These plastic containers immerse the chemicals in the water they once held, and immerse them in the port where the rubbish ends up. This is the conclusion of two new studies.

Rosemary Calver/Stone/Getty Images Plus

Plastic waste is everywhere in the world. From the depths of the ocean to Arctic glaciers and even European mountains, this has become a growing problem. Many recent studies have focused on how plastic products in the environment are broken down into smaller pieces and the final location of these pieces. But two new studies have found that it's not just plastic parts that cause problems. Intact plastic releases pollution-tens of thousands of chemicals. These studies have now concluded that these pollutants may eventually enter water and food.

Many of these chemicals come from additives. Such additives include pigments, flame retardants and the like. They somehow make the plastic stronger, more colorful, or better. But these additives are not chemically combined with plastics. This means that they can be moved out and into the environment through a process called leaching.

Most research on plastic pollution has focused on pure plastics. These are the types that have not been added with additives. Both new studies used plastic bags and containers when we used them and added additives. Research now reports that through normal use, these plastics can release other chemicals as pollutants.

"We don't know whether the plastic chemicals [pollutants] we studied have health effects," said Martin Wagner, one of the authors. However, he believes that people should be worried. "The products they sell are the products they use every day, but they don't know whether the chemicals they come into contact with are safe."

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Wagner is a biologist at the Norwegian University of Science and Technology in Trondheim. He recently collaborated with Lisa Zimmermann of the Goethe University in Frankfurt, Germany. She is an ecotoxicologist. This means that she studies how chemicals poison the living things in the environment. Together, they became part of a team investigating whether contaminants can seep into food from plastic.

They checked the daily food containers. These include different types of plastic bags, bottles, fruit trays, coffee cup lids, soft candy packaging, shower shoes and yogurt cups. In short, these include eight different types of plastics. Each type uses different additives. The team extracted chemicals from each plastic sample. They also put a piece of each sample in water and kept it in the dark at 40 degrees Celsius (104 degrees Fahrenheit) for 10 days. Afterwards, they tested whether the water showed signs of leaching chemicals from these plastics.

They also tested the extracted chemicals and the chemicals leached from the water in a toxicity test. For example, they studied whether these chemicals make cells sick. They also tested whether these chemicals might mimic or block hormones. They use a device called a mass spectrometer (Spek-TRAH-meh-tur) to identify the total number of different chemicals released by plastics.

They found that chemicals immersed in water are toxic at concentrations that might be encountered under normal use. Each type of plastic will leach at least some toxic chemicals. Only a few plastics can leach chemicals that mimic or interfere with human hormones. In general, some plastics can leach hundreds of chemicals. They found that others leached tens of thousands.

The team shared their findings on "Environmental Science and Technology" on September 7.

When plastic bags and products are discarded, they will eventually become garbage. A large amount of waste plastic eventually flows into our oceans. For many years, researchers believed that sunlight would only rupture or otherwise decompose garbage into smaller pieces of raw plastic. Anna Walsh wondered if sunlight could also cause plastics to soak pollutants into the water. As an environmental scientist, she works at the Woods Hole Oceanographic Institute. It's in Woods Hole, Massachusetts. There, she was a member of a team that studied marine chemistry.

Her team analyzed the fragments of ordinary plastic bags. They are made of polyethylene (Pah-lee-ETH-ul-een), which is a kind of plastic commonly found everywhere in the ocean. They cut the pieces into small pieces and put them in a beaker filled with sea water. Some were left in the dark at room temperature for six days. Others were placed in light of all wavelengths, including sunlight, for five days. These are cooled to keep the water at the same temperature as the dark sample.

They found that plastic leached in the sun twice as much pollution as in the dark. A bag can leach 263 different chemicals in the dark, but it can leach more than 13,000 kinds in the light! Others leached more. The longer the bags are exposed to the sun, the more chemicals they can leach. "Sunlight can cause these transitions relatively quickly," Walsh said. Within a few weeks to a few months, they can leach "tens of thousands of different chemicals."

Her team shared its findings in "Environmental Science and Technology" on September 21.

Walsh said that what this means for ocean health is still unknown. But scientists are studying it. "We have made great strides in understanding how many different types of plastics in the ocean break down, how long they last and their effects," she said.

Chemists have long believed that plastics will always exist in the environment. But the truth is much more complicated. "Plastic is an extremely hard material," Walsh admitted. "But sunlight has the ability to break them down into all these chemicals we have seen in research."

"It's great to see more and more studies using real-world environments for exposure experiments," Susanne Kühn said. She is a marine biologist at the Wageningen Marine Research Center in the Netherlands. She said that what is disturbing is that people are "exposed to substances that we don't know how toxic they might be."

More importantly, she added that there are no government regulations to ensure the safe use of these chemicals. Zimmerman’s research “supports growing evidence that plastics can be harmful, not only when ingested directly, but also when in contact with human food,” Kuhn said.

The good news is that we "can reduce our exposure to these chemicals by reducing the use of plastics," Norway's Wagner said. He recommends eating less food in plastic packaging. "It's not only good for us," he argued, "it's also good for the environment."

