Journal of Preventive Medicine and Public Health

Volume 21(1); May 1988

Original Articles

Produsctive Years of Life Lost by Pre-prtirement Deaths in Korea.: Timothy D Baker; Korean J Prev Med. 1988;21(1):1-4.

1,646 View
19 Download

Abstract PDF: No abstract available.; Summary

Injury Control : A Challenge for Health Professionals Presented at the 39th Annual Convention of the Korean Society for Preventive Medicine November 5, 1987 Cheju-do, Korea.: Susan P Baker; Korean J Prev Med. 1988;21(1):5-9.

1,392 View
21 Download

Abstract PDF: No abstract available.; Summary

Comparision of Maternal Characteristics and Birth Weight among Five Different Categories of Medical Facility for Delivery in Taegu.: Jung Hup Song, Jung Han Park, Gui Yeon Kim, Jong Rak Kim; Korean J Prev Med. 1988;21(1):10-20.

1,747 View
19 Download

Abstract PDF: This study was conducted to compare the maternal characteristics, and birth weight of infants delivered at five different categories of medical facility in Taegu to examine the risk level of pregnant women and children by the medical facility for delivery. The study population included 1,410 pregnant women who delivered a baby at one of nine medical facilities (3 university hospitals, 2 general hospitals, 2 private clinics, 1 midwife clinic, 1 MCH center) in Taegu in April, 1987(April and May, 1987 for K university hospital). Pregnant women were interviewed to ask the age and educational level of woman, payment of medical fee, birth order, delivery method. Birth weight of infant was obtained from medical record. Mean ages of the women delivering at the university hospitals(27.5 years) and at general hospitals(26.7 years) were higher than those at midwife clinic(25.4 years) and at MCH center(26.1 years). Also, mean years of school education were higher in women of university hospitals(12.7 years) and general hospitals(12.2 years) than in women of midwife clinic(9.2 years) and MCH center (9.3 years). The percentages of women covered by the medical insurance were far greater in the university hospitals(78.1%) and general hospitals(82.9%) than in private clinics(44.3%), midwife clinic(29.1%) and MCH center (5.4%). Infants born at the MCH center were mostly the second birth (47.3%) while 56.0% to 61.7% of infants born at all the other medical facilities were the first birth more women delivering at the university hospitals had history of spontaneous abortion as well as still birth than the women delivering at the other medical facilities. The preterm birth rate (11.4%) and low birthweight incidence rates(5.8-13.0%) in university hospitals were significantly higher than those of other medical facilities. Accordingly, c-section rates showed a wide variation among the medical facilities. Study findings revealed that most of women delivering at the university hospitals and general hospitals are in the middle of or upper socio-economic class and obstetrically high risk group regardless of socioeconomic class while the women delivering at the midwife clinic and MCH center are low risk group of low socioeconomic class. Therefore, the data of a specific medical facility are highly limited in interpretation and can not be generalized.; Summary

A Follow-up Study of Fertility and Pregnancy Wastage of Women in Rural Area.: Jung Han Park, Sin Hyang Kim, Byung Yeol Chun, Gui Yeon Kim, Min Hae Yeh, Seong Eok Cho, Jae Yeon Cho; Korean J Prev Med. 1988;21(1):21-30.

1,963 View
23 Download

Abstract PDF: To measure the fertility rate and pregnancy wastage of women in rural area, 3,780 married women under 50 years old who were not sterilized either woman or husband in Gunwee county were followed up for 2 years. Seventeen Myun health workers visited these women periodically to check the status of their family planning practice and menstruation. Pregnant women were interviewed for their past obstetric history and followed up to the time of delivery. Family planning was practiced in 51.6% of the 6,826 women-years observed during the period from April 1, 1985 to March 31, 1987. Pregnancy, abortion and delivery covered 7.6% of the observed women years and family planning was not practiced in 36.5% of the women-years. When sterilized women at the beginning of the study were included, the family planning practice rate was 72.1% which was slightly higher than the national family planning practice rate. However, 28% of the women of 30-39 years old had not practiced family planning although they had 2-3 children and they used more such less effective methods as safe-period method and condom than the women of 20-29 years old. Overall pregnancy rate was 14.3 per 100 woman-years. Women of 25-29 years old had the highest pregnancy rate of 27.4 per 100 woman-years. Pregnancy wastage including spontaneous and induced abortions and still births was 22.0% of all pregnancies and it increased with the age of women; 15.8% in women less than 30 years old and 43.7% in women of 30 years and over. Women who terminated the pregnancy with induced abortion had more pregnancies, more previous induced and spontaneous abortions and shorter pregnancy interval than those women who terminated with live birth. Pregnant women terminated with a live birth had received 4.2 prenatal cares on the average. Eighty-five percent of deliveries occurred at a medical facility and 15% at home which was substantially lower home delivery rate than the other rural area of Korea. This may be due to the effects of the demonstration project for the primary health care in 1970s in Gunwee county. These findings suggest that family planning service in rural area should be strengthened by promoting the use of more effective contraceptive method among women over 30 years of age.; Summary

