Bone and Blood Lead Levels of Middle Aged Koreans not Occupationally Exposed to Lead / 대한산업의학회지

OBJECTIVES: In order to investigate the level and the association between bone lead and blood lead levels of non-occupationally, lead-exposed Koreans, the authors studied the lead biomarkers of 137 middle aged Koreans (86 males and 51 females) older than whose age were above 40 years. METHODS: The tibia lead level was selected as the bone lead indicator of cortical bone, and the blood lead level was also measured. The tibia lead level was measured by K-shell XRF with 30-minute measurement of each subjects. The blood lead level was analyzed by AAS method. RESULTS: The mean (SD) of the tibia lead level of the 137 study subjects was 3.49 (4.99) microgram/g, and tended to be higher. The mean (SD) of tibia lead level in male subjects (was 3.90 (4.88) microgram/g) and larger than in that of female subjects (2.80 (5.14) microgram/g), but without no statistical significance was observed. The mean (SD) of blood lead level of all total subjects was 3.70 (1.35)microgram/dl, and tended to be higher. The mean (SD) of blood lead level in male subjects (was 3.93 (1.25) microgram/dl) and larger than in that of female subjects (3.30 (1.42) microgram/dl), but without no statistical significance was observed. In multiple regression analysis of blood lead levels after adjusting for covariates, age was a significant independent variable. A weak association of age with tibia lead in female subjects was also observed in multiple regression analysis. CONCLUSION: The mean (SD) of tibia and blood lead levels of middle aged Koreans whose ages were over 40 years old were 3.49 (4.99) microgram/g and 3.70 (1.35) microgram/dl, respectively. Age and sex were positive predictors of blood lead level in multiple regression analysis after controlling for the covariates. However, in multiple regression analysis whereas age was weakly association with tibia lead level only in female subjects in multiple regression analysis.

The Effect of ALAD and VDR Polymorphism on the Hematopoietic Biomarkers in Lead Exposed Workers / 대한산업의학회지

OBJECTIVES: This study was conducted with new workers who entered lead industries from 1992 to 2001 to evaluate the genetic susceptibility of ALAD (delta-aminolevulinic acid dehydratase) and VDR (vitamin D receptor) gene on health effect of lead exposure. METHODS: Among the subjects of the database of lead industries at the Soonchunhyang University Institute of Industrial Medicine, only new workers were selected for this study. The total of eligible workers for this category was 3,540 workers, including non lead exposed workers of same lead industries. From stored blood in specimen bank of Soonchunhyang University, genotype of ALAD and VDR were measured using PCR method. Variables for this study were blood lead as an index of lead exposure, ZPP (zinc protoporphyrin in blood), urine ALA (delta-aminolevulinic acid), and hemoglobin as an index of hematopoietic effect of lead. Information on sex, job duration, and weight were collected for personal information. The data were analyzed using SAS (version 8.2) with descriptive analysis of t-test and multiple regression analysis. RESULTS: Among 3,540 new employed study subjects during period of 1992-2001, 3,204 workers (90.5%) had ALAD genotype 1-1, while 336 workers (9.5%) had variant type of ALAD (1-2 or 2-2). For VDR genotype, 2,903 workers (89.7%) out of total tested 3,238 workers were belonged to type bb and 335 workers (10.5%) were type bB or BB. The distribution of genotype of ALAD and VDR were not different according to the job duration in male workers, but were different in female workers. The effect of ALAD and VDR genotype on blood lead were positively significant in the analysis of all cumulative data of new employed workers for 10 years. The effect of VDR genotype on blood lead were stronger than that of ALAD. While the variant ALAD gene made decrease of mean ZPP and ALA in urine after controlling for blood lead and other covariate, the variant VDR gene made increased the mean ZPP and ALA in urine in all cumulative data analysis and cross sectional analysis by job duration. For hemoglobin, ALAD and VDR genotype did not affect the mean value. CONCLUSIONS: From the above our results, we found that ALAD and VDR genotype exerted significant effect in various way. We confirmed that the finding of a cross sectional study of protective effect of variant ALAD on the effect of blood lead on blood ZPP in our retrospective study design. It was found that VDR did not exert protective effect for lead exposure as the variant ALAD did.

