Related Information

Overview of Policy Initiatives Relating to EDCs

An Emerging Environmental & Human Health Issue: Executive Summary

Within The European Union

 



AN EMERGING ENVIRONMENTAL & HUMAN HEALTH ISSUE

Background Information
Wildlife -- and humans -- are exposed daily to many different synthetic chemical compounds that, even in small doses, can disrupt development of the reproductive, immune, nervous, and endocrine systems of humans and wildlife by mimicking hormones, blocking the action of hormones, or by other interference with the endocrine system. Hormones play a key role in sexual differentiation and development of the brain, behaviour and intelligence.

Identified so far are some 51 different compounds (see box, p.4) present in many pesticides, some heavy metals, some synthetic organochlorines used and released in industrial processes and some substances contained in plastics. Scientists think that more such substances will be identified in the future. When these substances are present at critical development stages they can disrupt the construction of the endocrine, reproductive, immune and nervous system of a developing organism. The most sensitive life stages are the embryo, fetus and newborn. In most cases, the changes caused by the disruption are delayed and irreversible.

The Science

Prominent scientists have concluded that many wildlife populations are already affected by these endocrine disrupting chemicals. Impacts already identified are:

  • thyroid dysfunction in birds and fish
  • decreased fertility in birds, fish, shellfish, and mammals
  • decreased hatching success in birds, fish and turtles
  • gross birth deformities in birds, fish, turtles
  • metabolic abnormalities in birds, fish, and mammals
  • behavioural abnormalities in birds
  • demasculinization and feminization of male fish, birds and mammals
  • defeminization and masculinization of female fish and birds and compromised immune systems in birds and mammals.
They also concluded that some of the declines in a number of species and groups of animals and plants which are in progress on the North American continent are related to exposure to man-made chemicals. Moreover, these declines are not solely a US or North American problem but are occurring on a global basis.

Some Major Findings of the Erice Conference

  • endocrine disrupting chemicals can undermine neurological and behavioural development and subsequent potential of individuals exposed in the womb, or in fish, amphibians, reptiles, and birds, the egg

  • this loss of potential in human and wildlife is expressed as behavioural and physical abnormalities, eg. reduced intellectual capacity and social adaptability, and impaired responsiveness to environmental demands

  • widespread loss of this nature can change the character of human societies or destabilize wildlife populations which can have profound economic and social consequences

  • the developing brain exhibits specific and often narrow windows during which exposure to endocrine disruptors can produce permanent changes in its structure and function. The timing of exposure is crucial during early developmental stages, particularly during fetal development

  • thyroid hormones are essential for normal brain function throughout life. Interference with thyroid hormone function during development leads to abnormalities in brain and behavioural development... eg. motor dysfunction of varying severity including cerebral palsy, mental retardation, learning disability, attention deficit hyperactivity disorder, hydrocephalus, seizures and other permanent neurol ogical abnormalities. Similarly, exposure to man-made chemicals during early development can impair motor function, spatial perception, learning, memory, auditory development, fine motor coordination, balance, and attentional processes; in severe cases, mental retardation may result

  • because certain PCBs and dioxins are known to impair normal thyroid function, it is suspected that they contribute to learning disabilities, including attention deficit hyperactivity disorder and perhaps other neurological abnormalities. In addition, many pesticides affect thyroid function and therefore may have similar consequences.
WWF has played a lead role in facilitating development of scientific networks studying the endocrine disruption phenomenon. WWF US Senior Conservation Scientist, Dr. Theo Colborn, has been instrumental in organizing the following multidisciplinary scientific conferences attended by the leading scientific experts in the field: Wingspread I: Chemically-Induced Alterations in Sexual Development: The Human/Wildlife Connection (1991); Wingspread II: Environmentally Induced Alterations in Development: A Focus on Wildlife (1993); Chemically-Induced Alterations in the Developing Immune System: The Human/Wildlife Connection (1995); Erice, Italy: Environmental Endocrine-Disrupting Chemicals: Neural, Endocrine and Behavioural Effects (1995). A special edition of the Journal of Toxicology and Industrial Health bill publish papers from the Erice meeting. Another multi-disciplinary scientific workshop was held recently, specifically on endocrine disruption effects in fish, and the peer-reviewed papers are due to be published this spring in a book published by the Society of Environmental Toxicology and Chemistry (SETAC).