Knowledge and Practice of College Entrants Toward Hepatitis B.: Sung Ai Chi, Kyou Chull Chung, Jong Yoon Park; Korean J Prev Med. 1988;21(1):31-46.

1,667 View
22 Download

Abstract PDF: In order to designate a status necessary for establishment of preventive measures and guidelines of health education against hepatitis B in the course of secondary school education, knowledge and practice toward hepatitis B virus infection was surveyed by a questionnaire method on total of 4,855 college entrants in the academic year of 1987 and analyzed the data collected using IBM PC(Trigem 88-II) with SAS package program. About two percent of college entrants had past history of HBV infections not showing any difference between both sexes and geographical regions. About one third(33.7%) of total students had tested hepatitis B surface antigen(HBsAg), only 4% had tested hepatitis B surface antibody(HBsAb) and vaccination rate amounted to 24.6%, one fourth of total subjects. Both serological tests and vaccination were most commonly performed during adolescence, showing higher rates in female students than in male students. The rates also seemed to be higher in those from urban cities than those from rural cities. Students who had acquired correct knowledge that hepatitis B was infected by virus were amounted to 78.5% of college entrants, and remaining 21.5% had misunderstood that rickettsia, bacteria, fungi or parasites were casual agents. Female students were better aware of the causal agents than male students but there was no difference between places of growth. As for mode of transmission of HBV, 51.5% of male students and 47.7% of female students had correct knowledge. A very few student had known that fact that HBV was transmitted by body fluids such as tear (6.9%), nasal discharge(10.1%) and semen or vaginal secretion(19.2%) and majority(75%) of students had misunderstood that hepatitis B virus would be transmitted per os through food ingestion. Approximately one half(48.9%) of college entrants had correctly whom to be vaccinated. Approximately one half of the students knew that hepatoma(57.8%) and liver cirrhosis(57.4%) might complicate with hepatitis B virus infection, whereas 12.0% of the students responded that bronchitis was one of the complications of hepatitis B infection. In summary of the above results, we highly recommend that health education program for eradication of hepatitis B virus infection should be introduced in curricula of secondary school education in this country.; Summary

Comparision of medical care utilization between newly detected hypertensive patients and known hypertensive patients.: Byung Yool Cheon; Korean J Prev Med. 1988;21(1):47-60.

1,794 View
18 Download

Abstract PDF: The monthly ambulatory treatment days in newly detected hypertensive group and known hypertension group were analyzed. The population was identified through the records of screening examination given by Korea Medical Insurance Corporation during the period from April to July, 1986. From the records of screening examination, 11,614 hypertensive patients were identified. By random sampling, 959 patients were selected ; among them, 554 fell under the category of known hypertension group and the other 415 fell under the newly detected hypertension group. The monthly ambulatory treatment days of theses patients during the period from the April, 1985 to September, 1987 were analyzed in order to compare the exents of medical care utilization as well as to define and analyze the determinants responsible for the ambulatory treatment days between the two groups. The following results were obtained. 1) In the known hypertension group, no statistically significant changes in the ambulatory treatment days was observed after, in comparison to before, the screening examination. However, in the newly detected hypertension group the medical care utilization increased after the screening examination because of hypertension. 2) The ambulatory treatment days for hypertension of the known hypertension was statistically significant and higher than that of the newly detected hypertension group after screening examination. 3) There was no statistically significant change in the ambulatory treatment days in association with diseases other than hypertension in either group before and after the screening examination. 4) There was no statistically significant change in the ambulatory treatment days in the known hypertension group. However, the income was a statistically significant variable in the newly detected hypertension group. 5) After the screening examination, the variables determining the ambulatory treatment days were the age of the patient and the diastolic blood pressure in the known hypertension group. These variables responsible for 2.02% of the total ambulatory treatment days. In the newly detected hypertension group, the income was a statistically significant variable which was responsible for 2.10% of total ambulatory treatment days. The above results satisfied the hypothesis that there would be no significant changes in the ambulatory treatment days before and after the screening examination in the known hypertension group. Also the hypothesis that there would be no significant change in the exents of medical care utilization for the diseases other than hypertension before and after the screening examination in either group was satisfied. Also the medical care utilization was significantly higher in the known hypertension group than the newly detected hypertension group after the screening examination. This finding satisfied the hypothesis. This study was limited by the lack of considering fully the variables responsible for the clinical symptoms of hypertension as well as for the individual characteristics. Thus, the result of this study are not fully adequate to define the determinants responsible for the exents of medical care utilization. In the future studies on medical care utilization, additional variables should be considered.; Summary

