Scientists from Ohio reported that nanoparticles are currently being added to cosmetics, sunscreens, and many other beauty care products may be harmful to the environment.
Their report is part of a conference that includes dozens of articles at the 237th meeting of the American Medical Association, where scientists discuss the impact on the environment and human health. of nanotechnology. Hundreds of products using these tiny particles - 1/5000 in diameter of a hair - have been marketed. With many other products coming out, scientists are working hard to avoid the unwanted effects on this health and environment.
The study of Dr. Cyndee Gruden, and Olga Mileyeva-Biebesheimer focused on titanium dioxide nanoparticles (nano-TiO2) found in cosmetics, sunscreen and other beauty care products. These particles are added to the product because of the ability to block ultraviolet light in sunlight. However, too much use can cause premature skin aging or skin cancer.
Gruden, of the University of Toledo, explained that the particles were washed down the sewers after the users showered, and concentrated in the city's garbage disposal areas. From there, they can penetrate into lakes, rivers and other water sources where microorganisms play an important role in preserving a healthy environment.
Gruden asked the question: 'When these elements enter the lake, what happens. Will they get into the organism? Maybe they will destroy the creature - or do nothing. Those are important questions to determine the impact of nanoparticles on the environment. Right now, we still know the answer. '
Gruden studied the viability of Escherichia coli (E. coli) bacteria when exposed to various amounts of nano-TiO2 in the laboratory. Surprisingly, she found a sharp decline in the survival rate of samples exposed to low levels of nanoparticles for less than an hour. She commented: ' This rapid impact has taken me by surprise.' This finding opens the door to future research, including studies that determine whether these effects occur in the natural environment.
The method of determining damage from Gruden's nanoparticles is to use fluorescence to detect when cell membranes in bacteria are damaged . When the membrane - an important part of the bacteria - is damaged, the cells will glow red. 'Fluorescence-based methods allow us to get results faster, and possibly with higher sensitivity,' she said, adding that this method could accelerate efforts to understand the threshold when parts Nanoparticles become toxic to bacteria.
In the second study of the virulence of nanoparticles at the ACS Meeting, scientists from Utah described the development of a new biosensor, which flashed as a beacon when it was discovered. Nanoparticles in the environment.
Anne Anderson and her colleagues at Utah State University and the University of Utah put the gene into a line of Pseudomonas putida (P. putida) - a beneficial soil bacterium - that lets it emit light when exposed to nanoparticles of heavy metal. Bacteria glow when in a normal state. When exposed to toxic substances, light will fade.
'The superiority of this biosensor is that we have very fast results, and we can get the answer when the absence of other binding elements' , Anderson stressed that the methods Conventional measures of bacterial cell growth may take up to two days. 'In a blink of an eye, you can observe what's happening'.
Anderson's team found that P. putida could not tolerate silver, copper oxide, and zinc oxide silver nanoparticles. Toxicity occurs at a minimum of micrograms per liter. This is equivalent to 2 to 3 drops of water in an Olympic-sized swimming pool. Aderson warned that it was a threat to underwater life. 'If you look at the level of copper risk for fish and other aquatic organisms regulated by the Environmental Protection Agency, we are at a toxic level.'
There is a lot of debate in the scientific community about the toxicity of nanoparticles. Some scientists believe that nanoparticles in the environment will combine with silt and other organic substances, significantly reducing their toxicity. Anderson said: 'We still don't know if this is true.' Other members of the Utah research group are currently studying this issue.
Although the public is ultimately responsible for understanding the risks of products, Gruden said, science plays an important role in alerting possible risks. She said: 'The job of a scientist is to do good research and let the results speak for themselves. Until now, it is unclear whether the benefits of nanotechnology are greater than the environmental and health risks. '