Human Health Impacts
Scientists agree that human beings are also being affected by endocrine disrupting chemicals. Reproductive effects reported in wildlife should also be of concern to humans where they share exposure to the same resources, for example, contaminated fish. Evidence of lowered human sperm counts in industrialized regions and significant increases in testicular cancer, breast cancer, as well as of cases of undescended testes and endometriosis, is heightening the concern.

In November 1995, prominent scientists met in Erice, Italy, to discuss the scope of the problems posed to human health and the environment by endocrine disrupting chemicals. The Erice Conference was convened because of the growing concern that failure to confront the problem could have major economic and societal implications. The new evidence they reviewed about potential human health impacts is especiall y worrisome as it underscores the exquisite sensitivity of the developing nervous system to chemical disturbances that result in functional abnormalities, such as neurological problems, intelligence deficits and behavioural abnormalities.

Raising Awareness about EDCs
Without a doubt, one of the most influential books of the 20th century will turn out to be Our Stolen Future (Are We Threatening Our Fertility, Intelligence, and Survival?). Dr. Theo Colborn tells the fascinating endocrine disruptor story in this new book, coauthored with Dianne Dumanoski and Dr. John Peterson Myers, which is attracting major media attention wherever it is published. Our Stolen Future is now available in English, German, French, Norwegian and Spanish and will soon be available in Dutch/ Flemish, Japanese, Korean, Polish and Swedish.

Policy Initiatives Concerning EDCs
Many important policy initiatives on endocrine disrupting chemicals have been commenced during the last 2 years. Some of the more important are briefly described below.

Recent Developments at the Intergovernmental Forum on Chemical Safety (IFCS)
The IFCS, the post-UNCED body set up in 1994 to develop new international partnerships for dealing with chemical risks, decided in February 1997 that there is a need to investigate, in depth, the human, environmental and ecotoxicological aspects of endocrine disrupting substances, and recommended that the IOMC (Inter-Organization Programme for the Sound Management of Chemicals), and participating organizations (OECD, UNEP, ILO, UNIDO, WHO, FAO) do the following:

  • Compile and harmonize the definitions and terms appropriate to endocrine disruption;

  • Promote coordinated research strategies and processes, identify research priorities and gaps for all relevant research disciplines;

  • Delineate testing methods, harmonize guidelines, identify research priorities and gaps;

  • Adopt and maintain an inventory of research activities and other relevant and related information; and Facilitate information exchange on:
    • a. existing and new evaluations of the scientific issues related to endocrine disruption
    • b. research and testing results
    • c. surveys and survey results
    • d. hazard and risk management actions and options
    • Report to the Standing Committee of the Forum and the next Forum meeting on these efforts
In addition, the IFCS Standing Committee will consider how to address urgent issues and new developments related to endocrine disruption and report to the next Forum meeting on this effort. International consensus for the need for a legally binding instrument to phase out Persistent Organic Pollutants (POPs), promoted the UNEP Governing Council at its 19th session in Jan/Feb'97, to call for the beginning of negotiations on such a convention in early 1998 (to be concluded by the year 2000). This will cover some endocrine disruptors, but further action is needed as many endocrine disruptors are not POPs. In addition, many of the substitutes for POPs, either are known to be, or may turn out to be EDCs. It is crucial that the convention contain a hierarchy of recommended alternatives to avoid substituting one environmental problem for another. The IFCS (see box) Ad Hoc Working Group on POPs observed that: "... where applicable, it would be best to shift to approaches that reduce reliance on chemical pesticides..."

Also the initiatives to phase out POPs through the Mediterranean regional sea and the UN ECE Long-Range Transboundary Air Pollution conventions will face similar problems in design and implementation unless preventative action is taken.

During the 6th Conference of the Parties of the Ramsar convention on wetlands, March 1996, toxics were the subject of a keynote address. The Contracting Parties agreed Recommendation 6.14 on Toxic Chemicals which recognizes that the adverse impacts of toxic substances compromise the ecological character of wetlands and invites the Parties to undertake pollution prevention measures and report back on their progress at the next meeting.