Projection of Physician Manpower Supply in Korea.: Seung Hum Yu, Woo Hyun Cho, Yong Ho Lee, Byung Yool Cheon; Korean J Prev Med. 1988;21(1):61-69.

2,021 View
22 Download

Abstract PDF: In this study, the number of physicians presently living in Korea thoroughly estimated by several means and, on this bases, their productivity and level of supply were estimated. The results were as follows : First, the number of physicians who did not notify the Korea Medical Association in May 1987 were 10,110, including 4,093 emigrant physicians(40.5%), 861 military medical officers, 745 public health doctors, and 107 decreased physicians. A total of 1,330 physicians could not be identified by any effort. Second, among the 34,897 registered physicians as of May 1987, 29,933(85.8%) were residing in Korea, 4,115 physicians(11.8%) had emigrated to other countries, and 849 physicians(2.4%) were decreased. Practicing physicians defined as those in Korea who were not retired, serving in the military, or completing residencies or internships, comprised 78.6%(27,414 physicians) of the total number of registered physicians. Third, it is estimated that in the year 2000 the number of registered physicians, physicians residing in Korea, and practicing physician will be 75,040, 64,038 and 57,655, respectively and these are increases of 115.0%, 113,9%, and 110.3%, respectively, compared to 1987. Fourth, the population physician ratio will be 759 to one physician in the year 2000. Fifth, the productivity of physicians, as calculated by relative values defining the productivity of 35 to 44 year-old male physicians as 10, will increase 110.7% in the year 2000 compare to that of 1987, and this increment is almost the same level as that of physicians supply. From the results of the present analysis of physicians manpower and supply projection, it can be recognized that the development of a regular notification system is necessary in order to identify precisely the number of physicians. Also a policy a physician supply is essential in order to adjust in advance the number of physicians, otherwise there will be surplus to the medical demand.; Summary

Birth Registration Rate and Accuracy of Reported Birth Date in Rural Area.: Jung Han Park, Chang Yik Lee, Jang Rak Kim, Jung Hup Song, Min Hae Yeh, Seong Eok Cho; Korean J Prev Med. 1988;21(1):70-81.

2,048 View
21 Download

Abstract PDF: To measure the birth registration rate and the validity of birth registration data in rural area, all of the 4,014 married women under 49 years of age who had not been sterilized in Gunwee county of Kyungpook province were followed by Myun health workers for 2 years from April 1, 1985 to March 31, 1987 and 766 births were detected. All of the birth registration records of Myun offices were reviewed on September 30, 1987 and 944 births which occurred within the above mentioned period were found. Actual birth date obtained by follow-up study were compared with the birth date on registration card. Among 766 births detected by follow-up study, 576 births(75.2%) which were reported within 6 months after birth were ascertained on the official registration records and 96 births(12.5%) were not found on the records although mother stated that the birth was registered. The registration rate within legal due date was 61.3% among 576 births detected by follow-up study and also ascertained on the official records. The registration rate within legal due date was lower in mothers under 20 years of age and above 35 years and in mothers who had only primary education. It was decreased as the birth order increased. The registration rate was higher in births occurred from October to March than births occurred from April to September. All of the births of 7 neonatal deaths were not reported. The registered birth date was consistent with the actual birth date in 78.0%. Birth date on record was earlier than the actual birth date in 6.8% and later in 15.3%. The consistency rate was lower in mothers above 35 years of age(54.5%), and in infants of 4th birth order and above(56.3%). The rate was increased as the maternal education level increased. The rate of boys was higher than that of girls. A higher percentage(17.4%) of infants born in March was registered with earlier date than the actual birth date and most of these registered birth dates were lunar calendar date. This might be related with the age for entering the primary school. The study findings revealed that the birth registration rate within legal due date and accuracy of report have been increased in recent years, but the infant mortality rate derived from the birth registration seems to be very inaccurate. It is suggested to let the medical personnel who delivered the baby report the birth by mail directly to the current address of parent while infants delivered at home without professional attendant may comply with the present registration system.; Summary

