The Environmental and Biological Risks of Micro and Nano Plastics:
A Review
Rakesh Kumar
Associate Professor, Department of Chemistry, MMM PG College Bhatpar Rani, Deoria, UP, India – 274702.
*Corresponding Author E-mail: drrakesh01071982@gmail.com
ABSTRACT:
The presence of micro and nano plastics in the environment is a growing threat to ecosystems and human health. These small plastic particles are either produced intentionally or resulting from the degradation of larger plastics and have been found in nearly every habitat, from oceans to soil, and even in the atmosphere. Their persistence in the environment is concerning due to their ability to interact with both living organisms and non-living elements such as water and soil. Micro and nano plastics can act as vectors for harmful chemicals like persistent organic pollutants (POPs) and heavy metals, further increasing their toxicity. This paper explores the environmental and biological risks posed by micro and nano plastics, highlighting their sources, distribution, and impact on marine, freshwater, and terrestrial ecosystems. The ingestion of these particles by organisms at all levels of the food chain leads to bioaccumulation and potential health risks, including toxicity and disruption of biological functions. Additionally, emerging research points to the potential for human exposure through contaminated food, water, and air. Given the challenges in detecting and mitigating micro and nano plastics, this study underscores the need for stricter regulations, advanced detection technologies, and innovative waste management solutions to address this growing global issue. This study aims to explore the environmental and biological risks associated with micro and nano plastics, focusing on their sources, environmental distribution, impact on ecosystems, and potential health hazards. By examining the challenges posed by these emerging pollutants, this research underscores the urgent need for innovative solutions and global action to mitigate their impact.
While large plastic debris is visibly problematic, the emergence of microplastics (less than 5 mm in size) and nano-plastics5 (less than 100 nm in size) poses an even greater, largely invisible threat to the environment and biological systems. These tiny plastic particles, generated through the breakdown of larger plastics or manufactured intentionally for industrial use, have permeated every corner of the planet- from the deepest oceans to the most remote terrestrial ecosystems. Microplastics have been detected in sediments at depths of up to 3,500 meters in the ocean6. The Studies show that microplastic concentrations in oceanic surface waters range from1 to 9 particles per cubic meter while in freshwater their concentrations reach up to1,000 particles per cubic meter in certain polluted rivers7-8. Micro and nano plastics enter the environment through various pathways, including industrial discharges, wastewater effluents, and the degradation of consumer products9. Once introduced, these particles are incredibly persistent and have been found in water bodies, soil, and even the atmosphere10.
Due to their size and widespread distribution, they interact not only with living organisms but also with non-living components such as air, water, and sediments, contributing to far-reaching environmental consequences11. Beyond the direct physical impact, micro and nano plastics are known to carry toxic chemicals, including persistent organic pollutants (POPs) and heavy metals, which can adhere to their surfaces12-13. These pollutants amplify the risks associated with plastic contamination by entering food webs and accumulating in organisms, leading to a cascade of ecological and biological disruptions. Recent studies have revealed the presence of microplastics in marine species, terrestrial animals, and even human tissues, raising significant concerns about their long-term effects on both environmental and public health.
MATERIAL AND METHODS:
For this review article, data were collected from journals, conference proceedings and reputable databases. Inclusion criteria focused on recent studies (2015-2023) related to the Environmental and Biological Risks of Micro and Nano Plastics. The study data involved thematic analysis and comparison of methodologies and findings across sources.
Sources of Micro and Nano Plastics14-15:
Micro and nano plastics originate from a variety of sources, either intentional or unintentional and the pathways how they enter in environment is diverse. Their sources are broadly classified into primary and secondary sources.
Primary Sources:
Primary micro and nano plastics are intentionally manufactured at small sizes for specific industrial purposes or consumer products. Some of the major primary sources are
· Industrial Applications: Micro and nano plastics are used in industries for sandblasting, cleaning, or molding. They are also found in pre-production plastic pellets (nurdles), which are used as raw materials in manufacturing.
