Plastics are rife in the modern world, with demand for the resource only increasing. The global market for plastic products was worth $1.1 trillion in 2016, with a view to grow to $1.2 trillion by 2020 (the largest segment for this being plastics for packaging materials and unlaminated film, accounting for 20% of the total).
What affect is plastic having on the human health?
Due to plastic’s resistance to chemical, physical and biological degradation, human society relies heavily on this resource, particularly in the health sector. Containing a wide number of potentially harmful additives, what risks do plastics pose on the human health?
Plastic is now being found in our food and water and is subsequently being said to be in the bloodstream of almost every one of us. Whether or not this has a detrimental effect on our health is a topic which faces immense controversy. That said, there is a growing consensus that plastics and their additives are not as ‘benign’ as first thought.
Rolf U. Haden, of Arizona State University, published in 2010 a research study titled “Plastics and Health Risks”. Human health risks from plastics can stem from the building blocks that make up the components of plastics (e.g. bisphenol A, widely known as BPA) and their additives (e.g. plasticizers), or from a combination of the two (e.g. antimicrobial polycarbonate).
Chemical structures of bisphenol A and di-(2-ethylhexyl) phthalate (DEHP), which illustrate the use of endocrine-disrupting monomers and plasticizers in contemporary plastics (Halden, 2010).
Bisphenol A (BPA) is a well-known monomeric building block of polycarbonate plastics, used for products which require transparency and high-impact resistance such as plastic bottles and automotive components. It is also frequently used as an additive to other plastics such as polyvinyl chloride (PVC); the majority of PVC goes into long-lasting building and construction applications, however it also used for consumer products such as shrink-wrap product packaging, shower curtains and rain coats.
Products containing BPA can “leach” their molecules from food and beverage containers into food and drink over time. Repeated washing of containers containing BPA, along with storing acidic products inside the containers, causes accelerated leaching as it can break down the polymer. Re-useable water bottles, baby bottles and inner lining of food containers for example are known to leach molecules into food and beverage over time, particularly at higher temperatures.
After decades of study the health risks of BPA are said to still not be fully understood. From as early as 1936 though, BPA has been said to have estrogenic properties which can disrupt the chemical balance of the female sex hormone oestrogen in humans and animals.
In 2005, the Centers for Disease Control and Prevention (CDC) assessed 394 American adults with 95% of urine samples showing detectable levels of BPA. A larger follow-up study was conducted showing 92.6% of 2517 people as having BPA in their system.
Still, in the UK, the Food Standards Agency deem BPA to be a safe chemical for use in the production of plastics due to the relatively low level of exposure that an average human has over their lifetime. Ongoing research is being carried out to confirm whether or not this is the case.
Adverse effects in animals range depending on the amount the animal is exposed to. These include, but are not limited to (in order of BPA exposure, low-high):
- • Increased postnatal growth in both sexes
- • Early onset of sexual maturation in females
- • Decreased plasma testosterone in males
- • Increased prostate size of male offspring
- • Decreased sperm production and fertility in males
- • Significant disruption of chromosome alignment during puberty
- • Increased mortality in embryos
- • Hyperactivity
- • Increased aggression
Research still continues to take place on the potentially damaging effect that plastic can have on humans and animals, with often conflicting conclusions, demonstrating our lack of understanding of this relatively new but ubiquitous product which is now inside almost all of us.