Plastic material's universal application and its use by human beings are the cause of omnipresent environmental pollution. The terrible impact of plastics on the environment have received considerable attention but the relationship of chemicals used in synthetic plastics and its effect on health has received less attention. Plastics processing is rooted in toxic compounds, which are crucial roadblock to the urgently needed global transition to sustainability.
Plastics are the world's most useful materials and have countless applications. It is used to manufacture everything right from toys, medical equipment, kitchen, and bathroom accessories and is now the material of choice for numerous applications. Different sectors have taken note of plastic's strength, resilience, and moldability for their goods. Nevertheless, the indestructibility of plastics has made them a major environmental hazard, creating waste pollution and its harmful effect on ecology.
Plastic was a ground-breaking invention that altered the creation of industrial and everyday goods. It attracted the attention of scientists and inventors as a malleable, flexible, and long-lasting substance. Different features, traits, and strengths can be engineered into the various plastic compositions. Plastic material can be modified and altered to have different levels of strength, toughness, resilience, hardness, and heat resistance using a number of chemical processing procedures.
What are plastics?
Plastic materials are created from organic compounds known as polymers and additional components. They are extremely formable materials. In addition to being formable, plastics are typically recognised for being inexpensive, lightweight, flexible, resilient, and corrosion-resistant. Petrochemical feedstocks are transformed into unprocessed plastic resins through the process of polymerization. A petrochemical facility creates raw plastic resins. The thermoplastic and thermosetting polymers are two broad categories for plastic polymers. They can also be separated based on the primary polymer used. Injection moulding, casting, blow moulding, rotational moulding, compression moulding, extrusion, calendering, thermoforming, and spinning are a few of the fabrication methods used for plastics.
Majority of us consider plastics in their consumable, packaging, or other useful forms, as all plastics are actually formed of intricate chemical combinations. Concerns for health are raised by the characteristics of those chemicals, notably the "additives," which are frequently not connected to the plastic substance itself.
The presence of heavy metals in plastics, flame retardants, phthalates, bisphenols, and fluorinated compounds in the form of additives are only a few of the largest and most dangerous chemical families that are directly linked to the manufacture of plastics. From the coatings and resins used in building and industry to the synthetic textiles that make up our clothing to the rubber granules recovered from tyres that wind up on children's football grounds, plastics constitute a remarkably diversified range of substances. Many of these compounds, which we regularly consume or breath, have negative effects on our health.
The conversation shifts around plastic pollution away from a materials-focused discussion on the consequences of plastics on the environment and towards the molecular effects of chemicals connected with plastics on human health. The close relationship between the production of plastics and hazardous chemicals, the health risks linked to plastics throughout their entire lifecycle, the serious threat that plastics and plastic additives pose to the circular economy, the need for a broad definition of plastics that enables us to understand the full scope of contamination, and the pervasive issue of microplastics. In order to lessen the hazardous effects of plastics on human health and the environment, it is realised how urgently our laws need to be strengthened.
How is plastic made?
Several chemical substances produced synthetically that can be moulded or shaped into useful shapes are referred to as "plastics." When making plastics, small molecules, or "monomers," are first combined into long strands, or "polymers," by being repeated thousands or millions of times. Natural gas and crude oil are a source of almost all polymers. Many monomers, some of which have negative health effects, are employed to create common plastics.
The majority of plastic packaging has numerical codes on the bottom. These tags identify the type of plastic used, allowing each item to be processed and sorted for the right kind of recycling (where possible and available). Many other plastics, however, lack a code and are typically not recyclable.
Beyond monomers and polymers, there are numerous more chemical components in plastics. The majority of plastics also contain a number of "additive" compounds that have various functions. These may be included in plastic to improve its flexibility or strength. They could counteract sunlight's destabilising effects or stop plastics from fading over time. In order to reduce their flammability, many plastics contain a high concentration of flame retardants, which when burned create hazardous poisonous by-products. And many additives do multiples of these tasks, which is why plastic mixing is a very complex field.
Along with several additives, leftover monomers and related compounds are frequently discovered in small quantities in the final products. Polymers can disintegrate both during and after use into smaller parts or into the monomers that make them up, for instance when they are exposed to moisture and sunshine.
Nevertheless, polymers are free from registration under regulation globally despite these issues with their use. This means that businesses are not required to provide information on the health and environmental risks associated with their exposure or to track how they are affecting the environment and the food chain. NGOs have urged government authorities to remove this loophole on numerous occasions.
