SafeFood Home

Topic Map SF

    Pesticides linked to infertility - new evidence

    Endocrine Disruptors Block Sperm Function

    The link between male fertility and hormone disrupting chemicals is now more fully understood. A new study shows that adult sperm, when exposed to hormone disrupting chemicals (often called endocrine disruptors), mature too quickly and fail to reach and fertilize the egg. Dozens of pesticides are known or suspected endocrine disruptors. The list includes widely used herbicides such as 24D, atrazine and simazine, common organophosphates (e.g. mala-thion and chlopyrifos), the fungicide mancozeb and persistent chlorinated pesticides such as endosulfan and DDT. Individuals face potential exposure to endocrine disrupting pesticides through food residues, home pesticide use, and soil, water and air contaminated by agricultural pesticide use.

    This study, released in July this year, provides the first direct evidence that endocrine disruptors affect sperm function.

    In the past ten years, dozens of studies have linked endocrine disrupting chemicals to a number of reproductive and other health effects. The chemicals closely mimic naturally occurring hormones and can disrupt the functioning of hormone systems in humans and other animals at very low levels of exposure. Dr. Theo Colburn's research more than a decade ago linking reproductive failure in alligators with chemical exposure led researchers to further explore the reproductive and other effects of this class of chemicals.

    Exposure to endocrine disrupting pesticides adds to an individual's ongoing exposure to dozens of other chemicals that also mimic hormones, from by-products of industrial production and incineration (dioxins and furans) to chemicals in widespread use in formulating products for everyday use. Phthalates, for example, are endocrine disrupting chemicals used as softening agents in many plastic products (including medical devices) and in beauty products such as deodorants, lotions and nail polish.

    The recent evidence on blocked sperm function adds new urgency to regulatory efforts to understand and address endocrine disruptors. The U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program, established in 1996 under the Food Quality Protection Act to test pesticides and other chemicals and prioritise them for regulatory action, has been unacceptably slow to identify priority chemicals and recommend action.

    In New Zealand, regulators take a 'wait and see' attitude, only doing something when there is overwhelming evidence of harm. Our newly established Environmental Risk Management Authority is likely to take some years before it gets around to reviewing endocrine disruptors. In the meantime endocrine disruptors are being found in our food: the Ministry of Health's latest Total Diet Survey detected eight known endocrine disruptors.SF

    From PANUPS 2 August 2002

    Action ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

    • Write to ERMA, PO Box 131, Wellington, email asking them to urgently review pesticides which are endocrine disruptors.
    • Buy and grow organic food ­ in this way you lessen your exposure to these harmful chemicals

    Reducing pesticides

    a policy for New Zealand

    Recently the Ministry for the Environment put out a public discussion paper "Towards a pesticides risk reduction policy for New Zealand". The Safe Food Campaign organised a public meeting in Wellington on 17 June with various Government officials to discuss this paper. That this opportunity has occurred at all is a cause for celebration among environmentalists who for years have been trying to get the government to do something about the indiscriminate and needless spraying of hazardous pesticides over people and the countryside.

    Below is the executive summary and some extracts from a submission that Alison wrote on behalf of the Safe Food Campaign

    Executive summary

    The Safe Food Campaign welcomes the development of this policy and we support the general thrust of the document, that there are real opportunities to reduce the overall burden of pesticides on the environment. It is essential that the Government, growers, communities and pesticide users work together to achieve this aim. A change of mindset is essential in those governing to provide clear leadership and to truly achieve the aim of pesticide reduction.

    We believe that the best way of achieving a reduction of risk from pesticide use is to adopt the principle of minimum harm: that the least toxic method or strategy be used for any particular problem or situation. The endorsement by Government and the adoption of the policy of working towards an organic nation is the most effective and economically and strategically beneficial method of reducing the overall burden of pesticides on the environment. Avoiding the use of pesticides, not just reducing their use, is the most important step that can be taken. In this way, various risks will automatically be reduced.

    There are a number of flaws in the present management of pesticides which result in an underestimation of the risks involved and the maintenance of the status quo, even when this is detrimental to human health and the environment. We suggest several changes to the laws, following the overarching principle of doing minimum harm. In some situations local groups can give insight and offer co-operation to finding solutions to particular problems. Risk management tools include supplying data sheets on pesticides including up-to-date long term risks and ecotoxicity, the compulsory registration of all commercial applicators of pesticides, along with the outlets selling them, and the levying of an environmental user charge, based on the level of hazard of the pesticide and the efficacy of the application method.

    Improving pest control methods involves changing attitudes to look at ways of improving management plans, considering the complex interactions within the ecosystem, instead of just reaching for a reductionist quick-fix, the "magic bullet". We recommend that Government and its delegated bodies carry out in practice the precautionary principle and also give priority to considerations of public health, safety and damage to the environment over trade.

    Flaws in the present management of pesticide risks

    People in key positions within the present system of pesticide management commonly hold the view that "some people in the community are concerned about risks when an expert would regard the risks as low or well-controlled by good management practices". Any view that pesticides need to be restricted further is dismissed as a "perception", and that only "science-based decisions" are valid.

    This concept that the expert knows best and the public doesn't, quite overlooks the fact that value judgments and estimations are made at every stage of scientific assessment of risk and that experts will commonly disagree about the implications of studies concerning the effects of pesticides on human health and the environment. An additional difficulty in New Zealand is that a small number of experts are relied on for their assessments compared to bigger countries, leading to a particular bias and allowing no room for opinions different to the accepted view to be effectively voiced.

