EPA Announced Intention to Ban Carbofuran in July 2008
Carbofuran (commercial name is "Furadan") is one of the most widely used pesticides in the world. It also happens to be one of the most toxic pesticides ever manufactured. It kills millions of wild birds, bees, and other wildlife each year. It causes an untold number of cancers in humans each year. Scientists have found that 45% of urban African-American women in the United States have detectable levels of carbofuran in their plasma (Bonner et al., 2005). It is a toxic pollutant in our surface waters and groundwater—our sources of drinking water. Good news: It is to be banned by the United States Environmental Protection Agency (EPA).
The EPA announced on July 24, 2008, that it will no longer allow residue of the toxic pesticide carbofuran on domestic or imported food, a decision that would effectively remove the chemical from the U.S. market. This ban is good news for reducing water pollution and possible contamination of our drinking water and groundwater. . In 1994, the US Congress banned the granular form of carbofuran, which was blamed for the deaths of more than a million birds each year because birds often mistook the granular pesticide for seeds. In humans, the pesticide can cause long-term damage to the body's neurological and reproductive systems (New York Times, July 25, 2008; the Associated Press, July 24, 2008).
Statistics on the use of carbofuran varies: scientists publishing in a peer-reviewed research article estimated that 5 million pounds of carbofuran are used in the US annually (Bonner et al., 2005), while the Washington Post published that only 1 million pounds of carbofuran are applied each year affecting less than 1% of the US farmed acres according to the EPA (July 25, 2008). The EPA had indicated in early 2008 that it would not apply the ban to imported food, but it reversed the decision on July 24 and said it will. (Washington Post, July 25, 2008) This pesticide is particularly popular in China for killing pests afflicting rice, cotton, corn, soybean, and sugar cane crops (New York Times, July 25, 2008).
Carbofuran as a carbamate insecticide is registered for use for the following crops in the United States (Washington Post, July 25, 2008):
- Sugar cane
However, this list of crops should be a lot longer. According to the EPA, EPA is proposing to revoke all of the existing tolerances for residues of carbofuran. Currently, tolerances have been established on the following crops: alfalfa, fresh; alfalfa, hay; artichoke, globe; banana; barley, grain; barley, straw, sugar beet; sugar beet, tops; coffee bean; corn, forage; corn, fresh (including sweet corn); corn, grain (including popcorn); corn, stover; cotton, undelinted seed; cranberry; cucumber; grape; grape (raisin); melon; milk; oat, grain; oat, straw; pepper; potato; pumpkin; raisins, waste; rice, grain; rice, straw; sorghum, fodder; sorghum, forage; sorghum, grain; strawberry; soybean; soybean, forage; soybean, hay; squash; sugarcane, cane; sunflower, seed; wheat, grain; wheat, straw. The EPA is proposing to revoke tolerances for these crops because aggregate dietary exposure to residues of carbofuran, including all anticipated dietary exposures and all other exposures for which there is reliable information, is not safe (EPA, 40 CFR, Part 180; EPA-HQ-OPP-2005-0162).
The EPA documented in 2006 that it knew of carbofuran's toll on wildlife: It found that if a flock of mallard ducks (see photographs of mallard ducks below) wandered into an alfalfa field within a week after the pesticide was applied, 84% of the ducks would die (Washington Post, July 25, 2008).
What Is Carbofuran?
The Chemical Structure and Chemistry of Carbofuran
Carbofuran is one of the most toxic pesticides ever manufactured. It is a carbamate type of pesticide. Its chemical structure is presented as follows (middle: a three-dimensional model of the compound) and carbofuran grains are shown here:
Toxicity of Carbofuran: Cancers among Agricultural Workers
As one of the most toxic pesticides ever produced, carbofuran's toxicity and carcinogenicity have been investigated by scientists. The EPA published in a fact sheet that carbofuran "can overstimulate the nervous system, causing nausea, dizziness, confusion, and at very high exposures respiratory paralysis and death." A one-quarter teaspoon (1 mL) of carbofuran can be fatal to humans.
Scientists have found that 45% of urban African-American women in the United States have detectable levels of carbofuran in their plasma (Bonner et al., 2005). The scientists with the Occupational and Environmental Epidemiology Branch of the Division of Cancer Epidemiology and Genetics with the National Cancer Institute (Bethesda, Maryland, U.S.A.), Korea University's College of Medicine, and the Epidemiology Branch of National Institute of Environmental Health Sciences (USA) found that
"...the metabolites of carbofuran may be mutagenic, and there is good evidence that nitrosated carbofuran is mutagenic. This study suggests that carbofuran may be associated with an increase in the incidence of lung cancer" (Bonner et al., 2005).