Microplastics and its impact on health
There are many ways that microplastics might enter the human body, including through the air we breathe, food we eat, or products we use. Many consumer products now contain "microplastics," or minute particles with sizes ranging from a few millimetres down to miniscule "nanoplastics" smaller than bacteria. Both plastic and non-plastic products frequently contain microplastics on purpose, such as the tiny plastic particles that make toothpaste and exfoliating scrubs work better or the plastic "microbeads" that make sunscreen spread more evenly.
Microplastics also develop when plastic materials degrade in the environment. Furthermore, they could be hazardous to human health because they build up in animals like fish and aquatic invertebrates and enter our food chain directly. At a level that is virtually unthinkable, microplastics now pose "a huge potential threat to worldwide aquatic ecosystems."
More than 250 samples of bottled drinking water from nine different nations were tested in 2018, and it was discovered that 90% of the samples were contaminated with plastic, notably polypropylene (54%) nylon (16%), and polyethylene or PET (6 percent). The World Health Organization (WHO) started an assessment of the dangers of microplastics in drinking water as a result of these findings. The WHO has emphasised the need for additional study on the health impacts of microplastics following this initial review.
According to a recent analysis of the production and consumption of all plastics over the previous 70 years, the mass of virgin polymers produced between 1950 and 2015 was 8.3 billion metric tonnes, which is about the same as a medium-sized comet. Only 30% of all plastics created in history are still in use. Only 9% of the more than 6 billion tonnes of plastic garbage produced as of 2015 were recycled; 79 percent of it ended up in landfills or the environment. Plastic takes 400 to 1,000 years to disintegrate, significantly longer than the average human life. 12 billion metric tonnes of plastics are anticipated to enter landfills or the environment by 2050.
We frequently read about the severe harm that plastic pollution causes to the ecosystem, such as rivers that are overflowing with trash or whales that wash up on shore after consuming tens of kilograms of plastic bags. But while considering the issues with plastics, it's vital to take into account not just the issues with plastic materials but also the issues with the other compounds employed throughout the entire life cycle of plastics manufacturing and use.
Humans are exposed to harmful chemicals at each of these stages, either through ingestion, inhalation, or direct skin contact. Even during everyday use, such as when washing synthetic textiles and rolling tyres on the ground, microplastics are emitted at all of these stages. We don't know how these exposures together will affect our health. However, the health impacts of each of those compounds, including bisphenol A and phthalates like DEHP, have been extensively studied.
Toxic chemicals in plastics
People can be exposed to toxicants from plastics in a variety of ways. Workers who make plastics are frequently exposed to high amounts of additives and monomers, many of which are carcinogenic. The use of plastic packaging by retailers, as well as the handling of receipt paper by cashiers and nail salon staff, exposes workers outside the plastics industry to significant amounts of plastics and additives. When plastic chemicals, particularly additives, move from the plastic into the surrounding environment, users of plastic items may be exposed. Examples include the migration of additives or monomers from food packaging into the food products, such as bisphenols (BPA) from polycarbonate water bottles or styrene from microwaved Styrofoam; the direct ingestion of phthalates from toys or baby products; and the migration of additives from products onto the skin, particularly the hands, where they may be absorbed or consumed.
People can be exposed in their daily lives, whether or not they use plastic items, once these compounds enter the environment. For instance, flame retardant compounds are frequently applied to office furniture and move into the dust and air of the workplace, where they can be inhaled or consumed. Through the food chain, persistent toxins that are released into the environment might bioaccumulate and expose people to them through contaminated food. For instance, the majority of people's exposure to fluorinated "forever chemicals" (PFAS) comes from their diet. The very high exposures that may result from sending plastics to low- or middle-income nations for reuse, recycling, or disposal should also be noted. Many times, "informal" employees who are working alone or with their families and lack proper training in safety precautions will conduct this work. Toxic substances in the plastics will also be exposed to the workers' family and communities through improper disposal, recycling, or burning.
A multitude of health issues, including breast cancer, infertility, early puberty, epidemics like diabetes and obesity, and neurological abnormalities in children have all been linked by scientists to exposure to Bisphenol A (BPA). Unfortunately, additional bisphenols like BPS, BPF, BPAF, and BPZ have taken the place of BPA as worries about it have grown. Many of these BPA-related alternative bisphenols also seem to share some of the same hazards.
Due to their features, phthalates are synthetic compounds that are added as additives to a wide range of consumer goods because they add flexibility and other desirable qualities. Phthalates are frequently added to polyvinyl chloride (PVC), which is used to make packaging, textiles, flooring, and a variety of cosmetic products. To make children's toys soft and squishy, to make IV bags more malleable, to make artificial nails more flexible and less likely to chip, and as a solvent in cosmetics, phthalates were utilised in very high quantities until only a few years ago. In recent years, researchers have discovered a number of health effects associated with exposure to the most prevalent phthalates, including reproductive issues, obesity, insulin resistance, asthma, and attention deficit hyperactivity disorder.
