, Volume 5, Issue 1, pp 1–13

Nano-Technology, Ethics, and Risks


    • Department of PhilosophyRochester Institute of Technology
Original Paper

DOI: 10.1007/s11569-010-0108-5

Cite this article as:
Robison, W.L. Nanoethics (2011) 5: 1. doi:10.1007/s11569-010-0108-5


Nanotechnology is developing far faster than our understanding of its effects. This lapping of our understanding by speedy development is typical of new technologies, and in the United States we let development occur, introducing new artifacts into the world, without any serious attempt to understand beforehand their effects, long-term or short-term. We have been willing to pay the price of pushing the technological envelope, but pushing the nanotechnological envelope has some special risks, requiring more caution.


UnpredictabilityNano artifactsTestingSelf-reportingModerate caution

We humans have a history of introducing new artifacts into ourselves and our environment without a serious examination of their consequences—leaded gas, drugs, chemical compounds, medical devices, and on and on. The standard recent examples in the United States include drugs that cause the sort of problems they were supposed to prevent—Avandia, which is supposed to decrease the possibility of heart disease for diabetics but instead increases it, and the drugs Fosamax, Actonel and Boniva, which are supposed to reduce the risk of bone fractures but instead increase them.1 A standard older example is asbestos and the asbestosis that occurs long after a person’s initial exposure, but we have introduced many substances and artifacts which have produced, and continue to produce, harms to us and to the environment—a history that in itself ought to make us chary of introducing nano-artifacts into our world without a serious examination of their consequences.

Nano-artifacts, however, have two properties that are cause for special concern:
  • The behavior of materials at the nano-level is curiously unpredictable from their behavior at the macro- or even micro-level. We have thus found new and wonderful uses for some old standbys, but we have been surprised and, predictably, will continue to be surprised by the effects of nano-particles.

  • Nano-particles are so small they can go through cell membranes. That is part of the point of nano-biotechnology, of course. Nano-artifacts are to deliver lethal drugs precisely to wayward cells, for example, killing only them. The concern is that such tiny particles may migrate into cells where they could do great damage—in the brain, for instance.

These two features of nano-particles ought to give us pause in introducing nano-artifacts into us and our world.

Dolly, the cloned sheep, is all the evidence we need to know that once a technology is available, we have no control over who will use it or how it will be used. No one else working on cloning had any idea that Dolly was in the offing. Just so, those doing research on nanotechnology have little inkling what other researchers are doing: the field is new, the techniques proprietary, the rewards great, the incentives for secrecy high. We can presume that research on nanotechnology is taking place all over the industrialized world and that given their special features, we ought to be concerned that, accidentally or on purpose, nano-artifacts will be introduced without testing for their consequences.

Unfortunately, we cannot take comfort either from the kind of stance we in the United States take towards the introduction of new artifacts into us and our environment or from the testing procedures used to weed out those artifacts that may be harmful to us or the environment. Neither provides a model for how we ought to respond to the special problem those two features of nano-particles present.

Let us look at testing procedures first. I will focus on testing procedures in the United States for the entry of new artifacts—an “artifact” being anything that we produce and introduce into ourselves or into the environment, e.g., chemical compounds such as sunscreen, cell phones, nano-biological bombs for destroying particular cells, solar panels, plastic bottles, and on and on. Though some of the examples I use are peculiar to the United States, the arguments and conclusions have a more universal application.

If we treat nano-artifacts as we have generally treated artifacts, we leave a relatively open gate for nanotechnology, encouraging the introduction of all sorts of nano-artifacts—from nano-enamel to make our teeth impervious to decay and white as white can be, to far more efficient filters for arsenic in water made of nano-magnetite, to sensing devices smaller than grains of sand, to medicinal bullets for zapping cancers at the cellular level. There is a huge world down there in nano-land, with room for all kinds of beneficial artifacts, and with plenty of money driving the research, that world will soon be inundated, as it were, with nano-artifacts of all kinds—especially with an open-gate policy.

My concerns cut directly against that vision. I think we ought to be particularly chary of introducing nano-artifacts. As I have indicated, they have two features which ought to give us special pause—their curiously unpredictable behavior and their ability to penetrate cell walls. We know that the smaller a particle, the worse the damage to our lungs if we breathe it in, for instance, and some evidence indicates that nano-particles can or do migrate to the brain and also affect our reproductive organs, with potentially harmful consequences [See e.g. 35].

Putting our current testing procedures as gates for the introduction of nano-artifacts will not suffice. Our present system of testing for the harmful effects of new artifacts is inadequate:
  1. 1.

    Many artifacts are not tested.

  2. 2.

    When they are tested, we have no guarantee that they are tested thoroughly, and we know that sometimes they are not.

  3. 3.

    Even when an artifact is tested thoroughly and problems are found, the form of the testing leaves it to the manufacturers to report on those problems, and they tend to give themselves the benefit of the doubt because, no doubt, they have a conflict of interest.


We will consider each of these in turn and then turn to the issue of nano-artifacts and the presumption of guilt.

