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The late American comedian George Carlin had a hilarious routine where he made fun of our existential crisis about plastics and the environment. “The planet . . . is a self-correcting system,” he’d say, “The air and the water will recover, the earth will be renewed.” Then he’d add, “And if it’s true that plastic is not biodegradable, well, the planet will simply incorporate plastic into a new paradigm: the earth plus plastic.”

We might as well be living in that reality now—of the earth plus plastic. In the same way different eras of human history are named for the materials that most defined them, like the Iron and Bronze Ages, some geologists now refer to our time as the Plasticene—The Age of Plastics. We’ve never mass produced or distributed any other synthetic substance at so large a scale across the world as we have plastic. With it has come vast plastic pollution, finding the solution to which is hampered by the fact that we created plastic and now need it despite the dangers it poses to every living thing on earth.

Plastic, broadly defined as “a synthetic material made from a wide range of organic polymers”, is a relatively modern invention. Although its history dates back to the 19th century, we didn’t start large-scale production of completely synthetic everyday materials until the 1950s. And we’ve never stopped.

In the seven decades since the ‘50s, human beings have created more than 9 billion metric tons of plastic, more than half of them in the last two decades alone. That’s billions of tons of a material we know to be essentially non-biodegradable.

Some optimistic estimates by organisations such as UNEP are that we have recycled about 9 per cent of it, while environmental activists say it is a lot less than that. Either way, it means that most, if not all, the plastic ever made is still around, and every year, we add nearly 400 million tons more. A lot of it is single-use plastic, destined to be used once and thrown away.

“We currently dump 11 million metric tons of plastic into the ocean each year and this figure is projected to double by 2030 and nearly triple by 2040,” UNEP Executive Director Inger Andersen said recently, adding, “In 2018 alone, impacts on tourism, fisheries, and aquaculture together with other costs such as those of clean-ups, were estimated to be at least US$6-9 billion globally.”

Plastic was originally good for the environment. When it was first invented in the mid-19th century, it was primarily made from cellulose, the basic building block of all plants. Its biggest selling points, even then, were that it was malleable, meaning it could be moulded into different shapes and designed for different uses. In fact the word plastic—from the Greek word “plastikos” which means to “grow” or “form”—initially referred to this capacity to be deformed without rupturing. A derivative type of that early plastic made in the 1860s soon found use as an alternative to ivory, which was harvested off slaughtered elephants and used to make everything from piano keys to billiards.

Modern hydrocarbon-based plastics trace their history back to 1907, when Leo Baekeland, a Belgian-American chemist, invented a fully synthetic plastic, the first of its kind, and called it Bakelite. Known as the “material of a thousand uses”, it was Bakelite that ushered in the age of plastics that we are still living in more than a century later. Unlike the cellulose-based plastics that had come before, Bakelite was cheap to make and could be easily mass-produced. But it would be another four decades before plastics spread across the globe. In that time, research focused on making new plastics and finding uses for them. Plastic and other related inventions of the pre-World War II era, such as nylon, soon found uses on the war fronts, increasing demand and boosting production.

Known as the “material of a thousand uses”, it was Bakelite that ushered in the age of plastics that we are still living in more than a century later.

We still make plastic because we need it. Plastic is the medium through which we transport and store food, medicine, water, and just about everything else. It’s in our homes, our offices, our cars, our computers and phones, and in nearly every aspect of our lives. It makes toys, pipes, building materials, furniture, medical equipment and countless other things.  For example, by the time Kenya banned single-use plastic carrier bags in 2017, the plastic industry was supplying an estimated 100 million plastic bags to supermarkets every month.

A prevailing defence by Big Plastic is that when it comes to transporting food, beverages and other essentials to 8 billion people, plastic has the lowest carbon footprint compared to alternatives. The main problem though, is that its relatively short useful lifespan does not justify how long it persists in the environment. Even worse, most consumer plastic is designed to be used only once and discarded; US magazine advertisements in the 1950s pushed plastic as better than existing reusable products because it was cheap and easily replaceable.

Such overt advertising of the most visible pollutant we’ve ever made would not work today. The reason is that in the last six decades, plastic has progressively lost its lustre. It is unclear when plastic began losing the crowd, but one aspect of this decline in reputation was the very things that made plastic such a popular material in the first place. Plastic is cheap, so the word ‘plastic’ soon acquired a new use, as a word used to describe something that is cheap (in quality), and fake. By the late 1960s, it was increasingly clear that plastic was here to stay, and that it was not good for the environment. The growth and impact of the anti-plastics movement in the next two decades triggered questions about how the situation could be salvaged, hence the birth of recycling campaigns from the early 1970s.

Recycling was never going to work, and the proof of this is that it was a compromise solution driven primarily by the plastic industry. After a major oil spill in the United States in 1969 kindled political pressure to act on the environment, the plastic industry lobbied heavily against drastic action. Their solution was to push for recycling, although everyone involved already knew that it would not work because the technology to do it effectively did not exist at the time.

Recycling has improved since the 1980s, but it is still an ineffective way of managing all the plastic waste produced each day. Another very problematic aspect of recycling is the global waste trade, which sees countries in the West send their plastic waste to poor countries to be sorted and recycled.

We’ve always known that the hydrocarbons we so lucratively mine from the earth and transform into fuels and plastics are not just polluting the planet, but could also be affecting our health. Part of the reason for the slow pace in dealing with the threat posed by plastics, despite the fact that their ubiquity means that any potential harm could be widespread, is that the “war on plastics” has focused mainly on where discarded products end up, and the indirect impact on health. In a 2018 report, UNEP reiterated the known risk that “By clogging sewers and providing breeding grounds for mosquitoes and pests, plastic bags can increase the transmission of diseases like malaria.”

