The association of exposure to some heavy metals and neurodegenerative diseases in Armenia

Abstract

Introduction According to research, more than 50 million people worldwide suffer from neurodegenerative diseases (NDDs). In Armenia, NDDs are becoming increasingly significant due to population aging (individuals aged 65+ in 2025 is 14.4%), regional environmental risks - particularly heavy metal (HM) pollution, underdiagnosis (especially of Alzheimer’s disease), and the absence of a national registry, which complicates healthcare planning and research. According to the literature, Fe, Zn, Cu, Cd, Pb, Hg, Al, As, and Mn are considered possible risk factors for the development of NDDs. In Armenia, non-ferrous metal mining is a leading economic sector and also a major polluter. Therefore, our research aims to identify these metals in environmental samples and biological material (hair). Aim of the study To investigate the content of certain HMs in environmental samples: arable land, street/house dust, and the incidence of NDDs in Armenia. Material and methods Research type: mixed case-control and ecological (correlational), methods: hygienic, chemical analytical, epidemiological, statistical. The concentration of heavy metals in all samples will be determined using an Agilent 4210-MPAES atomic emission spectrometer. All data will be stored in specially created databases and encoded. For association determination, the presence and content of HMs will also be assessed in the hair of individuals with NDDs, namely Alzheimer's disease (AD) and Parkinson's disease (PD), as well as in hair samples from a control group. To achieve this objective, the following tasks will be completed: (1) Determine the presence and levels of HMs in selected samples. (2) Study the incidence rate and structure of NDDs in the study regions. (3) Conduct a comparative analysis of the content of certain HMs in environmental samples. (4) Comparative analysis of the prevalence of NDDs in the studied regions. (5) Study of the possible relationship between actual concentrations of HMs in environmental objects and the prevalence of NDDs. Results Regional differences in heavy metal contamination are expected, with higher levels potentially associated with increased prevalence of AD and PD and elevated metal concentrations in patients’ hair samples. Exposure to heavy metals may contribute to oxidative stress, neuroinflammation, mitochondrial dysfunction, and abnormal protein aggregation, which are considered important mechanisms in the pathogenesis of neurodegenerative diseases. Conclusion The findings may support a possible link between environmental heavy metal exposure and neurodegenerative diseases in Armenia, providing a basis for preventive public health strategies and further research.