Groundbreaking scientist and environmental activist

Dr Morag Parnell and Máire McCormackDr Morag Parnell

Morag is co-founder of the Women’s Environmental Network, Scotland (WENs). She was born in 1926 in Ballachulish, a West Highland industrial village where almost all the male population (and some women) worked in the slate quarries. After primary school in Ballachulish and secondary school in Oban, Morag worked with the Forestry Commission and a year nursing in a burns unit where she worked with badly burned ex-servicemen. Her admission to Edinburgh University was delayed to allow for returning ex-servicemen. Morag graduated in Medicine in 1952. She then worked as a GP for 20 years and 8 years in Community Child Health. She joined the Socialist Medical Association in the 1950s, the time of the ‘Inverse Care Law’. Morag has been actively involved in Peace and Environmental Health Campaigns since the 70s, including several visits to Greenham. She has 3 children, 8 grandchildren and 1 great grandchild.

Máire McCormack

Máire comes from St Helens, Merseyside. A graduate of London and Bristol Universities, she also holds an MSc from the Centre for Human Ecology (CHE). Máire spent four years working in Java, Indonesia, for Voluntary Services Overseas and taught English in Italy, Spain and Taiwan. She then worked as a researcher at the European Parliament for five years and three years with the European Association of Mining Regions. Máire came to Scotland in 1998 and is Head of Policy at the Children’s Commissioner’s Office. She is also Chair of Friends of the Earth, Scotland and has been active in WENs since 2002. She has a son, aged 23 and 2 step children.


What does it mean to be a dangerous woman? To whom and why was Theo Colborn a danger?

Her own words perhaps provide the answer:

In my business, you measure your respect by the enemies you make. [1]

During her lifetime, Dr Theo Colborn made many enemies, confronting some of the world’s most powerful industries – chemicals, oil and gas, plastics and household product manufacturers – and exposing how their products have wreaked havoc on the human endocrine system.[2]

Born in Plainfield, New Jersey in 1927, for many years she combined working as a pharmacist with sheep farming. Both professions made her aware of industrial pollution in a nearby river and its effects on wildlife, which in turn led to a lifetime focused on research and activism. It would be Colborn’s research in particular that made her dangerous – research which was often deliberately obscured or mocked by the establishment.

Her first taste of this was during her Masters research, which had focused on the effects of metals on small vertebrates – metals which had been introduced into the water through mining activity. She spotted the Head of the Mining Corporation, AMAX, entering the room of one of her thesis Committee members. Rightly concerned, she alerted her adviser to this potential breach of academic integrity. During her thesis defence, the Committee member asked her about the effect her thesis would have on his ‘associates from AMAX up the mountain’. The defence was halted, but her thesis nevertheless approved and she was recommended for further PHD work. [3]

At 58, she started a PhD in Zoology, minoring in epidemiology, toxicology, and water chemistry, so as to ‘maybe undo some of the things that my generation basically foisted on society’.[4]

By this she was referring to the hundreds of synthetic chemicals and their thousands of by-products found in every-day use, such as plastics, pesticides, flame retardants and personal care products. 287 of such toxins have been found in the umbilical cord blood of babies.[5]

Robert Musil observed that: ‘if the implications of the science Coborn pioneered are fully accepted by society, it will mean changing almost every product we now manufacture and our social values too’. [6]

It is little wonder then that Colborn was feared by these same manufacturers.