Case-Control Study on Some Risk Factors of Cerebrovascular Diseases in Rural Community: Matched Analysis with One Control per Case.: Sung Hyun Han, Sung Soo Lee; Korean J Prev Med. 1988;21(1):82-88.

1,821 View
22 Download

Abstract PDF: The main objectives of this study were to know the prevalence of cerebrovascular disease, to find the important risk factors of cerebrovascular diseases. This study is a part of Eumseong Community Health Project supportes by GTZ(West German Government). 116 perceived cases of cerebrovascular disease were first screened by health interview and examinations and 80 cases were diagnosed as a cerebrovascular group. For comparison, 80 cases were matched with their neighbor controls of the same sex and the similar age. 1. The prevalence rate for cerebrovascular diseases was 476.3 per 100,000 population which is considered to be very high compared with that of other countries. Age adjusted rate for cerebrovascular diseases was 261.6 per 100,000. 2. Among the risk factors examined for the association with cerebrovascular diseases by case-control study, and analyzed by paired marginal test(McNemar's chi-square-test) and odds ratio, only hypertension showed high significant statistical association.; Summary

Seroepidemiology of Hepatitis B virus Infection in Healthy Korean Adults in Seoul.: Keun Young Yoo, Byung Joo Park, Yoon Ok Ahn; Korean J Prev Med. 1988;21(1):89-98.

2,051 View
35 Download

Abstract PDF: While there have been not a few reports on the seroepidemiological characteristics of hepatitis B virus (HBV) infection in Korea, most of them, however, have had several limitations; operational definition of HBV infection, validity of detection methods of HBV serologic markers, size of the study population, and confirmation of the vaccination history against HBV, etc. In order to avoid such limitations, authors randomly selected 1,495 healthy adults among the 217,511 insured (target population) of Korean Medical Insurance Corporation, living in seoul, and tested HBV(HBsAg, anti-HBs and anti-HBc) of all the subjects were tested, 392(26.2%) of interview failure cases 742 nonvaccinee were excluded from the actual population. Finally, the serologic markers tested of 742 nonvaccinee (study population) only were analyzed for the seroepidemiologic observation of the natural infection of HBV. The seroepidemiological characteristics of HBV infection in Korea were as follows ; 1 Point prevalence of HBs antigenemia was 11.7(9.1-14.3)% in male, which was slightly higher than that of female, 9.5(3.7-15.3)%. This level was one of the highest among those of Asian-Pacific countries. Decreasing tendency of HBsAg prevalence after the age of 50 was observed, which seems to be due to selective attrition of HBV chronic carriers among the healthy adults and/or to the limited-lasting duration of the HBs antigenemia, in part. 2. Point prevalence of anti-HBc(78.8% in male, 50.9% in female) was higher than that of anti-HBs(65.2% in male, 46.6% in female), respectively. And both of them were higher in male than in female. Increasing tendency of the prevalence of both antibodies was observed by age, which seems to be largely due to recurrent infection in adults and to some cumulative effect, in part, of their relatively longer-lasting duration. 3. The level of HBV infection defined by positive for at least one of the 3 serologic markers of HBV by RIA method was 84.7(81.8-87.6)% in male and 61.2(51.9-70.5)% in female, which was also one of the highest among those of Asian-Pacific countries. The proportion of susceptible population to HBV infection among healthy adults was 15.3% in male and 38.8% in female. 4. The relative frequency of current or past infection and chronic carrier among HBV infected person was estimated. The currently or past infected was estimated 75.7% in male and 71.8% in female, and chronic carrier state, 13.8% in male and 14.1% in female. The analysis of the geometric mean of the antibody titer in anti-HBs positive sera indicated also to be compatible with the above findings, suggesting that active, even though inapparent, infection of HBV occur so frequently among healthy adults in Korea.; Summary

The Relationship of Psychosocial Factors to Blood Pressure.: Choong Won Lee, Sung Kwan Lee; Korean J Prev Med. 1988;21(1):99-112.