Associations of ALAD Genotype with Renal Function Indices in Lead Workers / 대한산업의학회지

OBJECTIVES: delta-Aminolevulinic acid dehydratase (ALAD) is a polymorphic enzyme that has two alleles, ALAD1 (ALAD1-1 as genotype) and ALAD2 (ALAD1-2 or ALAD2-2 as genotype). ALAD genotype has been reported to modify the pharmacokinetics and toxicity of lead. The authors investigated the influence of ALAD genotype polymorphism on renal function in lead workers METHODS: We studied 935 male lead workers and 87 male non-lead workers in the same industries. For cross-sectional renal indices, blood urea nitrogen (BUN), serum creatinine, serum uric acid and urine total protein were selected. Blood lead level was also measured an index of lead exposure. Information on weight, age, job duration, and smoking and drinking habits was collected. RESULTS: Whereas the mean blood lead level of lead workers was 25.4+/-10.9 microgram/dL, that of non-lead workers in the same premise was 10.1+/-2.8 microgram/dL, and the difference between the two groups was statistically significant. Whereas the prevalence of the variant allele, ALAD2 in 935 lead workers was 10.6%, that in 87 non-lead workers was 4.6%. However there was no difference of prevalence between the two groups. The mean blood lead level of subjects with ALAD1 was 23.9+/-11.4 microgram/dL, which was slightly lower than that of subjects with ALAD2 (25.8+/-10.7 microgram/dL). However, this difference was not statistically significant. After adjustment for the covariates, the subjects with ALAD2 allele were 12.8% less likely to have a median value or more of BUN than subject with ALAD1. The adjusted odds ratio was 0.59 (95% confidence interval; 0.38-0.91). After adjustment for the covariates, the subjects with ALAD2 allele were 9.3% less likely to have a median value or more of serum creatinine than subject with ALAD1. The adjusted odds ratio was 0.64 (95% confidence interval; 0.41-0.98). CONCLUSIONS: From the above results, it was found that the variant allele, ALAD2 appeared to modify the association of lead and renal function, and that ALAD2 genotype may be supportive for the protective effect of lead.

A Study on Liver Function Indices in Male Lead Workers / 대한산업의학회지

OBJECTIVES: To evaluate the effects of lead on the liver function indices in male lead workers. METHODS: The study comprised of 274 lead workers and 113 non-lead workers who were confirmed not to have HBsAg (Hepatitis B surface Antigen). Blood lead (PbB), blood zinc protoporphyrin (ZPP) and urinary delta-aminolevulinic acid (ALAU) were selected as parameters for monitoring exposure to lead while aspartate aminotransferase (SGOT), alanine aminotransferase (SGPT) and gamma-glutamyltransferase (gamma-GTP) were chosen as parameters for monitoring liver function. Demographic information, such as age, smoking and drinking histories were collected. The duration of work for the lead workers, and their BMI(body mass index), were also obtained. RESULTS: After adjusting for possible confounders {age, BMI, work duration, smoking (pack-year) and drinking (bottles of Soju consumed per week)}, blood lead was observed to be a significant variable from the logistic regression analysis of the abnormalities of SGOT( >35 IU/L), with an odds ratio of 1.04 (95 % CI, 1.008-1.066). The amount of alcohol drunk (odds ratio 1.28: 95 % CI, 1.054-1.549) and BMI (odds ratio 1.24: 95 % CI, 1.075-1.421) were also significant variables. From the multiple linear regression analyses, blood lead was significantly, and positively, associated with SGOT (p<0.05). CONCLUSIONS: These findings suggest that exposure to lead may have an effect on SGOT in male lead workers.

The Effect of ALAD Polymorphism on the Relationship of Blood and Bone Lead with Hematologic Biomarkers in Lead Exposed Workers / 대한산업의학회지