After her PhD, Colborn joined the US Conservation Foundation Great Lakes Study team. It was known that there had been industrial pollution in one of the lakes and unusual disorders had appeared in many of the species inhabiting the lake and its shores. Colborn’s study files were labelled: Population Decline, Reproductive, Tumours, Wasting, Immune Suppression and Behaviour Changes. She concentrated on the sixteen species worst affected – predators at the top of the food chain. Her research uncovered behaviours such as same sex nesting, inter-sex in the reproductive organs of male species, grotesque birth defects including club feet, missing eyes, deformed spines, and crossed bills.[7]

Like others, Colborn initially focused her attentions on cancer, but having measured the industrial chemicals in the animals’ body fat, she found that they differed from cancer causing chemicals. What these chemicals had in common was that they interfered with the hormone system. Colborn persisted where others would have given up, revisiting countless studies, reports and data, determined to get to the source of the problem and understand what had been happening in the Great Lakes. That ability to be open to new ideas – to challenge age-old assumptions and ignore conventional wisdom when it instinctively felt wrong – was also what made Colborn dangerous.

A significant discovery was bio-accumulation, where toxic materials build up in the fat of wildlife. As larger animals eat smaller animals, the level of toxins rises in their bodies to much greater concentrations. It was calculated that the top predators of this food chain had a level of toxins a staggering 25 million times that originally in the water. Humans come at the top of the food chain when we eat the top predators[8]. Researchers continue to work on this topic, adding to the results found by Colborn and colleagues[9]. They confirm that hormones and ‘hormone-mimics’ act at infinitesimal concentrations i.e. parts per billion (ppb[10]) and parts per trillion (ppt).

A growing list of synthetic chemicals have been found to have hormone-like activity and find their way into thousands of products in daily use. We absorb them by ingestion, inhalation and through our skin. Some of the ill effects in females now reported in the scientific literature[11] include reproductive effects, such as early puberty, impaired fertility, endometriosis, miscarriages, shorter lactation, breast cancer, pre-term birth. In males, impaired fertility, reduced sperm count, impaired sperm quality, testicular cancer, prostate cancer, altered male/female ratio have been noted. Developmental disorders include ADHD, autism, co-ordination and behavioural difficulties, late neurological disorders, obesity and type 2 diabetes; immune system impairment, hormone dependent cancers and allergies.


Wingspread Consensus Statement (1991)

Dr Colborn’s research on the Great Lakes inspired her to organise a ground-breaking Convention at Wingspread Conference Centre, Wisconsin. In 1991, 21 international scientists from 15 different disciplines, including ecology, comparative endocrinology, immunology, biochemistry, law, psychiatry, reproductive physiology, toxicology and zoology met to discuss the prevalence of ‘endocrine disrupting chemicals’ in the environment (the term ‘endocrine disruptors’ was coined at the Convention). Their consensus statement concluded that unless the environmental load of synthetic hormone disruptors was abated and controlled, large scale dysfunction at the population level was possible. Prescient words indeed.

Manuscripts from that Convention, other publications and Colborn’s fieldwork, fed into a remarkable book which Colborn co-authored with Dr John Peterson-Myers and Dianne Dumanoski. Our Stolen Future, was vilified by many. Du Pont, Monsanto and other corporations criticised her openly, publishers were threatened with lawsuits, and some doctors and scientists questioned her scientific credentials. The Wall Street Journal referred to the book and its supporters as ‘an environmental hype machine’ and the American Council for Health and Science, backed by food, drug and chemical industries dismissed it as ‘innuendo piled on top of hypothesis on top of theory’ [12]

The book is now regarded as ground-breaking and visionary. Former US Vice President Al Gore’s foreword states:

 Our Stolen Future takes up where Carson left off and reviews a large and growing body of scientific evidence linking synthetic chemicals to aberrant sexual development and behavioural and productive problems… Our Stolen Future raises compelling and urgent questions that must be addressed. [13]

Colborn also had that rare – and ultimately dangerous – ability to make science accessible, knowing that once people are armed with facts and evidence, they become empowered. The book has been referred to as ‘a detective story which makes endocrine disruption understandable’. [14]  Readers follow an endocrine disrupting chemical on a long journey from a broken transformer in Texas to the breast milk of an Inuit mother in the Arctic, illustrating beautifully and powerfully how synthetic chemicals can interfere with the ways that hormones work in humans and wildlife.

