Microplastics
Microplastics are fragments of any type of plastic less than 5 mm (0.20 in) in length, according to the U.S. National Oceanic and Atmospheric Administration (NOAA) and the European Chemicals Agency. They cause pollution by entering natural ecosystems from a variety of sources, including cosmetics, clothing, food packaging, and industrial processes.
The term macroplastics is used to differentiate microplastics from larger plastic waste, such as plastic bottles. Two classifications of microplastics are currently recognized. Primary microplastics include any plastic fragments or particles that are already 5.0 mm in size or less before entering the environment. These include microfibers from clothing, microbeads, and plastic pellets (also known as nurdles). Secondary microplastics arise from the degradation (breakdown) of larger plastic products through natural weathering processes after entering the environment. Such sources of secondary microplastics include water and soda bottles, fishing nets, plastic bags, microwave containers, tea bags and tire wear. Both types are recognized to persist in the environment at high levels, particularly in aquatic and marine ecosystems, where they cause water pollution. 35% of all ocean microplastics come from textiles/clothing, primarily due to the erosion of polyester, acrylic, or nylon-based clothing, often during the washing process. However, microplastics also accumulate in the air and terrestrial ecosystems.
Because plastics degrade slowly (often over hundreds to thousands of years), microplastics have a high probability of ingestion, incorporation into, and accumulation in the bodies and tissues of many organisms. (A) The toxic chemicals that come from both the ocean and runoff can also biomagnify up the food chain. In terrestrial ecosystems, microplastics have been demonstrated to reduce the viability of soil ecosystems and reduce weight of earthworms. (B) The cycle and movement of microplastics in the environment are not fully known, but research is currently underway to investigate the phenomenon. (C) Deep layer ocean sediment surveys in China (2020) show the presence of plastics in deposition layers far older than the invention of plastics, leading to suspected underestimation of microplastics in surface sample ocean surveys. (D) Microplastics have also been found in the high mountains, at great distances from their source.
Question 1: According to the passage, what is the definition of microplastics?
A) Microplastics are fragments of any type of plastic that are greater than 5mm in length.
B) Microplastics are fragments of only biodegradable plastic that are less than 5mm in length.
C) Microplastics are fragments of only specific types of plastic that are less than 5mm in length.
D) Microplastics are fragments of any type of plastic that are less than 5mm in length.
Question 2: According to the passage, what is the difference between microplastics and macroplastics?
A) Macroplastics are larger in size than microplastics.
B) Microplastics are biodegradable while macroplastics are not.
C) Microplastics are smaller in size than macroplastics.
D) Macroplastics are not recognized as a cause of pollution.
Question 3: According to the passage, which of the following is NOT true about microplastics?
A) Microplastics arise from the degradation of larger plastic products.
B) Microplastics cause pollution in natural ecosystems.
C) Microplastics do not persist in the environment.
D) Microplastics are found in aquatic and marine ecosystems.
Question 4: What can be inferred from the passage about the impact of microplastics on the environment?
A) The impact of microplastics on the environment is unknown.
B) Microplastics have a positive impact on the environment.
C) Microplastics have a negative impact on the environment.
D) Microplastics have a neutral impact on the environment.
Question 5: Which of the following can be inferred from the passage about the effects of microplastics on the environment?
A) They are a relatively new phenomenon and not yet well understood.
B) They are only affecting the ocean and not other ecosystems.
C) Their movement and cycle in the environment is fully understood.
D) They cause pollution primarily in marine and aquatic ecosystems.