By Anita Desikan, Union of Concerned Scientists
When you encounter chemicals in the normal course of your life—while eating food, drinking water, playing in the backyard, or breathing air—do you want the assurance that these chemicals have been deemed safe using the most rigorous scientific methods available? Of course you want that! But the Environmental Protection Agency (EPA) has just implemented a policy that has the real possibility of making this science less rigorous and less thorough.
The EPA is wading into uncharted territory with its announcement that, when assessing the dangers of chemical exposures, it will dramatically reduce its testing on animals. To be clear, we should be aiming to reduce our reliance on animal testing and improve our testing methodologies. However, the EPA is taking a sledgehammer to the problem in a way that could severely compromise human health.
The EPA performs (or requires chemical companies to perform) tests on animals to gauge the safety of chemicals, such as from a new pesticide or from a new pollutant in the environment. The EPA plans on reducing mammal testing by 30 percent by 2025 and end nearly all chemical testing on mammals by 2035. This is the first time that a federal agency has put a hard deadline on phasing out animal research.
According to research scientists in the field, the EPA’s approach demonstrates a failure to appreciate how complex mammalian biology is and the inherent weaknesses of the alternative approaches. The agency is demolishing the scientific methodologies that we currently use to evaluate the safety of chemicals, which could jeopardize the health and safety of all Americans.
How does alternative testing compare to animal testing?
Scientists have made a lot of breakthroughs in recent years with alternative non-animal testing methods, such as computer simulation programs and “organ-on-a chip” technology, which are a collection of cells that are designed to mimic entire organs. These tests are an exciting area of research and have the real potential to enhance the field of toxicology with its quick and cheap chemical assessments.
However, scientists caution that the alternative technologies do not have the ability to completely replace mammal testing yet. If we are only studying cells or organs, we will miss significant whole-body effects that only animal testing can show us. To give some examples of environmental exposures or health conditions that so far only animal experiments can show us:
- Polychlorinated biphenyls (PCBs)—it is not PCBs themselves that cause major problems in the body, but its active metabolites (the stuff that our bodies break PCBs down into when processing them). This discovery wouldn’t have been possible without mice experiments.
- Lead poisoning—lead poisoning can cause cognitive impairment, such as learning disabilities and memory impairment. For ethical reasons, this outcome can only be studied experimentally via animal testing.
- Immunological conditions—in order to determine if a chemical can cause immunological conditions, such as lupus, researchers need to be able to study the impact on the whole immune system, not just the impact on a few cells or in a computer simulation.
- Developmental conditions—the processes by which a single cell becomes an adult human being are not fully understood. We therefore require animal models to determine if a chemical can cause health effects in pregnancy and during childhood and adolescence.
Total reliance on alternative testing is likely to hamper the EPA’s ability to ban dangerous chemicals
There is currently no regulatory framework in place that will allow the EPA to determine if a chemical is “bad” via alternative testing. Here’s the way animal testing works—we expose animals, like mice, to a chemical in different doses and see if a certain health effect is observed, such as birth deficits or cancer. This helps a regulatory agency determine what a safe dose in humans is and provides evidence of whether a ban or a restriction of the chemical is warranted in certain circumstances.
But a finding that suggests adverse health effects in an alternative test—such as observed changes in cells or organs that are associated with cancer—fails to provide a regulatory agency with actionable evidence that they can use to decide if a chemical is dangerous or not. Instead, alternative methods only prioritize the chemical for further testing, which could take years.
The bottom line is that without animal testing, regulatory agencies like the EPA face a higher burden of proof to demonstrate that a chemical is harmful and should be restricted or banned. As you might imagine, this situation is beneficial if you are a chemical manufacturer and want to avoid restrictionson your products. Groups like the American Chemistry Council have a long history of trying to evade regulation of chemicals that EPA scientists have found harmful to human health.
Did the EPA rely on any science advice to make this decision?
