Humans and plastic. Relationship status: it's complicated

(source: The Guardian)

The human body is exposed to plastic via a number of different ways, whether it be inhalation when you open a brand new plastic product, children putting plastic toys in their mouth, or in the case of this post, through the consumption of marine animals.

But is plastic so bad for us?

There is great debate over this question and we will take a look into some of the current research.

There are several toxic elements contained in plastic and there are many other toxins that naturally occur in sea water. These naturally occurring toxins can get concentrated in microplastics which make their way up the food chain starting from the zooplankton right up to us, where the toxins have been allowed to increase in concentration (this is known as biomagnification). Some toxins that are actually contained in plastic are carcinogenic and cause problems in the immune system and in the development of children (more of which we’ll see later on in this post).

BPA

Bisphenol-A (BPA) is one toxin that is commonly talked about. When products containing BPA are made, some of the BPA can leach out when food or liquid is introduced as it doesn’t all get locked into the product.

BPA is found in many types of food packaging (especially the lining of canned foods), plastic cutlery, plastic tupperware and most worryingly, in baby bottles. According to the Food and Drug Administration (FDA) in the U.S., each day young children are exposed to 13 times more BPA than adults (predominantly from baby bottles). However, in 2008 the FDA stated in their report that the level of BPA exposure on humans is negligible and isn’t a cause for concern which has been reiterated in their most recent 2014 report. Closer to home, the European Food Safety Authority (EFSA) state that there’s a possibility of BPA affecting the immune system of animals but there’s not enough evidence to draw conclusions about human health.

So if these big governmental food standards agencies are telling us there’s nothing to worry about, then why is there so much information telling us BPA is more BP-Nay?

It is studies by authors like Huo et al. (2015) that lead us to believe it is harmful. They found BPA can influence hormone function, specifically affecting ovulation, puberty and most worrying of all, fertility, since it disrupts the reproductive system in females at different stages of their cycle. Other authors like Schecter et al. (2010) claim it is also linked to heart disease and diabetes.

(source: IFL Science)

In terms of these dangerous chemicals being passed up the food chain from marine life, there is still a lot of uncertainty, with researchers unsure exactly how much plastic, and associated chemicals, make their way into us. In a study by Browne et al. (2008) on the ingestion of microplastics in mussels, it was found that microplastics between the sizes 3.0 and 9.6 microns can leave the gut and travel elsewhere in the organism, staying there for up to 48 days. It has also been found that approximately 66% of mussels in the waters around Kent contain microplastics. It's not a nice idea that we could then eat these microplastics the next time we have mussels for dinner.

Plastics and the Inuits

One very alarming case of the adverse effects of plastic in the human system is that of the Inuits. A large portion of their diet depends on marine mammals such as seals, walrus and whale. The bowhead whale is able to support a whole Inuit community for almost a year. As we’ve already seen, microplastics can quite easily make their way up the food chain and in this case into these marine mammals where it is stored in their fat. It has been found that the breast milk of Inuit women of northern Quebec contains the highest level of PCB’s (polychlorinated biphenyls) in the world. PCB’s have been linked to several types of cancer including liver, brain and breast cancer and, you guessed it, is another chemical that builds up in the fat of marine mammals (amongst other marine animals). 

But the disturbing facts don’t stop there. 

Research has found that a quarter of these Inuit babies develop chronic hearing loss due to the higher than normal rate of infections they receive and children exposed to this chemical pre-birth, grow up with learning difficulties. They receive more infections than normal because they are born with low levels of white blood cells due to the presence of these PCB’s. It is clear that this is a huge threat to not just the traditional way of life of the Inuit people but on the natural mother-baby feeding process. These people will have to find an alternative diet and mothers will be forced to use baby formula to feed their children.

The severity of the effects of plastic on the human body can be debated but this is perhaps one of the most noticeable and unequivocal cases of the effects of marine plastic pollution on the human system and society.

The video below is a good representation of how plastic ends up in the food we eat and the effect that has on our health. It also addresses why we are unsure of the risks on human health since the plastic producing companies keep their operations very secretive.

So it seems like there is strong evidence to suggest that plastic is not good for us at all, but as we’ve seen, some governmental bodies (like the FDA and EFSA) are telling us that some of these chemicals are fine and pose no risk to our health. Why do governments say that it’s fine whilst others prove it’s not? I’ll leave that one up to the conspiracy theorists out there.

Why do you think there’s a big contrast of opinions in, for example, the safety of BPA?