· Textile Fibers: Synthetic textiles, like polyester and nylon shed microfibers during washing. These fibers, too small to be caught by wastewater treatment plants, end up in rivers, lakes, and oceans.
· Paints and Coatings: Microplastics are added to industrial paints and coatings for cars, ships, and buildings to enhance durability. Weathering and abrasion release these particles into the environment over time.
· Road Markings and Construction Materials: Plastics used in road markings and certain construction materials break down due to environmental wear and tear, releasing microplastic particles into the surrounding environment.
Secondary Sources:
Secondary micro and nano plastics arise from the breakdown of larger plastic materials due to environmental factors like sunlight, wind, and wave action. The major contributors include:
· Plastic Waste in the Environment: Large plastic items such as bottles, bags, and packaging degrade slowly into smaller particles through photodegradation, oxidation, or mechanical abrasion. These particles are then dispersed into various ecosystems.
· Tire Wear Particles: As vehicles travel, friction with roads causes tires to wear down, releasing tiny plastic particles made from synthetic rubber. These particles are washed off roads by rainwater, eventually making their way into water bodies.
· Degradation of Marine Plastics: Plastics floating in the ocean, such as packaging, bottles, and bags, degrade due to sun exposure and wave action, leading to the formation of secondary microplastics. Lost or discarded fishing nets, ropes, and traps are a significant source of microplastics in marine environments. Over time, exposure to saltwater and UV radiation breaks down these materials.
· Urban Runoff: Rainwater runoff from urban areas carries plastics from streets, landfills, and construction sites into rivers, lakes, and oceans, contributing to the environmental load of micro and nano plastics.
· Wastewater Treatment Plants: While wastewater treatment plants can capture larger particles, many micro and nano plastics pass-through filtration systems and are released into water bodies. These plants become major sources of microplastics in aquatic environments.
RESULTS AND DISCUSSION:
The results drawn from ongoing studies indicate relates with notable variations in methodologies and outcomes. The discussion is focused for future research and practice are explored, emphasizing the need for standardized approaches and further investigation in Environmental and Biological Risks of Micro and Nano Plastics.
Environmental Impact of Micro and Nano Plastics16-17: The environmental impact of micro and nano plastics is far-reaching and affects various ecosystems and organisms across the globe. These particles persist in the environment due to their resistance to biodegradation, leading to long-term ecological consequences. Some of the environmentally important impacts are discussed here.
· Aquatic Ecosystems: Bioaccumulation of micro and nano plastics are ingested by marine organisms such as plankton, fish, and seabirds, often mistaking them for food. This leads to bioaccumulation in the food chain, impacting not just individual species but entire marine ecosystems. These particles often carry adsorbed toxic chemicals, including persistent organic pollutants (POPs) like polychlorinated biphenyls (PCBs) and heavy metals. These substances are then transferred to organisms that ingest the plastics, causing cellular damage, oxidative stress, and endocrine disruption. They affect nutrient cycling, and disrupt the natural behaviours of sediment-dwelling organisms.
· Terrestrial Ecosystems: Microplastics have been found in agricultural soils, largely through the application of sewage sludge as fertilizer and runoff from urban areas. These particles affect soil structure, water retention, and microbial communities, potentially reducing soil fertility. Studies have shown that microplastics can hinder the growth of plants by altering soil chemistry and reducing the availability of nutrients. This could affect crop yields and food security in the long term.
· Atmospheric Deposition: Microplastics are now found in the atmosphere, transported over long distances by wind. They can settle in remote areas, including mountains and polar regions, far from their original sources. Atmospheric microplastics may also contribute to air pollution and impact human respiratory health.
· Ecotoxicological Impact: Ingested microplastics can cause physical damage to the digestive systems of animals, reduce feeding efficiency, and lead to malnutrition or starvation. These effects have been observed in a wide range of species, from zooplankton to fish and marine mammals. Microplastics can serve as vectors for harmful chemicals, which can be more readily absorbed by organisms that ingest them. This increases the risk of toxicity, reproductive harm, and even death in wildlife populations.
