Plastics are ubiquitous environmental contaminants with large amounts dumped everywhere. The consequence is inevitable human exposure to its effects on health.
Microplastics (MPs) result from a variety of plastics, including the breakdown and weathering of plastic objects, clothing, paint and car tyres. They may be deliberately added to products like cosmetics and abrasive cleaners. They are of various sizes, shapes, and are of complex chemical substances.
Biofilms that grow on MPs may a source of harmful micro-organisms. Their omnipresence raises serious concerns about their effects on human and animal health.
Humans are exposed to MPs by ingestion of food and water, inhalation and skin contact because of its presence in food, air and various products in daily life.
Tons of MPs reach the sea to enter the food chain through ingestion by marine life, sea salt and drinking water. Studies have also reported that MPs have been found in edible fruit and vegetables and store-bought rice.
Microplastic exposure may be toxic in all biological systems. The inability of the immune system to remove the synthetic particles may lead to chronic inflammation and increased risk of cancer.
MPs may also release their constituents, contaminants and pathogenic organisms. However, knowledge of microplastic toxicity is still limited.
MPs have been reported to have been found in human faeces, as well as in food and drinking water and the air humans breathe in. Details of its effects are still limited.
Microplastics In Human Blood
On March 24, 2022, Leslie et al from the Netherlands reported, in the journal, Environment International, the detection of MPs in human blood for the first time in a pioneering human biomonitoring study. They analysed blood samples from 22 healthy adult volunteers with quantifiable microplastic particles found in 17 (77 per cent).
Half of the samples (50 per cent) contained polyethylene terephthalate (PET) plastic, which is commonly used in disposable drink bottles; 36 per cent contained polystyrene, which is used for packaging food and other products; and 23 per cent contained polyethylene, which is used in plastic carrier bags.
The authors state “The plastic particle concentrations reported here are the sum of all potential exposure routes: sources in the living environment entering air, water and food, but also personal care products that might be ingested (e.g. PE in toothpaste, PET in lip gloss), dental polymers, fragments of polymeric implants, polymeric drug delivery nanoparticles (e.g. PMMA, PS), tattoo ink residues (e.g. acrylonitrile butadiene styrene particles).”
The authors concluded that their findings “supports the hypothesis that human exposure to plastic particles results in absorption of particles into the bloodstream. This indicates that at least some of the plastic particles humans come in contact with can be bioavailable and that the rate of elimination via e.g. the biliary tract, kidney or transfer to and deposition in organs is slower than the rate of absorption into the blood”.
“It remains to be determined whether plastic particles are present in the plasma or are carried by specific cell types (and to which extent such cells may be involved in translocating plastic particles across mucosa to the blood-stream). If plastic particles present in the bloodstream are indeed being carried by immune cells, the question also arises, can such exposures potentially affect immune regulation or the predisposition to diseases with an immunological base.”
Concerns
Data from global studies have reported the occurrence of plastic particles in gut contents, air, water, sediment, and food. The majority of data involved particles above 10 or 50 um. There have been fewer studies on submicron sized particles reported in seawater.
Other researchers have reported that MPs can deform the outer membranes of red blood cells and affect their function. MPs have also been found in human faeces, colectomy specimens, and placenta.
While the sample size of the study was small and there was lack of data on the volunteers’ exposure level, scientists like Fay Couceiro of the University of Portsmouth have told AFP that the study was “robust and stand up to scrutiny”.
Dick Vethaak, a co-author of the report, told the Guardian: “Our study is the first indication that we have polymer particles in our blood — it’s a breakthrough result. But we have to extend the research and increase the sample sizes, the number of polymers assessed etc. It is certainly reasonable to be concerned. The particles are there and are transported throughout the body.”
He added that microplastics were 10 times higher in babies’ faeces compared with adults and that babies fed with plastic bottles swallow millions of microplastic particles daily.
He asked: “The big question is what is happening in our body? Are the particles retained in the body? Are they transported to certain organs, such as getting past the blood-brain barrier?” And are these levels sufficiently high to trigger disease? We urgently need to fund further research so we can find out”.
Currently, there are gaps in the knowledge on the additives used in the plastics industry and their fate when microplastics are disposed into the environment and their consequent effects on human health.
Gruber et al, in their March 22, 2022 article in the journal Exposure & Health, “To Waste or Not to Waste: Questioning Potential Health Risks of Micro- and Nanoplastics with a Focus on Their Ingestion and Potential Carcinogenicity”, stated succinctly the current situation.
“More detailed research on how micro- and nanoplastics (MNPs) affect the structures and processes of the human body, and whether and how MNPs can transform cells and induce carcinogenesis is urgently needed, particularly in light of the exponential increase in plastic production and the ensuing accumulation of non-degradable MNPs, the problem is becoming more urgent with each day.”
Urgent Action Needed
Global plastic production is expected to double by 2040. Current data indicate that the overexploitation of plastic products and unsystematic dumping have adverse consequences for human health.
Everyone has a right to know what plastics are doing to our bodies. However, the scientific community needs time to come up with definitive answers.
In the meantime, everyone can do their part by reducing usage of plastics (biodegradables are an alternative) and not dump plastics indiscriminately.
The authorities have a duty to ensure that their plastics policy and management do not impact negatively on human health. If there is no such policy, then it is time to formulate one urgently.
The policy should, among others, include laws on plastics standards and packaging, systematic plastic waste disposal, and import and export of plastic waste; as well as strategies for public health education and to ensure that all plastic packaging used are recyclable, reusable or compostable by a targeted date.
Dr Milton Lum is a Past President of the Federation of Private Medical Associations, Malaysia and the Malaysian Medical Association. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organisation the writer is associated with.
- This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.