However, a growing body of research now shows that plastic is not just in the environment around us, it is also inside us. Plastics and their additives are in the air we breathe, the food we eat, the water we drink, and the things we touch. We eat seafood and land animals that have consumed plastics. For example, a 2018 study by the National Environment Management Authority (NEMA) found plastic bags (and nylon strings and synthetic hair) in the stomachs of more than half the animals slaughtered in three major abattoirs.

“Marine and other species ingest plastics and absorb the chemicals within them,” says Erastus Ooko, Plastic Project Engagement Lead for Greenpeace Africa, “and then we ingest them. It has been clear for a long time that the toxins in their bodies are going up the food chain but it is hard to quantify in practice.”

Plastics and their additives are in the air we breathe, the food we eat, the water we drink, and the things we touch.

Further, chemicals such as Bisphenol A, also known as BPA, which is used to harden plastics and is found in a number of consumer products, including drinking containers, baby bottles, and the linings of infant formula and food cans, have also been shown to leach into foods and beverages. Thus the question is not whether we are consuming plastic, but how much of it we are consuming and with what impacts.

Although plastic is non-biodegradable in that it takes a long time to degrade, it does break down with time and usage into smaller particles known as microplastics, which can also degrade over time into even smaller particles known as nanoplastics. Most of the plastic we consume is in this micro and nano form, making it hard, but not impossible (in the case of microplastics), to detect or even study. A 2020 study found that infants consume millions of microplastic particles per litre when fed using polypropylene (PP) infant feeding bottles. PP is a common household plastic, and other studies have shown PP microplastic release from food containers, kettles, and other everyday items.

That we eat a substantial amount of microplastics is not itself a surprise—we also inhale and consume dust, sand, insects and other minute things unknowingly every day. The difference is that microplastics are synthetic and pose direct risks as foreign bodies in our bodies, and because of their chemical makeup.

We most likely excrete most of these micro plastics. But there is a significant gap in research on the damage they do to our bodies, and in what gets absorbed into the body. What is known so far is that many of the materials used to make everyday plastics are harmful to human health, and that the plastics in our bodies could be harming us in multiple ways. A 2020 report by The Endocrine Society found that “one hundred and forty-four chemicals or chemical groups known to be hazardous to human health are actively used in plastics.”

The dose makes the poison

One of these is BPA, a known endocrine disrupting chemical that interferes with normal hormonal function. These effects are not minor; studies have suggested that the disruption can lead to birth defects, developmental problems in children, cancers, and immune system suppression.

The key challenge in assessing just how badly this chemical group has affected human health is that within plastics, which are complex polymers, BPA is a benign addition. It can, however, be released as plastics wear down, or are heated repeatedly, meaning that it’s hard to trace just when and where it enters the human body and what damage it leaves behind.

Another chemical, Diethylhexyl phthalate (DEHP), is a suspected carcinogen and potential endocrine disruptor. DEHP was the most common plasticiser for decades, mainly used in the making of Poly Vinyl Chloride (PVC) but is slowly being replaced with alternatives due to concerns about its toxicity to multiple organ systems, including the reproductive system and thyroid function. A recent study compared the levels of DEHP and two other chemicals in dog testes from several regions in Europe and found a parallel between high DEHP and testicular conditions. The study suggests that this may be indicative of the situation among human males, because dogs and human beings share the same everyday environment and are exposed to the same household contaminants.

What is known so far is that many of the materials used to make everyday plastics are harmful to human health, and that the plastics in our bodies could be harming us in multiple ways.

The most obvious place to begin when assessing the direct effects of plastics to human health is with those who make them. Since the 1970s, for example, scientists have suspected, and subsequently confirmed, that vinyl chloride, the building block of PVC, is a carcinogen that can and has led to occupational cancers. A 2011 study found a link between high DEHP concentrations in the air breathed by workers in PVC plants with negative effects on sperm motility, among other adverse effects. Another exposed group, Ooko says, are communities who live around plastic manufacturing plants, who could be suffering health conditions due to the fumes and other chemicals released during the manufacturing process.

For these and other reasons, the European Union has banned DEHP and two other chemicals from all plastic items that children might put in their mouths, such as toys, since 2007. Under new rules that came into force in 2020, this ban is now extended to all other consumer products, regulating the amount of DEHP and other potentially harmful chemicals that people come into contact with. “There has been a huge knowledge gap in how plastics affect human health. Things get attention when direct connections can be made, and the direct connections between plastic and health conditions came in at a later stage,” Ooko explains.

Similarly, chemicals used to make styrofoam products such as styrene monomer and benzene are suspected carcinogens. Then there’s the heavy metals, water repellents, and flame retardants used in the making of plastics. Although heavy metals such as lead, mercury, chromium, arsenic, and bromine are found in nature, our current exposure to them is primarily through synthetic things like plastic. Some research has shown that not only are these metals, which in substantial quantities are detrimental to human health, present in plastics, but they can also be absorbed by microplastics from the environment.

In the 2000s, as our appetite for plastic exploded, scientists began focusing more and more on the health effects to human beings and animals beyond just marine life. Bans such as the DEHP bans in Europe and single-use plastic bans in Kenya and other places are driven not just by environmental concerns, but also by human health ones. This transition is still slow, because the research on health effects is still scant, and is held back by complications such as how to determine what harm plastic is doing to our health when it is present in the body of nearly every living human being.

Carlin’s comedy set ends with the idea that perhaps plastic was the only reason the earth allowed us to be spawned in the first place. “It wanted plastic for itself. Didn’t know how to make it. Needed us.” Then he’d add, “Could be the answer to the age-old egocentric philosophical question: ‘Why are we here?’” It is an answer that may be slowly poisoning us.