Low-dose Ionizing Radiation Research The Relationship Between The Risk Of Cataracts

Objective:To study the relationship between long-term low-dose ionizing radiation exposure and the risks.of cataracts.Methods:Taking radiation workers and residents living in Guangdong Yangjiang high background radiation area and control area whose External irradiation dose is comparable as the research object, information of risk factors about cataracts was collected through questionnaire investigation, cataracts were examined using slit-lamp microscope, and put the survey datum into statistical analysis.Results:Taking residents living in Guangdong Yangjiang area as the research objects,with the gender, age, smoking, drinking adjusted,50～100mSv,100-200mSv group,200mSv group show risks of cataracts with the OR values1.58(95%CI:0.98～2.56),1.06(95%CI:0.72～1.56) and2.31(95%CI:1.21～4.42) respectively compared with the control group (<50mSv),the200mSv group has statistical significance; the risks for cortical opacities are1.40(95%CI:0.74～2.63),1.66(95%CI:0.96～2.90) and1.99(95%CI:1.03～3.85) respectively, the200mSv group has statistical significance; the risk for nuclear opacities are1.76(95%CI:1.10～2.84),0.91(95%CI:0.62～1.34) and2.04(95%CI:1.11-3.73) respectively,50-100mSv group and200mSv group show statistical significance; the risks for posterior subcapsular opacities are3.93(95%CI:0.42～36.76),11.89(95%CI:1.49～95.03) and9.63(95%Cl:1.06～87.17) respectively,100-200mSv group,200-mSv group show statistical significance. Further analysis showed that the cumulative dose has no significant correlation with the nuclear opacities (P>0.05), and significant correlation with the cortical opacities and posterior subcapsular opacities with a linear trend (P<0.05), the risk for cortical and posterior subcapsular opacities increased30%and80%respectively with the exposure dose increased per100mSv.Combined analysis results of radiation workers through occupation health examination in Sichuan, Henan, Jiangsu, Guangdong, Shandong Province showed that compared with the radioactive diagnosis and treatment of staff with the gender, age, length of service factors adjusted,workers engaged in nuclear medicine, and interventional radiology had higher risks of eye lens opacities, and there was a statistical difference, OR values were1.81(95%CI:1.01～3.26),1.49(95%CI:1.01～2.18) respectively, industrial application workers and logging workers show no significant difference,the OR values were1.07(95%CI:0.80-1.44) and1.54(95%CI:0.42-5.63) respectively.Compared with the radiation workers in class3hospitals, radiation workers in lower class hospitals suffer increased risks of eye lens opacities, the OR value was2.21(95%CI:1.50～3.26).The location of eye lens opacities is analyzed according to the examination datum about the radiation workers in Henan Province which are more standardized and complete.The results showed that compared with the radioactive diagnosis and treatment workers with the gender, age, length of service adjusted,the OR values for eye lens opacities were1.89(95%CI:0.97～3.71),0.82(95%CI:0.42～1.59),0.90(95%CI:0.45～1.82) for the workers engaged in nuclear medicine,interventional radiology, industrial application respectively; the OR values for cortical opacities were1.99(95%CI:0.72～5.48),0.64(95%CI:0.21～1.93),0.65(95%CI:0.18-2.36); the OR values for nuclear opacities were0.76(95%CI:0.17～3.31),0.79(95%CI:0.26-2.38),0.75(95%CI:0.24～2.40); the OR values for posterior subcapsular opacities were2.66(95%CI:1.08～6.56),1.88(95%CI:0.79～4.44),1.51(95%CI:0.56-4.08).Workers engaged in nuclear medicine have higher risks for posterior subcapsular opacities than the workers engaged in radioactive diagnosis and treatment (P<0.05), workers engaged in interventional radiology have higher risks also,but the difference is not significant(P<0.05).Conclusion:Long-term low-dose ionizing radiation exposure will probably increase the risks of cortical opacities and posterior subcapsular opacities for residents. According to the estimation results of the residents living in Yangjiang high background area who suffered long-term low-dose radiation, the risk for cortical and posterior subcapsular opacities increased30%and80%respectively with the exposure dose increased per100mSv. Long-term working in nuclear medicine and interventional radiology will probably increase the risks of eye lens opacities especially the posterior subcapsular opacities which is considered having close relationship with the radiation. This point out that occupation health protection should be further strengthened for the workers engaged in nuclear medicine and interventional radiology in hospitals.