Heavy metals in the volcanic environment and thyroid cancer

Area of Science:

• Environmental Health
• Oncology
• Toxicology

Background:

• Global thyroid cancer incidence has significantly increased, exceeding other cancers.
• While overdiagnosis plays a role, evidence suggests a true increase possibly linked to environmental factors.
• Volcanic regions exhibit a marked rise in thyroid cancer, making them valuable models for studying environmental influences.

Purpose of the Study:

• To investigate the role of environmental factors, specifically heavy metals, in the increased incidence of thyroid cancer.
• To explore the potential mechanisms by which heavy metals contribute to thyroid carcinogenesis.
• To highlight the need for further research on heavy metal accumulation and effects in the human thyroid.

Main Methods:

• Documenting non-anthropogenic heavy metal pollution in volcanic areas (e.g., Mt. Etna).
• Assessing heavy metal biocontamination in residents through urine and scalp hair analysis.
• Reviewing existing literature on heavy metal effects on the thyroid, focusing on endocrine disruption and carcinogenicity.

Main Results:

• Volcanic areas show documented non-anthropogenic heavy metal pollution affecting soil, water, and atmosphere.
• Residents in these areas exhibit higher heavy metal levels compared to non-volcanic regions, indicating bioaccumulation.
• Heavy metals can act as endocrine disruptors and carcinogens, with potential synergistic effects from mixtures and hormesis at low concentrations.

Conclusions:

• Environmental heavy metal pollution, particularly in volcanic regions, is a potential contributor to the rising incidence of thyroid cancer.
• The effects of heavy metals on the human thyroid, including accumulation, metabolism, and carcinogenic activity, are poorly understood.
• Further investigation into heavy metal speciation, dosage, and thyroid-specific effects is crucial for understanding and preventing thyroid carcinogenesis.