§1. Untested Artifacts

Many artifacts are not tested. Polybrominated biphenyl is used as a fire retardant. One of its primary uses was in movie projectors, for example. In the early 1970’s, PBB, as it is known, was accidentally mixed with animal feed at a Michigan Farm Bureau. When that occurred, over 2,000 new chemical compounds were being introduced every year, most without any testing of their potential effects on the environment or on us. There simply was no gate to the entry of these compounds and artifacts. I would assume that the number of new compounds introduced yearly has increased, but, so far as I know, there is no comprehensive database to check that assumption.2 In any event, it is still true that most are never subjected to any tests to determine their toxicity if they somehow make their way into us or to determine any other effects on the environment. Given the costs of testing, that makes some sense: no one anticipated that PBB would enter into the food chain by being mixed with feed for farm animals, and so no one bothered examining its effects on our health should we ingest it.

It is not difficult to find harmful compounds introduced into the food chain either accidentally or intentionally that have never been tested for the harm they may cause. The melamine found recently in cat and dog food and traced to the adulterated wheat gluten in the food is a case in point. Even at apparently small concentrations, it has killed dogs and cats and significantly harmed many, and though there is no evidence that any wheat gluten contaminated with melamine has entered the food we eat, that way of putting it—the way the FDA has carefully put it, hedging its wording—is just the problem: we also have no evidence that it did not enter the food chain and some compelling reasons to think it did. The wheat gluten sold by the Chinese company was a general product, sold to whatever company wished to purchase it, for whatever purpose, and purchased by producers who wished to game the test for protein content because that test does not distinguish between wheat gluten and melamine.3 As far as we know, no experimental work has been done on the long-term, or short-term, effects of melamine on us—or, indeed, on any animals. Like PBB, the likelihood of animals ingesting it on purpose can be presumed nil, and so there is a good financial reason not to test for the effects of its being ingested.

It is also not difficult to find examples of compounds or artifacts with toxic effects introduced without any apparent concern of their toxicity. Reebok gave away 300,000 charms as part of a shoe promotion, and they were determined to be 90% lead, and recalled, only after a young boy swallowed the charm and died of lead poisoning.4 Of course, no one intends that young children should eat the charms given away with shoes, but we all know that young children put many things in their mouths without a second thought and that, like adults, they sometimes swallow what is in their mouths without intending to. So manufacturing artifacts designed for children to play with and not testing them for toxicity is tantamount to making a Spring Surprise, to use an example from Monty Python, a chocolate loaded with a spring that will pop open and impale your cheeks once the chocolate has been thinned through sucking: we know that people will be harmed. Just as we would hold the chocolate confectioner morally and legally culpable, so we should hold the manufacturers of charms made with 90% lead morally and legally culpable. The bottom line is that such artifacts should not be introduced into our environment and that testing is needed to ensure that they are not. The rash of baby toys recalled recently in the United States because tainted with lead is clear evidence that such items are not being tested for their toxicity.

The REACH initiative in the European Union—the “Registration, Evaluation, Authorisation and Restriction of Chemical substances”—marks the beginnings of an effort there to regulate the introduction of some artifacts into us and our environment:

One of the main reasons for developing and adopting the REACH Regulation was that a large number of substances have been manufactured and placed on the market in Europe for many years, sometimes in very high amounts, and yet there is insufficient information on the hazards that they pose to human health and the environment. There is a need to fill these information gaps to ensure that industry is able to assess hazards and risks of the substances, and to identify and implement the risk management measures to protect humans and the environment.5

We might compare this initiative to one regarding the introduction of new drugs. We ought to know what a drug’s properties are so that we can then both test for its effects, sorting out from among those properties which, if any, are problematic and which are not, and also, just as important, test for how it interacts with other drugs.

Of course, discovering the intrinsic properties of chemical substances—as the REACH initiative puts it—does nothing in itself to impede the introduction of harmful chemical substances and does nothing regarding the chemical substances already in the market or for any other substances that may be introduced. But the stance driving the initiative is the right stance to take: we should at least know the properties of what we are introducing. At least we can then begin to test for the effects and for how something with those properties will interact with other substances already on the market.

We have concentrated here primarily on chemical compounds, and we need to remember that there are other artifacts besides chemical compounds introduced into us and into our environment which may be harmful in other ways. That we have such an initiative as REACH is all the evidence we need of our history of introducing artifacts without testing.

§2. Porous Testing

Even when artifacts are tested, we have no guarantee that they are tested thoroughly, and we know that sometimes they are not.—Even when artifacts are introduced that we would presume are tested extensively, it is not difficult to find harmful aspects of those artifacts that either were not tested or somehow escaped detection. The sources of the slips almost defy categorization, but here are four samples.
  1. a.

    Incomplete tests—Recent experiments indicate that some common environmental contaminants widespread in humans act as estrogen does, eliciting allergic responses by mast cells. These contaminants are called “environmental estrogens,” EEs for short. They are ubiquitous in the environment, found in polychlorinated biphenyl (PCBs), plastics and pesticides and thus in the water, air, food, consumer products, and us. They intensity the reaction of mast cells. That reaction is called degranulation, and the intensification of degranulation means that allergic reactions are both stronger than they would normally be and may occur even when none would normally occur. As the authors of the study indicate, the “effects of EEs on mast cell degranulation may help explain the increasing prevalence of asthma and other allergic diseases in recent decades,” a rise that cannot be attributed to dirtier air or exposure to more allergens [15].


