Microplastics were first discovered in the blood of cows, pigs, and other animals. This raises concerns about how they might travel through the food chain.
Scientists believe the discovery could have serious consequences for public health. However, they warn that further research is needed to determine the extent of toxic effects and how many people may be exposed.
Experts are concerned about the possibility that microplastics could get into breast milk, or in organs.
New discovery: Microplastics found in the blood of cows, pigs and sheep for the first time. This raises concerns about how these particles might travel through the food chain (stock photo).
WHAT CAN MICROPLASTICS DO TO THE HUMAN BODY IF ENDED UP IN OUR FOOD SUPPLY?
According to an article published in the International Journal of Environmental Research and Public Health, our understanding of the potential human health effects from exposure to microplastics ‘constitutes major knowledge gaps.’
Plastic particles can be introduced to humans through the consumption of seafood, terrestrial food products, water, and air.
However, the human exposure level, chronic toxic effects concentrations, and the underlying mechanisms that microplastics cause harmful effects are not fully understood. This makes it difficult to assess the human risks.
Rachel Adams, a Cardiff Metropolitan University senior lecturer in Biomedical Sciences, says that microplastics can have a variety of potentially harmful effects.
- Inflammation is when there is inflammation. The body’s white blood cell and the substances they produce protect against infection. This normally protective immune system can cause tissue damage.
- An immune response to something that is ‘foreign’ to your body. These immune responses can cause harm to your body.
- Other toxins can be carried by microplastics: Because microplastics repel water, they can bind to toxins which don’t dissolve. Microplastics can also bind organic pollutants like pesticides and chemicals called dioxins. These compounds are known to cause cancer as well as reproductive, developmental and other problems. These microplastics can build up in fatty tissues if they are introduced to the body.
Heather Leslie, from Vrije University Amsterdam, led the research that involved 12 cows as well as six pigs.
She stated that she had found preliminary evidence of trace amounts plastic particles in the bloodstreams of farm animals.
‘It is in the interest of animal and human health protection to further explore this nascent signal of plastic pollution exposure in the food chain.’
Leslie said, “We already know that hundreds more animals have microplastics in them.” It was not known that microplastics were present in cows or pigs.
The researcher presented her findings to a conference in Amsterdam on microplastics.
When she was asked what the risk to humans was, she replied that it was difficult to assess the risks without knowing the actual exposure and the toxicity.
‘If we are above the values that are still safe and responsible, then we have to do something about it.’
Microplastics could end up in the soil of crops that are eaten by farm animals, according to some experts.
Research has shown that these particles are not easily broken down by the intestines. They often end up as manure.
Leslie said, “It has to contain very fine particles that cannot been seen with the naked eyes before it can enter bloodstream.”
Scientists found plastic in the muscles and bones of sea turtles for the first time earlier this year. This confirms that pollution is affecting marine life at a chemical level.
There may be some hope for mussels.
Researchers at the Plymouth Marine Laboratory discovered that a group of 300 mussels weighing in at 11 lbs (5 kg) could filter out 250,000 microplastic particles per hour.
The sea creatures produce particles in pellets which sink.
Around 3,760 tonnes of plastic debris – the equivalent weight of eight jumbo jets – are currently floating in the Mediterranean, according to a study published earlier this month.
Researchers from the Hellenic Centre for Marine Research in Greece estimate 17600 tonnes of plastic enters the sea every year. 84% ends up on beaches, and 16% in the water column or the sea floor.
Microplastics measure 5mm in size (the length of a lentil), and are formed when plastic breaks down into tiny pieces.
The tiny particles are everywhere.
They are in our water, food and on surfaces we touch — and scientists are only just understanding their impact.
According to King’s College London’s 2018 review, our bodies can remove some microplastics, but newer research suggests that microplastics could pass from the gut or airway into the bloodstream and our organs.
Heather Leslie of Vrije University Amsterdam led the research. Stock image
Microplastics are less than 5mm in length (the same size as a lentil) and are formed when plastic is broken down into tiny particles.
The plastic could in theory then cause severe inflammation or leach harmful chemicals.
