Monday, April 20, 2026

E-cigarette devices expose users to toxic metals, UTS study finds

University of Technology Sydney

Vaping is largely believed to be a safer alternative to cigarettes, but new research shows that vaping devices can deliver toxic metals directly into lung tissue.

A study published in Analytical and Bioanalytical Chemistry by University of Technology Sydney (UTS) researchers showed that even short‑term vaping at exposure levels below typical daily human use resulted in measurable accumulation of toxic metals in lung tissue – including lead, copper and nickel.

Lead researcher Dr Dayanne Bordin, a lecturer in analytical chemistry, said the pre-clinical study provides the first evidence that e-cigarette aerosols include metal-containing (organometallic) species, including those associated with tin and mercury – forms that are often more bioavailable and biologically reactive than inorganic metals.

“From a risk perspective, the findings reveal under‑recognised hazards associated with vaping,” she said. “Metal emissions and their biological effects are rarely incorporated into current safety assessments or public understanding. Unlike cigarettes, which are a relatively consistent products, e-cigarettes and devices are often manufactured with poor quality control involving materials and components with unknown toxicological relevance.

“The metal profiles observed are consistent with emissions from heating coils and electrical components, identifying the device itself as a critical source of exposure and highlighting important gaps in how vaping risks are evaluated.”

Dr Bordin explains this is important because many people believe vaping carries less risk than conventional cigarettes. This perceived reduction in harm, along with misleading marketing campaigns, has contributed to the rapid uptake of e-cigarettes globally, particularly among younger demographics. In Australia, for example, e-cigarette use among young adults increased from 5.3% in 2019 to over 21% in 2023, with a similar rise in adolescents.

“Our findings challenge the assumption that e-cigarettes are safer and shows how critical it is to review current vaping regulations, which should be expanded to include device-derived emissions, not just e-liquid composition,” she said.

“Vaping can deliver toxic metals directly into the lungs, even after short-term use. This information is important for anyone considering vaping, especially young people, because these metal exposures are largely invisible and rarely discussed.

“Specifically, there is a need for standards and routine testing of metal and organometallic emissions from e-cigarettes, particularly from heating coils and internal components,” said Dr Bordin.

“The results also support updating risk assessment frameworks and public health guidance to incorporate metal exposure and bioaccumulation and improving consumer awareness around these previously unrecognised risks.”

Journal

Analytical and Bioanalytical Chemistry

DOI

10.1007/s00216-026-06487-1

Method of Research

Observational study

Subject of Research

Animals

Article Title

Analytical investigation of metal distribution from e-cigarette aerosols to lung deposition using multi-platform mass spectrometry

Article Publication Date

16-Apr-2026

Hong Kong’s waters at risk from over-the-counter (OTC) drug pollution

KeAi Communications Co., Ltd.

image:
A novel holistic paradigm for effective control of priority pharmaceuticals in complex river-estuary continuums.
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Credit: City University of Hong Kong

A recent study of Hong Kong's river and estuary systems has uncovered an overlooked major source of water pollution: common over-the-counter (OTC) drugs. Researchers from City University of Hong Kong (CityUHK) found that accessible, everyday OTC drugs, such as painkillers, antihistamines, and caffeine, accounted for up to 85% of pharmaceutical pollution in these waters during the wet season—far outpacing prescription-only medicines.

The study was led by Professor Kenneth Mei-Yee Leung, Director of the State Key Laboratory of Marine Environmental Health (SKLMEH), Chair Professor of Environmental Toxicology and Chemistry, and Associate Dean of Science College at CityUHK, in collaboration with the Guangdong Research Institute of Water Resources and Hydropower at Guangzhou in China.

"We often assume that complex or restricted prescription medications pose the greatest environmental risk, but our findings shine a new light on everyday household medicines," says Professor Kenneth Leung. "Because OTC drugs are easily accessible and continuously consumed, they act as 'pseudo-persistent' pollutants. Even if they break down easily, our constant use means they are always present in our aquatic ecosystems."

Pharmaceuticals tend to be mobile in water due to their molecular properties, allowing them to transport through river networks and enter the ocean via estuaries, posing further threats to marine ecosystems. In fact, it is well known that pharmaceuticals are present in rivers, estuaries, and coastal waters worldwide.

"Pharmaceutical pollution is not a local pollution issue at a specific site. Hence, we should adopt a river-estuary-sea perspective to prioritize pollutants for control and management," Leung adds.

Notably, existing site-specific risk assessments lack a macroscopic perspective, making it difficult to distinguish widespread ecological threats from localized contamination. To address this concern, the research team introduced a newly developed paradigm that could advance the risk assessment.

"Our approach integrates the river/estuary-to-sea transport trajectory modeling with consideration of persistence, mobility, and toxicity (PMT) of the pharmaceutical pollutant and thus the results can better evaluate and prioritize pharmaceuticals for risk management," explains Leung.

They team found that 80% of the investigated pharmaceuticals met the criteria for being PMT pollutants in water environments. Caffeine, paracetamol, cetirizine, cimetidine, sitagliptin, and fexofenadine were identified as priority pollutants for control in the river-estuary system of Hong Kong, exhibiting a greater potential to harm sensitive marine habitats of the endangered Indo-Pacific humpback dolphin. Among those, the top four pharmaceuticals with the highest risks were all OTC drugs.

By pinpointing high-priority pharmaceuticals and the rivers that contribute most to their spread, the team suggests that targeted interventions, such as upgrading sewage treatment and installing stormwater retention tanks along major discharge rivers, could effectively reduce their emissions into the sea.

"Raising public awareness is also essential," says Leung. "Residents should return unwanted or expired medications for proper disposal rather than throwing them away or flushing them. Clearer government guidance on safe drug disposal is urgently needed."

Measurement of water quality parameters

Water sampling from Shing Mun River, Hong Kong

Credit

City University of Hong Kong

Contact the author: Kenneth Mei-Yee Leung, State Key Laboratory of Marine Environmental Health and Department of Chemistry, City University of Hong Kong, Hong Kong, China, kmyleung@cityu.edu.hk

The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).