• Using nano-paint on boats: exploring the toxicity of antifouling paints

    POST DATE: 2018-05-08 at 08:00:00

    Publication: “Release and detection of nanosized copper from a commercial antifouling paint

    Quick Summary:

    Antifouling paints are often used on boats as a way to prevent algae and barnacles from growing on the hull. They can contain copper or zinc, which are known to be biocides (they kill or have a neutralizing effect on microorganisms). Some commercially-available paints could cause copper nanoparticles to be released from the paint and into water under a variety of conditions, and could be harmful to at least some types of marine life. 

    The Full Story:

    Waters analyzed in harbors and marinas show abnormally high levels of copper. This is because copper is often used in paints for the bottom of boats and ships, and some copper can leach out of the paints when the boats are in the water, or when the hulls are scraped for boat maintenance. Copper levels in one estuary were also higher in the summer, indicating that there could be seasonal effects. However, most studies consider a very wide range of copper materials when looking at copper release into waters: copper ions (dissolved, charged atoms of copper), copper nanoparticles (1-100 nm in diameter) and bulk particles (101-450 nm in diameter). UC CEIN researchers looked at the impact of several factors on the composition of various copper materials in water.

    Caption: Some commercial antifouling paints include nano-sized copper. Here, a special type of microscope called an electron microscope helps researcher image the copper nanoparticles, and to identify that they can be classified into two broad categories: nanoparticles (less than 100 nanometers) or bulk particles (larger than 100 nanometers). Reprinted with permission from the authors.

    The researchers found some important information about the paints. First, more copper is leached from painted wood than from painted aluminum, suggesting that the boat material can play a big role in the environmental fate of nano-sized copper in the antifouling paint. They also found that the type of water (freshwater or seawater) can make a big difference as well, since different amounts of dissolved copper, copper particles, and copper bulk particles were observed for the different water types. They also showed that the longer the antifouling paints were allowed to dry (or “cure”), the more total copper was released into the water samples.

    Why is this important?

    Marine phytoplankton are important to the health of the environment. They produce up to half of all photosynthesis on the planet, and are an important food source at the bottom of the food chain. They can also serve as indicators of ecosystem changes, since phytoplankton survival can change based on things like water temperature and availability of nutrients, and the availability of phytoplankton can impact many higher organisms. Too little phytoplankton could have a big impact on the ability of many other organisms to survive, but too much phytoplankton is also harmful, since a large accumulation of algae (called a harmful algal bloom) can release compounds that are toxic.

    In this study, UC CEIN researchers showed that a number of different consumer behaviors and physical properties can impact the amount of copper that is leached from antifouling paint (the type of material used, the drying time of the paint, the type of water where the boat is docked, and the salinity, or saltiness, of the water). While it is not clear whether nano-sized copper specifically imposes an environmental threat (compared to copper ions or bulk carbon), it is clear that the use of antifouling paint with nano-sized copper particles causes the release of all three sizes of carbon materials and is harmful to marine phytoplankton.

  • Improved Method to Understand if a Material is Toxic

    POST DATE: 2017-12-15 at 08:00:00

    Publication: “Semiconductor Electronic Label-Free Assay for Predictive Toxicology

    Press release: "Nanomaterial safety screening could become faster, cheaper with new laboratory test"

    Quick Summary:

    Researchers at CEIN have developed an improved test for the toxic effects of nanomaterials. This type of toxicological testing is often time- and labor-intensive, and very expensive. This new test allows researchers to prioritize the nanomaterials to fully test by rapidly identifying those that are predicted to have toxic effects.

    The Full Story:

    Whenever there is a new chemical or material that is proposed for human use, it is important to evaluate its safety. This means that a scientist needs to do a lot of experiments in the lab first to understand the behavior of the new material. Then, the scientist can introduce the material to cells that are grown in the lab to see if there are any adverse effects. Next, the scientist can use an animal model to understand if the material might have some effects in the body that are not able to be seen in cells that are grown in the laboratory. This process is not only time- and labor-intensive, it is also really expensive. There are more than 90,000 chemicals and materials that exist or are being developed, and this type of testing is important for each one. The guidelines for each of the chemicals is not always the same. For example, the way that something like table salt is evaluated will be very different than the way a new chemotherapy is evaluated. Since more people are likely to be exposed to table salt on a frequent basis, it is important that it doesn’t have any toxic effects. However, it might be ok for a new chemotherapy to have some toxic effects if it is effective at treating the cancer and extending life and quality of life for cancer patients.

    Caption: The device (on the bottom left panel “e”) is made using nanowires (on the top left panel “b”). The use of engineered nanomaterials allows the researchers to increase the sensitivity of the device compared to methods that are currently used. This technology could help researchers more quickly detect the toxic effects of various materials. Image reprinted with permission by Nature Publishing Group from Mao, Shin, Wang, Ji, Meng and Chui, Scientific Reports (2016).

    If scientists had a better way to screen a large number of materials to easily and rapidly determine if toxic effects are predicted (research of this type is called predictive toxicology). There are currently some methods that can be used to predict the safety of new compounds, but these tests are quite long, can have a high cost, and required highly trained employees to run the tests and analysis.

    Researchers improved on existing technology to develop a rapid screening method, based on a nano-scale transistor. They used this as a sensor to detect a protein called interleukin-1-beta (also called IL-1b). This is a protein that your immune system can produce in response to inflammation in your lungs. Researchers demonstrated that they were able to detect IL-1b as well as the currently used method (the expensive one that requires a skilled technician).

    Caption: Using this new technology, researchers are able to quickly scan a wide variety of different nanomaterials. The images above represent different types of nanomaterials, that differ in their chemical composition, size, and shape. Image reprinted with permission by Nature Publishing Group from Mao, Shin, Wang, Ji, Meng and Chui, Scientific Reports (2016).

    Why is this important?

    Engineered nanomaterials are being developed at a rapid pace in research laboratories, and being proposed for use in consumer products. However, their full safety profiles have not yet been determined. When a new consumer product goes on the market, it is important to consider the health and environmental impact of the product. What is the impact of manufacturing the product? What is the impact of using the product? How does the product get disposed, and what is the impact of the product on the environment after its disposal? This device can help to answer the question about the potential health effects on users in a way that is faster and more efficient than traditional methods.