What to Expect When Expecting in Lab: A Review of Unique Risks and Resources for Pregnant Researcher

[ACSGCI]

Contributed by Dr. Mahlet Garedew & Dr. Hanno Erythropel, Center for Green Chemistry & Green Engineering at Yale University

“I’m pregnant!” After receiving the big news, one of the next questions for those working in chemical laboratories is, “Is it safe for me to continue to work in a lab environment?”  These were the same questions that Ph.D. candidate Mary Kate Lane and Postdoc Dr. Mahlet Garedew from the Center for Green Chemistry and Green Engineering at Yale had when they learned they were expecting. In a broader context, these questions are also relevant in the context of gender equality, as studies show that women scientists leave full-time STEM employment positions much more frequently after the birth of their first child than men.

To find answers to some of their questions, Mary Kate and Mahlet led a team of several researchers from the Yale Center and compiled a review focusing on the topic of the safety of pregnant researchers in a chemical laboratory. The open access review, “What to Expect When Expecting in Lab: A Review of Unique Risks and Resources for Pregnant Researchers in the Chemical Laboratory ” was recently published in ACS Chemical Research in Toxicology.

Figure 1: Risks for pregnant researchers depends on hazard, exposure, and vulnerability, where each exists on a scale that contributes to overall risk. Types of hazards in a chemical lab include chemical and radiation hazards, among others. Main routes of exposure are dermal, oral, and inhalation exposure, along with ambient exposure to hazardous environments such as radiation or sound. A pregnant researcher and their developing fetus can be more or less vulnerable to certain hazards and exposures based on the progression of their pregnancy. (https://doi.org/10.1021/acs.chemrestox.1c00380)

About the Review

Most institutions have guidance documents for pregnant researchers to develop an individualized plan. However, much of the work of identifying and assessing specific laboratory hazards usually falls back to the researcher, and such information is usually scattered and generally not readily available. Therefore, the goal of the review paper is to serve pregnant researchers as a starting point for their own risk assessment, and to provide as much relevant data about hazards and risks in one place.

The review tackles the question of risk to a pregnant researcher as a function of hazard (an inherent property of a chemical), exposure (how, when, and how much of the chemical a person is exposed to), and importantly, vulnerability windows (referring to timeframes of susceptibility to the effects of a chemical) during pregnancy and beyond (see Figure 1). The author team, led by Drs. Julie Zimmerman and Paul Anastas, assembled and analyzed relevant literature with a special focus on particularly problematic compound classes including solvents, heavy metals, engineered nanomaterials, and endocrine disruptors, but also included equipment-generated ionizing and non-ionizing radiation as well as the physical stressors noise, heat, and psychosocial and physical stress. Knowledge of these topics is presented in detail and discussed in the context of hazard, exposure, and vulnerability (see Figure 1). For example, the review provides summary tables with a list of 49 common solvents and 29 heavy metals along with their reproductive and developmental toxicity profiles based on information found in the literature and in online databases.

Figure 2: Personal identity (including, for example, identifying as black, indigenous, or a person of color (BIPOC) or low socioeconomic status (SE)) can impact each person’s unique exposome, which arises from their specific external, general external, and internal environments, which can lead to health impacts over an entire lifetime of exposures. This review focuses specifically on pregnant lab researchers and potential reproductive and developmental health impacts resulting from exposure via their occupation (e.g., a specific external environment) (https://doi.org/10.1021/acs.chemrestox.1c00380)

Key Findings and Takeaways

1. There is no single, comprehensive resource with information on chemical hazards and resulting risks for pregnant researchers in the laboratory workplace. This makes it difficult for pregnant researchers to take precautions or be aware of the specific risks during the early stages of pregnancy when vulnerability may be particularly high for miscarriage and birth defects.
2. Most of the available information is largely scattered and is sometimes unspecific beyond a certain class of materials. For example, different organic compounds can be referred to as “solvents” without giving much information on specific compounds, or information on “heavy metals” may focus largely on known environmental toxicants such as lead, arsenic, mercury, and cadmium, which may not be relevant for those working with other metals, metal salts, or organometallic compounds.
3. Information regarding permissible exposure levels and tangible ways of gauging one’s exposure to many hazards is largely missing - especially pertaining to pregnancy.
4. It is particularly difficult to find information on windows of heightened vulnerability during fetal growth for each identified hazard group.
5. While there is some data from observational human cohort studies, many studies are based on exposure in animals or in vitro human tissues, and as a result, findings might not translate directly to humans. However, the review does describe a method to convert animal-relevant doses to human-relevant doses for the reader’s benefit.
6. Most of the available data on reproductive and developmental toxicity only pertains to single exposures. However, in reality, there are likely exposures to a variety of different chemicals at the same time - both at and outside the workplace. Therefore, the review comments on the importance of exposome studies that take into account various intersecting factors that contribute to one’s unique and complex risk profile (see Figure 2).
7. While the review presents many recommendations for both pregnant researchers and lab managers, which include moving as many processes as possible to utilize non-hazardous materials – aligned with the Principles of Green Chemistry and Green Engineering – and fostering a safe, inclusive, and transparent laboratory environment, first author Mary Kate Lane describes the ultimate goal as follows: “First and foremost, this review is meant to provide a resource for pregnant researchers and empower them to assess their risks of working in a chemical lab and allows them to make decisions that they feel confident in.”

The review is open access and can be found at https://doi.org/10.1021/acs.chemrestox.1c00380.