OBJECTIVES: To evaluate the effect of ALAD polymorphism on the relationship of blood and bone lead with hematologic biomarkers in lead exposed workers, 450 lead exposed workers and 85 non-lead exposed workers were selected. METHODS: Blood lead and tibia bone lead were selected as parameters of lead exposure and blood ZPP, urinary ALA (ALAU), hemoglobin (Hb) and hematocrit (Hct) were chosen as parameters of hematologic effect of lead exposure. Genotype of each subject was assayed and expressed as ALAD1 and ALAD2. Demographic information such as sex, age and personal habit of smoking and drinking were collected. Job duration of lead exposed workers was also obtained. RESULTS: The overall prevalence of the variant allele, ALAD2 in lead exposed workers was 9.6 %(43 out of 450 lead workers) which was not differed from control workers (9.4 % : 8 out of 85). The means of tibial lead and blood ZPP in lead workers with ALAD2 were lower than those of lead workers with ALAD1, but the differences were not statistically significant. After adjusting for possible confounders (sex, job duration, BMI, drinking and smoking status) only blood lead and bone lead contributed negatively to the level of hemoglobin with statistical significance without any contribution of ALAD genotype. On the other hand, no significant effect of blood lead, bone lead and ALAD genotype were observed on the level of hematocrit after controlling possible confounder. ALAD genotype in the multiple regression analysis of blood lead and bone lead with log transformed urinary ALA (LogALAU) after adjusting for possible confounders showed significant main and interaction effect on LogALAU simultaneously, which resulted lower LogALAU in lead exposed workers of ALAD2 than ALAD1. It was also observed only main effect of ALAD gene type on blood ZPP after adjusting possible confounder resulting lower ZPP in lead workers of ALAD2 than ALAD1. CONCLUSIONS: With above results, it was found that ALAD polymorphism did not affect on the level of hemoglobin and hematocrit, but ALAD polymorphism made significant effect on the association of blood and bone lead with urinary ALA and blood ZPP. The lower urinary ALA and blood ZPP in ALAD2 lead workers suggested that ALAD2 genotype may be supportive for the protective effect of lead.

Associations between Lead Exposure and Dose and Protein Kinase C Activation in Erythrocytes Among Lead Workers / 대한산업의학회지

OBJECTIVES: Protein kinase C(PKC), a calcium and phospholipid dependent enzyme, is activated by lead in vitro at picomolar concentrations. However, the effect of lead on PKC has never been studied in a human population. The purpose of the study was to evaluate whether lead exposure was associated with PKC mediated-phosphorylation in erythrocytes among lead workers. METHODS: Two hundred and twelve lead workers were studied. To determine the levels of phosphorylation in vivo, an in vitro back phosphorylation technique was used by adding PKC and gamma-32P to preparations of erythrocyte membranes. We measured back phosphorylations of erythrocyte membrane proteins, spectrin, and 52 kDa and 48 kDa, as an indirect measure of PKC activation in vivo. RESULTS: The mean(SD) age and exposure duration was 39.1(10.0) years and 8.1(6.5) years, respectively. Tibial lead ranged from 0.8 to 290.8 microgram Pb/g bone mineral with a mean(SD) of 34.4(35.2) microgram Pb/g bone mineral. The means(SD) of back phosphorylation levels of the three proteins were 540.7(304.1), 198.6(78.2), and 247.7(83.3) photostimulated luminescence units(PSL), respectively, by phosphoimager. After adjustment for potential confounding factors, tibial lead and exposure duration were significantly and inversely associated with back phosphorylation levels. One unit of increase in tibial lead(1 microgram Pb/g bone mineral) is associated with a decline in spectrin, band 4.9 52 kDa, and band 4.9 48 kDa back phosphorylation levels by 1.4(P<0.05), 0.34(P<0.05), and 0.47(P<0.01), respectively. However, there were no associations between the back phosphorylation levels and either blood lead or ZPP levels. CONCLUSIONS: These findings suggest that the PKC activity in erythrocytes is increased by chronic lead exposure and that erythrocyte membrane protein phosphorylation may be a biomarker of lead exposure.

The Relationship between Psychosocial Distress and Lead Exposure Indices in Lead Workers / 대한산업의학회지

OBJECTIVES: This study was carried out to assess psychosocial distress of lead workers and to examine the relationship between lead exposure indices and psychosocial distress. METHODS: The study design was cross-sectional and research subjects were 234 lead workers in primary smelting industry. General characteristics, job characteristics and social support were obtained by self-administered questionnaire and history taking. Psychosocial distress was measured using PWI(Psychosocial Well-being Index), a 45-item self-administered instrument. Blood lead(PbB), zinc protoporphyrin(ZPP), -aminolevulinic acid in urine(ALAU) were selected as indicators of lead exposure. RESULTS: There was significant difference in PWI according to lead exposure level and job characteristics. The results of correlation analysis showed that PWI was significantly correlated with PbB(r=0.203, P=0.002). CONCLUSIONS: Our results supported the association between lead exposure and psychosocial distress. The inclusion of psychosocial distress measurement as a special health examination for lead workers was highly recommended for the effective health management.

