BUAV condemns university duplication of chemical tests on animals
The BUAV has today raised concerns about the growing trend for universities to duplicate animal tests to re-assess the safety of controversial substances. The BUAV has uncovered recent examples of universities in the EU and USA inappropriately re-testing chemicals and genetically modified (GM) food that have already undergone extensive tests (see examples below). The testing is of additional concern to the BUAV because it often duplicates animal experiments carried out by the manufacturers for regulatory purposes.
New and existing chemicals have to undergo safety tests in which animals are exposed to high doses of a substance. A substance undergoes several types of these animal tests and if no overriding concerns are found the substance is placed on the market. For controversial substances like GM food and pesticides, scientists based in universities can receive public funding to re-assess the safety of these substances in response to apparent public concern. The BUAV claims that by repeating these already flawed studies, universities are simply adding to the number of wasteful safety studies carried out on innocent animals every year.
The BUAV research shows that these academic studies are often criticised by the regulatory community because they do not follow standard protocols. For example, they may use a different number of animals compared to the standard regulatory tests, use inappropriate routes of administration such as injection or use unrealistically high doses. Furthermore, they may not have been conducted according to good laboratory practice (GLP) or under blind conditions (where the researchers do not know what they are testing to remove bias). Some of the animal tests may be novel, speculative tests looking for specific effects for which there is no established animal ‘model’. The results are often dismissed by the chemical manufacturers and the regulatory authorities for these reasons.
As a result of the inherent doubts about the validity of all animal tests, the safety of substances such as pesticides, flame retardants and bisphenol A has been debated for decades. The BUAV’s experience is that adding more, inconsistent animal data, generated under different conditions, to the knowledge base on a substance simply compounds the problem. Once a chemical is already on the market, information from well-designed human epidemiological (population) or workplace studies that demonstrates a potential effect in humans carry more weight than additional animal studies but researchers are reluctant to conduct these as they are more expensive and time consuming.
The BUAV is calling on national authorities to prevent speculative and duplicative animal tests such as these and to insist that university researchers employ non-animal methods such as in vitro tests and human workplace studies to assess genuine concerns about the safety of chemicals instead of animals. Repeating animal tests ad nauseum will not lead to greater human safety.
Pesticides are substances that are used to repel plants or animals deemed ‘pests’ such as weeds, insects or larger animals including fish and rats. They are most commonly used for plant or crop protection and their effect on human health has been a source of controversy for many years. In order to assess whether there is a link between pesticide exposure and Parkinson’s disease in humans, researchers at Dresden University in Germany force-fed mice the pesticide rotenone through a tube directly into their stomachs every day for up to four months.1 To monitor the progression of the chemically-induced form of the disease, the mice were placed on a suspended rotating cylinder nine times every month to determine their ability to keep moving in order to avoid falling off. This is designed as a crude measure of the extent of brain damage as brain damaged mice cannot keep their balance and fall off the cylinder. All of the animals were killed and dissected at the end of the study. Previous animal tests suggesting a link between pesticides and Parkinson’s have been disputed by the manufacturing companies because they are inconclusive. For example, in response to a previous, similar finding in rats, the British Crop Protection Association and its US counterpart, CropLife said “we think that the results of this study are preliminary at best. They have seen effects in rats, we don’t think they have any data that would link disease (effects) to humans”.2
Genetically modified (GM) food is a term that most commonly refers to crops that have been created for human and animal consumption using genetic engineering techniques. These plants are modified in a laboratory to enhance desired traits such as nutritional content or resistance to weed killers. The commercial sale of GM food began almost 20 years ago, yet despite the approval from regulatory authorities, many scientists are concerned that introducing foreign genes into food plants could have an unexpected and negative impact on human health. In a recent experiment that sparked controversy across Europe, scientists from Caen University in France fed 200 rats for their entire lifetime (two years) a diet of one of the bestselling strains of GM corn produced by agricultural biotechnology giant Monsanto along with their popular weed killer Roundup in order to induce cancer in the animals.3 The rats developed shockingly large, cancerous tumours that led to multiple organ damage and premature death in 50% of males and 70% of females sparking renewed claims that GM food leads to cancer. However, a broad range of scientists have strongly criticized the research on statistical grounds and because the strain of rats used are prone to develop cancer as they age anyway. Monsanto, who had already carried out similar research and found no risk to humans, also disputed the results of the experiment, claiming “the study does not meet minimum acceptable standards for this type of scientific research”.4 The results have also been dismissed by the European Food Safety Authority (EFSA).5