Biological Impact on Marine, Terrestrial and Freshwater Life18-21: The biological impact of micro and nano plastics on marine, terrestrial, and freshwater life varies based on the species, ecosystems, and the extent of exposure. These impacts include physical damage, chemical toxicity, and long-term ecological consequences that affect various organisms from microorganisms to large animals.
Marine Life: Micro and nano plastics have a profound impact on marine life, affecting organisms at all levels of the food chain. The planktons are the foundation of marine food webs and play a crucial role in ecosystem health. They often mistake microplastics for food, which reduces their nutrient intake, impacting growth and reproduction. Plankton also facilitates the transfer of plastics up the food chain to larger organisms. Many marine species, such as fish, crabs, and bivalves (e.g., mussels and clams), ingest microplastics directly from the water or through their prey. Once inside their digestive systems, plastics can block the passage of food, cause tissue damage, and trigger inflammatory responses. Research has found that microplastic ingestion can reduce reproductive success in fish by disrupting hormonal balances and causing physical stress. Furthermore, microplastics settling in sediments disrupt benthic ecosystems, while corals are physically damaged, leading to reduced biodiversity and compromised marine habitats.
Microplastics settling on the ocean floor impact bottom-dwelling species like corals, mollusks, and sea cucumbers. The plastics can interfere with nutrient exchange, oxygen levels, and substrate quality, affecting these organisms' health and behavior. They damage coral reefs by causing physical abrasions and introducing pathogens. This leads to coral bleaching (a critical issue as coral reefs support a wide variety of marine life).
Freshwater Life: Microplastics have a significant impact on freshwater life, affecting organisms from microorganisms to fish. Freshwater species like fish, amphibians, and macroinvertebrates ingest microplastics, which can cause physical blockages, tissue damage, and reduced feeding efficiency, leading to malnutrition and decreased reproduction. Amphibians, with their permeable skin, are particularly vulnerable to nano plastics, which can penetrate tissues and cause developmental abnormalities. Additionally, microplastics in freshwater environments act as carriers for toxic chemicals such as persistent organic pollutants (POPs) and heavy metals, which are ingested by aquatic species, leading to bioaccumulation, endocrine disruption, liver damage, and reduced reproductive success. Microplastics also settle in sediments, affecting benthic organisms and altering the physical and chemical properties of freshwater habitats, further disrupting the ecosystem and reducing biodiversity.
Terrestrial Life: Microplastics in terrestrial ecosystems pose significant threats to soil organisms, plants, and higher animals. Earthworms and invertebrates ingest microplastics, which alters their burrowing behavior, reduces reproduction, and negatively affects soil structure and nutrient cycling. Microplastics also provide surfaces for microbial colonization, potentially disrupting microbial communities and introducing harmful pathogens. For plants, microplastics can alter soil properties, affecting water retention and nutrient availability, while nano plastics can penetrate root systems, stunting growth and reducing crop yields. Additionally, microplastics that adsorb harmful chemicals may transfer these toxins to plants, affecting their development. Higher animals, such as herbivores and grazers, ingest contaminated vegetation or plastic debris, which can lead to digestive blockages, malnutrition, and exposure to toxins. Predators, consuming affected animals, face bioaccumulation of toxins, further disrupting the food chain and impacting ecosystem health.
Human Health Concerns and accumulation in Human Organs: Human health concerns regarding plastic exposure are growing, particularly due to the ingestion and inhalation of microplastics and nanoplastics. These particles can enter the human body through contaminated food, water, and air, accumulating in organs such as the liver, kidneys, lungs, and even the placenta. Recent studies have shown that microplastics are found in 90% of bottled water samples, with concentrations ranging from 10 to 315 particles per liter22. Upon accumulation, these plastics can trigger inflammatory responses, oxidative stress, and immune system dysfunction. Toxicological effects are linked to both the physical presence of the particles and the chemical additives they carry, such as bisphenol A (BPA), phthalates, and heavy metals, which can disrupt endocrine function, impair reproductive health, and elevate cancer risks23-24. The nanoscale size of some particles also raises concerns about their ability to cross biological barriers, including the blood-brain barrier, potentially causing neurotoxic effects. The long-term impacts of chronic exposure to micro- and nanoplastics on human health remain an active area of investigation.