Chemicals Considered to Have Reproductive and Endocrine Disruptor Effects

  • Pesticides (commercial and/or domestic)
    2,4,5-T, 2,4-D, alachlor, aldicarb, amitrole, atrazine, benomyl, lindane, carbaryl, chlordane, cypermethrin, DBCP, DDT, dicofol, dieldrin, endosulfan, esfenvalerate, ethyl parathion, fenvalerate, heptachlor, hexachlorobenzene, malathion, mancozeb, maneb, methomyl, methoxychlor, metiram, metribuzin, mirex, nitrofen, oxychlordane, permethrin and other synthetic pyrethroids, toxaphene, transnonachlor, tributyltin oxide, trifluralin, vinclozolin, zineb, ziram

  • Heavy Metals
    Cadmium (used in nickel/cadmium batteries, coatings, pigments, stabilizers in plastics and synthetic products and alloys, fossil fuels) Lead (used in lead batteries, paints, pipes, leaded gasoline) Mercury (used in nickel-cadmium batteries, fluorescent lighting ballasts, seed dressings, chlorine production, dental amalgams, fossil fuels)

  • Organochlorines
    Dioxin ((2,3,7,8-TCDD) a by-product of other organochlorine production, use & disposal (not intentionally produced). Examples include incinerator emissions, metal smelting, PVC (vinyl) plastic production, chlorine-bleached pulping PBBs & PCBs (Production now banned but PCBs still used in electrical transformers. PCBs still reside in landfills, toxic waste dumps and sediments) Pentachlorophenol (wood preservative, used in textile industry)

  • Plasticizers & Surfactants
    Phthalates, Polycarbonates, Styrenes (used to make plastics soft) Alkyl & Nonyl Phenol Ethoxylates (used in detergents, pulp & paper and textile industry, some plastic products, paints, pesticides)

    Source: WWF Canada Eagle's Eye, Special Issue on Toxics that Tamper with Hormones, Summer 1995, and Wingspread I Statement, recorded in Chemically Induced Alterations in Sexual and Functional Development: The Wildlife/Human Connection, eds. T. Colborn and C. Clement, Princeton Scientific Publishing, Princeton, NJ, 1992

Regional Seas Agreements have been in the forefront of international commitment to the reduction of toxics. At the 3rd North Sea Conference, the ministers agreed to "phase out those pesticides which are the most persistent, toxic and liable to bioaccumulate". At the 4th North Sea Conference in 1995, the definition of toxicity was expanded to include chronic effects such as carcinogenicity, mutagenicity and teratogenicity and adverse effects on the function of the endocrine system (emphasis added).

The Ministers also invited the Oslo and Paris Commissions and the Commission for the European Communities as a matter of urgency to launch investigations and/or risk assessments to improve knowledge of the consequence of substances, such as pesticides, suspected to have endocrine or hormone-like effects, and to adopt and implement necessary measures at least by 2000.

The OECD is reviewing testing methods for chemicals to identify gaps concerning endocrine disruption potential and to recommend action. The OECD is also conducting a survey on how countries currently test and assess, if at all, for endocrine disrupting chemicals.

The US EPA & EC have also agreed to cooperate on research on EDCs.

Precautionary Principle = Prevention The problem is very urgent. At Wingspread I prominent scientists agreed: "Unless the environmental load of synthetic hormone disruptors is abated and controlled, large scale dysfunction at the population level is possible."

One of the great difficulties in identifying exactly how these chemicals affect wildlife and humans is the recognition that the pattern of effects varies among species and among compounds. However, general conclusions can be drawn. First, even one, very low dose of an endocrine disruptor at a crucial stage in the development of an embryo is sufficient to cause irreversible damage. The amounts of endocrine disruptors required to cause fundamental and irreversible changes can be as little as a concentration measured in parts per trillion. To understand how infinitesimally small an amount this is, imagine one drop of gin in a train full of tonic. One drop in 660 carriages would be one part in a trillion; such a train would be six miles long!

Second, the gap between exposure and effect may be a generation or two as the damage caused will be more likely to turn up in the offspring of the affected organisms. In other words, the effects are "transgenerational" -- the exposed individual may be completely unaffected whereas the offspring may have reproductive difficulties.

Third, endocrine disrupting chemicals, like other synthetic chemicals, can be cumulative and have synergistic effects.

Given the state of science, the ability to accurately quantify and contrast risks of EDCs, in all the combinations encountered in the real world, is probably centuries away. Indeed, scientists are just now attempting to develop a first generation of in vitro assays able to detect the capacity of a chemical to bind or block hormone receptors.