Bisphenol A (BPA) is a chemical that has been used for over 60 years to produce polycarbonate plastics and epoxy resins that are found in many consumer products. Polycarbonate plastics are used in water and baby bottles, CDs and DVDs, sports equipment, household electronics and medical devices while epoxy resins are used to coat metal products such as food cans, bottle tops and water supply pipes. Due to its widespread use, scientists have become increasingly concerned about the almost continuous exposure to BPA as it is thought to be an endocrine disruptor that can lead to reproductive problems such as birth defects and miscarriages. In order to examine the effect of prenatal BPA exposure on egg formation, scientists from Washington State University forced pregnant rhesus macaques to ingest pieces of fruit containing the chemical every day throughout their pregnancy.6 Another group of pregnant monkeys received continuous BPA exposure through tubes implanted into their bloodstream. At the end of the study, the foetuses were removed by caesarean section and dissected. In another study carried out in the USA, scientists from North Carolina University exposed pregnant rats to BPA through their drinking water and continued to expose the new-born animals to the chemical until after they reached puberty in order to determine if early exposure contributes to ‘adolescent anxiety’.7 The rats were then subjected to behavioural tests designed to make them anxious before being killed and dissected. Despite results from thousands of animal experiments like these demonstrating adverse effects of BPA exposure, action to remove the chemical from all consumer products has not been taken. In April, the FDA rejected a petition from the National Resources Defence Council (NRDC) to ban BPA because the findings in animals cannot be applied to humans. In their response the agency said, “while evidence from some studies have raised questions as to whether BPA may be associated with a variety of health effects, there remain serious questions about these studies, particularly as they relate to humans”.8
Flame retardants are chemicals that inhibit or resist the spread of fire and are used in a variety of products including curtains, upholstery, rugs, electronics and construction materials. There are several different classes of flame retardant chemicals and many are thought to pose health risks. A commonly used flame retardant called Firemaster 550 has recently been put to the test by researchers from North Carolina State University and Duke University in the US who believe it to be a potential endocrine disrupter that leads to serious cardiovascular and developmental effects.9 Firemaster 550 is produced by global chemicals manufacturer Chemtura and is used in polyutherane foam in products such as mattresses and infant nursing pillows. To investigate the endocrine disrupting potential of the chemical, the researchers fed pregnant rats different doses of the chemical in treat pellets every day throughout pregnancy and nursing. Standard prenatal developmental studies use at least 20 pregnant rats per dose; however, this study used only three! At the end of the study, some of the pups and all of the mothers were killed by carbon dioxide inhalation followed by decapitation before being dissected. They found that the chemical caused extreme weight gain, early onset of puberty and heart problems in the rats and consequently questioned its safety. Chemtura has hit back at these claims and released a statement which said, “the published article is based on a small-scale pilot study that exposed nine adult rats to doses much higher than would be typical for human exposures in the real world”. They also said that the product had already passed similar safety studies that were “carried out under the supervision of EPA regulators by GLP-certified, third-party laboratories”.10
Triclosan is an antibacterial chemical commonly used in lipsticks, soaps, deodorants, toothpastes, mouthwashes, detergents and thousands of other cosmetic and household products. Although it has been widely used for over 40 years, scientists have recently begun to question its safety. Researchers from the University of California found that, in mice, triclosan hinders the process by which muscles, including the heart, receive signals from the brain.11 In their experiment, 8-10 week-old male mice were anesthetised before undergoing surgery in which the carotid artery in their neck was exposed. A pump was inserted into the artery to measure the volume and pressure of blood that passed through. Various doses of the chemical were then injected into their abdomens. The mice were then killed and their hearts were punctured to collect blood for analysis. In a another procedure, 3 month-old male mice were injected with triclosan before being subjected to a grip strength test in which they were made to grab onto a wire mesh with all four paws before being pulled away by their tails. The scientists found that triclosan exposure significantly reduced heart function in the mice and warned that the chemical could be detrimental to human health. However, the Cosmetic, Toiletry and Perfumery Association (CTPA) said, “this new study does nothing to undermine the proven, safe use of Triclosan in cosmetic products. It must be remembered that the doses used in the study are unrealistically large when compared with the maximum permitted level of triclosan in cosmetic products and the amount people will be exposed to”.12
1. Environmental toxins trigger PD-like progression via increased alpha-synuclein release from enteric neurons in mice. (2012). Scientific Reports; 2: 898.
2. Breathing pesticides can trigger MS and Parkinson’s disease. Daily Mail, Aug 2006.
3. Long term toxicity of a Roundup herbicide and a Rounder-tolerant genetically modified maize. (2012). Food and Chemical Toxicology.
4. Study linking GM maize to cancer must be taken seriously by regulators. The Guardian, Sep 2012.
5. EFSA Press release 28 November 2012
6.Bisphenol A alters early oogenesis and follicle formation in the fetal ovary of the rhesus monkey. (2012). PNAS; 109(43): 17525-17530.
7. Anxiogenic effects of developmental bisphenol A exposure are associated with gene expression changes in the juvenile rat amygdala and mitigated by soy. (2012). PLOS ONE, 7(9);e43890.
8. FDA rejects call to ban BPA from food packaging. USA Today, April 2012.
9. Accumulation and endocrine disrupting effects of the flame retardant mixture Firemaster 550 in rats: an exploratory assessment. (2012). J Biochem Molecular Toxicology, 00: 1-13.
10. Chemtura comments on Firemaster 550 flame retardant study. Chemical Watch, Nov 2012.
11. Triclosan impairs excitation-contraction coupling and Ca2+ dynamics in striated muscle. (2012). PNAS, 109(35): 14158-14163.
12. CTPA: Avoid unrealistic scare stories, cosmetics are safe. Cosmetics Design-Europe, Aug 2012.