1. What is the main contributor to microplastic creation?
Agricultural fertilizers are one of the main contributors. Their microplastic content is retained in the soil, washed into rivers and streams, or eventually ends up in the ocean. Once dried, fertilizer microplastics can also be carried by wind and end up suspended in the air we breathe. Other sources of primary microplastics include microbeads in the ocean (tiny plastic beads that are used in exfoliating and personal care products) and synthetic plastic fibers used in the manufacturing of clothing.
The other type of microplastics are secondary microplastics, which are created from larger plastic objects that include plastic bottles, food containers, and fishing nets. So why is plastic bad? Over time, it can be broken down by exposure to ultraviolet rays, wind, and wave action, eventually ending up as tiny microplastics and leaching contaminants into the surrounding environment.
2. Can you ingest microplastics?
It’s been estimated that the average human ingests thousands of microplastic particles each year. This may be through the consumption of microplastics in fish, drinking bottled or tap water, or through the necessary activity of breathing air. It can also be from tiny bits of plastic in food because of its packaging.
Microplastics have been found in many fish and seafood species that are regularly consumed by humans, as well as in common table salt and tap water. Up to 90% of bottled water is thought to contain microplastics and they have also been detected in household dust. Through the simple acts of breathing, eating, and drinking, it’s thought that the average American ingests more than 74,000 microplastic particles every year!
3. Are microplastics toxic?
It’s still unclear as to just how toxic microplastics might be to humans. But we do know that even non-toxic substances can become toxic at certain concentration levels or after exposure to ultraviolet rays. Various chemicals that are linked to human health risks are added to plastics during their manufacturing and may end up being leaching into the surrounding environment.
Some microplastics pass through wastewater or sewage treatment plants before reaching the ocean and run the risk of absorbing harmful bacteria along the way. In other cases, microplastics absorb toxic pollutants and heavy metals on their surfaces when suspended in the ocean. They may then be ingested by marine life, biomagnified, and later consumed by humans. Persistent organic pollutants (POPs) are abundant in our marine environment and can easily be transferred from microplastics to animal tissues where they can have toxic consequences.
4. What are the health risks of ingesting microplastics?
The human health risks of ingesting microplastics are still largely unknown. Of most concern are the toxic pollutants and heavy metals absorbed by microplastics and the effect they may have on the human body. Once ingested, persistent organic pollutants (POPs) can make their way into bodily tissues. Some of these have been associated with the improper functioning of hormones, nervous system issues, a weakening of the immune system, reproductive concerns, and various cancers. The dangers of microplastics are of particular concern when the products are manufactured using phthalates, bisphenol A and styrene.
5. How do microplastics harm marine life?
The effects of microplastics on marine life affect those both large and small. In some cases, the particles pass through the animals, while in others they are retained in the gut and can lead to internal damage through lacerations or inflammation. If they break down into nanoplastics, they may end up passing through the wall of the gut and traveling to various organs.
Research indicates that ingesting microplastics is associated with reduced reproduction and growth rates in some species as the animals don’t receive the nutrients they require from digestible food. Filter feeders such as mussels and oysters are particularly vulnerable due to the high volume of microplastic-filled water that passes through their bodies every day.