Pollution Prevention Policy Tool:

    Pollutant Release and Transfer Registers (PRTRs)

  • Chapter 19 of Agenda 21 called for the development of guidance for governments on collecting crucial information by using chemical inventories. Taking up this challenge, the Organization for Economic Cooperation and Development (OECD) hosted five workshops with the UN International Programme for Chemical Safety (IPCS) on what are called internationally Pollutant Release and Transfer Registers (PRTRs). PRTRs are a system of tracking chemicals use, transfer and release which record chemical specific and standardized data on emissions of toxic substances to air, water and land (including off-site disposal) from polluting industrial facilities - private, municipal, or state -- and chemicals contained in products.

  • As recognized in Chapter 19, the classic example of risk reduction is to reduce use through substitution of harmless alternatives and alternate methodologies. Experiences with publicly-accessible PRTRs have shown them to be powerful tools which lead to reductions in the use and release of toxics and the adoption of less-polluting materials and technologies (so called "cleaner production"). Establishing and linking these chemical registers in countries around the world provides vital information on the sources of contamination by chemicals, information critical in addressing substances which are increasingly transported long distances through the air and water.
Thus, the only way forward is pollution prevention/reduction of toxics at source; for example through cleaner production methodologies, including cleaner agricultural production. The priorities are those substances which are persistent, bioaccumulative and/or toxic.

A. Community Right-to-Know First and foremost there is an obligation to enhance public understanding of the hazards and risks.

Recommendation: Governments must legally require industries to provide information for inventories of toxic chemical releases and toxics in products (see box on PRTRs).

PRTRs are publicly accessible multimedia inventories of sources of pollution by release and transfer of chemicals in the waste stream and in the product stream. PRTR data provide an invaluable baseline for measuring progress on pollution prevention programmes. Analysis of the data trends can be used to measure both business accountability and performance, as well as national successes in meeting international and regional commitments and obligations.

B. Pesticides Reduction Policies = Reducing the Use of, and Reliance on, Pesticides
A large percentage of EDCs identified to date are pesticides and therefore they may be seen to be a priority in terms of regulatory action. However, it may be equally necessary to target industrial chemicals, such as phthalates and nonyl phenols (which are already subject to phase out measures agreed under the Paris Convention and the 4th North Sea Ministerial Declaration), and heavy metals for regulatory action.

What is worrying is that many of these pesticides are the newer generation products developed to replace the organochlorines. Although they may not be as persistent as the "POPs", acute toxicity to aquatic organisms is already recognized as an effect of some of these products and now endocrine disrupting ability is implicating even more of these newer generation pesticides.

Recommendation: As an overall prudent approach, the use of, and reliance on, pesticides should be minimized. Countries such as Sweden, the Netherlands and Denmark have demonstrated that is it possible to reduce pesticide use by over 50%. Therefore, governments should implement national pesticide reduction programmes which are based upon consultation with, and the participation of, the interested stakeholders such as farmers, retailers, consumers groups, environmental groups, and agrochemical manufacturers. In order to assess progress, governments need to set targets, timetables and measures of reduction of use of, and reliance on, pesticides, in consultation with those stakeholders.

C. Registration/Reregistration of Synthetic Chemicals Current testing is inadequate. New evidence is coming to light which demonstrates that the combined impacts of complex mixtures are highly unpredictable and sometimes synergistic. Moreover, one of the paradoxes of endocrine disruption is that it appears that in some cases higher doses do not cause effects, whereas very low doses can.

In addressing the risks posed by chemicals in the environment and human health, scientists and policy makers have in the past focused their attention and efforts on a few hundred chemicals, proceeding on a chemical-by-chemical basis, directed largely by concerns over acute toxicity, carcinogenicity, environmental persistence, and tendency to bioaccumulate. As a practical matter, a chemical-by-chemical approach is inadequate to determine -- either effectively or efficiently -- the safety of the roughly 100 ,000 already in use and the 1000 new chemicals estimated to enter the market every year.

Recommendation: All chemicals which are released into the environment should be tested throughout a minimum of two generations for a wide variety of effects including reproductive, immunological, endocrinological, and neurological endpoints. Chemicals should be assumed guilty of endocrine disruption until proven innocent.




Copyright 1997, The World Wide Fund For Nature