2,016 View
19 Download

Abstract PDF: Questionnaires and blood pressure measurements were administered to 279 medical school undergraduates in 1987 to investigate the relationship between psychosocial factors and blood pressure as well as reliability and validity of the Framingham Type A Behavior Scale(FTA). The reliability coefficients of SCL-90-R and FTA measured by Spearman-Brown haves split test were 0.57-0.91, The factors of FTA extracted by principal component analysis were hard-driving competitiveness factor and impatience factor(2-factor solution). The total score of FTA was positively correlated with relative weight and place raised but the correlations were insignificant, and had significantly positive but weak correlations with depression, anxiety hostility, paranoid, and psychoticism subscales of SCL-90-R. In the univariate analysis of blood pressures, relative weight and family history were significant in systolic pressure in males and economic status was significant in blood pressures in both sexes. For diastolic pressure, relative weight and frequency of alcohol intake were significant in males and relative weight was in females. After controlling relative weight, the frequency of alcohol intake for diastolic pressure and economic status for systolic pressure were significant in males. The important variables selected by stepwise regression analysis were relative weight and economic status for systolic pressure of males and relative weight and the frequency of alcohol to the model, changing coefficient of determination 0.206 to 0.217. In females, economic status and relative weight were selected for systolic pressure and for diastolic pressure body mass index alone, but the model of blood pressure for females was considered to be unstable due to small sample size(56). FTA was unrelated to the blood pressures in both sexes.; Summary

A Study on the Epedemiological Characteristics of Industrial Ocular Injuries.: Won Chul Lee, Sang Moon Chung, Kang Sook Lee, Kwang Ho Meng, Seung Han Lee; Korean J Prev Med. 1988;21(1):113-120.

1,661 View
19 Download

Abstract PDF: A total of 181 cases of industrial ocular injuries hospitalized and treated at the St. Mary's Hospital, Seoul during the 5-year period was studied on their epidemiological characteristics. Of there patients 96.7% were males, and 43.6% were in twenties, 49.7% of the cases were injured on left eyes. There were no statistically significant differences in frequencies of study subjects by day of the week and month of the year. Most common injury hour were between 10- < 12 AM(13.6%) and between 2- < 4 PM(20%). Of the total 101 cases, 37.6% were working less than 6 months, and 73.7%, less than 2 years. Of the total, 42.3% were involved in machinery work and 13.9%, in construction work. According to the American National Standard Method of recording basic facts relating to the nature and occurrence of work injuries, 62% among all source of injuries was metal item and the most common accident type was struck by flying objects(76.2%). Among 181 cases, only 2 cases wearing protective equipment when the accidents occurred.; Summary

A Study on the Heavy Metal Contents in Freshwater Fishes of the Mankyung River.: Nam Song Kim; Korean J Prev Med. 1988;21(1):121-131.

1,692 View
21 Download

Abstract PDF: This study was performed to investigate the heavy metal contents of freshwater fishes. The samples of 24 species were collected at 7 areas located on the Mankyung River during September in 1987. And then the contents of lead, cadmium, copper and zine were analyzed by atomic absorption spectrophotometer. The results were summarized as follows ; 1. The mean value of lead, cadmium, and copper contents of fishes collected in the downstream were significantly higher than those of upstream. 2. The mean lead content of C. auratus was the highest 1.50+/-0.98 microgram/g in viscera and statistically significant difference from muscle content. 3. The mean cadmium content of C. auratus was the highest 0.087+/-0.054 microgram/g and significantly higher than that of muscle, skeleton and gill. 4. In the copper contents, the viscera of C. auratus was the highest 5.25+/-0.94 microgram/g and significantly higher than that of muscle, skeleton and gill. 5. The mean value of zinc content of C. auratus was shown the order of gill, skeleton, viscera and muscle.; Summary

A Study on the Indoor-Outdoor NO2 Levels and Personal Exposures to NO2 with Analysis of Factors Affecting the NO2 Concentrations: Centering on Urban Homes and Housewives.: Jin Ho Chun, Chae Un Lee, Joon Youn Kim, Yo Han Chung; Korean J Prev Med. 1988;21(1):132-151.