These experiments need to be confirmed, but it is the form of the result that is of interest here. The researchers used the standard test for degranulation, measuring the percent of a protein called β-hexosaminidase in mast cells that is released in an allergic reaction. For each environmental estrogen, the strongest reaction was at intermediate doses (one tenth of a part per billion) with no reactions at the highest concentration (10 parts per billion) or at the lowest (1 part per trillion), and over half the cell’s available β-hex was released within 30 min—a very fast reaction. Most importantly, “this non-monotonic response (an inverted U-shaped curve), where the lowest and highest amounts produced weaker effects than the middle concentrations, will not be detected by traditional toxicity tests, which are the basis for setting public health standards.”6 The standard tests begin at a high dose where there is an effect and then decrease the dose until there is no effect. But that test will not sort out toxic from nontoxic dosages of a substance if you working with a compound that suppresses the harmful effect at a high dosage and causes an increase at a low dose.7

So we have, ubiquitous in our environment, and in us, a set of chemicals which produce and enhance allergic reactions and which cannot be detected by the traditional tests used to determine public health standards. It is too late, of course, to remove these toxins from the environment or from us. They are fat-loving and so are in our fatty tissues, are thus likely to be passed down to nursing babies, and are so ubiquitous that removing them is for all practical purposes impossible. We thus face a rising epidemic of asthma and other allergic responses that we could not have avoided even if we had tested all the substances being introduced into the environment.

The gatekeeper of a toxicity test that is supposed to prevent harmful substances from entering the environment tells us that the substances will not cause harm when they will. So we ought to look with suspicion upon the tests used to preclude the introduction of artifacts into the environment. Our sense of security is itself an artifact of a faulty test.
  1. b.

    Gamed tests—It should not be a surprise that any test can be gamed—as we know from all the examples of individuals in sports. The problem that arose with melamine in cat and dog food was the result of purposefully introducing a substance that mimics wheat gluten. The standard tests for wheat gluten are unable to distinguish between gluten and melamine. They measure nitrogen content, using that as a base for determining the protein content. Adding a substance rich in nitrogen will thus make it appear that the protein content is higher than it is. That is the reason melamine was used: it elevates the reading given by the test, making it seem that the product is richer in wheat gluten than it is [see 1].8


Once we know how a test works—what it is seeking to isolate and what methods are being used to isolate it—then if you wish to game the test, the first order of business is to ensure that what you want to put into what is being tested is not culled out by the test. It could be a poison; it could be a filler; it could be something that mimics what is being isolated. You would then be in the position of those who added melamine to wheat gluten: the tests do not distinguish the sources of nitrogen, and so the melamine is not culled out by the test. The test effectively masks the adulterant while elevating what the test recognizes as protein. If melamine is less costly than wheat gluten, you have gained monetarily, and if elevated wheat gluten is more valuable, you have gained even more. There is thus an incentive to game the test. The cost of production is lowered, and the product can be sold at a higher cost.

The general problem is straight-forward: tests are designed to sort out one thing from another, but each is conditioned. That is, they only work under a set of conditions that may or may not be satisfied. The PBB crisis in Michigan was uncovered only because of a persistent farmer with a degree in chemistry kept sending off samples of his feed stock to be tested and lucked into an answer. The person in the Ames Lab in Iowa to whom he sent a sample went out to lunch after putting the sample in a spectrometer. That heats the sample to determine its chemical composition. Because PBB is a fire retardant, it does not react to heat except after long exposure. The person ended up taking a long lunch and came back to find that the sample had left its mark. Previous tests had ended before the PBB had heated up sufficiently. The farmer then sent the results of the test to someone who made a hobby of doing tests for new compounds, and PBB was finally identified as the adulterant. The test to determine the chemical composition of the feed was conditioned by the assumption that it would be sufficient to heat the material for a half hour or so. That assumption made PBB impossible to detect.

Gaming a test only requires working out the assumptions the test makes and then figuring out how to make use of one or more of the assumptions to rig the test. One assumption made in the test for measuring the quantity of wheat gluten is that it would not be contaminated with melamine: the test was not designed to sort those two compounds from each other.
  1. c.

    Ignorance—Some slips occur because no one has any idea what to hunt for. The discovery that painters with ten years experience or more have a significantly higher risk of bladder cancer—30%—than others would seem to imply that there is something about long-term exposure to paint that causes the problem, but it is unclear what causes the increased risk [16]. So it is unclear what to test for, and since the evidence regarding this increased risk has only recently surfaced, no one testing paint for toxicity before now would have thought to hunt for something—and we do not know what—related to the increased risk. Rather obviously, anyone now testing paint for toxicity cannot know what to hunt for either.


It is this sort of problem that is likely to cause the most difficulties with nano-artifacts. As mentioned, substances that we seem to know well at the macro-level can act very differently at the nano-level. We normally distinguish between a substance’s essential properties and the properties it displays when in contact with other substances. Sugar is crystalline, but loses that shape and gains other properties when immersed in water. But nano-particles present problems in regard to both these features—both its essential properties and those it takes on in contact with other substances.

