The rise of chemophobia: Are we right to be worried about chemicals?

by Jacqueline Rowarth / 09 October, 2017
RelatedArticlesModule - Chemicals

Photo/Getty Images

In the face of public anxiety about synthetic chemicals, scientists are working on a “green and sustainable chemical future”.

Beware dihydrogen monoxide. It’s everywhere. An internet search quickly turns up reports that it’s a major component of acid rain and causes death when accidentally inhaled, tissue damage after prolonged exposure and severe burns when in gaseous form. It is also routinely found in biopsies of precancerous tumours and lesions. The calls are strident: dihydrogen monoxide (DHMO) should be banned.

Dig deeper and you’ll find that the DHMO, so named because its molecule contains one oxygen and two hydrogen atoms, is properly called H2O. You may know it as water.

The celebrated DHMO hoax has become a byword for how a lack of scientific literacy and analysis based on prejudice rather than science can lead to misplaced fears. In the scientific community, it is commonly called chemophobia.

Since the term first appeared in print in the 1960s in relation to anxiety about food production, the fear it refers to has widened to include anxiety about all chemicals – never mind that we, and everything around us, are made of nothing else.

Chemophobia is on the increase in the First World, where people have the money and choice to seek what they see as a natural and chemical-free life. They appear to believe, first, that such a thing is possible and, second, that such a life will be healthier than the alternative.

In developing countries, however, chemicals are recognised as enabling healthier lives by improving agricultural yields and slashing the incidence of preventable disease. In short, and in contrast to chemophobic anxieties, life has never before been healthier or more predictable in terms of food supply for the developed world.

In his 2016 book Progress: Ten Reasons to Look Forward to the Future, Johan Norberg, a fellow of the Washington DC think tank the Cato Institute, writes of the role that synthetic chemicals have played in creating the highest living standards the human race has known and concludes that “we’re living in a golden age”.

Humans are predisposed, says Norberg, to think that things are worse than they are and to overlook the environmental improvements all around them. That’s because many – including, for example, the removal of lead from petrol – are invisible. Yet the galloping progress in science constantly protects humanity: when the swine flu pandemic threatened to become catastrophic in 2009, scientists sequenced the genome of the virus within a day. A vaccine was produced in less than six months.

Johan Norberg: synthetic chemicals have created a golden age.

No escape

As most of us know, or should know, all things are composed of chemicals. The human body is almost 99% made up of oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus – big hitters in the periodic table. The way those chemicals interact is extraordinary and we are still learning about them in the life sciences, but we do know that we are chemicals and we live surrounded by other chemicals – in plants, animals, rocks, water and the atmosphere.

Chemophobia, more an aversion than a true phobia, is a term applied to those people who try to avoid exposure to synthetic chemicals. The anxiety may go back to the 1962 publication of Rachel Carson’s Silent Spring, which documented the detrimental effects on the environment of the indiscriminate use of pesticides. What is certain is that chemists in laboratories have experienced mistrust for decades.

Making matters worse is that fewer and fewer people understand what chemistry involves. Most people either find it dull or suspect it is dangerous. School chemistry is one of the harder subjects because exams call for both memory and precision. Research published by Durham University in 2009 rated chemistry as the third-most-difficult of 33 A-level subjects.

The result is that many people are unaware of the chemicals that surround them. Michelle Francl, a professor of chemistry at Bryn Mawr College in Pennsylvania and one of the 1000 most-cited chemists, has likened chemophobia to colour blindness because, “chemophobics are blind to most of the chemicals that they encounter: every substance in the universe is a chemical.”

Indonesian woman Siti Aisyah (head bowed), accused of killing Kim Jong-nam in Malaysia in February with nerve agent VX. Photo/Getty Images

The harmlessness myth

Chemophobics fear synthetic chemicals, and such incidents as the murder of Kim Jong-nam, half-brother of North Korean leader Kim Jong-un, in a VX nerve-agent attack at Kuala Lumpur airport in February, stoke such worries. VX was originally developed in the  UK in the 1950s during research into pesticides, but was deemed too toxic to be used safely. It is banned under the Geneva Convention.

But the fact that a chemical is natural rather than synthetic tells us nothing about whether it is dangerous. Ricin, for instance, which the KGB liked using to assassinate dissidents abroad, is a natural chemical found in castor-oil beans. Botulinum, which caused Fonterra headaches in 2013, also occurs naturally, and it is estimated that one teaspoon of it could kill a quarter of the world’s population.

The active ingredient in derris dust, commonly used in home gardens to control insects, is rotenone, a natural component in the roots of various members of the fabaceae (bean) family, approved for use in organic production systems. Rotenone interferes with cellular respiration and was used in some cultures to harvest fish.

Most of the pesticides found in plants are generated by the plants themselves, but they have not been examined in as much detail as synthetic chemicals. Ironically, this research imbalance has probably contributed to people’s fear of synthetic chemicals because so much focus has been on chemicals coming from laboratories rather than nature.

It is important to remember that all chemicals have the potential to cause harm if ingested at high-enough doses. The recent focus on sugar is a case in point. Sugar is not toxic but, eaten in large quantities, can lead to obesity and other negative consequences. The same is true of H2O, whatever name you give it.

Glyphosate weed killers are effective but widely mistrusted. Photo/Getty Images

Hazard or risk?