Fig. An animated view of microplastics in blood stream.
Challenges in their detection:
Detecting and quantifying micro- and nanoplastics pose significant challenges due to their small size, diverse shapes, and chemical compositions. Sampling is often complicated by contamination risks, and methods for isolating particles from complex environmental matrices (e.g., water, air, food) are inconsistent. Quantifying nanoplastics, in particular, is difficult due to their size (<100 nm), as they often fall below the detection limits of conventional analytical tools. Advances in techniques such as Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy have improved the identification and characterization of microplastics, enabling the detection of particles as small as 1µm25. However, these methods still face limitations in detecting nanoplastics, especially in distinguishing them from organic matter. Additionally, mass spectrometry (MS) and pyrolysis-gas chromatography/mass spectrometry (Pyr-GC/MS) are being utilized to assess the polymer composition of microplastics, but there are limitations in throughput and cost26. Current research methods also lack standardization, leading to variability in reported results, and further development is required to enhance sensitivity, accuracy, and cross-study comparability.
Mitigation Strategies and Solutions:
Mitigating the environmental and health impacts of plastics requires a multi-faceted approach. A key strategy is reducing plastic production and waste by promoting circular economies, recycling, and shifting towards reusable alternatives. Global plastic production reached 390 million tons in 2021, with only 9% being recycled, underscoring the need for drastic waste reduction measures27. Innovations in biodegradable plastics, such as polylactic acid (PLA) and polyhydroxyalkanoates (PHA), offer potential alternatives, as these materials can break down under certain conditions, reducing long-term environmental accumulation. However, challenges remain in ensuring these alternatives degrade effectively in real-world environments28. Additionally, policy and regulatory approaches are critical for managing plastic pollution. Countries and regions, such as the European Union, have implemented bans on single-use plastics and mandated producer responsibility schemes. Extended producer responsibility (EPR) policies, coupled with international agreements like the Basel Convention's plastic waste amendments, aim to reduce plastic waste generation and improve global management efforts. To be effective, these strategies require global collaboration, technological advancements, and strong enforcement mechanisms.
CONCLUSION:
In conclusion, the environmental and biological risks posed by micro- and nanoplastics are significant, with growing evidence of their pervasive presence in ecosystems and potential impacts on human health. These plastics accumulate in water bodies, soil, and even the air, and have been detected in human organs, raising concerns about long-term toxicological effects. The health risks are compounded by the release of harmful chemicals, such as endocrine disruptors, which can lead to serious medical conditions. Future research must focus on improving detection methods, understanding the mechanisms of toxicity, and assessing the full scope of environmental and biological interactions. Additionally, standardization of sampling and analytical techniques is needed to enhance comparability across studies. A global call to action is critical—reducing plastic production, advancing biodegradable alternatives, implementing stricter regulations, and fostering public awareness will be essential in addressing the growing threat of micro- and nanoplastics. Coordinated efforts among scientists, policymakers, industries, and communities are crucial for mitigating the risks and ensuring a sustainable future.
REFERENCES:
1. Plastics Europe. Plastics– the Facts 2020: An analysis of European plastics production, demand, and waste data, 2020.
2. Saini Rummi Devi. New Age Biodegradable and Compostable Plastics. Asian J. Research Chem. 2018; 11(1): 179-188. doi: 10.5958/0974-4150.2018.00037.8
3. Dey Uttiya, Mondal Naba Kumar, Das Kousik, Datta Jayanta Kumar. Development of New Methodology for Melting of Plastic: A Chemical Approach. Asian J. Research Chem. 2012; 5(3): March 397-400.
