Individual dose monitoring and registry for radiation workers plays a significant role in ionizing radiation protection and occupational health management. Since the nationwide implementation of monitoring from the 1980s, individual dose monitoring for radiation workers in China has been going on nearly 30 years, which is of significance in radiation protection optimization, and occupational health and protection for radiation workers. In order to improve individual dose monitoring and registry, to prevent and control occupational radiation diseases, and to help build "Healthy China" program, this paper presents the evolution of individual dose monitoring and registry in China, discusses the key points and difficulties faced, and proposes suggestions.

The Fukushima nuclear accident happened in 2011.This article introduced the recent studies about thyroid dose estimation,incidence of thyroid nodule,thyroid cyst and thyroid cancer in the children in Fukushima prefecture after the accident.The results suggested that the incidence of thyroid nodule and thyroid cyst had no significant increase.Nevertheless,the present research noted that the incidence of thyroid cancer was obviously higher than that in other areas in Japan,but high incidence may be due to the choice of the control group or the screening effect.Meanwhile,the contribution of 132Te to the thyroid dose and the incidence of thyroid cancer might not be ignored.The continuous monitoring before and after the operation of the nuclear power plant and the health evaculation after the accident are of importance.

Objective To introduce the general international method for estimation of lifetime risk of developed cancer,and to estimate the lifetime risk baseline values of several kinds of cancers related to radiation exposures in China.Methods The risk estimation was based on the data from Chinese Cancer Registry Annual Report (2010) and China Population & Employment Statistics Yearbook (2009),and made according to the method previously published by National Cancer Institute (NCI) in USA.Results The lifetime risk of all cancer in China in 2007 was estimated to be 27.77％,that of lung cancer 5.96％,that of breast cancer for female 3.34％,that of all leukemia 0.14％,that of thyroid cancer 0.37％.The lifetime risks of all cancer were estimated to be 32.74％ for males and 24.73％ for females,and that was 36.47％ for urban residents and 26.79％ for rural people.Conclusions The lifetime risk of all cancer for males in 2007 was about 1.25 times as much as that for females.The value of all cancer for urban residents was about 1.35 times as much as that for rural residents.The lifetime risk of developed cancers in 2007 in China is lower than that in the developed countries,such as Japan.

Objective To provide the dose information from the epidemiological cohort established in 1980 in Jiangsu province using normalized workload method,and to estimate cumulative skin dose to medical diagnostic X-ray workers based on personal dosimeter were worn as members of the epidemiologicat cohort.Methods Data for fixed cohort members of X-ray exposure history from 1950 to June 2011 were collected.According to correction factors such as examination types and protection conditions,exposure doses from 1950s to June of 2011 were estimated through a Visual Basic language program.Results Average annual doses vary significantly between during different time periods:10.1 (6.1-12.3) mGy/year during 1950-1965,3.5 (2.1-5.4) mGy/year for 1966-1984 and 1.3 (0.9-1.9) mGy/year during 1985-2011,respectively.Conclusions Average annual doses received by 3 961 medical diagnostic X-ray workers during different time periods in this investigation are nearly consistent with the results reported previously and show a roughly similar trend.

Objective To investigate the leukemia incidence among residents in the vicinity area of a nuclear installation.Methods The data were collected by the retrospective survey.Diagnosis is based on the medical records in all the relevant hospitals.The study area was those residential areas within 10 km of radium surrounding the installation.All residents who had lived in the study area for six months and over were recruited into the study group.Results The survey ascertained 643 newly diagnosed leukemia cases in the study area during 1997 to 2007.The crude rate was 2.51/100,000,and its standardized rate to national population structure was 2.53/100,000.The incidence rate in the study area was slightly lower than that in the whole city.No increase trend was detected during the period.Conclusions No significant difference of the leukemia incidence rate was found between the vicinity area of the nuclear installation and the whole city.

Objective To ascertain the frequency distribution of CT examinations in children.Method A wide range of information was collected through the radiology information system (RIS),including ID,sex,birth date,examination time,the examined part of body and other relevant ones related to children who underwent CT examinations between Jan 1,2012 and Dec 31,2012.The SAS software was used for data processing and statistical analysis.Results A total of 1 542 children underwent 1 670 examinations,of which 67％ were male.Head CT examination was the most frequent,accounting for 71.9％ of all CT examinations,and followed by the abdomen/pelvis examinations.The number of examinations of children undergoing the repetitive examination accounted for 6.4％; 51.7％ of the examinations was for trauma.The positive rate of CT examination was 51％,dependent upon the age and examined body parts to some extent.The younger patients had lower positive rate,and the positive rate of head CT examination was lower than those in other parts.Conclusions To reduce the possible cancer risk to be induced by the ionizing radiation from CT,justification of CT examination should be considered for children.