    Because of the inexact nature of toxicology, precise and unequivocal risk assessments for pesticides are difficult. A pesticide is assumed safe if its concentration is below a certain level (Tolerable Exposure Limits (TELs) in the case of human environmental exposure in the HSNO Act, or Acceptable Daily Intakes (ADIs) in the case of exposure to pesticide residues in food in the Food Act.) With ADIs this level is arrived at by taking the "no effect" level from animal studies and multiplying it, usually by a hundred ­ the so-called "safety factor". This in turn assumes that if we all eat less than, or up to, one hundredth of the daily dose that failed to provoke an obviously toxic effect in animals, then we will be adequately protected. This is a crude way of assessing toxicity, and is little more than a calculated guess or stab in the dark.

    When pesticides are tested on animals for registration purposes, they are only tested individually, as if people were exposed to them one at a time. This does not reflect the reality of our exposure to a cocktail of chemicals over a lifetime. Possible additive, synergistic and accumulative effects are not taken into account. In addition, only the active ingredient of a pesticide is tested for long-term effects. The full pesticide formulation, containing possibly very toxic contaminants and other ingredients, is not tested for long term effects.

    Many important health effects of pesticides are not yet tested for in their registration. These include immune system suppression, behavioural and hormonal or endocrine effects, even though there are now a number of independent studies that link various pesticides in common use and these health effects.

    Safety factors, estimated from experiments on healthy animals, do not take adequate account of the huge range of individual susceptibilities present in humans. The effects of particular pesticides tend to be underestimated for the developing foetus, the very young and old, those who are chemically sensitive or who are immune compromised. As well, recent research on endocrine disruptors, which a number of pesticides in current use have been demonstrated to be, suggests that no threshold can be assumed, especially when considering the developing foetus. (1)

    These flaws in the assessment of pesticides result in a consistent underestimation of the risks involved. What makes it worse is that many of the pesticides in current use in New Zealand have not been assessed even according to the present inadequate registration process. These older pesticides were in use before the current registration requirements became enacted into law. In the meantime, these older pesticides with serious data gaps continue to be used and are assumed to be innocent until overwhelming evidence is produced to the contrary.

    Pesticides in the home

    The still current system of classification which allows the sale of "low" toxicity pesticides in supermarkets is completely outmoded: this system only takes short term acute effects into account, it does not consider ecotoxicity or the effect on the environment nor long term effects such as cancer, genetic damage, endocrine disruption, birth defects and immune system suppression. How many home gardeners (and other sprayers) are aware that a spray they might buy from the supermarket and put on their fruit trees contains mancozeb, a metabolite of which may cause cancer, genetic damage, birth defects, reproductive damage, immune system suppression and endocrine disruption among other things? (2)

    Data sheets with continually updated information on eoctoxicity and long term effects should be available. Sales of pesticides should be limited to outlets with properly trained staff, ie not supermarkets and department stores.

    Also covered:

    • Why the RMA isn't protecting us and the environment from the effects of pesticides,
    • the holistic vs reductionist approach of dealing with thistle,
    • why we can't assume that modern pesticides are safer than older ones, and more.

    If you would like to see a copy of the full submission (11 pages), contact us.SF

    (1) Solomon GM & Schettler T (2000): Endocrine disruption and potential human health implications, CMAJ 163(11):1471­6 Nov 28.

    (2) US EPA (1987): Guidance for the reregistration of pesticide products containing mancozeb as the active ingredient, Office of Pesticides and Toxic Substances, US Environmental Protection Agency, Washington DC. The US has since greatly restricted its use, including cancelling use in home gardens. New Zealand has not restricted any of this group of fungicides (dithiocarbamates or EBDCs).

    See also and

    Pesticides found in food linked to birth defects

    Hypospadias and other genital abnormalities were recently reported in mink and river otters on the Columbia River, North America. All the abnormal animals had elevated levels of organo-chlorine chemicals in their bodies. Some pesticides that are found in New Zealand food may contribute towards the occurrence of hypospadias.

    Hypospadias is arrested development of the penis, with the normal opening of the penis occurring not at the tip but on the underside, sometimes as far back as the scrotum.

    DDE (a breakdown product of DDT), vinclozolin, procymidone and linuron have all been classified as anti-androgens, meaning they disrupt the normal function of male sex hormones. These pesticides been shown to cause hypospadias in laboratory animals.

    The latest Total Diet Survey by the Ministry of Health found residues of DDE in 79% of animal samples analysed, with the highest levels in butter. The fungicide procymidone was found in beans, celery, lettuce and raisins or sultanas. Vinclo-zolin, no longer registered in New Zealand, was found in jam, tomatoes and white wine. The herbicide linuron, used on a number of food crops for weed control, was not detected in the 460 samples analysed. Whether birth defects can occur from these residues in food is unknown, but research is finding that effects of hormone disruptors such as these can occur at minute levels. We therefore strongly recommend pregnant women to eat organic food.SF
    Rachel's Environment & Health News #752 The Latest Hormone Science Part 3 19 Sept 2002, 1997/1998 NZ Total Diet Survey, Ministry of Health.

    December 2002

© Safefood Campaign