4. Kibet Kelvin, Nthiga Esther W., Ollengo Moses A. Removal of Cd2+ and Cr3+ ions from Aqueous Solution by Modified Polypropylene Plastic Waste: Equilibrium Study. Asian Journal of Research in Chemistry. 2023; 16(5): 349-7. doi: 10.52711/0974-4150.2023.00056
5. Cole, M., Lindeque, P., Halsband, C., and Galloway, T. S. Microplastics as contaminants in the marine environment: A review. Marine Pollution Bulletin, 2011; 62(12); 2588-2597.
6. Geyer, R., Jambeck, J. R., and Law, K. L. Production, use, and fate of all plastics ever made. Science Advances, 2017; 3(7); e1700782.
7. NOAA Marine Debris Program, Plastic Pollution in the Ocean, 2020.
8. Gigault, J., Halle, A. T., Baudrimont, M., et al. Current opinion: What is a nanoplastic? Environmental Pollution. 2018; 235: 1030-1034.
9. Jambeck, J. R., Geyer, R., Wilcox, C., et al. Plastic waste inputs from land into the ocean. Science, 2015; 347(6223): 768-771.
10. Thompson, R. C., Moore, C. J., Vom Saal, F. S., and Swan, S. H. Plastics, the environment and human health: Current consensus and future trends. Philosophical Transactions of the Royal Society B: Biological Sciences. 2009; 364(1526): 2153-2166.
11. Wright, S. L., and Kelly, F. J. Plastic and human health: A micro issue. Environmental Science and Technology. 2017; 51(12): 6634-6647.
12. Gouin, T., Roche, N., Lohmann, R., and Hodges, G. A thermodynamic approach for assessing the environmental exposure of chemicals absorbed to microplastic. Environmental Science and Technology. 2022; 56(2): 936-944.
13. Kim, S. W. and An, Y. J. Toxicological interactions between heavy metals and micro/nano plastics: Recent advances and future perspectives. Science of the Total Environment. 2023; 873: 162207.
14. Zhang, Y., Kang, S., Allen, S., Allen, D., Gao, T., and Sillanpaa, M. A review of current research progress and perspectives. Science of the Total Environment. 2023; 870: 161923.
15. Koelmans, A. A., Gouin, T., Thompson, R., Wallace, N., and Arthur, C. Sources of microplastics relevant to marine protection areas. Environmental Toxicology and Chemistry. 2022; 41(4): 1115-1124.
16. Li, Y., Li, W., Yin, X., et al. Environmental impacts of microplastics and their role in plastic biodegradation: A comprehensive review. Journal of Hazardous Materials. 2023; 453: 131330.
17. Windsor, F. M., Tilley, R. M., Tyler, C. R., and Ormerod, S. J. Microplastic ingestion by riverine fish is widespread in the United Kingdom and globally. Science of the Total Environment. 2019,
18. Li, B., Ding, Y., Cheng, X., Sheng, D., Xu, Z., Rong, Q., Ma, Y., Zhu, L. Microplastics in terrestrial ecosystems: Impacts on soil properties and plant growth. Science of The Total Environment. 2023; 875: 162485.
19. Reinold, S., Herrmann, J., Stock, F., and Drost, W. Microplastics in freshwater ecosystems: Accumulation, toxicological effects, and challenges. Journal of Hazardous Materials. 2021; 409: 124896.
20. Barboza, L. G. A., Vethaak, A. D., Lavorante, B. R. B. O., Lundebye, A. K., and Guilhermino, L. Marine microplastic debris: An emerging issue for food security, food safety, and human health. Marine Pollution Bulletin. 2018; 133: 336-348.
21. Wright, S. L. and Kelly, F. J. Plastic and human health: A micro issue. Environmental Science and Technology. 2017; 51(12): 6634-6647.
22. Mason, S. A., Welch, V., and Neratko, J. Synthetic Polymer Contamination in Bottled Water. Frontiers in Chemistry. 2018; 6: 407.
