Investigating the chemical weathering of erionite.

Erionite is a naturally occurring fibrous zeolite linked to malignant mesothelioma and lung cancer that was first identified in Cappadocia, Turkey, where construction using erionite-rich rocks caused widespread exposure and elevated disease incidence. The pathological effects of erionite inhalation resemble those of asbestos fibres, chronic inflammation, and tumorigenesis due to prolonged lung retention, identifying the need for further study of this hazardous mineral dust.

 

While the environmental weathering of asbestos fibres and its impact on toxicity are well documented, the effects of chemical weathering on erionite remain poorly understood. Addressing this knowledge gap is crucial, given erionite’s occurrence  in many countries (e.g. the USA, Italy and New Zealand) and the likelihood of human exposure from natural and anthropogenic activities. This research investigates factors affecting the kinetics of chemical erionite weathering and how it modifies erionite’s structural and chemical properties, with potential implications for its toxicity.

 

We conducted batch dissolution experiments simulating natural weathering processes to examine changes in surface chemistry, morphology, and fibre reactivity, particularly free radical generation - a key mechanism of toxicity. The experimental design included dissolution over a range of pH values and incubation periods, with the addition of salts to maintain consistent ionic strength. Additionally, ligand treatments were included to understand the role of their presence in fibre dissolution and the behaviour of metal ions within erionite’s aluminosilicate structure. Preliminary findings indicate that weathering alters erionite’s surface properties, potentially influencing its reactivity and toxicity. This work contributes to understanding erionite’s environmental behaviour and public health implications, supporting a multidisciplinary approach to managing risks associated with hazardous mineral dusts.