5.4 Science as a Double-Edged Sword
Science plays an important role in both injury prevention and compensation. It has identified hazardous chemical and biological agents, determined the mechanism(s) by which these substances cause harm, and suggested ways to control hazards and treat injuries. It is important for OHS practitioners to understand how scientific conclusions are reached and the limitations of these conclusions.
The scientific method is a process of formulating, testing, and modifying hypotheses. A scientific hypothesis is a proposed explanation of a phenomenon that can be empirically tested to confirm, refine, or refute this explanation. We conduct measurement, observation, and experimentation to gather data that is compared against the hypothesis. If the data agrees with our hypothesis, we may conclude the hypothesis to be true. However, we cannot be certain the results are not the result of chance or a flaw in the method design. In other words we need to ensure the results are both valid and reliable. Validity means the results of the experiment or observation accurately reflect the real world. For example, a scale measuring weight is valid if it correctly reports your actual weight. Reliability is the degree to which the results would be consistent if the measurement or observation were performed again. The scale in our example would be reliable if it produced the same result every time you step on it (assuming your weight has not changed).
The questions of validity and reliability plague scientific researchers, and achieving them is a key element of the scientific method. They are particularly challenging for the kinds of research usually associated with OHS-related matters because most of those issues involve human behaviour and physiology. When dealing with humans acting in the real world, there are limits to the control we can achieve over the measurement. It is unethical, for example, to intentionally expose someone to a toxic substance to measure its effects. Also, we cannot identify and control all the possible variables that may affect our results.
As a result, we can never be absolutely certain our results are accurate. As a result, scientists are concerned with false positives and false negatives. A false positive result occurs when we conclude a difference or relationship exists when it does not. False negatives occur when we conclude no difference or relationship exists when it does. Scientists tend to be particularly concerned with false positives because of their potential consequences. For example, saying a drug is effective at treating a disease when it actually is not can harm patients by subjecting them to an ineffective course of treatment. False negatives can also have real-life consequences as they may lead to inaction on health threats. The potentially harmful consequences of false positives means scientists are prone to being very conservative in their conclusions.
Further complicating matters is that most research conducted on OHS matters can only identify a correlation between two variables (e.g., exposure to asbestos and lung cancer). Demonstrating that asbestos (rather than some other, unmeasured, substance) causes lung cancer requires more complex research. The lack of clarity around cause also contributes to scientists’ conservatism around findings. Unclear causation also is used by employers and government agencies, such as WCBs, to deny the harmfulness of a substance and the injury claims associated with exposure to it. For example, smoking also causes lung cancer and so, if an asbestos-exposed worker also smokes, it can be much more difficult for her to demonstrate that her cancer was the result of the asbestos exposure. This is a common issue for workers who develop long-latency diseases.
The reason that scientific practices matter to OHS practitioners is that health and safety is contested terrain. As we saw in Chapter 1, the interests of employers and workers don’t always align. While scientific analysis has been immensely helpful to workers seeking to identify chemical and biological hazards or receive compensation for injuries caused by such hazards, employers can use the conservative culture of scientific research to slow or block worker efforts in these regards. As Box 5.4 shows, employers will often exploit such doubt in an effort to block regulation of hazardous substances.
Avoiding regulation by manufacturing doubt
Today we know that both vinyl chloride and benzene are dangerous chemicals that affect human health. Vinyl chloride is a polymer used in the production of many plastics, and until the 1970s, it was used in aerosol sprays and other products. Benzene is a component of crude oil that is a powerful industrial solvent and used in production of many products, including nylon. Their dangers were not always widely known.
Debra Davis, a renowned epidemiologist (a scientist studying the patterns and causes of illness and disease in the population), has traced what happened as scientists started to become aware of the health consequences of these chemicals. She found a story of active corporate involvement in the suppression of scientific evidence and discouragement of regulatory controls that she terms “a sophisticated game of scientific hide and seek.”[1]
These cases draw attention to the strategies employers use to protect their interests in the face of scientific, public, or government pressure for regulation. In both cases, the corporations possessed studies demonstrating the health hazards of the chemicals but refused to allow public access to the results. Insiders trying to get the information into the public’s hand were fired or silenced. Employer strategies in the face of growing public awareness are also illuminating:
To the manufacturing companies, it made sense to fight any effort to restrain production. From the very first reports that vinyl chloride could dissolve the finger bones of workers, cause cancer in animals and deform babies, the industry had a simple response: more research is needed.[2]
This tactic is aimed at delaying any regulation of the chemical in question. Employers would also sponsor their own research into a substance. In the case of vinyl chloride, employers hired prominent and well-respected scientists such as Sir Richard Doll, considered one of the world’s premiere epidemiologists, whose results downplayed health concerns.
