Abnormalities Of Sperms Associated With Chemical Exposure

Chemicals and radiations are known to cause DNA damage, but does chemical exposure also affect the wellness of your sperms? A recent research has established a strong association between the mutations of sex chromosomes after profound exposure to certain environmental factors. Based on the results of the cross-sectional study, significant exposure to chemicals such as organochloride (dichlorodiphenyldicloroethylene or p,p’-DDE) and PCB (polychlorinated biphenyls) can put people at risk of developing abnormalities of sex chromosomes; particularly of sperms.

How Does Chemical Exposure Affect The Wellness Of Sperms?

Most naturally occurring as well as man-produced compounds are lipophilic in nature and can easily disrupt the normal functioning of endocrine system. These organochlorines are also capable of crossing the natural barrier between the blood and testis; thereby concentrating in the testicular tissue to directly interfere with spermatogenesis (or sperm production). The findings of the study were reported in the peer-reviewed journal called Environmental Health Perspectives.

Details Of The Study On Chemical Exposure

As part of this study, investigators selected 192 men with age ranging between 20 and 54 years. The selected participants were then subjected to evaluation of infertility at the Massachusetts General Hospital Fertility Centre from the year 2000 to 2003. The eligibility criteria for the subjects was based on the contribution of sample of sperm for FISH analysis (fluorescence in situ hybridization) along with random blood sampling for analysis. The collected non-fasting samples of blood were tested for 57 different congeners of PCB and p,p’-DDE. For the analysis of sperms, three individual aspects were used:

• Sperm imaging

• Nuclei scoring
• FISH

The FISH analysis was used to assess the chromosomes Y and X. The evaluation of chromosome 18 was considered as constantand control.

The research team speculated that even when chromosomal abnormalities account for numerous reproductive and fertility issues, the risk imposed by other factors should not be overlooked. For assessing such influencing parameters the team of researchers came up with a strategy that could help in underlying the association between chemical exposure to p,p’-DDE and the abnormalities of sex chromosomes.

Upon evaluating the chemical exposure, the researchers noted a non-linear curve of the dose response. The increase in disomy was more evident in the first two quartiles of exposure to chemical. However, the research team did not find the disomy to increase or show additional progression in the other quartiles.

The researchers noted the findings to be similar in case of PCBs as well. The disomy increase was more prominent in the first two quartiles in contrast to the remaining quartiles.

Results Of The Study

The researchers believed that men who presents with increased p,p’-DDE serum levels are at significantly high risk of developing sperm abnormalities such as high levels of increased disomy of sex chromosome in XY and XX chromosomes. However, high levels of serum PCB have been correlated with an evident decline in the XX chromosome disomy rate.

Since the sample of the study was drawn from sub-fertile couples who were in search of infertility evaluation, the team of investigators proposed that findings may be different in case of general population. Nevertheless, the researchers believe that there’s no authentic evidence to claim that general population of men may respond differently to the investigated chemicals in comparison to the men who participated in the study. This also means the results and inferences are also applicable for the general population.

References

• McAuliffe, M. E., Williams, P. L., Korrick, S. A., Altshul, L. M., & Perry, M. J. (2012). Environmental exposure to polychlorinated biphenyls and p, p-DDE and sperm sex-chromosome disomy. Environmental Health Perspectives, 120(4), 535.
• Govarts, E., Nieuwenhuijsen, M., Schoeters, G., Ballester, F., Bloemen, K., De Boer, M., ... & Legler, J. (2012). Birth weight and prenatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE): a meta-analysis within 12 European Birth Cohorts. Environmental health perspectives, 120(2), 162.