5.5 Science as a Double-Edged Sword
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 behavior 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 the cause also contributes to scientists’ conservatism around findings. Unclear causation also is used by employers and government agencies, 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.
Box 5.4 Avoiding regulation by manufacturing doubt
Today, it is widely recognized that benzene and vinyl chloride are dangerous industrial chemicals that pose serious health risks to workers and communities. Vinyl chloride, used in the production of PVC plastics, and benzene, a volatile component of crude oil and a common industrial solvent, have both been linked to cancer, reproductive harm, and other chronic illnesses. Yet their dangers were not always acknowledged—or disclosed.
Renowned epidemiologist Devra Davis has documented how corporations actively worked to suppress evidence of harm and delay regulation of these substances in what she describes as a “sophisticated game of scientific hide and seek.” These cases offer clear examples of employer tactics used to protect business interests when faced with growing scientific and public concern. In many instances, companies possessed internal studies showing clear evidence of harm, but withheld that data from the public. Whistleblowers who attempted to speak out were silenced, reassigned, or fired.
A parallel story unfolded in Grand Bois, Louisiana, where oilfield service companies dumped millions of gallons of toxic drilling waste in a low-income, majority-Black and Native American community. When residents began reporting alarming health issues—such as skin rashes, respiratory conditions, and elevated cancer risks—industry representatives deflected concern with a familiar strategy: “more research is needed.” Despite independent assessments confirming the presence of hazardous chemicals such as benzene, arsenic, and toluene, industry-sponsored studies questioned these findings and portrayed the waste as being within “safe” exposure limits.
Years later, investigative reporting and community advocacy revealed that many of the consultants cited by the companies had financial ties to oilfield contractors and environmental service providers. This raised serious concerns about the credibility of the scientific claims used to justify continued dumping and underscored how corporate-sponsored research can delay justice and prolong harm—particularly in vulnerable communities.
This strategy mirrors what the vinyl chloride industry did decades earlier. When reports surfaced in the 1960s and 1970s that vinyl chloride could dissolve bones, cause cancer, and deform fetuses, the industry funded its own studies to downplay these concerns. One of the most well-known examples involves Sir Richard Doll, a leading epidemiologist, who for decades publicly minimized the health risks of vinyl chloride. It wasn’t until after his death in 2005 that a letter surfaced revealing he had been a paid consultant to Monsanto, a vinyl chloride manufacturer, since at least 1979—earning $1,500 per day.
These tactics are part of a well-documented employer playbook for delaying recognition and regulation of chemical hazards:
- Deny the evidence: Employers often start by claiming there is insufficient proof of harm and dismiss worker concerns as anecdotal.
- Demand more research: If evidence emerges, companies challenge the research methods and push for more studies—delaying action for years.
- Suppress or distort findings: When research is conducted under contract, employers may prohibit publication or selectively present findings to regulators.
- Hire compliant experts: If prior researchers reveal troubling data, companies may replace them with more agreeable scientists who produce favorable conclusions.
- Shift blame: Once the hazard is undeniable, the narrative may shift to blaming workers for their exposure or arguing that the chemical is too economically essential to regulate further.
Even with overwhelming scientific evidence, neither benzene nor vinyl chloride has been banned in U.S. industrial use. While OSHA has established exposure limits and implemented some safety requirements, thousands of American workers—including many in Louisiana’s petrochemical industry—continue to be exposed daily.
These examples highlight how regulatory systems in the United States can be slowed, shaped, or undermined by private interests—often at the expense of worker and community health.
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.
Box 5.5 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, Authorization 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.
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.