In the classic 1967 film The Graduate, a family friend of lead character Benjamin Braddock (played by Dustin Hoffman) offers him career advice: “One word. Plastics!”

I was 16 when The Graduate was released, and, like Hoffman’s character, completely uninterested in plastics as a career option. But here we are nearly six decades later, and I must admit that, from a purely economic standpoint, Benjamin Braddock received a smart tip.

World plastics production exploded over the intervening decades, from about 25 million metric tons in 1967 to roughly 450 million in 2024. The stock prices of plastics manufacturers soared as the industry expanded, capitalizing on research into new kinds of (and ways of using) synthetic, polymer-based materials. Seemingly endless varieties of vinyl, polystyrene, acrylic, and polyurethane could be extruded, injection-molded, pressed, or spun into a blizzard of products with a stunning array of desirable properties—including durability, disposability, flexibility, hardness, insulative properties, heat resistance, and tensile strength. Plastic was cheap and it could take on any shape or color. It was a magic material that could do almost anything. Soon it was everywhere: in toys, packaging, fabrics, paints, building supplies, medical devices, car interiors, electronics, and more.

The chemical stability of plastics meant that, as objects made of it were eventually discarded, shards and particles would make their way into the natural environment and persist there. Today, traces of plastic can be found everywhere on our planet—in rivers, the air, Arctic snow, at the tops of mountains and bottoms of seas, in plants and soil, and in the bodies of animals from insects to humans.

If fossil fuels enabled the modern age by providing the energy for industrial expansion, they also radically altered the materials that both support and imperil human life. Most plastics are made from fossil fuels, and, like it or not, we now live in an age of oil and plastic. Since fossil fuels are finite, depleting resources, this age will necessarily be brief in geologic terms. If there are future geologists and archaeologists, they will easily identify strata from our fleeting era by evidence of the rapid growth (and decline) of human numbers and their environmental impact, and by durable materials we have left behind—many of which will be plastics.

In this article, we’ll explore plastic’s impacts on humans and nature. And I’ll indulge in a little speculation on the world after plastic.

My wife Janet and I have been concerned about plastic pollution for years. We keep food in glass containers, and we use fabric shopping bags. And yet, looking around our house, I see plastic everywhere. The keyboard on which I type this article is plastic. So is the computer monitor in front of me. Even the cloth shopping bags we use (to avoid single-use polyethylene bags) have plastic as a fabric component and are sewn with nylon thread. If people who try to steer clear of plastics are still thoroughly enmeshed in them, what does that say for everyone else? And how worried should we all be?

Scientific data on the human health impacts of environmental plastic, and especially microplastics, has burgeoned in recent years. We eat microplastics, inhale them, and absorb them through our skin. They can impair respiratory and cardiovascular health and disrupt the normal functioning of digestive systems. Studies have shown that microplastics can induce persistent oxidative stress, inflammation, and DNA damage, and are implicated in chronic diseases like cancer.

One potentially existential impact, explored in Shanna Swan’s book Count Down (and my recent article on the subject) is the impact of plastics and other chemicals on sperm counts and women’s reproductive health. Men’s average sperm counts have declined by over half in the last 50 years. During the same period, estrogen-mimicking synthetic chemicals (including plastics) have proliferated in the environment. Correlation does not prove causation, but research has shown clear pathways by which plastics-related chemicals disrupt reproductive cells and systems. One of the most widespread disruptors of sperm cells is a group of chemicals called phthalates, which we absorb from plastic food packaging. Phthalates are easily measured in urine, and elevated levels typically follow the consumption of plastic-packaged cheese.

Often there simply is no option for receiving the health benefit of supplements, organic foods, medical care, and medicines without a concomitant exposure to health-compromising plastics.

Here's another correlation in which causation is implicated, though in this case still unproven: As sperm counts are declining, so are population growth rates, with global human population set to shrink in the decades ahead (many countries are seeing plummeting fertility rates, while others are still adding population rapidly). While some environmentalists are breathing a sigh of relief, since fewer people could translate to reduced pollution and resource depletion, growthist commentators see population shrinkage as a crisis requiring heroic pushback; hence the recent rise of pronatalism in many nations. Falling birthrates are usually ascribed to families delaying childbirth for economic reasons, but the reproductive impacts of chemical pollution cannot be ruled out as a contributing cause. In a recent article, chemistry professor Ugo Bardi argues that the link between plastics and plummeting fertility is real, and that the result will be, in the best case, a shrinking and aging population; in the worst case, extinction.

Just as frightening as losing the ability to reproduce is losing the ability to think. Recent studies have documented the presence of microplastics in the human brain. Of even greater concern is the finding that the brains of dementia patients tend to contain more plastic particles than others. Are plastics a cause of dementia? We don’t know yet.

Trying personally to avoid the dangers of plastics invites irony and contradiction. An example that springs to mind is the food supplements industry. Its products appeal to consumers who seek “natural” health benefits from vitamins and other micronutrients. Yet most of the health-promoting pills, powders, and potions that consumers take are delivered in plastic bottles; even glass bottles are often shrink-wrapped. Much the same could be said for pharmaceuticals: Most are plastic packaged. Similarly, the food industry, including its health-food segment, relies on sanitation and food preservation typically entailing plastics. Often there simply is no option for receiving the health benefit of supplements, organic foods, medical care, and medicines without a concomitant exposure to health-compromising plastics.

(Photo: Adobe Stock)

If the negative impacts of plastic affected only humans, it might be possible (though callous) to say that our overly clever species is just reaping its just deserts. However, those impacts are falling on other creatures as well, and on whole ecosystems. As a result, our entire planet is being transformed—and not in a good way.

Let’s start with water. As Jeremy Rifkin argues in Planet Aqua: Rethinking Our Home in the Universe, life is all about water. Unsurprisingly, plastic pollution is typically swept via storm drains into streams, rivers, and lakes, which supply drinking water for local communities.

Rivers then carry plastic particles (as well as plastic bags, toys, and other larger objects) into the oceans—which provide the world with food and oxygen, regulate the global climate, and are home to between 50 and 80% of all life on Earth. Intact plastic objects, such as single-use shopping bags, may entangle, or clog the digestive systems of, animals such as fish, whales, and sea turtles, in some cases causing them to die of malnutrition. Gradually, the churning of ocean waters breaks these objects down into smaller and smaller particles, which even more marine creatures ingest. Ocean plastics also impact the overall health and function of marine ecosystems by altering habitats, such as by changing the physical structure of coral reefs and seagrass beds. A widely cited 2016 report by the World Economic Forum estimated that by mid-century, plastics in the world’s oceans will outweigh all the remaining fish.

They don’t just harm the humans who have unleashed them. They impact all of life.

Microplastics are dispersed not just in water, but also in the atmosphere. In an urban environment, humans may be exposed to as many as

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