As we have pointed out, even if we know the essential properties of a substance at the macro- or micro-level, we cannot thereby know what its essential properties will be at the nano-level, and, just as important, even if we know how a substance interacts with other substances at the macro- or micro-level, we cannot thereby know how it will interact with those substances at the nano-level. A metaphor for this problem is the complications that arise for patients taking two or more drugs whose effects on each other cause new kinds of harm to the patient.
  1. d.

    Seemingly incomprehensible failures—Some slips occur because it does not occur to those introducing the artifact to test what slips by. Consider the foam that is used to blanket and so keep cold the rocket fuel inside the booster rockets for the space shuttles. Every time a shuttle blasts off, bits and pieces of foam become dislodged and fall towards the shuttle, directly below. The Columbia burned up on reentry because a piece of foam had torn a 12″ hole in the left wing and the opening let the hot gases generated upon reentry into the internal wing scaffolding, melting it. No tests had ever been done on the effects of any foam hitting the shuttle until after the loss of Columbia. Experiments showed that a piece of foam would hit the shuttle at more than 500 mph and that a chunk the size that came off the booster rocket when Columbia was launched could tear a 16″ hole in the leading edge of the wing [6].


The results of the test are what make incredible the failure to test prior to the disaster: how could the engineers have missed that the foam presented a potential for such harm? They knew from the very start of launching the shuttle rockets that foam came loose from the booster rockets on liftoff. It approaches the incomprehensible that not even rocket scientists thought to see if pieces of foam could cause damage to the shuttle, but, apparently no one did think of that or, if they did, did not follow through or convince anyone of the need for a test.

That sort of issue seems commonplace—especially in complex engineering projects. No one tested the Vitron used for the O-rings in the booster rockets to determine its resiliency under conditions of cold [see 17]. No one tested the ignition switches in Fords for their potential for shorting out and causing fires.9 No one tested the Firestone tires on Fords that shredded for the manufacturing defect that caused the shredding.10 No one tested the cargo door on the DC-10 that tended to blow open when the cargo hold was pressurized [8].11 The list is long, and what is interesting about these examples is that the artifacts in question were tested, sometimes extensively, but the fault was missed because it never occurred to anyone to test for the problem that arose.

It is not always quite clear what went wrong in these cases, but it does not matter to the point at hand: we know that artifacts can have faults we miss even in extensive testing. So even extensive testing does not provide us with the assurance of safety we should want for something that could cause great harm.

§3. Reporting Procedures

Even when a substance or artifact is tested thoroughly and problems are found, the form of the testing in the United States leaves it to the manufacturers to report on those problems, and they tend to give themselves the benefit of the doubt because, no doubt, they have a conflict of interest.—The Kugel hernia patch is a case in point. Two pieces of mesh surround a flexible plastic ring—a “memory recoil spring.” Surgeons fold the ring, put it in place next to the hernia, and then let up. The ring springs open, and the mesh covers the hernia and also serves as a medium for internal tissue to grow and replace the hernia. But the spring was prone to break, with its sharp edges causing sometimes severe complications, including several fatalities. The company decided the fault lay with the surgeons not holding the patch properly while trying to insert it. It began training sessions for the surgeons and began revising its instructions. The complications continued, and in early December 2005, “tests run by the company on a failed patch ‘suggested for the first time that the source of the ring break was caused by a failure at the ring weld [14].’” So it was not the fault of surgeons, as the company argued, but of the product.

It took a long time for the company to take action, the first patches at issue being introduced in 2002, a recall of their largest patch coming late 2005, with recalls of two more in 2006 and 2007 after pressure from the FDA. Reports of problems came in much earlier than 2005. Why the delay? It is unclear whether the Bard Company, which manufactures the Kugel patch, thoroughly tested the ring for resiliency when the product was designed or whether it tested the rings after manufacture to see if the manufacturing process produced a safe ring. It is difficult to imagine that it did not do such tests, but, in any event, the case illustrates well how difficult it is to be sure that an artifact has been properly vetted before its introduction into us or the environment.12

First, our procedures for reporting problems with such a product in the United States generally depend upon the manufacturers of the product collecting evidence and then reporting any problems found. We have self-regulation or, rather, are supposed to have self-regulation. But it is a standard problem that companies do not keep good track of complaints about their products, and, even if they do, “a company can decide not to forward a complaint to the agency if it decides after an internal review that its product was not at fault.”13 And if it does report a complaint, we are dependent upon the company to report with accuracy its severity and frequency, but companies have an interest in downplaying both the severity of injuries and the frequency with which they occur. So we cannot be sure, even if a company reports problems, that it has done so accurately.

Second, the companies are necessarily in the position of having to weigh the potential benefits of a product against the potential harms of recalling the product. Given their interest in continuing what can be a lucrative revenue stream, it is likely that the potential harms must be of greater magnitude than normal and their likelihood must be greater than merely “potential” for them to announce a problem with their product and curtail their income. Self-regulation is not the best solution to any problem where those doing the regulating have an interest in not finding a problem.