1,892 View
23 Download

Abstract PDF: This study was conducted to establish the control program for preventing unfavorable health effects of nitrogen dioxide(NO2) exposure in homes by preparing the fundamental data for evaluation of relationships between NO2 levels and influencing factors through measurements of indoor-outdoor NO2 levels and personal NO2 exposures for housewives with questionnaire survey on 172 homes in Pusan area from April to June, 1987. NO2 measurements were made by using diffusion tube samplers(Palmes tube NO2 sampler) for one week at 4 sites in homes ; kitchen(KIT), bedroom(BED), living room(LIV), outdoor(OUT) and near the collar housewives(personal exposure livel, PNO). The details of questionnaire were number of household members(FAM), number of regular smokers(SMOKER), daily number of meals eaten(MEAL), type of housing units(HOUSE), location of house with distance from the heavy traffic roads as walking time(DIST), and of kitchen(KAREA), kind of cooking fuels(FUEL), cooking time of each meal(CTIME), usage of kitchen fan for cooking(FAN), type of heating facilities(HEAT) and so on of subject homes. The obtained results were as follows : 1) The mean NO2 level was significantly higher at indoors than outdoors(p<0.01) and the kitchen NO2 level was the highest with 33.7+/-13.6ppb(9.5-81.5ppb). The mean personal exposure level of NO2 for housewives was 20.6+/-8.8ppb(3.1-46.9ppb). 2) The mean indoor NO2 level was significantly higher in the group of household members above 5 than below 4(p<0.05), in detached dwellings than apartments(p<0.001), within 5 minutes of distance than over 5 minutes(p<0.001), in the group of unusing fan(p<0.001), in the group of longer cooking time(p<0.001), and it was in order of coal briquette, gas, electricity and oil by kind of cooking fuels(p<0.05). 3) Variables showing significant correlation(p<0.001) with indoor NO2 level were kitchen NO2 level(r=0.8677), cooking time(r=0.5921), outdoor NO2 exposure level(r=0.4615), usage of kitchen fan(r=0.3573) and location of house(r=-0.2988). 4) As a result of multiple regression analysis, the most significant influencing variable to the kitchen NO2 level was cooking time [KIT=-0.378+/-11.772(CRIME)+0.298(OUT)+3.102(FAN)], it was kitchen NO2 level to the indoor NO2 level [IND = 6.996+0.458 (KIT) + 0.230 (OUT) - 1.127 (KAREA)], and it was indoor NO2 level to the personal NO2 exposure level [PNO=15.562+0.729(IND)-4.542(DIST)-0.200(KIT)]. 5) It was recognized that artificial ventilation in the kitchen, suppression of unnecessary combustion and replacement of cooking fuel, as much as possible, were effective means for decreasing indoor NO2 levels in homes.; Summary

Effect of STEL-toluene on Metabolism of Benzene in Rats.: Jaehoon Roh, Dong Chun Shin, Jung Gyun Park, Young Hahn Moon, Ho Keun Chung; Korean J Prev Med. 1988;21(1):152-162.

2,054 View
23 Download

Abstract PDF: Benzene and toluene, which are widely used aromatic hydrocarbons in workplace, are recently proved to cause health hazards due to their toxic effects. This study investigated the influence of toluene on the urinary excretion of benzene metabolite by administering short term exposure limit(STEL) of these compounds(i.e., 13.8mg/kg of benzene and 108.8mg/kg of toluene) intraperitoneally into Sprague-Dawley rats. After administration, urinary phenol concentration of rat was measured by gas chromatography for every three hours. Data were analyzed by non-parametric statistical methods using Kruskal-Wallis multi-sample test and Mann-Whitney U test. The following results were obtained: 1. Administration of STFL-benzene increased urinary phenol concentration in rats. 2. Urinary phenol concentration was increased logarithmically according to the dosage of benzene. 3. Excretion of phenol in urine was decreased when benzene and toluene were administered simultaneously compared with administering benzene alone. In Summary, these results reveal that administration of STEL of toluene has antagonistic effect of urinary excretion of benzene metabolite in rats.; Summary

First
Prev
Page of 2
Next
Last

Previous issues