Arctic: It belongs to the area within the Arctic Circle. The edge of the circle is defined as the northernmost point at which the sun can be seen at the northern winter solstice and the southernmost point at which the midnight sun can be seen at the northern summer solstice. The Arctic highlands are the northernmost third of the region. This is an area dominated by snow for most of the year.

Biologist: A scientist engaged in biological research.

Cell: (in biology) the smallest structural and functional unit of an organism. Usually too small to be seen with the naked eye, it consists of a water-like liquid surrounded by a membrane or wall.

Chemical substance: A substance formed by combining (bonding) two or more atoms in a fixed ratio and structure. For example, when two hydrogen atoms combine with one oxygen atom, water is a chemical substance. Its chemical formula is H2O. Chemistry can also be used as an adjective to describe the properties of materials, which are the result of various reactions between different compounds.

Chemistry: The field of science that deals with the composition, structure, and properties of substances and how they interact. Scientists use this knowledge to study unfamiliar substances, copy a large number of useful substances or design and create new useful substances.

Concentration: (in chemistry) the amount of one substance dissolved into another substance.

Environment: The sum of all things that exist in an organism or process, and the conditions created by these things. The environment may refer to the weather and ecosystem in which some animals live, or it may be temperature and humidity (or even the location of things near objects of interest).

Extraction: (v.) To separate a chemical (or a component of something) from a complex mixture. (Noun) A substance removed from some source material, usually in a concentrated form.

Glacier: A slow-moving glacier hundreds or thousands of meters deep. Glaciers are located in valleys and are also part of the ice sheet.

Hormone: (in zoology and medicine) a chemical substance produced in the glands and then transported through the blood to other parts of the body. Hormones control many important physical activities, such as growth. Hormones work by triggering or regulating chemical reactions in the body. (In botany) A chemical substance used as a signal compound that tells plant cells when and how to develop, or when to grow old and die.

Leaching: (in geology and chemistry) water (usually in the form of rain) removes soluble minerals or other chemicals from solids (such as rocks) or sand, soil, bones, garbage, or ashes.

Garbage: Materials scattered in the open air, which have been discarded or left where possible. (Biology) Rotting leaves and other plant matter on the forest floor. (In zoology) a group of small animals born at the same time with the same mother.

Marine biologist: A scientist who studies organisms that live in seawater, from bacteria and shellfish to kelp and whales.

Organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.

Pigment: A material, such as the natural pigment in the skin, that can change the light reflected or transmitted by an object. The overall color of a pigment usually depends on the wavelength of visible light it absorbs and the wavelength of visible light it reflects. For example, red pigments tend to reflect red wavelengths very well, and usually absorb other colors. Pigment is also the term for the chemical used by manufacturers to color paint.

Plastic: Any of a series of materials that are easily deformed; or synthetic materials made of polymers (long chains of some building block molecules). These materials are often lightweight, inexpensive, and resistant to degradation.

Pollutants: substances that pollute certain things-such as air, water, our bodies or products. Some pollutants are chemicals, such as pesticides. Others may be radiation, including excessive heat or light. Even weeds and other invasive species can be considered a biological pollution.

Polyethylene: Plastic made from chemicals refined (produced) from crude oil and/or natural gas. The most common plastic in the world, flexible and tough. It can also resist radiation.

Risk: The probability or mathematical possibility that something bad may happen. For example, exposure to radiation brings the risk of cancer. Or danger-or danger-itself. (Example: The cancer risks people face include radiation and drinking water contaminated with arsenic.)

Sea water: The salt water found in the ocean.

Spectrometer: An instrument that measures light, energy, or atomic mass. Typically, chemists use these instruments to measure and report the wavelength of light they observe. The process of using this instrument to collect data is called spectral analysis, which can help identify elements or molecules present in unknown samples.

Technology: The application of scientific knowledge for practical purposes, especially in industry-or the equipment, processes, and systems that result from these efforts.

Toxic: Toxic or capable of harming or killing cells, tissues or whole organisms. The measure of the risk this poison brings is its toxicity.

Toxicity: A measure of the possibility of a certain substance being poisoned or causing harm to organisms. The injury may not happen immediately. The injury may not happen immediately. Depending on the dose, organism, and toxic substances, any harm may not occur for days, weeks, or even years.

Journal: Plastic formulations such as AN Walsh are emerging controls for their photochemical fate in the ocean. Environmental Science and Technology. roll. 55, September 21, 2021, page 55. 12383.doi: 10.1021/acs.est.1c02272. 

Journal: L. Zimmerman et al. Chemical substances leached from plastic products can induce in vitro toxicity under actual conditions of use. Environmental Science and Technology. roll. 55, September 7, 2021, page 55. 11814.doi: 10.1021/acs.est.1c01103. 

Alison Pearce Stevens is a former biologist and eternal science geek who writes articles about science and nature for children. She lives with her husband, their two children, and a group of cute (and not so cute) animals.

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