Researchers in Italy discovered microplastics in human placentas, which could have adverse effects on foetus health and development.
Researchers previously suggested that plastic in the stomach could also affect the digestive system’s immune response and aid the transfer of chemicals or pathogens.
Scientists are concerned that there is a risk to human health and although no conclusive link has been made, they believe more research is necessary.
WHAT FUTURE RESEARCH IS REQUIRED TO ASSESS THE SPREAD & IMPACT OF MICROPLASTICS
The 2019 World Health Organisation report, “Microplastics In Drinking Water” outlined many areas for future research that could shed some light on the extent of the problem of microplastic pollution, how it might impact human health, and what can be done about it.
What is the prevalence of microplastics?
The following research would clarify whether microplastics are found in drinking-water or freshwater sources.
- To properly assess human exposure from drinking water, additional data are required on the presence of microplastics.
- For studies on the occurrence of microplastics, they must use quality-assured techniques to determine the numbers, shapes, sizes, composition, and distribution of the particles. They should determine whether microplastics come from freshwater environments or from the extraction, treatment, distribution, or bottling drinking-water. This research should begin with drinking-water that is most at high risk for particulate contamination.
- Drinking water studies could be enhanced by better data on freshwater that allows freshwater inputs to a be quantified and major sources to be identified. This could require reliable methods to identify and track origins.
- A set of standard procedures is required to sample and analyze microplastics in drinking water and freshwater.
- There is a substantial knowledge gap in understanding nanoplastics in aquatic environments. This gap can be addressed by developing standard methods to sample and analyse nanoplastics.
What are the health consequences of microplastics for your health?
Water treatment can remove particles, but data is very limited on microplastics. The following data gaps regarding water treatment are needed to support human health risk assessment, and management options.
- More research is needed in order to understand the fate and effects of microplastics on wastewater and drinking water treatment processes (such clarification processes and oxidation), under different operating conditions, including optimal and suboptimal operation, and the impact of particle size, shape, and chemical composition on removal efficacy.
- It is important to understand the particle composition of water treatment systems, including distribution systems. It is important to consider the role of microplastics in water treatment systems and the microplastic contribution from these processes.
- Once standard methods for nanoplastics have been developed, it is important to gain more knowledge about the presence and removal nanoplastic particles in water and wastewater treatment.
- It is essential to understand the relationship between turbidity (and particles counts) and microplastic concentrations throughout treatment processes.
- Research is required to determine the importance of microplastics’ potential return to the environment from sludge, and other treatment waste streams.
To better understand microplastic-associated biofilms and their significance, the following research could be carried out:
- Further studies could be conducted on the factors that influence the composition and potential specificity of microplastic-associated biofilms.
- Researchers could also examine the factors that influence biofilm formation on plastic surfaces, such as microplastics. They could also study how these factors differ for different plastic materials and what organisms are more likely to bind to plastic surfaces when used in freshwater systems.
- Research could be done to better understand how microplastics can transport pathogenic bacteria over longer distances downstream, their rate of degradation in freshwater systems, and the relative abundance of microplastics and other particles.
- Research could look at the possibility of horizontal transfer of antimicrobial resistant genes in plastisphere microorganisms in comparison to other biofilms like those found in WWTPs.
Can water treatment prevent microplastics from entering our water supply?
Water treatment can remove particles, but data is very limited on microplastics. The following data gaps regarding water treatment are needed to support human health risk assessment, and management options.
- More research is needed in order to understand the fate and effects of microplastics on wastewater and drinking water treatment processes (such clarification processes and oxidation), under different operating conditions, including optimal and suboptimal operation, and the impact of particle size, shape, and chemical composition on removal efficacy.
- It is important to understand the particle composition of water treatment systems, including distribution systems. It is important to consider the role of microplastics in water treatment systems and the microplastic contribution from these processes.
- Once standard methods for nanoplastics have been developed, it is important to gain more knowledge about the presence and removal nanoplastic particles in water and wastewater treatment.
- It is important to understand the relationships between turbidity and microplastic concentrations during treatment processes.
- To understand the implications of microplastics’ potential return to the environment, it is important to conduct research from sludge and other waste streams.
