by Meriel Watts
An estimated 1.15 million women were diagnosed with breast cancer in 2002 and 411,000 died from the disease. There are an estimated 4.4 million women alive who have had breast cancer diagnosed within the last five years, and the incidence rate continues to climb in all age groups.
Poisoning from exposure to pesticides is a problem the world over, but most especially in developing countries and most especially for women. Estimates of acute poisoning of agricultural workers range from 1.5 million through 25 million in developing countries alone, to 50–200 million worldwide. An estimated 99 percent of acute poisoning deaths are believed to occur in developing countries.
Women account for more than 50 percent of the agricultural labor force in Asia. In Bangladesh, Cambodia, China, India, Laos, Vietnam, and India, more than 70 percent of women are employed in agriculture, with this figure rising to 98 percent in Bhutan and Nepal. They are severely overexposed to pesticides.
No attempts have been made to estimate how many of these women are affected by chronic poisoning caused by exposure to pesticides. Women in poorer developing countries are much more vulnerable to exposure to pesticides than other agricultural workers. Women who were once self-sufficient farmers have become displaced menial workers in the most marginal positions in the workforce.
Women comprise an estimated 70 percent of the world’s 1.3 billion absolute poor. The number of rural women living in poverty has almost doubled in the last 20 years.
Many of these women have been driven into the plantation sector or into other forms of corporate cash-cropping (such as floriculture) where their exposure to pesticides has increased dramatically. In some countries, women make up 85 percent or more of the pesticide applicators on commercial farms and plantations, often working whilst pregnant or breastfeeding. There are an estimated 30,000 women pesticide sprayers in Malaysia alone. They spray pesticides—and frequently highly toxic ones like paraquat—on average 262 days per year. Eighty percent of the spraying is carried out with leaky hand-held spray equipment. Because of their poverty, an incentive of only 50 cents extra per day is enough to encourage women to spray.
Women work and raise their children in a toxic environment—mixing the pesticides, weeding while they are being applied, washing out the pesticide containers, or harvesting the pesticide-doused crops. They wash pesticide-soaked clothing and store pesticides in their homes.
Women’s exposure to pesticides is significantly higher than is formally recognized and pesticide poisonings are greatly underestimated for women. These problems are compounded by gender biases in epidemiology. Most researchers looking at links between cancer and farming have concentrated on male farmers. There have been very few epidemiological studies investigating a potential link between exposure to pesticides and breast cancer, especially those pesticides in current usage.
Women’s greater vulnerability to pesticides is also overlooked in the toxicological risk assessment of pesticides. Women’s higher proportion of body fat provides a greater reservoir for fat-loving pesticides, some of which are known to be hormonally active and/or carcinogens, and are associated with breast cancer. Women may also absorb pesticides through their skin more easily than men—dermal absorption of the organochlorine lindane has been found to be three times greater for women than for men.
Women’s higher level of hormonally sensitive tissues make them more vulnerable to the effects of pesticides, especially those that are endocrine disruptors, capable of effecting profound changes on hormonally sensitive tissues—such as breast tumors.
According to a March 2003 U.S. Government Accounting Office report, cigarette tobacco has been found to contain traces of the following pesticides:
1,3-dichlorpropene, aldicarb, benefin, carbaryl, carbofuran, chloropicrin, chlorpyrifos, clomazone, dimethomorph, diphenamid, disulfoton, endosulfan, ethephon, ethoprop, fenamiphos, flumetralin, fonofos, imidacloprid, isopropalin, mancozeb, mefenozam pebulate, metalaxyl, methadathion, methomyl, methyl bromide, napropamide, sethoxydim, spinosad, sulfentrazone, and trichlorfon.
Malnutrition can enhance the adverse effects of pesticides. Where there is poverty, there is malnutrition and women are the ones that eat last, the least and the leftovers. As poverty and marginalization have deepened, so has women’s exposure to pesticides increased. Not surprisingly, the corporate economic agenda that has driven women into this position has also failed to do anything to stop the escalating epidemic of breast cancer. While billions of dollars are being poured into an attempt to develop a vaccine against breast cancer, these corporations are contributing almost nothing to preventing breast cancer from occurring in the first place.
Most government breast cancer programs, driven by the self-interest of drug companies and specialist medical sectors, continue to focus on understanding the genetic factors that underlie less than 10 percent of breast cancer cases, on early detection, and on treatment with increasingly expensive and sophisticated drugs like Herceptin.
The U.S. National Breast Cancer Awareness Month was founded and sponsored by Zeneca Chemicals, which ironically earns millions from sales of carcinogenic pesticides such as acetochlor and now, as AstraZeneca, from the breast cancer treatment drug tamoxifen (which is itself carcinogenic). Zeneca was a subsidiary of ICI chemicals. Zeneca/ICI pesticides that increase the risk of breast cancer included lindane, permethrin, cypermethrin and captan. Zeneca also purchased the largest for-profit chain of cancer treatment centers in the U.S., Salick Health Care Inc., neatly assuring profits from both the causing and the curing of breast cancer, as well as massaging their corporate image.
