Dec. 11 (UPI) -- Liquid crystal monomers are used to make a variety of electronics, including smartphones, televisions, computer displays and solar panels. New research suggests these materials contain a variety of toxic chemicals, which tests showed can leach into everyday environs.
"These chemicals are semi-liquid and can get into the environment at any time during manufacturing and recycling, and they are vaporized during burning," lead researcher John Giesy, an environmental toxicologist at the University of Saskatchewan in Canada, said in a news release. "Now we also know that these chemicals are being released by products just by using them."
For the new study, Giesy and his international team of research partners looked at the chemicals used in 362 of the most common liquid crystal monomers, surveying the scientific literature for evidence of each chemical's toxicity.
The scientists also identified several monomers featuring chemicals hazardous to animals and the environment in six of the most popular smartphone models.
In the lab, animals exposed to several of the toxic monomer ingredients were unable to properly digest nutrients. The chemicals also exhibited characteristics known to interfere with the functioning of the gallbladder and thyroid glands.
The harmful qualities observed among monomer chemicals resembled those found among dioxins and flame retardants, chemicals that are known to be toxic to humans and animals.
"We don't know yet whether this a problem, but we do know that people are being exposed, and these chemicals have the potential to cause adverse effects," said Giesy.
To help quantify exposure levels, scientists tested dust samples from a variety of buildings in China -- in student dorms, a classroom, a hotel, several homes, a science lab and an electronics repair shop.
Almost half of all the dust samples tested positive for liquid crystal polymers. Scientists described the prevalence of liquid crystal monomers and their toxic components this week in the journal PNAS.
"Ours is the first paper to list all of the liquid crystal monomers in use and assess their potential to be released and cause toxic effects," said Giesy. "We looked at over 300 different chemicals and found that nearly 100 have significant potential to cause toxicity."
In addition to having potentially toxic effects on animal and human health, the chemicals found in liquid crystal monomers also feature a variety of worrisome qualities. Many of the chemicals accumulate in organisms, are slow to degrade and can travel long distances through the atmosphere.
Now that scientists know these chemicals are making their way into the environment, scientists now plan to figure out how they move and where they go.
"Right now, there are no measurements of these monomers in surface waters. Our next steps are to understand the fate and effect of these chemicals in the environment," said Giesy.