We thus have a decision-procedure that encourages inaction in the face of potential harms. We give the collecting and reporting function to just those parties who are prone not to report failures or to take them as seriously as such other interested parties as the FDA or consumers likely would, and we put in the hands of those parties a decision which favors the status quo. Those parties must decide between a known harm (the loss of income) and a potential harm (the loss of life and other harms), and even if they weigh into that calculus long-term concerns about lawsuits and the subsequent losses to income those would entail, they are still calculating potential losses against known losses. And it is their known losses they are calculating. Another factor weighing in the calculus is that if they recall the product, they admit a problem with the product and so make themselves more likely to lose subsequent lawsuits. So even if they weigh in their long-term interests, they have good reasons for favoring the status quo.

A second example, if one is needed, concerns defibrillators. One device had a problem with a battery that failed significantly before its stated lifetime, requiring a new operation to replace the device. Another device’s lead, the wire threaded into the heart to carry the electrical charge to jolt it to start, could puncture the heart because of its shape. But the issue with defibrillators became news because of a flaw in a Guidant model. The lead wires projecting from the $25,000 device were susceptible of being eaten away by the bodily juices surrounding them. When that happened, the unit would short circuit, fail, that is, just when it was needed. It was the death of a 21-year-old college student that occasioned examination of the issue [13].14

Again, it is up to the manufacturer to decide whether to disclose a product flaw, and Guidant decided not to tell physicians that its product had this design flaw. Indeed, despite having manufactured a version of the device that corrected the flaw, Guidant continued to sell the flawed product to unsuspecting surgeons and patients, apparently until it had cleared its shelves of its flawed product, making its money while putting in harm’s way the patients who received the faulty defibrillator. Something was, or is, seriously awry at a company supposedly committed to helping patients.

In any event, it is difficult to know what to make of this case. How could anyone design a product for insertion into the body without making sure that the exposed parts would not deteriorate within the body? Checking for that is not rocket science, but then, as the problems with Columbia and the foam show, being a rocket scientist is not the gold standard it used to be. In any event, the fault here may lie in the testing process within Guidant: did they test for this problem? We do not know, and until a lawsuit makes its way to court, without a settlement denying access to Guidant data, we shall not know. What we do know is that the procedures we currently use even for something as important as a defibrillator depend upon the manufacturer’s being the party to call attention to problems with its product. Those procedures thus force the manufacturer, as we have noted, into making a decision between known and potential harms—known harms to it versus potential harms to others. We can hardly expect disinterested decisions in such a situation.15

It seems an odd system, indeed, in which we rely upon those who introduce compounds and artifacts to tell us whether there are problems with what is introduced, and the situation is complicated still more by our reliance on testing procedures that, because of the form of the tests, necessarily fail to detect problems in regard to some compounds and artifacts. Both these features need to be corrected if we are to have a system that will ensure us a modicum of safety.

§4. Nano-Artifacts

So the present system in the United States of testing for the harmful effects of new artifacts is inadequate. Most are not tested, and even when they are, we know that sometimes they are not tested thoroughly, and even when they seem to have been tested thoroughly, some obvious problems seem to slip by, and, in any event, we leave reporting those problems in the hands of those who make the artifacts and have an economic incentive in maximizing the benefits, minimizing the harms, and not reporting any problems at all. We thus ensure that companies will only reluctantly report problems with their products.

All these difficulties with the gates for entry into the market in the United States should be enough to give us pause. Even where we would expect the most careful scrutiny of the introduction of artifacts—when they concern our health—we are continually finding problems. In a press conference on Monday, November 15, 2010, the FDA announced that it was investigating problems with defibrillators in general. It announced that in the “past five years there have been 68 recalls involving hundreds of thousands of individual machines made by a wide range of companies. Over the same period there have been 28,000 formal reports of defibrillator problems to the agency, including nearly 700 deaths [10].”16 These machines are advertised as life-savers, and so it is more than a little shocking to discover that far from saving individuals, the failure rate is so high that almost 700 have died because of machinery malfunctions over the past five years. We can have few better examples of the failures of the regulatory process in the United States—healthcare companies marketing a device to save lives that costs lives. We have a very low gate for entry into our world of healthcare—exactly the place where we might have presumed a high gate.

Having a low gate for entry that is not well latched is of special concern, however, when the potential harms is significant. That is just the situation with nano-artifacts. I am not concerned here with “grey goo” or any other science fiction scenarios. I am concerned with the two features of nano-artifacts that should cause us pause.

First, as noted above, nano-artifacts have features that are unpredictable from the features of such artifacts at the micro- or macro-level. Gold is a standard example of this. At the macro-level, it appears yellow, but at 10 nanos or so, it appears red. It is the source of the red color in stained glass windows: spread gold thinly enough, and it changes its color. Nothing about gold as we know it from its features at the macro-level would allow us to infer that at a particular nano-level it appears red—or that, as it happens, at other nano-levels it appears other colors.17

Or consider that magnetite at 12 nanometers binds “up to 100 times as much arsenic as the larger iron particles currently used in [water] filters” and yet is “much more sensitive to low-strength magnetic fields than would have been expected based on the behavior of larger particles [7, 9, 20]” Nothing in the behavior of magnetite would have led anyone to expect such features at the nano-level.

These unpredictable features have beneficial properties. Sprinkle some magnetite of 12 nanometers into a well, and it will bind the naturally occurring arsenic much more efficiently than anything else. Throw small magnets into the well, and the magnetite, and arsenic, will sink to the bottom.

