Hong Kong researcher sounds alarm after toxic electronic waste found in dolphins
E-waste Recycling | 2026-03-16 02:11:11
The department said stringent enforcement action will be taken against any contraventions of the law.
By Paul Ploumis
SEATTLE (Scrap Monster): A Hong Kong researcher has called for stricter regulations and urged the public to use electronics more responsibly after a study found toxic pollutants from laptops, televisions and smartphones in the bodies and brains of endangered dolphins and porpoises that washed up on the city’s beaches.
Yuhe He, an associate professor at City University of Hong Kong and one of the study’s authors, said he was alarmed to find that liquid crystal monomers (LCMs) – the pollutants identified in the research – were capable of breaching the protective blood-brain barrier in dolphins, which is also found in humans and other animals.
LCMs are synthetic, organic chemicals used to manufacture liquid-crystal display (LCD) screens for laptops, television and smartphones.
In the study, researchers from City University and mainland China analysed 63 samples from 16 Chinese white dolphins and 26 Indo-Pacific finless porpoises that died after being stranded on the city’s beaches between 2007 and 2021.
The team performed tests on blubber, muscle, brain, liver and kidney tissues to look for 62 types of LCMs.
About 88 per cent of samples were found with detectable concentrations of LCMs, with the pollutants most concentrated in the blubber of dolphins and porpoises, followed by the muscles and brains.
Associate professor He said it was alarming to discover the pollutants in the brains of dolphins and porpoises, a previously undocumented phenomenon in marine mammals.
He explained that the blood-brain barrier, a protective mechanism present in both marine mammals and humans, typically prevented harmful chemicals from entering the brain.
However, the discovery of LCMs in brain tissue indicated that these pollutants were capable of breaching that barrier, raising serious concerns about their potential impact on neurological health, he said.
“In brain cells they can interfere with DNA replications and cause oxidative stress, which indicates a possible direct impact on nerve functions,” He said. “This could have an adverse effect [on animals].”
Chinese white dolphins inhabit the Pearl River Delta in the northern South China Sea.
Green groups have reported that the local dolphin population in Hong Kong has declined by 76 per cent over the past two decades, with only about 2,000 to 2,500 remaining in the broader region, threatened by habitat loss and water pollution.
LCM pollutants might have leaked into the ocean from electronic waste at landfills years ago, He said. The particles can also stick to dust, enter sewage or waste-watering plants and eventually flow into the sea.
In a 2022 study, He found the highest concentrations of LCMs in sediments in the western waters of Victoria Harbour in Hong Kong and the estuary area.
“Hong Kong is small and densely populated, but people use a large number of smartphones, monitors and commercial screens,” He said. “These devices continuously release such chemicals, most of which end up in wastewater treatment plants and are eventually discharged into the ocean.”
The toxic waste had also been detected in scallops, shrimps and fish, all part of the natural diet of dolphins and porpoises, suggesting that dietary intake might be one possible route through which mammals absorbed these pollutants, He said.
The study, published in the Environmental Science and Technology journal, also found that some LCMs can interfere with cell cycles and cause oxidative stress reactions.
While underscoring the findings were preliminary, He said the results suggested current levels of LCMs might already be harming the health of dolphins and porpoises.
The researchers also observed that the concentration of LCMs in porpoise blubber rose between 2007 and 2015, before declining from 2017 to 2021.
This trend aligned with the emergence of light-emitting diode (LED) displays in Asia from around 2015, which gradually replaced LCDs in electronic devices.
But despite the shift, the study cautioned that existing LCD devices continue to release LCMs into the environment and pose ongoing ecological and health risks.
Hong Kong treated 24,579 tonnes of electronic waste last year, according to the Environmental Protection Department.
From 2019 to 2025, the department conducted 14,500 inspections and found 41 recycling sites involved in illegal disposal of e-waste or relevant chemical waste, resulting in 210 prosecutions during the period, the department said.
The department said stringent enforcement action will be taken against any contraventions of the law.
Since 2018, Hong Kong has implemented a producer responsibility scheme on waste electrical and electronic equipment to curb illegal disposal of e-waste into landfill, including televisions, computers and monitors.
But smartphones and other screen-bearing electronics are not currently regulated.
To mitigate further damage, He called for tougher regulatory measures and urged residents to reduce e-waste to help safeguard ecological and human health.
“The more smartphones one has, the more electronic waste is generated – and the more pollutant chemicals end up in the environment,” he said.
Courtesy: www.scmp.com
