an adverse effect in an organism that results from a single or short-term exposure to the substance.
[7] The ESA raised doubts about whether insecticides were actually manufactured at Oscar Mayer, but based on the company’s history, the fact that it had several chemistry labs and insecticide patents, and did pesticide studies and experiments, we think it is highly likely that they were.
[8] Piperonyl Butoxide is a synthetic derivative of benzodioxole and used as an insecticide synergist, Piperonyl Butoxide enhances the active properties of pyrethrin, pyrethroid, rotenone, and carbamate pesticide ingredients by inhibiting insect microsomal enzyme detoxification activity. It is toxic and suspected of causing anorexia, carcinogenesis, convulsions, and dermal irritation, as well as hepatic and renal damage. (NCI04)
(c) 2021 Maria C. Powell