Yet the features of nano-particles and artifacts are unpredictable. The only way we can find out how they work in situ is to put them in situ and see what happens. The problem is obvious. Although we would have expected the designers of a $25,000 medical device to check to see if the covering for the wire leads would disintegrate when subjected to the body’s fluids, we can hardly expect those developing nano-artifacts to check to see how they react in all the situations in which they can and will be found once introduced. Because they are so tiny, they can migrate without much difficulty—like weed seeds attaching themselves to our clothing—into situations we would never have anticipated and so never would have thought to check.

The second problem we have also mentioned. Because nano-artifacts are so small they can penetrate the sides of cells, for instance, or migrate, apparently, into the brain, they present special problems that other artifacts—defibrillators, for instance—do not present.18 They are more like the micro-particles that we have recently discovered are ubiquitous in pollution and tend to lodge in the fine tissue deep within our lungs, causing disease and premature deaths. Unseen, unfiltered by manufacturing and coal-firing plants because less than 5 microns in size, they are a leading cause of death and disease where prevalent.

We cannot predict what effects introducing various nano-artifacts into the environment, and into us, will have. We do know, with a high degree of certainty, that nano-artifacts and nano-particles will make their way into our bodies. Some will be purposefully introduced in order to deliver medicine, for instance, or to coat our teeth with an impervious enamel. But others, like environmental estrogens, will make their way into our systems. 95% of us carry Bisphenol A, a plastic molecule used in polycarbonate water bottles, dental sealants, resin coating for food containers, and so on. Yet recent research indicates that Bisphenol A promotes prostate cancer growth in about 31% of those with advanced tumors.19 Who would have thought?

We are likely to be as surprised by nano-artifacts and nano-particles.

§5. Our Epistemological Position

It might seem that we should adopt as our guiding maxim here some version of the precautionary principle. As I have argued at great length elsewhere, choosing that as our guiding maxim is the reasonable and moral response when we have even a small risk of great harm. It is not the likelihood of harm that drives adoption of the maxim, but the magnitude of the harm, and we do not need evidence that harm will occur to respond cautiously, only evidence that it may occur. One core feature of the precautionary principle, in short, is that we are entitled to a preemptive strike in situations where great harm may ensue even though we do not have sufficient evidence to prove that it will occur. Indeed, it is arguable that the greater the magnitude of harm, the less evidence we need to provide that it may occur.20

It is important that these claims about how we ought to proceed are not unusual. They find a natural home, and so find their footing, in ordinary situations we face every day. We know we ought to take this sort of stance all the time when driving, for instance, or when walking on ice. We should know that the risk of having a catastrophic accident is high if we drive too fast or erratically or if we walk too carelessly on ice, and so we moderate our behavior accordingly. We watch where we step and walk more slowly. We watch other drivers and moderate our driving. These are normative claims, of course: this is how we ought to behave if we are to act reasonably in such situations. But these normative claims have traction for others. We criticize those who drive too fast in snow and ice, and we can only wonder at the lack of care of those who ignore the ice beneath their feet. That such normative claims find a home in our ordinary lives is what gives them traction when they are applied to what for some are esoteric examples such as the depletion of the ozone layer.

Yet the situation we are now in—at least in the United States—is different enough from the paradigmatic cases for the adoption of the precautionary principle to make me cautious about adopting it as our maxim for action and about its having any traction if we were to recommend adopting it. I have three reasons for caution:
  • The precautionary principle does not sit well with the presumption of innocence.

  • Even if it did, the global pace of development in nanotechnology will continue.

  • In any event, we are not in the most favored position epistemologically, and probably will not be for some time, to obtain convincing evidence of potential harms: the presumption of innocence and proprietary concerns will ensure our continued ignorance.

First, were we to start anew, we would face a choice between two different presumptions. We could presume that any artifact to be introduced into us or our environment is harmful until proven innocent, or we could presume that artifacts are beneficial or at least neutral until proven harmful. The choice of what presumption to adopt depends upon a difficult set of calculations: will we cause more or less harm, and produce more or less good, if we presume that artifacts are generally safe or if we presume they are generally harmful? The former presumption encourages the proliferation of products and so encourages research, but puts us at greater risk of something harmful being introduced. The latter presumption best protects us from the harms of new artifacts, but dampens the spirit of discovery because whatever is discovered will be presumed harmful until it can be proven safe, a presumption that will undoubtedly delay the introduction of the product and so the profits that fuel research.

But we are not starting anew. In the United States, at least, we live with the presumption that, generally, new products are innocent until proven guilty. Suggesting that we change that presumption is a non-starter—politically as well as economically in a global economy—and that presumption does not sit well with being cautious about introducing new products. Legal liability is always a problem, of course, and companies generally calculate in the potential legal costs when they consider the harms a product may cause. But if we are to presume a product’s innocence until it is proven guilty, we have no reason to exercise caution in introducing it.

A warning to be cautious will find no footing in such an environment. If we warn someone of ice on the sidewalk, telling them, in effect, that they should not presume it an easy walk, we are far more likely to have them exercise caution as they proceed. But why would they exercise any more caution than normal if the sidewalk is free and clear?

