The Human Health Impacts of Plastic
by Alexis McGivern
January 21, 2019
For a long time, plastic pollution has been defined as an oceans issue, with many players referring only to the issues as 'marine litter' or 'ocean plastics'. In fact, the impacts of plastic are far more wide-reaching, affecting populations far from the coasts. Human health is affected by plastic at each stage of the life cycle, from extraction of raw materials, through production, during use and after disposal.
In order to make plastic, fossil fuels like oil and natural gas are extracted and refined into different fractions, meaning the different hydrocarbons contained within these fossil fuels are separated out into individual monomers.
The ´cracking` of these hydrocarbons is done in petrochemical factories, affecting nearby communities through contamination of the air with pollutants and carcinogens. St. James Parish, Louisiana, one of the hubs of the American petrochemical industry, is also known as “Cancer Alley”, so-called due to its disproportionately high rates of cancer as compared with the rest of the United States. Residents attribute to this to the high concentration of petrochemical factories, and, in recent weeks, have been organising against a proposed $9.4 billion chemical plant proposed by the Formosa Petrochemical Corporation, citing the irreversible human health impacts as a key concern.
It is, of course, no coincidence that the majority of these petrochemical factories are located in communities predominantly populated by people of colour, thereby adding an additional layer of environmental injustice onto this issue.
Monomers are linked up through a process known as polymerisation in order to make plastic polymers, which are the basis for all plastic products. Then, the product-specific properties of different plastic items, such as malleability, durability and colour, are generated through the inclusion of additives. These affect health through exposure during the use phase of plastic.
Plastic affects human health through the multi-pronged exposure to chemicals in plastic, with differing impacts according to the specific additives and the levels of exposure. Chemicals from plastic migrate from food packaging into food through heat, long-term storage and small surface-area ratios (i.e., small packaging sizes). The additives included during the production process affect our health through disruption of our delicately-balanced endocrine systems, the glands and organs and that produce, store and secret hormones.
Endocrine-disrupting chemicals in plastic disrupt mimic hormone receptors and disrupt other important hormonal functions.
Our ability to effectively regulate and minimise the negative impacts of additives in plastic is severely hampered by a lack of transparency from industry on what additives are even included in plastic products. The majority of these additives have not been tested, and therefore cannot be meaningfully assessed for their potential dangers or restricted from the market. In many places, regulatory bodies, like the Food and Drug Administration in the United States, cannot keep up with the proliferation of new chemicals entering the market each year and therefore many enter the market without a full understanding of how they might impact our health and environment.
Phthalates and Bisphenol A (BPA) are two additives used in plastic that have been widely tested, and have been collectively linked to early onset puberty in girls, increased obesity prevalence in adult men, breast and prostate cancer and reproductive abnormalities.
In response to the growing controversy over BPA, many plastic producers in the United States, Canada and Western Europe self-regulated and phased out most of BPA from food grade plastics. However, BPA was largely replaced with BPS and BPF, two additives which, while chemically different to BPA, have been shown to have almost the exact same effects on our health.
The impacts of plastic after its disposal depend largely on what pathway it takes after consumption. Organisations like GAIA, the Global Alliance for Incinerator Alternatives, have highlighted the human health impacts of incineration plants, citing both the occupational health impacts as well as those on populations living near to incinerators. Exposure to dioxins, heavy metals and biomarkers have been linked to lung, larynx and liver cancers, respiratory effects and congenital abnormalities, among other impacts.
Open landfilling outside of sealed engineered landfills and open burning, two techniques commonly employed in areas without waste management infrastructure, affect nearby populations through contamination of groundwater sources and through chemicals released through burning plastic.
When plastic ends up in the ocean, it can end up back on our dinner plates through fish or even salt, making us at risk for ingesting not only the plastic pieces themselves but also all of the associated toxic chemicals that it has been exposed to in the water, including many persistent organic pollutants POPs. It is, however, still unclear how pieces of plastic that have not been exposed to any additional chemicals affect human health during ingestion.
As plastic pollution becomes more widely understood as a human issue, as well as an environmental one, the pressure on manufacturers of plastic will hopefully increase and therefore encourage different product distribution models, fewer greenwashed solutions and options that are safer for our health and for the planet.
On an individual level, minimising or eliminating your own consumption of plastic, where possible, can help limit your exposure to the wide range of chemicals included in everyday items. You can limit the chemical migration between your food packaging products and your food by following guidance from the Food Packaging Forum, namely heating your food in inert containers like glass rather than plastic, limiting the storage time of foods in plastic and avoiding small portion sizes to limit the exposure through a high surface-to-volume ratio.
Finally, and most importantly, transparency from industry players is vital in order to assess the wide range of additives used in plastic for their potential health and environmental impacts.
The precautionary principle is of utmost importance, allowing regulators the time and capacity to assess the wide range of chemicals that we are exposed to on a daily basis and regulate as necessary.