Effect of Micro Plastics and Nano Plastics in TerrestrialEcosystem

Microplastics (MP) (less than 5mm in size) and nanoplastics (even smaller particles) are emerging as significant pollutants that are increasingly being found in various ecosystems, including soil, water, and even the air. These plastic particles can come from both primary sources (manufactured as small particles) and secondary sources (degradation of larger plastic items). Due to their persistence, they pose long-term environmental threats. The paper highlights the global concern around the contamination of ecosystems and the potential consequences on animals, birds, and humans.

Sources and Types of Microplastics

Microplastics originate from various sources:

Primary microplastics are those intentionally produced for industrial purposes, such as in cosmetics, cleaning agents, and pharmaceuticals.
Secondary microplastics come from the breakdown of larger plastics through weathering processes like ultraviolet exposure, heat, or mechanical abrasion.

Common sources of microplastic pollution include household products, synthetic clothing fibers, and plastic packaging. These plastics enter ecosystems through improper waste disposal, abrasion of tires, agricultural runoff, and even sewage sludge used as fertilizers.

Impact on Terrestrial Animals

Terrestrial animals are highly susceptible to the ingestion and exposure to microplastics, with various studies showing their potential harmful effects:

Ingestion of Microplastics: Animals often mistake microplastic particles for food. The ingestion of these particles can lead to physical damage to the digestive tract, malnutrition, and reduced reproductive success.
Toxic Chemical Transfer: Microplastics can absorb harmful chemicals like heavy metals and persistent organic pollutants (POPs). When ingested by animals, these chemicals may accumulate in tissues, leading to physiological and metabolic disruptions.
Bioaccumulation: The persistence of microplastics in food webs means that these particles can accumulate in higher concentrations in top predators, potentially leading to more severe health consequences.

For example, earthworms ingest microplastics present in soil, and the bioaccumulation of plastic particles may increase the risk of contaminant transfer within the food web, affecting birds and larger mammals that feed on them.

Impact on Birds

Birds, especially seabirds, have been documented to ingest microplastics through their food sources. However, terrestrial birds are also affected:

Ingestion: Many bird species ingest microplastics indirectly by consuming prey that has ingested plastic, or directly by mistaking plastic debris for food. This leads to gastrointestinal blockages, reduced food intake, and decreased body condition.
Impact on Predatory Birds: Raptors and other top-tier birds are particularly vulnerable to the bioaccumulation of microplastics. They may experience higher toxin levels due to their diet of small mammals and other prey contaminated by microplastics.
Effects on Physiology: Studies have shown that microplastics can cause oxidative stress and other metabolic disruptions in birds, which may reduce their survival and reproductive success.

Human Health Implications

Human exposure to microplastics occurs mainly through ingestion, inhalation, and skin contact. Microplastics have been found in food products like seafood, salt, and even drinking water. Key points include:

Ingestion: Humans consume microplastics through food sources, particularly seafood. Plastic particles have been found in human stool, lungs, and potentially even blood, suggesting widespread human exposure.
Health Risks: Although the full extent of the health impacts is still being studied, potential risks include gastrointestinal inflammation, disruption of the endocrine system, and an increased risk of cancer. Microplastics are also carriers of chemical pollutants, which could exacerbate their toxic effects on human health.
Potential Long-term Effects: Microplastics can interact with human cells, potentially leading to oxidative stress, immune responses, and other harmful effects. Nanoplastics, due to their smaller size, can penetrate deeper into tissues and organs, increasing the likelihood of systemic health problems.

Effects on Soil and Terrestrial Ecosystems

Microplastics have significant effects on soil health and structure, impacting the organisms that depend on healthy soil environments:

Soil Organisms: Earthworms, nematodes, and other soil-dwelling organisms are affected by the ingestion of microplastics. This can alter their behavior, reproduction, and survival, thus impacting soil fertility and nutrient cycling.
Changes in Soil Structure: The presence of plastics alters soil properties such as bulk density and porosity, which in turn affects water retention and root growth in plants.
Impact on Ecosystem Services: Since soil organisms play a critical role in nutrient cycling and organic matter decomposition, disruptions caused by microplastics can reduce soil productivity, which is essential for agriculture and biodiversity.

Potential Solutions and Mitigation Strategies

The study suggests various strategies to mitigate the impact of microplastics on ecosystems:

Improved Waste Management: Reducing plastic production and improving recycling processes are critical to limiting the entry of plastics into natural environments.
Regulation and Policy: Strict regulations on the use of microbeads in personal care products, and better management of plastic waste from industries and households, can significantly reduce pollution levels.
Biodegradable Alternatives: Promoting the development and use of biodegradable plastics can help reduce the persistence of plastics in the environment. However, these alternatives must also be carefully studied for potential environmental risks.
Awareness and Education: Public education on the sources and risks of microplastics is essential for reducing their use and improving waste disposal practices.

Conclusion

Microplastics (MP) and nanoplastics (NP) are a growing environmental concern with profound implications for terrestrial ecosystems, animal health, and human well-being. The persistence of these materials in the environment and their ability to bioaccumulate in food webs pose significant risks that need urgent attention. Ongoing research and stronger regulatory actions are required to address this emerging environmental challenge and safeguard ecosystem functionality and human health.

Reference

Roopika, S., & Siddhuraju, P. (2022). Effect of Micro Plastics and Nano Plastics in Terrestrial Animals, Birds, Human and Implications on Integrated Functional Ecosystem. Indian Journal of Ecology, 49(6), 2415-2430. 10.55362/IJE/2022/3842