The attack on the book only served to make Colborn more determined, campaign harder and become arguably more dangerous. It was no longer enough to raise awareness of the dangers of endocrine disrupting chemicals to wildlife and humans. This had also become a question of morality, cutting right to the heart of the human condition. She wrote:

The time has come to pause and finally ask the ethical questions that have been overlooked in the headlong rush of the twentieth century. Is it right to alter the chemical environment in the womb for every unborn child? [15]

In 2013, Colborn established the Endocrine Disruption Exchange (TEDX) in 2003. [16] This not-for-profit centre compiles and disseminates the scientific evidence on the health and environmental problems caused by low-level exposures to endocrine disrupting chemicals. It has influenced a movement for safe chemicals, added to a huge body of research into endocrine disruptors and prompted the enactment of legislation across the world. Colborn was surprised at its success and in 2014 said that she had expected it to be a two-person team, not anticipating ‘the overwhelming encouragement from those who in the past supported my work, nor the number of academicians around the world who would continue to provide comfort and advice.’ [17]

In her biography of Colborn, science journalist Elizabeth Grossman remarked that it is hard not to overemphasise how revolutionary the recognition of endocrine disruptors has been to toxicology, and to understanding how environmental chemicals exposure can affect human health. Grossman noted: ‘endocrine disruption science has upset the age-old assumption of how the dose-makes-the-poison. In doing so it has posed numerous challenges to how we assess and prevent harmful chemical exposures’. [18]

Robert Musil notes that Colborn was not bound by long-held theories and positions and could ask refreshing questions, leap over disciplinary boundaries and departments. He called this a blessing and a curse, noting that she did not get the automatic deference that comes with early successes, high positions in academia, government or even NGOs, without classmates or cronies to welcome her inside the doors of influence and power.[19] Arguably, it was that freedom to speak truth to power that ultimately made her dangerous.



In her later years, Colborn and TEDX focused on the threats posed by toxic chemicals associated with oil and gas development, such as hydraulic fracturing and what Colborn referred to as ‘the fossil fuel connection’, i.e. the link between the production of fossil fuels and the use of the fuel and their by-products. Her concerns about the extensive fracking operations in the US led her to initiate a major study of the chemicals used in this industry.[20] It found that, of the 353 products used in Unconventional Gas Extraction with CAS (Chemical Abstracts Service) accreditation: [21]

  • 75% affect skin and eyes and respiratory and digestive system;
  • 40-50% affect the brain and nervous, immune, renal and cardiovascular systems;
  • 37% affect the endocrine system; and
  • 25% could cause mutations and cancer.

Today, Colborn’s research is invaluable to campaigners in Scotland fighting for a ban on unconventional gas extraction, and who have cited her work in briefings and at venues across the country.

Over her lifetime, Colborn served on numerous advisory panels, published widely, and won many awards, including the Blue Planet Award (2000), National Council on Science and the Environment Lifetime Achievement Award (2007), Time Magazine’s Global Environmental Hero (2007)and The Society of Toxicology and Environmental Chemistry’s Rachel Carson Award.

TEDX colleagues speak of the person behind these awards.

If you ever had the chance to meet her, even once, you knew Theo Colborn. She didn’t have a single hidden agenda. Her commitment to uncovering the truth was for the world to see. For nearly 30 years she dedicated herself to revealing the dangers of endocrine disrupting chemicals to wildlife and humans. More recently she alerted us to the threats posed by chemicals associated with oil and gas development….

Theo’s visionary leadership and passion shone most brilliantly when she made direct connections between new ideas, scientists whose work confirmed them, impacted individuals, and people in positions to change what needed changing. She will be remembered for many generations to come, generations she worked tirelessly to protect. [22]

In September 2012, ailing but still campaigning, Dr Colborn compiled ‘A letter to the President and the First Lady,’ expressing her concerns for future generations:

…There is no safe level of exposure for many of these chemicals. They penetrate the body and the womb at levels so low they have to be radio labelled so each atom can be counted and their weight extrapolated from that to get the count….