Pesticides can contribute to breast cancer as carcinogens, by disrupting hormones, by altering development of the mammary gland, by undermining the immune system, interfering with intercellular communication, and interfering with metabolic activities. While increasing (but still insufficient) attention is now being paid to some industrial and household chemicals (such as phthalates, bisphenol A, polyvinyl chloride, polycholorinated byphenyls, polycyclic aromatic hydrocarbons and dioxin) as known, probable, or possible causes of breast cancer, scant attention is being paid to the role of pesticides. Generally, only the organochlorine insecticides like DDT have been linked with breast cancer. But this review has, conservatively, identified 98 pesticides (plus one adjuvant and two contaminants) as potentially increasing the risk of breast cancer. Most of these, unlike the organochlorines, are still in widespread use in many countries.
Most of the pesticides implicated in breast cancer are still in common use because of the prevailing regulatory failure to access up-to-date independent scientific research, and to apply the Precautionary Principle. Instead, regulators invariable rely on toxicological data provided by the pesticide manufacturers as “proof” that a pesticide is “acceptable” because it doesn’t identify effects such as breast cancer. This regulatory approach is underpinned by an increasingly widely applied paradigm of “science-based” decision-making. “Science-based” decision-making is erroneously taken to mean quantitative risk assessment and proof of a causal link between a pesticide and an “unacceptable” effect before action should be taken.
In the words of Dr. Janette Sherman, Adjunct Professor in the Department of Environmental Sciences, Western Michigan University, this “grant[s] to chemical companies the right to claim their product ‘innocent’ until proven guilty beyond the shadow of a doubt.” The burden of proof then falls on the community and those who work in the public interest. Decision-making based on quantitative risk assessment and the need for causal proof is, in fact, politically-based, not science-based, because it implicitly places more importance on the commercialization of pesticides than it does on the community’s health.
Chronic effects are complex and difficult to link back to pesticide exposure and, especially, to prove. They usually arise from ongoing low-dose exposures to pesticides that do not result in acute poisoning. Thus, the real effects of that exposure often lie below the radar. As breast cancer can have a very long latency period, linking its onset to an original pesticide exposure is extraordinarily difficult. For some pesticides, such as DDT and dieldrin, there is sufficient evidence of sufficient quality to assert a positive link with breast cancer.
Some, like the triazine herbicides, remain a subject of controversy. For others, the evidence is slimmer, largely because of a lack of studies. They are included in the list of 98 on the basis of the Precautionary Principle—as an early warning that these pesticides possess the ability to interfere with mechanisms involved in the genesis and development of breast cancer.
In 2003, the British Royal Commission on Environmental Pollution, alarmed at the rising concentration of synthetic chemicals in breast milk and human tissues, recommended that “steps be taken to remove them from the market immediately.” There is no longer any doubt that exposure to toxic synthetic chemicals contributes significantly to cancers worldwide, including breast cancer. As the Standing Committee of European Doctors concluded in 2005: “The current proliferation of a number of diseases is a consequence of environmental degradation and that chemical pollution poses a serious threat to children and to the human race.”
Meriel Watts, PhD, is a PAN Asia/Pacific scientist, the coordinator of PAN Aotearoa/New Zealand and an environmental advisor to the New Zealand Government. Pesticides and Breast Cancer: A Wake-Up Call was published by PAN Asia and the Pacific (2007) and is available from www.panap.net. This excerpt is published with the permission of the author and the publisher.
101 Chemicals Linked to Breast Cancer
Organochlorine Insecticides
DDT, dieldrin, chlordane, methoxychlor, heptachlor, endosulfan, lindane (HCH, BHC), toxaphene, hexachlorobenzene (HBC), chlordecone, dicofol, mirex, endrin, aldrin
Synthetic Pyrethroid Insecticides
Permethrin, deltamethrin, cypermethrin, fenvalerate, d-trans allethrin, sumithrin (d-phenothrin), cyhalothrin, flucythrinate, pyrethrins, cyfluthrin
Organophosphate and Carbamate Insecticides
Malathion, parathion, diclorvos, methyl parathion, chlorpyrifos, diazinon
Other OPs: bromophos-ethyl, bromophos-methyl, butamiphos, cyanofenphos, dichlofenthion, ethion, EPN, isofenphos, isoxathion, leptophos, monocrotophos, omethoate, phenthoate, phosmet, pirimiphos-methyl prothiophos, quinalphos, tolchlofos-methyl
Carbamates: aldicarb, propamocarb, pirimicarb, methiocarb
Triazine Herbicides
Atrazine, simazine, cyanazine, propazine
Other triazines: terbuthylazine, terbumeton, terbutryn
Other Herbicides
2,4-D, paraquat, alachlor, diuron, triclopyr, tribenuron methyl, oryzalin, ethalfluraline, sulfallate, prosulfuron, silvex (2,4,5-TP/fenoprop), trifluralin
Others: chlornitrofen, diclofop-methyl, fluazifop-butyl, pendimethalin, thenylchlor
Fungicides
Mancozeb, captafol, folpet, fenarimol, triphenyltin, captan, maneb, vinclozolin
Others: biphenyl, dodemorph, triademefon, triademenol
Other Pesticides
DBCP (1,2-dibromo-3-chloropropane), ethylene dibromide (1,2-dibromoethane), ethylene dichloride (1,2-dichloroethane), ethylene oxide, propylene dichloride (1,2-dichloropropane), PFOS (perfluorooctane sulfonic acid potassium salt), clonitralid, chlorobenzilate
Others: bromopropylate, chloropropylate
Adjuvants, Inerts and Contaminants
Nonylphenol, 1,4-dioxane, dioxin