Chemicals from household electronics are accumulating in the brains of dolphins and porpoises in the Indo-Pacific, according to a new study that calls for urgent regulation to cut e-waste pollution.
Liquid crystal monomers, or LCMs, are chemical components of laptop, television and smartphone screens that control how light passes through the displays. While they are known to be persistent pollutants due to the ubiquitous nature of these electronic devices, their threat to marine life isn’t well understood.
The new study notes that LCMs can accumulate in dolphin and porpoise tissues, including blubber, muscle and brain, demonstrating their ability to cross the blood-brain barrier.
“This is a wake-up call. The chemicals powering our devices are now infiltrating marine life, and we must act now on e-waste to protect ocean health and, ultimately, ourselves,” Yuhe He, an author of the study published in the journal Environmental Science & Technology, said.
“Our research reveals that LCMs from everyday electronics are not just pollution – they are accumulating in the brains of endangered dolphins and porpoises,” said Dr He from the City University of Hong Kong.
Previous studies have shown that LCMs pose health risks to humans and several aquatic species but just how the pollutants move through various food chains and whether they reach top predators has been unclear.
The new study analysed tissue samples from Indo-Pacific humpback dolphins and finless porpoises collected in the South China Sea between 2007 and 2021, a critical habitat for the two endangered marine animals.
Researchers analysed tissue samples for 62 LCM chemicals and found that dolphins and porpoises contained four main LCMs that were previously detected in smaller fish and invertebrates. This indicates the pollutants enter the marine mammals through their diet rather than directly from water.
The LCMs found in dolphins and porpoises seemed to originate mostly from television and computer screens, with smaller contributions from smartphones.
Laboratory tests confirmed that the LCM chemicals altered gene activity in cultured dolphin cells, affecting DNA repair and cell division. “The findings suggest that LCMs may pose potential risks to the nervous system and other organs of marine mammals, warranting further investigation into their toxicological effects and possible implications for human health,” the study noted.
Researchers call for further investigation into the effects of LCM pollution on wildlife. The findings, they say, underscore the need for urgent regulatory action and improved e-waste disposal.
