Liquid Crystal Monomers: An Emerging Pollutant Closely Associated with E-waste Waste
LCM1
Figure 1: Release mechanism of LCMs from cell phones (ES&T 57, 10319-10330)

Involved Member: Dr. Henry Yuhe HE

Dr. He’s team has conducted a series of groundbreaking studies on an emerging pollutant related to e-waste – Liquid Crystal Monomers (LCMs). Dr. He's recent series of research systematically revealed, for the first time, the mechanisms by which these emerging pollutants are released from e-devices (ES&T 57, 10319-10330). The studies also investigated their accumulation in indoor environments and potential health risks to humans (EI 180, 108212; STOTEN 908, 168328), their migration into the marine environment through landfill leachate (JHM 423(PtB), 127146), and municipal wastewater discharge (WR 247, 120784). Additionally, the distribution and preliminary risk assessment of LCMs in the Pearl River Estuary region were explored (JHM 437, 129377). Importantly, Dr. He's research proposed for the first time that the use of electronic products indoors releases LCMs, which are then discharged into the marine environment through municipal sewage networks, potentially serving as a significant source of LCMs pollutants in the marine environment. It is estimated that approximately 3 kilograms of LCMs are discharged into the surrounding sea areas annually through treated municipal wastewater in Hong Kong, leading to the widespread distribution of LCMs in the Pearl River Estuary and certain environmental pressures. These studies not only expand our understanding of LCMs as emerging pollutants but also draw attention to the need for reasonable regulation of such chemicals, raising public awareness of electronic waste pollution and making new contributions to the sustainable development of public health and marine environments.

LCM2
Figure 2: Discharge of LCMs through Shatin Sewage Treatment Works (WR 247, 120784)

 

LCM3
Figure 3: Widespread occurrence of LCMs in the Pearl River Estuary (JHM 437, 129377)

Reference:

Jin, Q., Yu, J., Fan, Y., Zhan, Y., Tao, D., Tang, J., He, Y.H., (2023). Release behavior of liquid crystal monomers from waste smartphone screens: occurrence, distribution, and mechanistic modeling. Environmental Science & Technology, 57(28), 10319-10330. (impact factor: 11.357)

Zhan, Y., Jin, Q., Lin, H., Tao, D., Law, L.Y., Sun, J., He, Y.H., (2023). Occurrence, behavior and fate of liquid crystal monomers in municipal wastewater. Water Research, 247, 120784. (impact factor: 12.8)

Tao, D., Jin, Q., Ruan, Y.F., Zhang, K., Jin, L., Zhan, Y., Su, G., Wu, J., Leung, K.M.Y., Lam, P.K.S., He, Y.H., (2022). Widespread occurrence of emerging E-waste contaminants - Liquid crystal monomers in sediments of the Pearl River Estuary, China. Journal of Hazardous Materials, 437, 129377. (impact factor: 13.6)