Additionally, these scientists concluded that
"An association between carbofuran and lung cancer has not been previously reported. Several studies, however, have found pesticides (Brownson et al. 1993; Wesseling et al. 1999) and more specifically carbamate pesticides (Pesatori et al. 1994) to be associated with lung cancer, although not all studies have reported this association (McDuffie et al. 1990). In our study, lung cancer was associated with lifetime exposure-days where risk increased across exposure categories to more than a 3-fold increase in the RR in the highest category when compared with those who had applied < 9 lifetime exposure-days. The risk estimates were also elevated when the components of the lifetime exposure-days exposure metric were considered separately" (Bonner et al., 2005).
In another study of non-smoking farm women exposed to pesticides, scientists with the National Institutes of Health (Department of Health and Human Services, USA) found that "Pesticides as well as grain and dust exposures were associated with chronic bronchitis among nonsmoking farm women" (Valcin et al., 2007).
Toxicity of Carbofuran to Local Birds and Migratory Songbirds in the United States
Carbofuran is one of the most toxic carbamate pesticides ever manufactured. Not only does carbofuran pose health hazards to farm workers, the pesticide is most dangerous to wildlife. In the 1980s carbofuran first came under fire after EPA estimated that more than a million birds were killed each year by the easily eaten granular formulation, which was banned by the agency in 1994 (Chemical & Engineering News, February 13, 2008). Since then, the liquid form of the pesticide has remained on the market and is still used to spray crops and kill insects—until July 2008 when EPA announced intentions to ban this pesticide.
According to two US environmental groups, Nature Conservancy and Natural Resources Defense Council, carbofuran has killed millions of wild birds—including golden and bald eagles, red-tailed hawks, and migratory songbirds—during the past four decades that this pesticide was in use (Washington Post, July 25, 2008). A spokesman for the American Bird Conservancy said, "This is really a big step for wildlife. I think the EPA deserves a lot of credit for trying to figure out a way to get this done quickly" (The Associated Press, July 24, 2008).
One study linked carbofuran to dieoff of 558 separate bird flocks since 1972 (Denver Post, March 3, 2008).
Photographs: Millions of migratory songbirds and eagles are killed each year by carbofuran pesticide.
also kills bees, which have experienced an unexplained massive population
collapse in recent years (Washington Post, July 25, 2008).
Toxicity of Carbofuran to Wildlife in Africa:
Dead Hippos and Poisoned Lions and Vultures
Carbofuran is widely used in Africa. In northern Tanzania, for examples, small farmers use carbofuran and a wide variety of pesticides, fungicides, herbicides, nematicides, and rodenticides (Ngowi et al., 2007). But it is in Kenya where carbofuran gained the most notoriety. In April 2008, Dr. Richard Leakey, the famed archaeologist, issued a warning about carbofuran killing hippos and subsequently poisoning lions that ate hippo carcasses in Kenya's wildlife park. He said, "Incidences of poisoning represent a critical threat against Kenya's wildlife particularly through the use of Carbofuran."
According to WildlifeDirect.org, intentional poisoning of predators by farmers is frequent:
"Several cases of intentional use of carbofuran to kill predators have also been reported to the Kenya Wildlife Authorities. Earlier this year, conservation group, the Lion Guardians reported a case of two lions intentionally poisoned in Kajiado, Kenya. Poisoning is not only decimating Kenya's lion population which is estimated to be mere 2,000 individuals but also scavengers birds such as vultures and other birds of prey. In 2004, 187 vultures died as a result of just one poisoning incident. Raptor specialist, Simon Thomsett believes, "that if the current level of usage continues, it is possible that two different species of vultures in Kenya could go extinct within the next ten years."
Photographs: Dr. Richard Leakey urged Kenya to ban carbofuran: Hippos died after eating vegetation sprayed with carbofuran. Hippo carcasses were eaten by lions, which subsequently poisoned and paralyzed them in the Mara Conservancy.
In the 1990s, concerns about carbofuran were first raised when large number of wild ducks and other waterfowl were poisoned and killed near Ahero (western Kenya) and Mwea (central Kenya) rice fields, according to the WildlifeDirect.org. The poisoned waterfowl were then sold for human consumption in the local markets.
According to WildlifeDirect.org, there are several well-documented cases of wildlife poisoning in Kenya, as follows:
- November 2007—near Lewa Wildlife Conservancy, Isiolo District a camel that had been killed by lions was smeared with Furadan (the commercial name of carbofuran) by local pastoralists with the purpose of killing predators that came to feast on the carcass. As a result, at least two lions and 15 vultures died and their bodies were collected in the immediate vicinity of the carcass.
- 2007 and 2008—near Lewa, a group of nine lions from the nearby Samburu reserve were poisoned; five of which died along with large numbers of birds of prey and other scavenging animals.
- April 2005—the poisoning of at least 30 vultures occurred near Athi River.
- March 2005—a breeding Mackinder's eagle owl was a victim of secondary poisoning after eating dying mousebirds that were poisoned with Furadan by farmers near Mweiga, Nyeri District.
- April 2004—the largest-known incident of vulture deaths in Kenya occurred near Athi River when 187 vultures died as a result of carbofuran poisoning. The hardest-hit species were white-backed vultures, but Ruppell's griffin and lappet-faced vultures also died. A large portion of the resident hyena population also perished.