23. Wright, S. L., and Kelly, F. J. Plastic and Human Health: A Micro Issue. Environmental Science and Technology. 2017; 51(12): 6634-6647.
24. Smith, M., Love, D. C., Rochman, C. M., and Neff, R. A. Microplastics in Seafood and the Implications for Human Health. Current Environmental Health Reports. 2020; 7(4): 620-628.
25. Prata, J. C., da Costa, J. P., Lopes, I., Duarte, A. C., and Rocha-Santos, T. Methods for sampling and detection of microplastics in water and sediment: A critical review. Trends in Analytical Chemistry. 2019; 110: 150-159.
26. Nguyen, B., Claveau-Mallet, D., Hernandez, L. M., Xu, E. G., and Farner Budarz, J. Challenges in microplastic analysis for environmental research: Current methods and perspective. Journal of Environmental Chemical Engineering. 2019; 7(3): 103333.
27. Geyer, R., Jambeck, J. R., and Law, K. L. Production, use, and fate of all plastics ever made. Science Advances, 2017, 3(7), e1700782.
28. Dilkes-Hoffman, L. S., Ashworth, P., Pratt, S., Laycock, B., and Lant, P. A. Public attitudes towards plastics. Resources, Conservation and Recycling. 2019; 147: 227-235.
29. Zaineb Derrag, Nacéra Dali Youcef, Souheyla Boudjema. Bioaccumulation of trace elements in Cyprinus Carpio’s organs collected from Hammam Boughrara dam. Asian J. Research Chem. 2021; 14(1): 79-85.
30. Snusha R. Dharmik, Radharaman Shaha. Using series facts device for protection of transmission line on distance Protection relay and its Mitigation. Int. J. Tech. 2015; 5(1): 11-20
31. M. Anil Kumar, S. Keerthana, Adyasa Pani, D. Suresh, M. Seenuvasan. Dynamic and Stability Criteria for a Continuous Bioaccumulation of Reactive Red C2G 29 Dye using Penicillium chrysogenum MTCC 6477. Research J. Engineering and Tech. 2011; 2(3): 167-171.
32. Gupta Rashi, Mandloi Rampal, Pillai Sujit, Birla Nikhlesh. A Review on Medicated Lollipops. Res. J. Pharmacognosy and Phytochem. 2021; 13(1): 33-38.
33. Pallavi M Patil, NJ Durugkar, PP Kakolkar, PD Chaudhari. Bioaccumulation of Cadmium Chloride in the Fresh Water Fish Cattle-Cattle. Research J. Pharm. and Tech. 2011; 4 (1): 121-123.
34. R.C. Pantola, Rakesh Bahuguna. Polymorphism: Quality rationalization, mitigation and authentication strategies with respect to regulatory compliances in pharmaceutical industry. Research J. Pharm. and Tech. 2012; 5(10): 1264-1269.
35. R.C. Pantola, Rakesh Bahuguna. Polymorphism: Quality rationalization, mitigation and authentication strategies with respect to regulatory compliances in pharmaceutical industry. Research J. Pharm. and Tech. 2012; 5(10): 1264-1269.
36. Satvir Kaur. Sustaining Environment with Green Initiative: A Conceptual Study of Green Marketing Practices in India. Asian J. Management; 2017; 8(3): 761-768.
37. Deepika Upadhyay, Priyanka Sharma, Swetha Wenona Suvarna. Green Bonds: Investment for Greener Future. Asian Journal of Management. 2018; 9(1): 730-732.
38. Arti Jha, Neha Singh, Shubham Singh Chauhan, Smita Mehendale. Environmental Awareness in Small and Medium Scale Enterprises- A Methodological and Thematic Review. Asian Journal of Management. 2018; 9(1): 779-784.
|
Received on 17.09.2024 Revised on 09.10.2024 Accepted on 24.10.2024 Published on 25.11.2024 Available online from December 27, 2024 Asian J. Research Chem. 2024; 17(6):387-391. DOI: 10.52711/0974-4150.2024.00064 © AJRC All right reserved
|