Different Effect of Blood Lead on Zinc Protoporphyrin by Gender in Korean Lead Workers / 예방의학회지

OBJECTIVES: To evaluate whether a relation between blood lead and zinc proto porphyrin(ZPP) was modified by gender in Korean lead workers. METHODS: A cross-sectional study was conducted with 1,304 male and 101 female subjects in 1997. The relation between blood lead and ZPP were evaluated with linear, exponential, and quadratic models. Then, the different effect of gender on the relation was examined by adding the interaction terms in the each model. RESULTS: Mean+/-SD of blood lead and ZPP level was different between male(27.7+/-10 microgram /dl and 51.3+/-23.4 microgram/dl) and female subjects(22.5+/-9.2 microgram/dl and 78.7+/-38.6 microgram/dl). After adjusting for possible confounders, the effect modification by gender was significant in linear(beta=1.119, p<0.001), exponential(beta=Exp(0.008), p<0.05), and quadratic model(beta= 1.388, p<0.001). In separate analysis, a quadratic relation between blood lead and ZPP was shown in male lead workers(beta=0.036, p<0.001), but an exponential relation in female lead workers(n=Exp(0.029), p<0.001). CONCLUSION: Our data showed that the increasing rate of ZPP in female were always higher than in male lead workers, suggesting that females were more susceptible to occupational lead exposure than males.

Some Renal Function Indices in Workers Occupationally Exposed to Lead / 대한산업의학회지

The influence of lead exposure on renal function was studied. Three hundred forty two male lead exposed workers who worked in 3 storage battery factories, 5 secondary smelting factories and 3 litharge making factories, and 60 male control workers who were not exposed to lead occupationally were chosen for this study. Blood lead (PbB), zinc protoporphyrin in whole blood (ZPP) and delta-aminolevulinic acid in urine (DALA) were selected as indicators of lead exposure. As indicators of renal function blood urea nitrogen(BUN) , serum creatinine(S-Cr), serum uric acid (S-UA), N-acetyl-beta-D-glucosaminidase in urine (NAG) and urine protein (U-TP) were selected. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of renal function indicators of exposed except S-UA were significantly different from non-exposed. The frequency of workers whose value of renal function indicators were over the nor mal criteria (BUN>20 mg/dl ; S-Cr>1.2 mg/dl ; S-UA>7.0 mg/dl ; NAG>8.0 U/liter; U-TP>8.0 mg/dl) by the level of lead absorption in terms of PbB, ZPP and DALA were calculated. Age adjusted odds ratio of over the normal value of BUN and NAG were statistically significant by the level of ZPP and that of BUN only showed the dose-dependant relationship. But the frequency of over the normal criteria of renal function indicators were not increased by the level of PbB and DALA. On stepwise multiple regression using renal function indicators as a dependent variable and each lead exposure indicator and age as independent variables, only BUN, NAG and U-TP were contributed by the lead exposure indicators. It was found that only NAG of renal function indices was most reliable indicator who showed dose-response relationship with lead exposure and the measurement of NAG for lead workers whose relatively high exposure is highly recommended.

The effect of smoking and drinking habit on the health status of lead workers / 예방의학회지

To investigate the effect of smoking and drinking habit on the health status in lead using industries, 2,785 male workers in lead using industries (7 storage battery industries, 7 secondary smelting and related industries, and 4 primary metal and other manufacturing industries) were selected for this study. This study was carried out as a part of periodic health examination. Selected study variables were zinc protoporphyrin in whole blood (ZPP), SGOT and SGPT for laboratory test. Questionnaire for lead related symptoms and smoking and drinking habit was provided to all the workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The overall smoking and drinking rate of study population were 69.8% and 73.6%, respectively. While the smoking and drinking rate of storage battery workers were 68.8% and 72.3%, those of secondary smelting industries and other industries were 66.0% and 66.4% and 74.6 and 80.3% respectively. 2. While the mean values of blood ZPP of lead exposed workers were significantly higher than other group, those of SGOT of storage battery workers were significant higher than other worker. But there were no differences of mean values of other variables. 3. Smoking habit did not affect on the mean value of blood ZPP of workers in special health examination group, but there were significant differences of blood ZPP and SGOT between drinker and non-drinker. 4. Symptom prevalence of lead exposure were higher in drinking and smoking group than non-drinking and non-smoking group. 5. In multiple regression analysis of the total lead related symptoms, blood ZPP, SGOT, and SGPT as dependent variable, respectively, and age, work duration, blood ZPP, pack year and amount of alcohol drinking as independent variables, work duration, pack year, amount of alcohol drinking, age contributed to total symptoms; and age, work duration, pack year contributed to blood ZPP; and age, amount of alcohol drinking, work duration contributed to SGOT; and pack year contributed to SGPT.