Large doses of glyphosate, commonly sold under the brand name Roundup, can also cause health problems, but when it is used as directed, no detrimental health effects have been recorded. The ongoing debate about its use hinges on two reports released in 2015, one categorising glyphosate as a “probable human carcinogen” and the other stating that, “on the available scientific evidence, there were no grounds to classify the controversial herbicide glyphosate as a carcinogen, as a mutagen or as toxic for reproduction”.

The difference is between hazard and risk. A rockfall on a road could be a hazard to traffic, but the risk it posed would be calculated according to size of the fall, encroachment on to the road and volume of traffic. If the risk was high, the road might be closed and diversions put in place, as has occurred in the Manawatu Gorge. But if the risk was deemed manageable – with barriers, lane closures and so on – the road might remain open: the decision is made on the basis of the need to keep people safe while considering the inconvenience caused by diversions.

For the first glyphosate report, by the independent International Agency for Research on Cancer (IARC), 17 experts reviewed all published, peer-reviewed literature. IARC identifies hazards; it does not take into account the likelihood of exposure to the substance, so it does not address the risk of exposure.

By contrast, the second report was by the European Chemicals Agency (ECHA) Committee for Risk Assessment, which carried out an extensive evaluation of all the information available, including human evidence and “the weight of the evidence” of animal studies.

The IARC’s list of known carcinogens includes alcoholic beverages, tobacco, solar radiation and wood dust. The probable carcinogens include shift work, processed meat, frying and red meat, as well as glyphosate. But, as the American Cancer Society explains, “carcinogens do not cause cancer at all times, under all circumstances. Some may only be carcinogenic if a person ingests it, for example, as opposed to touching it; some may cause cancer only in people with a certain genetic makeup; some agents may lead to cancer after only a very small exposure, while others might require intense exposure over many years.”

The debate about glyphosate’s effects on human health continues, but it is clear that banning the chemical would have a detrimental effect on food production as well as having potentially negative environmental  implications. Glyphosate, which degrades quickly, affects actively photosynthesising material, so reduces weed competition. It cuts production costs and minimises the need for tillage, which saves fuel, reduces greenhouse-gas production and limits the potential for soil erosion and loss of organic matter. Estimates in Europe are that a ban would reduce crop yields by 20-40%.

Calculating net benefit

Chemical regulators such as New Zealand’s Environmental Protection Authority (EPA)take a net-benefit approach, but calculating the benefit rests on two key foundations: being able to work out how much better off we are with an item than without it, and making the correspondence between willingness to pay and well-being comparable across different social groups.

In developing countries, people seeking better health status and food production are more likely to accept the use of synthetic chemicals in medicines, fertilisers and pesticides; in developed countries, people seeking a synthetic-chemical-free existence weight avoidance highly, and are prepared to pay more for food, though health decisions are more complicated because there are few so-called natural alternatives as efficacious as modern antibiotics, no matter how much you are prepared to pay.

In response to concerns, science is working on what is termed a “green and sustainable chemical future”. The terms “green chemistry” or “sustainable chemistry” are appearing in scientific literature more frequently, as is the phrase “isolated from natural products”. But high research costs may be hard to recover in an increasingly risk-averse regulatory environment.

Regulations governing the use of chemicals are having unintended consequences, particularly in the stifling of innovation. Martin Kayser, a medical doctor and senior vice-president of product safety at German chemical company BASF, has suggested replacing the so-called precautionary principle with an innovation principle and urged a rethink to enable the chemical industry to be a “solutions provider, with a prerequisite of sound chemical management”.

The industry seeks to produce chemicals that yield equal (or higher) performance at equal (or lower) cost while providing a positive environmental balance. This “benign by design” approach will create green and sustainable chemicals of the future.

Gwyneth Paltrow. Photo/Getty Images

Public understanding

The biggest challenge for “green chemistry” is engaging the public in overcoming negative perceptions. As science and technology become increasingly complex, it is easier to understand somebody’s story about how they have been or will be affected, than explain the greater, more complicated good. It doesn’t help that celebrities wade into the debate. Alarmingly, the international 2017 Edelman Trust Barometer indicated that celebrities are more trusted than scientists.

Yet Gwyneth Paltrow, for example, has had to be requested by Nasa to stop making inaccurate claims on her website about scientific research. The agency’s former human research division chief scientist, Mark Shelhamer, told technology website Gizmodo that online claims that “wearable healing stickers” promoted by Paltrow company Goop used the same material that lines Nasa space suits were “a load of BS”. He said “not only is the whole premise like snake oil, the logic doesn’t even hold up. If they promote healing, why do they leave marks on the skin when they are removed?”

Well-meaning commentators such as Paltrow have been directed to the Sense about Science website (, which underlines the fact that it is not possible to lead a chemical-free life, whatever celebrity websites promise.

New Zealanders can be reassured that regulations about the use of chemicals are the responsibility of the EPA and the Ministry for Primary Industries and there are regular checks of chemical residues in food to ensure that producers are using chemicals responsibly. 

It is possible to use chemicals, synthetic or natural, to improve the quality of life for us all.

Jacqueline Rowarth is the Environmental Protection Authority chief scientist.

This article was first published in the September 30, 2017 issue of the New Zealand Listener.


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