Not until 2000 did it become known that Doll’s efforts on vinyl chloride had not been the independent musings of a disinterested expert. A letter found after his death in 2005 indicated that Doll had served as a consultant to Monsanto [a manufacturer of vinyl chloride] since at least 1979, at a fee of $1,500 a day.[3]
These efforts are part of a well-documented employer game plan for delaying the recognition of chemical hazards. It starts out with the employer decrying the lack of evidence to substantiate worker concerns about a particular hazard. If the workers have managed to gather evidence to support their claim, employers—sometimes acting through industry associations—will often criticize the methods by which that research was conducted and request additional research, which can cause a multi-year delay in the process.
If the employer has generated research that suggests a substance is hazardous, they may prohibit the researchers they contracted to do the research from publishing the results. They may also misrepresent the findings to government or hire a more compliant researcher to create evidence that the substance poses no risk. Finally, when it is no longer possible to deny that a substance is hazardous, the employer may seek to blame the workers for their exposure or argue that continued use of the substance is economically necessary.[4]
Despite the voluminous research into the hazards of benzene and vinyl chloride, neither has been banned or significantly restricted in industrial processes. OELs have been established, and other safety regulations govern their handling, but thousands of workers continue to be exposed to both chemicals.
The standards set by scientific research can make it very difficult at times to establish that a chemical (or other exposure) is hazardous. Employer use of this conservatism can mean that workers can be exposed to hazards with inadequate information about their effects. By contrast, if those regulating chemical and biological hazards adopted the precautionary principle—where the absence of scientific certainty that a substance was hazardous did not preclude regulating potentially hazardous materials or activities associated with it and the burden of proof fell on those advocating its use—it would be much more difficult for employers to resist this regulation. Box 5.5 considers the precautionary principle in more detail.
Politics and the precautionary principle
The precautionary principle asserts that when a substance is suspected of causing harm to workers, the public, or the environment but there is no scientific consensus on the question, then those seeking to use the substance must prove it is not harmful. In essence, this principle reverses the current evidentiary burden around chemical and biological hazards, which requires critics to prove a substance is harmful before regulation occurs.
The precautionary principle is premised upon the notion that decision makers have a social responsibility to protect workers and the public from harm when there is a plausible case that a substance is harmful. Europe has moved in the direction of the precautionary principle with its Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulations. These regulations place a greater burden on employers and chemical companies to demonstrate that a new chemical is safe, although a number of significant loopholes remain.[5]
One of the impediments to the adoption of the precautionary principle is that it brings into stark relief and conflict the differing interests of employers and workers around safety. Governments generally prefer to avoid making clear choices between the demands of workers (from whom they derive political legitimacy and electoral support) and the demands of employers (who are economically powerful). Consequently, governments are reluctant to seriously consider the precautionary principle (which most employers oppose). One outcome of this reluctance (albeit an outcome that is difficult to see) is that employers retain the right to continue exposing workers to substances that are possibly (and even probably) hazardous.
- Davis, D. (2007). The secret history of the war on cancer. New York: Basic Books, p. 380. ↵
- Ibid., p. 372. ↵
- Ibid., p. 378 ↵
- Bohme, S., Zorabedian, J., & Egilman, D. (2005). Maximizing profit and endangering health: Corporate strategies to avoid litigation and regulation. International Journal of Occupational and Environmental Health, 11(6), 338–348. ↵
- Lokke, S. (2006). The precautionary principle and chemicals regulation: Past achievements and future possibilities. Environmental Science and Pollution Research International, 13(5), 342–349. ↵
A process of formulating, testing, and modifying hypotheses.
A proposed explanation of a phenomenon that can be empirically tested to confirm, refine, or refute this explanation.
The results of a scientific experiment or observation accurately reflect the real world.
The degree to which the results of a scientific measurement will produce the same result when repeated.
Concluding that a difference or relationship exists when it does not.
Concluding that no difference or relationship exists when it does.
Scientists who study the patterns and causes of illness and disease in the population.
The position that responsibility to establish that the activity will not (or is very unlikely to) cause harm falls to the proponent.
