Accurate risk assessment of low dose radiation exposure requires individuals who were exposed at an early age and had no other medical conditions. This would also ensure that biological material can be obtained for molecular epidemiological studies at later time points in the individuals' life. The DARK.RISK (Studies on a cohort of Serbian children exposed to x-irradiation to determine the contribution of the non-coding genome to susceptibility at low doses) project successfully established the Serbian Tinea Capitis Cohort to study the later effects of low-dose radiation exposure. Over 25 000 individuals who were exposed as children to X-irradiation of the head to treat fungal infection of the scalp have been enrolled in this cohort. Project researchers created a digital registry that links exposure data with government records and medical databases of over 9 000 people. Out of these, more than a 1 000 have given permission to access their data and agreed to provide biological material. The DARK.RISK team developed and validated standard operating protocols for the collection, storage and distribution of biological samples to find novel radiation biomarkers. Researchers came up with an innovative approach for biomarker identification using non-coding RNA and microRNA levels. They successfully mapped the non-coding transcriptome responses to 20mGy and 100mGy low dose radiation exposures. As a result, RNAs such as SMAD5-AS1 and miR34 were identified as potential radiation biomarkers for individual exposure response and outcome assessment. Current radiation protection legislation does not account for differences in individual susceptibility or the possible non-linearity of the dose response curve. In line with MELODI objectives, DARK.RISK has addressed these issues through the establishment of the Serbian Cohort of Tinea Capitis Children. Further molecular epidemiological studies on the use of radiation biomarkers could help optimise radiation protection legislation through a robust evidence base.
Low-dose radiation, biomarker, molecular epidemiology, DARK.RISK, Serbian Tinea Capitis Cohort