Liquid Crystal Monomers Released from LCD Displays Accumulate in Endangered Marine Cetaceans Triggering Health Concerns

Liquid crystal monomers (LCMs), critical substances of
liquid crystal
displays in consumer electronics, are persistent pollutants, posing
potential threats to marine ecosystems. Despite their bioaccumulative
potential, their occurrence and possible biological impacts on marine
megafauna remain understudied. We investigated LCM occurrence in Indo-Pacific
humpback dolphins (Sousa chinensis) and finless porpoises
(Neophocaena phocaenoides) collected from the South
China Sea (2007–2021) and assessed their toxicity through in vitro assays using established dolphin cell lines. By
employing robust source-tracing methodologies, we provide the first
evidence that LCMs from household electronics and coastal e-waste
accumulate in cetacean tissues, including blubber, muscle, and, critically,
brain tissues, demonstrating blood–brain barrier penetration,
a previously undocumented phenomenon of LCMs in mammalian wildlife.
The temporal trend of LCM burden in porpoise blubber is correlated
with shifts in global liquid crystal display production. Transcriptomic
profiling revealed LCM-induced DNA damage, cell cycle arrest, and
impaired cell division in cetacean cells. These 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. By bridging critical
gaps among everyday electronics, LCM contamination, and marine conservation,
this study highlights the need for urgent regulatory actions and improved
e-waste governance to mitigate ecological and public health risks.