The results are described of the study carried out with the aim of assessing doses received by the Cuban population due to the external exposure to environmental radiation sources. Contributions of cosmic radiation's ionising and indirectly ionising components to these doses, as well as the fraction resulting from terrestrial radiation, were also assessed as part of this study. Measurements made enabled us to estimate representative effective average doses received by the Cuban population from external exposure to cosmic and terrestrial radiation. Both outdoor and indoor permanency were taken into account for this estimate as well as the distribution of the Cuban population by altitude. The average representative dose due to cosmic radiation was estimated to be 298 +/- 17 microSv per year, while the dose received by terrestrial radiation represented 180 +/- 14 microSv per year, for a total annual dose of 78 +/- 20 microSv. These values are within the range of those reported throughout the world by other authors.

Parkinson's Disease (PD) is a progressive neurodegenerative disorder affecting 2% of the population over 60 years old, yet the exact molecular mechanism underlying its pathogenesis remains elusive. PD is a multifactorial disease with genetic and environmental factors intricately associated.Recently, epigenetic mechanisms have been recognized as potential mediators of environmental factors participating in the pathogenesis of PD. Epigenetics refer to the heritable changes in gene expression that do not involve changes to the underlying DNA sequence. Altered epigenetic mechanisms have been attributed to PD, Alzheimer's and Huntington's disease. Several studies have shown that DNA methylation, histone modifications and non-coding RNAs mechanisms contribute to the pathogenesis of PD. Accumulation of toxic metals such as manganese and iron, due to abnormal environmental exposure or increased dietary intake, can impact varied components of the epigenetic machinery through free radical formation.Current pharmacological agents only provide symptomatic relief, of which levodopa still remains the gold standard. However, drugs that halt or delay progression of PD are still lacking. In recent years, there has been considerable progress in the development of epigenetic drugs as a novel therapeutic modality in the management of PD. Cell replacement therapy is a promising avenue for the treatment of PD with scientific research making great progress in the development of Induced Pluripotent Stem Cells (iPSCs) to produce midbrain dopamine phenotypes. With direct access to the neurons that are affected in PD, the pace of discovery should speed up and the cure for PD should become an attainable goal.