In any event, even if we could convince them to exercise caution, we are in the midst of a global technological revolution. As I indicated above, once technology is available, it will be used. The cloned Dolly was a living example of that. The lesson such an example provides us is thus not that we should slow down technological development. We will not be able to do that. Just as we adopt as a condition for ethical judgment that we can only fruitfully say, “You ought to do X!”, in a situation where the person can do X, so we ought not to adopt as a maxim of action anything that tells us we ought to do what we cannot do. And it is not going to be possible to moderate in any significant way the development of nanotechnology. As I have said, we have little inkling what is being done worldwide because the techniques are proprietary and the incentives for secrecy are high, but we have good reason to believe that research is moving quickly because the rewards are great. We know all that even without considering the military applications of nanotechnology and thus the incentives for the military-industrial complex to push development.21 And once we consider the potential military applications, we can see how a concern for caution will have little traction. Innovation in nanotechnology is not going to slow down.

One reason is that we are not in a good epistemological position regarding potential harms in us or in our environment from the introduction of nano-artifacts and nano-particles. One of the essential features of the precautionary principle is that we are entitled to act even in the face of doubt, but we do need some evidence of potential harm if we are to have a reasonable chance of convincing anyone to adopt the principle. We know that the worst the potential harm, the more the need for caution, but if we lack significant evidence of potential harm, the principle will lack traction and because we will sound too much like Chicken Little. Someone who argues for caution without knowing that harm will ensue can always be accused of saying, “The sky is falling!”

Yet, as we saw, we cannot predict with any degree of certainty the essential features of nano-particles or how they will interact with anything in us or in the world. Experimentation in situ is the name of the game. It appears that we can only determine what happens to us and our environment when nano-particles and nano-artifacts are introduced by introducing them and effectively running a long-term experiment on the population—as we in the United States now do with many drugs, discovering side effects only long after their introduction that, had they been discovered sooner, would have precluded their introduction. Meanwhile, we remain ignorant of what effects nano-artifacts and nano-particles will have on us or our environment, and, in particular, we remain ignorant of their long-term effects—complicated because of their potential interaction with other new artifacts, with their own unanticipated effects, that will be introduced into us and our environment. We cannot properly hold up the prospect of catastrophic outcomes, that is, because such outcomes lack an undeniable foothold with our current knowledge.

This weak epistemological position is made worse in the United States where the gates for entry into the market are so low that almost nothing precludes the entry of nano-artifacts. Manufacturers are generally not required to provide evidence that their products will not cause harm. Samsung has thus introduced washing machines that through “electrolisation, [emit] 400 billion nano-sized silver ions..., directly penetrating into fabrics during the wash and final rinse cycles, creating an amazing anti-bacterial and sterilization effect on clothes.”22 That such nano-sized silver ions may cause damage to plant cells, for instance, apparently was not considered any more than the potential for the evolution of new bacteria immune to the effects of silver nano-particles. The waste water from the washing machine has to go somewhere, and the silver nano-particles it contains will thus readily make their way into the environment—and presumably into us as well.

We can anticipate many more companies making use of the available technology to introduce nano-artifacts, and we can also anticipate that our knowledge base of potential harms will not increase much, if at all, as a result of any research done before the introduction of new nano-artifacts. On the one hand, any research that is done is likely to be proprietary, and, on the other, the presumption of innocence discourages the research on a product’s effects that would give us leverage to rebut the presumption—even if rebutting the presumption were politically and economically feasible. So we find ourselves in a rather odd position. We have reason to be concerned about the effects of nano-artifacts in us and in the environment, but are precluded by the presumption of innocence for new products from gathering information that would be helpful in rebutting that presumption until after the nano-artifacts are introduced.

§6. Summary

It might seem that the appropriate response to the introduction of nano-particles and nano-artifacts is a caution born of our ignorance of their potential effects and of our knowledge that their behavior is curiously unpredictable and their potential for harm is high because they can penetrate cell membranes. In the face of such potential harm, in the condition of uncertainty we find ourselves, opting for caution would be no more than we demand of ourselves in any similar situation. It is the same sort of response we ought to make when we are driving and see an accident ahead or an erratic driver. We slow down and modify our driving as conditions require with the aim of minimizing potential harm to ourselves and to others.

Yet, although a moderate caution would seem the right stance to take towards the introduction of nano-particles and nano-artifacts, there is no closing the gate on research and innovation. It is too late, the potential benefits are too great, and the economic incentives too high. Arguing that we now ought to adopt such a stance would be to argue that we ought to adopt some version of the precautionary principle, but the situation is, to put it mildly, less than ideal for its adoption.

In addition, as I have argued at length, even if we were to urge caution and require testing, the present system of gate-keeping in the United States is woefully inadequate to prevent harmful artifacts from entering the market. The current testing procedures are imperfect, both permitting new artifacts to be introduced without testing for their effects, as with the “nano-sized silver ions” in the Samsung washing machines, and passing, even with testing, artifacts that can cause harm. We need only think of some of the recent medications that have had to be recalled or required warnings, years after they were introduced—e.g. Avandia, Paxil, Vioxx, and, most recently, Darvon [19].23 We seem unable to vet properly the details of even large complex engineering projects where, as I argue, things just slip by that, in retrospect, seem such obvious sources of problems that we cannot imagine why they were not tested. We are in a situation where even if moderate caution were the official position, we lack testing procedures in the United States to give backbone to the caution. “What is the point of requiring testing,” someone may well ask, “when the tests are so porous and ineffective?”

