Plastic is ubiquitous. When you wake up in the morning, you might brush your teeth with a plastic toothbrush, using toothpaste squeezed out of a plastic tube with a plastic cap. Perhaps you run a plastic hairbrush or comb through your hair. When you shower, there’s a good chance you use shampoo from a plastic bottle. Whether it’s yogurt, cereal or toast, your breakfast was most likely conveyed from the grocery store to your home in plastic — breakfast on the go is rarely plastic-free either. For biomedical scientists, the pervasiveness of this lightweight and durable material only intensifies when we pass through the laboratory door. From pipette tips, to tubes, to petri dishes, plastic consumables are considered indispensable to the modern lab.

In fact, the sheer omnipresence of plastic in our daily lives imbues it with an aura of safety and normalcy. But how accurate is that impression?

An insidious impact

My perspective on the potential hazards of myriad consumer products changed recently when I read Count Down, an illuminating — and alarming — book about how chemicals in modern products can make their way into our bodies and environment, impacting the health of humans and wildlife. Its author, Shanna Swan, has been researching fertility trends for over 20 years. Her team found in a 2017 study that sperm counts have dropped by more than 50% in the last four decades in Western countries, and there is evidence that diminished ovarian reserve and miscarriage are occurring more frequently than in previous generations as well.

The culprit? Emerging evidence points to endocrine-disrupting chemicals (EDCs) that mimic the body’s sex hormones, testosterone and estrogen. Plastics are common sources for these worrying toxins, although they can also be found in flame-retardants, some pesticides, personal care products and household items, particularly those with fragrance. Phthalates are among the most common EDCs. They are used to soften plastics that are common in food manufacture, processing and packaging. Phthalates have been detected in blood, urine and breast milk, and its exposure is widespread in the population. Bisphenols, such as bisphenol A (BPA), are another class of EDCs used to make plastic hard. Even plastics that don’t contain phthalates or that are labeled “BPA-free” may release chemicals with estrogenic activity. In the United States, unlike drugs, most chemicals are not tested before being incorporated into consumer products. So even when a chemical is publicly scrutinized, it is often replaced with another substance that has not been tested and may be just as harmful as the first — a process known as “regrettable substitution.” To make matters worse, these chemicals pose a disproportionate threat to disadvantaged communities because of racial and socioeconomic disparities in exposure, which likely exacerbates existing health divides.

Although humans created this problem, its impact is certainly not limited to us. The presence of “garbage patches” — giant floating masses of trash — in the oceans makes this point all too clearly. This ocean debris releases chemicals and microplastic particles that are consumed by marine organisms, disrupting their reproductive development with effects that are likely to reverberate throughout the food chain. Indeed, from amphibians, to insects, to birds, the recent population declines in so many wildlife species are an alarming bellwether for human health.

A science built on single use

How could humans produce so much garbage? The source of this problem is our society’s single-use mode of consumption, which has become so normalized that it is almost unavoidable, inside the lab and out. In our linear economy, materials are manufactured, used once or for a short time, and disposed of, even though most are simply vessels used to carry more important products — food, drink or biological samples — that are contained within. These single-use items add up quickly. In 2015, University of Exeter researchers estimated that bioscience labs alone produced 5.5 million tons of plastic waste in the previous year, accounting for a whopping 1.8% of global plastic production.

Outside the lab, inroads can be made through reusable grocery and produce bags, refillable water bottles and travel mugs, recyclable or compostable materials like paper straws, and other creative stopgaps. In modern bioscience, however, durability is paramount to prevent hazards, and concern about cross-contamination is a barrier to reuse. Moreover, manual decontamination of the large numbers of tubes and pipette tips used in high-throughput applications would be extremely time-consuming. Comprehensive solutions to the waste problem will require large-scale changes both in the lab and in the broader community.

The reuse revolution

Replacing our single-use mentality with a circular economy — in which materials are reused until the end of their useful life — would be a transformative step forward in addressing our waste dilemma. Although this vision may seem idealistic, some innovative companies are already working to make it a reality. A recently launched business called Loop has partnered with well-known brands to offer home delivery of over 200 products in fully reusable packaging. When the containers are empty, Loop picks them up and sterilizes them so they can be refilled and used by another customer.

A similar model may be possible in biomedical science. Richmond-based startup Grenova produces benchtop machines that wash and sterilize pipette tips in large quantities for reuse. The process has been validated for diverse research applications, even those that are sensitive to contamination, and expansion to other plastic items is easy to imagine. As an added benefit, the device helps labs reduce expenditures on single-use consumables and prevent shortages caused by supply chain disruptions, which became problematic during the COVID-19 pandemic.

Biomedical research is essential to produce the treatments, technologies and rapidly expanding knowledge that our modern world relies on. However, if we want to preserve the benefits that this research brings to society, we must rectify its contribution to the waste problem that threatens human health and the environment. Safer and better-regulated chemicals and consumer products may be on the horizon, but the technologies we need to drastically reduce our plastic usage are already at our fingertips. With bold action, biomedical research can be part of the solution to humans’ plastic waste predicament.

References

  1. Swan, S. H. & Colino, S. Count down: how our modern world is threatening sperm counts, altering male and female reproductive development, and imperiling the future of the human race. (Scribner, 2021).
  2. Levine, H. et al. Temporal trends in sperm count: a systematic review and meta-regression analysis. Hum. Reprod. Update 23, 646–659 (2017).
  3. Corbyn, Z. Shanna Swan: ‘Most couples may have to use assisted reproduction by 2045’. The Guardian (2021).
  4. Rozsa, M. How plastics are making us infertile — and could even lead to human extinction. Salon (2021).
  5. Yang, C. Z., Yaniger, S. I., Jordan, V. C., Klein, D. J. & Bittner, G. D. Most plastic products release estrogenic chemicals: a potential health problem that can be solved. Environ. Health Perspect. 119, 989–996 (2011).
  6. Sax, L. Polyethylene Terephthalate May Yield Endocrine Disruptors. Environ. Health Perspect. 118, 445–448 (2010).
  7. James-Todd, T. M., Chiu, Y.-H. & Zota, A. R. Racial/Ethnic Disparities in Environmental Endocrine Disrupting Chemicals and Women’s Reproductive Health Outcomes: Epidemiological Examples Across the Life Course. Curr. Epidemiol. Rep. 3, 161–180 (2016).
  8. Bell, A. Can laboratories curb their addiction to plastic? The Guardian (2019).
  9. Urbina, M. A., Watts, A. J. R. & Reardon, E. E. Labs should cut plastic waste too. Nature 528, 479–479 (2015).
  10. Woolven, J. The solution to plastic pollution. Circulate (2020).
  11. Blackwell, J. R. Richmond startup Grenova has developed high-tech equipment to help labs rethink waste and cost. Richmond Times-Dispatch (2020).


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