….both the ravages of climate change and the increasing endocrine related epidemics are intimately connected with the use of fossil fuels and their by-products. By drilling deep into the bowels of the earth for coal, oil and natural gas, we have unwittingly and catastrophically altered the chemistry of the biosphere. Something must be done immediately. You are in an excellent position to change this tragedy and get to the source of (it).. humankind is in the midst of a dire health crisis that requires immediate intensive care to survive…. Fossil fuels are not only linked to climate change, but also to the plethora of epidemics resulting from exposure to their end-use products—and the huge costs associated with this that are undermining the global economy and efforts to restore world peace. [23]

Truth seeker, risk taker, networker, committed to the health of our environment and a campaigner to her very last breath, it is no exaggeration to say that that our knowledge of the chemicals to which we are all exposed would not be the same without her work.

Dr Theo Colborn died in 2014. Now more than ever we need to heed her work and words.

We owe much to this dangerous woman.


Further information

Little Things Matter: The Impact of Toxins on the Developing Brain

10 Americans’ study carried out by the Environmental Working Group


About the Women’s Environmental Network, Scotland (WENs)

In 2004, five members of the Women’s Environmental Network attended a seminar at Stirling University’s Occupational and Environmental Research Group, where Canadian researcher Jim Brophy presented his occupational breast cancer work. Following this, WENs Scotland was established to allow us to work within the Scottish Health Framework. WENs now has a large contacts list. At the heart of our work is primary prevention.

We have run workshops, exhibitions and stalls and a day-long ‘toxic tour’ across Central Scotland with environmental experts. We petitioned the Scottish Parliament on Occupational and Environmental Exposures to Toxins (PE1089) and have supported numerous health campaigns, written many papers and lobbied legislators and regulators. Over the last 4 years our attention has focused on supporting campaigners against Unconventional Gas, including fracking.


[1] (accessed 04.02.2016)

[2] ibid (accessed 04.02.2016)

[3] Taken from Musil., K., Rachel Carson and Her Sisters (2014), Rutgers University Press

[4]Smith, H., (2014) ‘Remembering the genius who got BPA out of your water bottles, and so much more’

[5] (accessed 12.02.16)

Biomonitoring-based indicators of exposure to chemical pollutants (accessed 12.02.2016);

[6] Musil. Robert.K., op.cit p 246

[7] Colborn, T.E., Davidson, A., Green, S.N., Hodge, R.A., Jackson, C.I. & Liroff, R.A. (1990) Great Lakes, Great Legacy? The Conservation Foundation and the Institute for Research on Public Policy, Baltimore

[8] nb these toxins are measured and operate at ppm (parts per million, ppb (parts per billion) and ppt (parts per trillion)

[9] The Endocrine Society Scientific Report (accessed 01.02.16) State of the science of endocrine disrupting chemicals 2012; an assessment of the state of the science of endocrine disruptors prepared by a group of experts for the United Nations Environment Programme (UNEP) and WHO (accessed 01.01.16); State of the Art Assessment of Endocrine Disrupters, Final Report EU (2012) (accessed 02.02.16)

[10] A ppb is the equivalent of one second in 3169 centuries

[11] State of the Art Assessment of Endocrine Disrupters, Final Report EU 2012 (accessed 01.02.16)

[12] Taken from Musil op.cit p 248 (Interview with Theo Colborn)

[13] Colborn, T. Dumanoski, D. and Peterson Myers, J. (1996).  Our Stolen Future.  Dutton, New York


[15] Colborn, T. Dumanoski, D. and Peterson Myers, J. op.cit.


[17] Interview with Catherine Buni, Orion Magazine (2014) (accessed 02.02.2016)

[18] (accessed 04.02.16)

[19] Musil, op cit. p.247

[20] (2011) (accessed 02.02.16)

[21] Totals add up to more than 100% because many of the chemicals have multiple effects.


[23] (accessed 31.01.16)