Endocrine disruption is arguably the most significant health impact of the several chemicals connected to plastics. Hormones, which are small chemicals produced by a variety of organs and glands (endocrine system) and utilized to communicate changes to other body parts, regulate a large portion of the function of our bodies. Our hormones regulate a variety of important aspects of life, including patterns of growth, sexual development, metabolism, and others. Unfortunately, a lot of the additives and common monomers in ordinary plastics have chemical structures that are similar to those of hormones, and they occasionally fool the body into disrupting these vital functions. For instance, BPA mimics oestrogen, a crucial hormone involved in the growth and function of women's sex organs. Similar to this, certain phthalates alter male sex hormones, which can result in abnormalities of the genitalia or reduced sperm counts.
Since they can inhibit the spread of fire when used in very high concentrations, flame retardants are frequently applied to items in order to meet flammability regulations. However, a large body of research suggests that many flame retardants may be hazardous to human health, even if their contribution to fire safety is widely debated. Organohalogen compounds, such as polybrominated diphenyl ethers (PBDEs), which were widely used in furniture, electronics, and many other things before being outlawed in the 2000s, are some of the most dangerous flame retardants. Organohalogen chemicals are currently present in almost all human blood.
Flame retardants are utilised in a huge variety of products and uses today, such as furniture, vehicles of all types (including cars and aeroplanes), numerous plastics (including items for children like cribs and car seats), insulating materials for homes, and almost all consumer electronics. Strong evidence has connected some commonly used flame retardants to a range of health issues, including cancer, hormone disruption, decreased fertility, and children's hyperactivity and lower IQ scores.
More than 4,700 chemical compounds collectively known as PFAS—polyfluorinated and perfluorinated compounds—are employed in the production of a wide range of goods and applications because of their ability to repel grease, stick, and stains. Teflon, the first PFAS chemical of commercial significance, gained notoriety as a result of its pervasive usage in cookware. Similar substances are now found in an infinite number of items, including firefighting foams, stain-resistant carpeting, microwave popcorn bags, water-repellent outdoor clothing, and greaseproof food packaging like pizza boxes and pizza boxes. PFAS are exceedingly stable and do not degrade in the environment over time. They are now present in the blood of practically everyone in the world and are transported over extremely great distances by wind and water. Scientists have connected the most notorious member of the PFAS family to a number of adverse health outcomes, including thyroid issues, kidney and testicular cancer, high cholesterol, lower fertility, low birth weight, and a child's immune system's inability to respond to immunizations.
Plastic recycling must encourage clean production loops
A very small amount of plastic waste gets recycled today, despite decades of work and massive advertising campaigns highlighting their recycling efforts. Only around 9 percent of six billion tonnes of plastic that have been manufactured globally since 1950 have been recycled. If the world is to live up to its promises to the circular economy, these trends must drastically shift.
The recycled materials will become polluted if plastics include hazardous monomers or additives or if the plastic polymers degrade into hazardous components. Toxic compounds will continue to pollute current products and supply chains if they are allowed into recycling cycles. Recycling must encourage clean production loops as opposed to serving as a cover for hazardous substances to continue leaking into the air and into our bodies.
The plastics industry reports that 350 million tonnes of plastic were produced globally in 2017. According to current predictions, this number will increase by two fold during the following 20 years. By 2025, there will be a 33–36 percent rise in the production of ethylene and propylene alone, the two primary precursors used to make plastic. This translates to an additional 100 million tonnes. These developments raise significant concerns when viewed collectively and in light of the numerous unanswered questions regarding the long-term effects of our continuing exposure to toxics in and through plastics.
The current regulations do not cover all key parts of plastics, not pre-emptive, and ignore several dangerous chemicals used in the production of virgin and recycled plastics. They do not adequately safeguard us from harm. If we want to advance a truly non-toxic circular economy and fight this in the future, we need a new regulatory strategy.
Our phones, toys, food packaging, and medical equipment are all important to entrust to untested chemicals and unidentified, impure polymers. The only solution is to use less plastics because so many monomers and additives are dangerous and so many others are trade secrets.
It will be necessary to address the throwaway culture that fuels the current demand for and use of plastics as well as the loose rules that permit the widespread use of harmful compounds in them if we are to successfully tackle the problem of plastic pollution. The future circular economy, chemical control and safety, human and environmental health, and plastic pollution are all intricately linked.
The views of the author in the article are personal.