A study by the City University of Hong Kong revealed that chemicals present in household electronic waste accumulate in dolphin and porpoise tissues. The research was published in Environmental Science & Technology and raised environmental alarms.
In particular, scientists identified liquid crystal monomers (LCM), essential compounds in computer, television, and smartphone screens. These chemicals, considered persistent pollutants, were found in fat, muscle, and brain of the analyzed animals.
Furthermore, the results show that LCMs can cross the blood-brain barrier. Therefore, their presence in the brain poses potential risks to the neurological health of threatened marine species.
Electronic waste in dolphins and porpoises
LCMs allow controlling the passage of light in electronic devices, ensuring sharp images on everyday screens. However, due to their mass production, these substances disperse into indoor air, dust, and wastewater.
Over time, these residues reach coastal environments. Consequently, they integrate into marine food chains, affecting organisms that are then consumed by top predators.
To evaluate this process, researchers analyzed tissues of Indo-Pacific humpback dolphins and finless porpoises collected between 2007 and 2021 in the South China Sea. Samples of fat, muscle, liver, kidney, and brain were examined for 62 different LCMs.
The analysis determined that four compounds concentrated most of the detected contamination. Additionally, previous studies had identified similar LCMs in fish and invertebrates that are part of these mammals’ diet, supporting the hypothesis of bioaccumulation through feeding.
Contaminants in the brain and ecological risks
Although fat showed the highest concentrations, scientists detected small amounts of LCMs in vital organs, especially in the brain. This finding suggests possible neurotoxic effects and alterations in essential biological functions.
In fact, laboratory tests with cultured dolphin cells showed that several of the most frequent compounds altered genetic activity linked to DNA repair and cell division. Consequently, these contaminants could compromise the health and reproduction of marine populations.
Moreover, LCM levels varied over time. They increased during the expansion of liquid crystal screens and decreased when the industry shifted towards LED technologies, demonstrating the direct relationship between technological consumption and environmental pressure.
How does electronic waste harm terrestrial and aquatic animals?
The electronic waste not only affects cetaceans. In terrestrial environments, heavy metals and organic compounds released in landfills can infiltrate soils and groundwater, poisoning birds, mammals, and reptiles.
Similarly, in aquatic ecosystems, these substances adhere to sediments or are ingested by invertebrates. Thus, they ascend the food chain to reach fish and large predators, where they progressively concentrate.
Therefore, the poor management of electronic devices in disuse amplifies a global problem. Reducing, recycling, and regulating these wastes is key to protecting biodiversity and preventing the chemicals that sustain digital life from continuing to infiltrate ecosystems.
