Water bottles, plastics immediate chemical impact revealed

Scientists have discovered that plastics start releasing their chemical additives into the environment as soon as they are discarded

By Ground Report 09 Jan 2024

New Update

Water bottles & plastics immediate chemical impact revealed

Scientists have discovered that plastics start releasing their chemical additives into the environment as soon as they are discarded, not just when they start to degrade. Despite the slow process of plastic breaking down into smaller pieces, the chemicals it contains start to seep into the water immediately upon contact.

Research scientist Lisbet Sørensen from SINTEF Ocean explains that their study focused on the impact on marine life. They examined two groups of microorganisms: bacteria and microalgae, also known as phytoplankton.

Sørensen says, "Eventually we collaborated with cod eggs and larvae, a significant natural resource for us." She further explains, "We clearly understand that fish, similar to humans, are more susceptible to the health effects of pollution in their immature stages."

The research used 50 plastic products including supermarket bags, disposable cups, dishwashing gloves, car tire pellets, a variety of children's toys and balloons. They later added some other materials, such as plastic and rubber.

What happens when plastic breaks down?

Sørensen, who led a multi-country interdisciplinary team that included biologists and chemists, says, "The number of different chemicals we identified in these products greatly surprised us. We found only 30% of the identified chemical compounds in two or more products. A large number of chemicals also remained uncertain due to lack of appearance on the established lists of substances. This demonstrated how little we know about the composition of many of the everyday products that surround us," he says."

The project aimed to determine the toxicity of these chemicals to living organisms once marine environment gets the plastic products. Environmental factors break plastics down either physically into fragments or chemically, converting them into microplastic particles. However, chemical additives from plastics can leach into the natural environment long before this process completes.

Natural rubber is far from harmless

The research team examined the effect of chemicals leaching from microplastics and rubber particles into the marine environment.

Andy Booth, chief researcher at SINTEF, said: "What we have seen is that products with high levels of rubber have the worst impact on the microorganisms we have investigated in our experiment." "This was a bit surprising, especially since untreated rubber is considered a 'natural' product. However, we found that it was among the most toxic substances to the microorganisms we were studying," he adds.

Chemical compounds that leach from rubber gloves are especially harmful. Booth states that the most toxic chemicals to microorganisms are those added to natural rubber used in dishwashing gloves. She says that we found these substances in four of the 50 products we analyzed, which are dishwashing gloves, car tires, rubber balloons, and disposable gloves.

Deformed fish larvae

The project carried out another experiment that involved exposing both cod embryos and newborn larvae to microplastic particles and chemical compounds present in plastics. The team further exposed eggs and larvae to a combination of both since they are indistinguishable from each other in the real world. The team has published its results in the Journal of Hazardous Materials, Marine Pollution Bulletin and Science of The Total Environment.

First, the researchers characterized and extracted the toxic chemicals from the different plastics and investigated their effects on cod larvae.

Stefania Piarulli, a biologist and scientific researcher at SINTEF, says, "We observed that some chemicals directly prevented the eggs from hatching, while others exerted significant physical effects on the larvae. We discovered spinal deformities in the larvae that reminded us of what we call scoliosis," she explains.

What is worse, microplastic or chemicals?

But what about microplastic particles? Are they harmful in their physical state, or is it the combination of their size and the chemicals they give off that make them so toxic?

To clarify, the researchers separately compared the effects of the particles and the chemicals, and they made a surprising discovery that the chemicals were essential to produce the toxic effect.

Piarulli explains, "We have developed a completely new method to 'clean' the microplastics of all chemical traces, which is the particularity of this experiment. Only then can we ascertain something about the effect of microplastic particles with certainty."

In other words, if the physical particles did not contain chemicals, the team detected no toxic effects.

Elastic plastics are one of a kind

The research team discovered that not all types of plastic are toxic. The combination of different plastic products determines the level of toxicity, and they found elastic plastic products to be among the worst.

"Andy Booth notes, "We now know that by simply selecting alternative polymer combinations during manufacturing, we can reduce toxicity in various products"."

"The researcher highlights that the chemicals added to natural rubber, which are used in dishwashing gloves, turned out to be the most toxic to microorganisms - a fact worth noting,"

What about mammals and humans?

"The scientists analyzed the impact on humans as well. Do we have any reason to believe that wild and farmed fish, chicken, pork, or beef, used for food, contain many of these chemicals? Biologist and researcher Stefania Piarulli, a team member, explains, "Macro and microplastics, along with the chemical additives they contain, continually expose both humans and other animals."

"Therefore, we can naturally assume that our exposure to plastic-related chemical additives also comes through the food we eat. However, we need to conduct more research to determine how many of these chemicals come from meat products and how much comes from packaging," the statement reads.

Piarulli adds: "In my opinion, we expose ourselves to many more chemicals through food processing and cooking than through plastic packaging. We also subject ourselves to exposure to chemical additives related to plastic in many other ways."

Lisbet Sørensen from the research team clarifies that plastic products used for food storage pose minimal problems due to stringent regulations on 'food contact materials', including limits on chemical additives.

Sørensen warns that daily-used and children's plastic products performed poorly in experiments compared to food-related materials, with no direct human impact studied.

Stefania Piarulli said, "Never in history has pollution exposure been as prevalent as it is today. This is why we should always strive to lessen our plastic usage. We understand the negative impacts of plastic and we are aware there could be effects yet undiscovered, including direct impacts on terrestrial and aquatic ecosystems."

He asserts we overuse plastics, especially in unnecessary situations like in textiles and overpackaging. He stresses the need to avoid plastics and use our consumer influence to discourage their use.