Objective To explore whether low-dose occupational ionizing radiation exposure can affect the prevalence of lens opacity.Methods Annual occupational health checkup data of 1 007 radiation workers was taken from a provincial medical institution for the purpose of statistical analysis.Logistic regression analysis was used to estimate occupational exposure odds ratios (OR) of lens opacity,adjusted for age,gender and length of service.Eye lens opacity was grouped into cortical,nuclear and posterior subcapsular opacity according to the position of the opacity occurrence site.Opacity occurred in any one of the both eye lens was recorded as turbidity.Results Only 730 cases coupled with complete information could be used in the statistical analysis.The rate of lens opacity for all the radiation workers was 10.27％.The rates of lens opacity by exposure group were estimated to be 9.07％ for radiation diagnosis and therapy group,11.11％ for intervention group,18.18％ for nuclear medicine group,and 9.33％ for industrial application group,respectively.Compared with those in the radiation diagnosis and therapy group,the workers engaged in intervention medicine,or nuclear medicine,were more likely to suffer from the lens opacity in posterior subcapsular position.The OR and its 95％ confidence intervals were 3.00 (1.23-7.33),4.12 (1.68-10.11) for the workers in intervention medicine or nuclear medicine group.Conclusions Medical radiation workers,who were exposed to long-term low-dose of ionizing radiation,especially those who engaged in intervention or nuclear medicine,were at significantly higher risk to develop lens opacity.

Objective To study the relationship between the risk of malignant tumor and occupational radiation factor among medical diagnostic X-ray workers in Jiangsu province.Methods The retrospective and prospective cohort studies were adopted to investigate the incidence of cancer.Eligible medical diagnostic X-ray workers from the department of radiology in hospitals were selected and assigned into exposure group,while other medical workers from the departments of Internal Medicine,Ear-NoseThroat (ENT) or Pediatrics who attended work at the same period in the same hospital but not engaged in radiation work were regarded as control group during 1950-2011 in Jiangsu province.We calculated the total person-year and analyzed the relative risk (RR) of malignant tumor using Poisson regression model.Results 7 703 participants (3 961 in exposed group and 3 742 in unexposed group) were recruited and followed up,with a total of 315 309 person years and the lost follow-up rate was 6.92％ (533/7 703).During the follow up period,a total of 819 tumor cases were identified (771 were malignant tumors).We found the significant relationship between the risk of malignant tumor and occupational radiation factor,and the RR of solid cancer and total malignant tumor were 1.31 (95％ CI:1.11-1.55) and 1.33 (95％ CI:1.13-1.57),respectively.In addition,the risk of lung cancer in medical diagnostic X-ray workers was significantly higher than that in control group (RR =1.45,95％ CI:1.00-2.09).Conclusions The incidence risk of lung cancer,solid caner and total malignant tumors in medical diagnostic X-ray workers was significantly higher than that in the control group,which might be associated with occupational exposure to ionizing radiation.

Objective To continue following up the cohort members in Jiangsu province who were the largest subgroup in Chinese medical X-ray workers cohort subgroups on radiation carcinogenesis and analysis the cancer risk of medical X-ray workers which might be induced by chronic low-dose ionizing radiation between 1997 and 2011.Methods A retrospective cohort study was utilized to accumulate data.Epicure was applied to compute cumulative person years (with module of Datab) and relative risk (including 95％ CI) of malignant tumor on exposed group(with module of AMFIT) while the factors such as sex and attained-age were adjusted in the cohort members.Results The 7 708 follow-up members included 3 668 medical X-ray workers.The cumulative person-year in the cohort members was 94 651.2 (1997-2011) and its lost rate was 5.79％.During the follow-up period,441 cases had became cancer patients.The relative risk of all cancers was 1.44 (95％ CI:1.18-1.75),so was the solid cancers.Significant elevated risks of cancer were found on lung (RR =1.95,95％ CI:1.30-2.92),esophagus (RR =3.04,95％ CI:1.20-7.70),lymphoma(RR =2.24,95％ CI:0.67-7.48),leukemia(RR =1.57,95 ％ CI:0.33-7.39),throat (RR =2.47) and thyroid (RR =2.80,95 ％ CI:0.24-32.26) among medical X-ray workers.However,The RR of malignant tumors might not be associated with occupational exposure to ionizing radiation if we considered the lost factors (RR =1.2,95％ CI:0.94-1.46)Conclusions The RR of malignant tumors such as the cancer on lung,esophagus,thyroid among the medical X-ray workers in Jiangsu province were enhanced which might be associated with occupational exposure to ionizing radiation.

Purpose To develop a national registry and reporting system of individual monitoring for workers occupationally exposed to ionizing radiation.Methods In accordance with the relevant law,regulations,standards and the current health supervision practice for radiation workers in China,to ensure more effective collection of information on individual monitoring from all levels of service providers across the country and an easy query and analysis of the collected information for both service providers and administrative institutions,the register consisted of an offline-system and a web-based information system.The off-line system consisted of 8 tables,which could easily make annual and period monitoring reports,and upload individual monitoring data in compressed and encrypted format.Web-based system consisted of 6 modules,could easily make S customized tabulations of monitoring data and show 2 trend figures.SSLVPN secure remote access was used in the system.Arranged by the Ministry of Health,training courses provided to all individual monitoring service providers and provincial administrative institutions.Results A new and individual-based national register and reporting system of individual monitoring for workers occupationally exposed to ionizing radiation was successfully developed,and would be officially run soon.Conclusions The establishment and running of the register would be great improvement on the national radiological health reports and produce a far-reaching impact on the individual monitoring in China.