As plastic production continues to rise, the ubiquity of micro(nano)plastics in the environment raises concerns about their impact on both ecosystems and human health
In recent years, the surge in plastic production has led to a pervasive environmental and public health challenge.
The staggering global production of 8300 million metric tonnes of plastic from 1950 to 2017, with an anticipated increase to 34,000 million metric tonnes by 2050, underscores the urgency of addressing the consequences of plastic pollution. While the durability of plastics has been advantageous in various applications, their resistance to degradation poses a significant environmental threat.
Plastic residues, transported by natural forces and direct disposal, undergo transformations that give rise to microplastics (MP) and nanoplastics (NP), measuring less than 5 mm and less than 1 μm, respectively. This transformation creates tiny particles that are now pervasive worldwide, raising concerns about their impact on both environmental and human health.
The Ubiquity of Micro(nano)plastics
Plastics, with their diverse types such as polypropylene, polyethylene, polyethylene terephthalate, polystyrene, polyurethane, polyvinyl chloride, and polycarbonate, are integral to various consumer products due to their low density and cost-effectiveness.
The breakdown of these plastics into micro and nanoplastics, driven by environmental interactions, results in particles that are incredibly small and possess high biological penetrability.
This ubiquity and tiny size make them carriers of external toxic pollutants, which, when absorbed and transported, have detrimental effects on human and wildlife health.
Health Impacts of Micro(nano)plastics
Exposure to micro and nanoplastics has been linked to a range of health issues. These particles can alter physiological functions, affecting immunity and metabolism while modifying the intestinal microbiota.
The impact on different organisms triggered by micro(nano)plastics varies based on morphology, size, and concentration, causing ecotoxicological problems.
In humans, prolonged exposure to these particles, even in low concentrations, has been associated with local inflammation, oxidative stress, metabolic alterations, gastrointestinal toxicity, hepatoxicity, reproductive disorders, and neurotoxic effects.
The challenge lies in the fact that, despite the mounting evidence of the health risks, eradicating plastic waste remains a formidable task.
Human Exposure Pathways
Human exposure to micro(nano)plastics occurs through multiple pathways. These particles are found ubiquitously in the environment, including food and drinking water, making exposure to even low concentrations a persistent concern.
The Center for Disease Control and Prevention (CDC) identifies inhalation, ingestion, and dermal contact as the main routes of exposure to micro(nano)plastics. Marine animals ingest these particles, and as humans consume marine species, the particles are transferred through the food chain.
Even seemingly unrelated sources, such as table salt, have been found to contain micro(nano)plastics. In addition, plastic-packaged consumer goods may introduce these particles into the human body through ingestion, further emphasising the multifaceted nature of the issue.
Understanding the Impact
Research on the effects of micro(nano)plastics on humans is still in its early stages. While exposure routes such as absorption, ingestion, and inhalation have been identified, the gastrointestinal and pulmonary toxicity, leading to oxidative stress, inflammatory responses, and metabolic disorders, remain areas of limited understanding.
It is crucial to investigate whether ingested micro(nano)plastics can undergo further degradation within the human body, particularly under the acidic conditions of the stomach or within cell lysosomes.
Challenges in Research
The wide variety of particle sizes, shapes, and chemical compositions of micro(nano)plastics presents a challenge in understanding their potential hazards and risks to human health. Efforts should focus on chronic exposure to various types of micro(nano)plastics at relevant concentrations, considering their diverse impacts on marine organisms and human health.
While microplastics can accumulate in tissues and circulatory systems, nanoplastics pose an even greater threat due to their efficient spread within animal bodies and translocation between organs.
However, challenges such as their enigmatic existence, limitations in sampling and analysis protocols, and non-standardized basic parameter units hinder comprehensive studies on nanoplastics.
Conclusion
The indirect consumption of plastic nanoparticles presents a complex and pressing challenge for global health. As plastic production continues to rise, the ubiquity of micro(nano)plastics in the environment raises concerns about their impact on both ecosystems and human health.
Efforts to mitigate these risks require interdisciplinary research and a comprehensive understanding of the pathways, toxicological effects, and long-term consequences of micro(nano)plastic exposure.
Urgent action is needed to address the environmental and health implications of plastic pollution, emphasising the importance of reducing plastic use and implementing sustainable waste management practices.
(Bhagyashree Jain is founder of The Disposal Company.)