Pesticides in Our Food and Drinking Water:
How to Avoid Toxic Contaminants
Both public and private water supplies—wells or groundwater, rivers, streams, and lakes—can be sources of toxic exposure, especially for pesticides, herbicides, industrial solvents, heavy metals, and fertilizers.
The best way to avoid drinking pesticide contamination of our drinking water is to use filters (such as filters used in reverse-osmosis, or R.O., systems) to purify our drinking water. Carbofuran and other carbamate-type pesticides can be filtered out using common household R.O. systems.
Another way to avoid pesticides in our food and water is to purchase local and organic foods whenever possible. The U.S. EPA has proposed to ban carbofuran, but other countries have not banned this pesticide which is considered to be one of the most toxic ever manufactured. Vegetables, grains, and fruits sprayed with carbofuran in other countries are imported into the United States largely unregulated and unchecked. Therefore, it is safest to buy produce locally and it is always the best if people can afford to buy organic produce.
The best way to avoid pesticides in our food, however, is to consume less meat whenever possible or to avoid eating meat altogether. Livestock are fed with grains—often with conventionally grown, or pesticide-sprayed, grains. (If you're a farmer, you would not pay top dollars to buy "certified-organic" grains and feed for your cattle—unless you plan to sell that cattle's beef as certified-organic beef. Certified-organic feeds are simply too expensive as animal feeds if farmers do not plan to sell their meat as organic!) The pesticides then build up in the animals' bodies through the process of bioaccumulation. When humans eat these conventionally raised animals, the load of toxins and pesticides then transfer to humans via meat ingestion. Yes, vegetarians who also eat pesticide-laced vegetables and grains also will have pesticides accumulating in their bodies—but at much less than those carnivores. How does this bioaccumulation work? Let's assume that a steer eats five pounds of grains in order to gain one pound of flesh. When we eat that pound of beef, then we accumulate five times the pesticide residues in that pound of beef than if we were to eat that one pound of food in grains. Similarly, if it takes two pounds of feed to fatten a chicken by a pound, then when we eat that one pound of chicken meat, we will acquire twice the toxic residues than if we were to eat one pound of grains directly. Over a lifetime of several decades, these toxic residues do build up to a significant degree in people, which often leading to various diseases including cancers in people later in life. This is why people who eat more meat will have more pesticides and other toxic residues accumulating in their body than those who avoid eating meat altogether.
EPA Fact Sheet on Carbofuran.
The United States Environmental Protection Agency. 40 CFR, Part 180; EPA-HQ-OPP-2005-0162. "Carbofuran; Proposed Tolerance Revocations."
Matthew R. Bonner, Won Jin Lee, Dale P. Sandler, Jane A. Hoppin, Mustafa Dosemeci, and Michael C. R. Alavanja. 2005. "Occupational Exposure to Carbofuran and the Incidence of Cancer in the Agricultural Health Study," in Environmental Health Perspectives, Volume 113, Number 3, March 2005, pages 285-289.
Martin Valcin, Paul K. Henneberger, Greg J. Kullman, David M. Umbach, Stephanie J. London, Michael CR Alavanja, Dale P. Sandler, and Jane A. Hoppin. 2007. "Chronic bronchitis among non-smoking farm women in the Agricultural Health Study," in Journal of Occupational and Environmental Medicine, Volume 49, Number 5, May 2007, pages 574-583.
A.V.F. Ngowi, T.J. Mbise, A.S.M. Ijani, L. London, and O. C. Ajayi. 2007. "Pesticides use by smallholder farmers in vegetable production in Northern Tanzania," in Crop Protection, Volume 26, Number 11, November 2007, pages 1617-1624.
Chemical & Engineering News. February 13, 2008. "EPA Ban. FMC Defends Carbofuran: EPA wants to ban controversial pesticide, but manufacturer says agency ignores science," by Glenn Hess.
The Denver Post. March 3, 2008. "Cutting Carbofuran. EPA attempt to ban bird-killing pesticide runs into opposition," posted by Grist.com.
The Associated Press. July 24, 2008. "EPA moves to ban pesticide carbofuran from food," published by the Las Vegas Sun and CBS News.
The Washington Post. July 25, 2008. "In Surprise Move, EPA Bans Carbofuran Residue on Food," Page A02, by Juliet Eilperin.
The New York Times. July 25, 2008. "E.P.A. to Ban Use of a Pesticide," by Ashley Southall.
The Associated Press. July 25, 2008. "US environmental agency proposes carbofuran ban in food seeking to get pesticide off market," published in the International Herald Tribune.
WildlifeDirect.org Web site. (This is a wildlife charity based in Kenya, founded by Dr. Richard Leakey who envisioned the need for alternative sources of wildlife conservation funding to save Africa's rich wildlife heritage in case tourism fails.)
No More Carbofuran in Our Water!