All this may seem a depressing set of comments on what may lie ahead for us, and determining how to vet nano-artifacts is an important project, made more compelling by the history of slips and recalls that plague the system in place in the United States. I would like to say that without careful consideration of potential side effects and a clear understanding of how little we know about what harms we may introduce, we cannot safely, or morally, introduce nano-particles into humans or into the environment, where they may migrate to humans. We need a decision procedure that pays more than lip service to the risks involved. But it has not been my aim to suggest a decision procedure that will be responsive to the situation we find ourselves in. I have been concerned to get clearer on the kind of situation we are in so that when remedies are considered, they are responsive to real problems and will also have traction for those charged with responding. Unfortunately, determining what decision procedure to adopt towards the introduction of nano-artifacts is not as easy as deciding how to walk on ice.


For a succinct introduction to the problems, see [11].


There certainly was no database at the time. As we discuss below, the farmer who pushed the investigation into the cause of his animals dying determined the cause only after someone who investigated new chemical compounds as a hobby happened to recognize the unique signature of PBB. For details, see my Decisions in Doubt: The Environment and Public Policy (Dartmouth NH: University Press of New England, 1994).


See b) in §2 below for the details of this problem.


See Release O6-119 of the U.S. Consumer Product Safety Commission, issued March 23, 2006 and revised most recently October 27, 2010.


Environmental Health News, 3 April 2007 at See as well Environmental Health Perspectives summary at


See in this regard Pete Myers, on “Living on Earth,” April 13, 2007 at


A nice summary may be found in [2].


After a large number of fires, a great deal of bad press, and numerous lawsuits, Ford agreed to recall 7 million of the 15 million vehicles with ignition switches that caused a fire even when the engine was off. See e.g. “Ford Offers to Settle Class Action,” Consumer Affairs, August 1, 2000.


Congressional Record--Senate, October 6, 2000, pp. 21254–55.


This study details the four main cases where the cargo door blew out, including the crash outside Paris that killed 346 and the crash in Chicago that killed 273.


The patch is at the center of a series of law suits, and so the manufacturer has understandably been exceedingly reluctant to make public any of its own tests about the patches and their failures, and since some cases are settled out of court, the manufacturer follows the usual route for such settlements and demands that no information about the lawsuit be made public. It is, again, one of the features of the litigious United States that lawsuits are likely to cause information to be buried.


Meier, Op. cit.


For those familiar with regulation of medical devices, indeed with many devices, in the United States, it is not a surprise that the reference here is to the New York Times. Guidant did not release any information about the problems with its defibrillators until it discovered that the Times was about to print an extensive, and explosive, article on the problems and on how poorly Guidant responded to those problems. As we mentioned, it is an unfortunate feature of the ways in which medical devices, among other things, are regulated in the United States that companies self-report problems—if, and only if, they judge them serious enough to warrant disclosure. The failure of companies to do that is an object lesson in how the United States ought to reform its regulatory process as well as an object lesson for other countries about how not to regulate companies: a company’s self-interest is likely to trump any concern to self-report problems when the publicity will hurt the bottom line.


See the Report of the Independent Panel of Guidant Corporation, March 20, 2006 for a detailed analysis of what went wrong. Although the panel has “Independent” in its title, it was funded by Guidant.


The press conference transcript is not yet available at the time of this article.


It also seems unlikely that we will be able to go the other way, determining a substance’s macro-features from an understanding of its nano-features. John Locke was right in saying, “Had we Senses acute enough to discern the minute particles of Bodies, and the real Constitution on which their sensible Qualities depend, I doubt not but they would produce quite different Ideas in us; and that which is now the yellow Colour of Gold, would then disappear, and instead of it we should see an admirable Texture of parts of a certain Size and Figure,” but the hope he expressed of being able to know the world fully by understanding its atomic structure thus seems even less probable now that we have gotten down to the atomic structure of things [12].


See for a detailed bibliography of articles on the penetration of skin by nano-particles and some known and potential health effects.


The 31% are those with a mutant form of the androgen receptor AR-T877A. Other mutant forms may respond similarly, but the work to determine that has not yet been reported [18].


See my Decisions in Doubt, op. cit., where, among other things, I compare the responses to the PBB crisis in Michigan and the risk to health with the response to chlorofluorocarbons (CFCs) in the atmosphere and the potential loss of the ozone layer.


It is no cause for wonder that the latest Nobel Prize in Physics was for the development of graphene, that sheet of carbon one atom thick with incredible properties of strength, flexibility, and conductivity.


The quotation is from, Samsung’s press material. Accessed 8.5.2010.



I wish to thank the anonymous reviewer of the first draft of this article for some very helpful and insightful comments. I have not made all the corrections suggested, but the comments forced me to rethink a main point in the paper. I think the paper the better for it.

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© Springer Science+Business Media B.V. 2011