Semen abnormalities, sperm DNA damage and global hypermethylation in health workers occupationally exposed to ionizing radiation.
BACKGROUND
Cytogenetic studies have demonstrated that low levels of chronic radiation exposure can potentially increase the frequency of chromosomal aberrations and aneuploidy in somatic cells. Epidemiological studies have shown that health workers occupationally exposed to ionizing radiation bear an increased risk of hematological malignancies.


OBJECTIVE
To find the influence of occupational radiation exposure on semen characteristics, including genetic and epigenetic integrity of spermatozoa in a chronically exposed population.


METHODS
This cross sectional study included 134 male volunteers of which 83 were occupationally exposed to ionizing radiation and 51 were non-exposed control subjects. Semen characteristics, sperm DNA fragmentation, aneuploidy and incidence of global hypermethylation in the spermatozoa were determined and compared between the non-exposed and the exposed group.


RESULTS
Direct comparison of the semen characteristics between the non-exposed and the exposed population revealed significant differences in motility characteristics, viability, and morphological abnormalities (P<0.05-0.0001). Although, the level of sperm DNA fragmentation was significantly higher in the exposed group as compared to the non-exposed group (P<0.05-0.0001), the incidence of sperm aneuploidy was not statistically different between the two groups. However, a significant number of hypermethylated spermatozoa were observed in the exposed group in comparison to non-exposed group (P<0.05).


CONCLUSIONS
We provide the first evidence on the detrimental effects of occupational radiation exposure on functional, genetic and epigenetic integrity of sperm in health workers. However, further studies are required to confirm the potential detrimental effects of ionizing radiation in these subjects.
Division of Clinical Embryology, Department of Obstetrics & Gynecology, Kasturba Medical College, Manipal University, Manipal, India.
Dayanidhi
D
Kumar
Sujith Raj
SR
Salian
Guruprasad
G
Kalthur
Shubhashree
S
Uppangala
Sandhya
S
Kumari
Srinivas
S
Challapalli
Srinidhi Gururajarao
SG
Chandraguthi
Hanumanthappa
H
Krishnamurthy
Navya
N
Jain
Pratap
P
Kumar
Satish Kumar
SK
Adiga
D000328:Adult; D020552:Comet Assay; D004249:DNA Damage / Q000528:radiation effects*; D053938:DNA Fragmentation; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects; D011839:Radiation, Ionizing; D012661:Semen / Q000166:cytology*; D013094:Spermatozoa / Q000473:pathology*