Worryingly, we have no evidence that EPA’s science advisory board (SAB) was given an opportunity to weigh in on this policy change. Yet this is exactly the kind of sweeping science policy change that EPA should be consulting its science advisors on. The EPA’s SAB consists of a group of scientific experts that provide the EPA with a rigorous overview of the scientific literature so that its policies can be firmly grounded in the best available science. There is some indication that, in the future, the EPA will tap some experts to oversee the implementation of the plan to phase out animal testing. But one would hope the agency consulted relevant experts to understand the impacts of a decision as consequential as this.
Of note, the EPA currently has an abysmal record of consulting with its SAB (and when consulted, it is too little too late). If the EPA truly wants to implement an evidence-based policy that reduces animal testing without subjecting all of us to increased dangers from chemical exposures, then it is absolutely vital that the EPA consults with its SAB in good faith.
Why is the EPA so eager to carry this out?
Interestingly, the EPA is justifying this change because of a provision in the Toxic Substances Control Act (TSCA) reform from 2016, which requires the EPA to rely on non-animal tests when they’re as good as or better than animal research. And yet the EPA’s enthusiasm to carry out this part of TSCA is wholly different from how the EPA has been currently implementing the TSCA reforms.
Aside from this one provision, the agency has been heavily criticized for its failure to implement TSCA reforms. For instance, when the agency was conducting its TSCA risk assessments on its first ten chemicals, it went against the science and excluded chemical exposures that occur through air emissions, drinking water, and hazardous waste products. One of the chemicals being studied was asbestos—a substance we’ve known for decades can harm human health, yet the EPA is failing to consider all the relevant pathways of exposure to it. Furthermore, the agency has consistently failed to utilize its authority under TSCA. In June 2019, Senators Cory Booker, Tom Udall, Ed Markey, Jeff Merkley, and Sheldon Whitehouse wrote an official letter to EPA administrator Wheeler on this point, saying that “in the nearly 3 years since passage of TSCA reform, EPA has not once used these new authorities and seems to be avoiding them at all costs.”
Chemical industry pressures
This move will certainly be welcomed by those in the chemical manufacturing business. Chemical industries have long complained about conducting animal testing, calling it too expensive and too time-consuming. EPA administrator Wheeler has said that the policy decision was not influenced by chemical companies, that he had “not been lobbied by a single chemical company” and that this issue was “of long-standing interest to me personally.” But there are reasons to believe that the chemical industry did have an influence in this decision.
According to the Intercept, several emails were sent to Nancy Beck and others in EPA in July 2017 from senior representatives of Dow Chemical on the issue of using alternative techniques to replace animal testing. Nancy Beck is currently head of the EPA’s toxic division and previously served as senior staff for the American Chemistry Council, the trade organization that has aggressively prevented or delayed federal regulations of chemicals. The director of federal government affairs at Dow told Beck how “Dow is a leader in non-animal testing methods,” and that non-animal testing is “extremely helpful for us.” In another email, from Dow Chemical’s toxicology science director to an EPA toxicologist, “I think we share similar views on how alternative approaches could be used in the TSCA program.” The EPA toxicologist responded by saying, “looking forward to collaborations!”
Without animal testing, people become the guinea pigs
Personally, I want to believe in the EPA’s initiative to reduce animal testing in its chemical assessments. For three and a half years, my workplace was an alcohol binging lab where every day I greeted, cared for, and dare I say loved dozens of curious little rats. I used to say a prayer for my animals at the experiment’s end, as a way to express my appreciation and respect for these important creatures.
But the more I read up about the EPA’s animal testing phase-out, the more I believe that this policy has the potential of benefitting the chemical industries at the expense of all of our health and safety. There is a reason why scientists still carry out animal testing when determining whether a chemical is safe or not. Animal testing is by no means a perfect process, but it is one of the most powerful ways we have to determine whether a chemical will harm you, your neighbors, or your family. I will be watching closely to make sure the EPA under this new policy continues to prioritize protecting human health as its mission requires.