Occupational Lead Exposure of Storage Battery Industry Workers in Korea / 대한산업의학회지

In order to investigate the level of lead absorption of lead workers and to evaluate the effect of blood lead on blood zinc protoporphyrin (ZPP) and prevalence of lead related symptoms, 1,782 lead workers(male: 1,506, female: 276) from 8 storage battery industries were studied. Selected variables as indices of lead exposure were blood lead, blood ZPP, and hemoglobin (HB). Fifteen questionnaires of lead related symptoms were provided to all lead workers and filled up by themselves and confirmed by medical doctors. Personal variables such as age, work duration, smoking and drinking habits were also collected. The results were follows : 1. While the mean blood lead of lead workers of all lead companies was 31.0+/-3.0 ug/100ml (male: 31.5+/-2.9 ug/100ml, female: 27.9+/-3.3 ug/100m1), the mean blood ZPP of all lead workers was 66.7+/-4.1 ug/100ml (male: 59.6+/-3.3, female: 105.3+/-3.0 ug/100ml). The mean hemoglobin of male lead workers was 15.7+/-.3 gm/100ml and that of female lead workers was 13.0+/-.3 gm/100ml. 2. The percentage of lead workers whose blood lead was over 60.0 ug/100m1 and 40.0-59.9 ug/100ml was 2.81 % and 19.08 %, respectively. On the other hand, the percentage of lead workers whose blood ZPP was over 150 ug/100ml and 100-149 ug/100ml was 5.89 % and 8.31 %, respectively. 3. The slopes of simple linear regression of blood lead (independent variable) and blood ZPP in female lead workers was significantly steeper than that of male lead workers. The slope of storage battery industries with better working condition in terms of low air concentration of lead were less steeper than those with poor working condition with high mean air concentration of lead. 4. Stepwise multiple regression analysis, using overall symptom prevalence as a dependent variables, blood lead, blood ZPP, hemoglobin, age, work duration, drinking and smoking habits as independent variables, indicated that only drinking habit and age were significantly contributed to the dependent variable.

The change of validity of blood zinc protoporphyrin test by different cut-off level in level workers / 예방의학회지

Measurement of blood lead (PbB) and blood zinc protoporphyrin (ZPP) are most common biological indices to identify the individual at risk for excess or the health sequences by lead exposure. Because PbB is known most important and reliable index of lead exposure, PbB is often regarded as a gold standard to detect lead exposure. But in Korea PbB is a secondary test item of detailed health check-up with positive finding of screening test in most occasion. Our lead standard requires all lead workers to take annual heath-check twice a year for investigation of their health effect due to lead exposure. Blood ZPP is one of most important index to detect high lead absorption in lead workers as a screening test. Measurement of blood ZPP is known well to correlate with PbB in steady state of exposure in most lead workers and is often used as a primary screening test to detect high lead absorption of lead workers with the advantage of simplicity, easiness, portability and low cost. The current cut-off criteria of blood ZPP for further detailed health check-up is 100 ng/dl which is supposed to match the level of 40 ng/dl of PbB according to our standard. Authors tried to investigate the validity of current criteria of cut-off level(100 ng/dl) of blood ZPP and possible another better cut-off level of it to detect the lead workers whose PbB level over 40 ng/dl. The subjects in our study were 212 male workers in three small scale storage battery industries. Blood ZPP, PbB and hemoglobin(Hb) were selected as the indices of lead exposure. The results were as follows. 1. The mean of blood ZPP, PbB and Hb in lead workers were 79.5+/-46.7 ng/dl, 38.7+/-15.1 ng/dl, and 14.8+/-1.2 g/dl, respectively. There were significant differences in blood ZPP, PbB and Hb by industry(P<0.01). 2. The percents of lead workers whose blood ZPP were above 100 ng/dl in the group of work duration below 1, 1-4, 5-9 and above 10 years were 8.6%, 17.2%, 47.6%, and 50.0%, respectively. The percents of lead workers whose PbB were above 40 ng/dl in those were 31.4%, 40.4%, 71.4%, and 86.4%, respectively. 3. The percents of lead workers whose PbB were below 40 ng/dl, 40-59 ng/dl and above 60 ng/dl were 54.7%, 34.9% and 10.4%, respectively. Those of lead workers whose blood ZPP were below 100 ng/dl, 100-149 ng/dl and above 150 ng/dl were 79.2%, 13.7% and 7.1%, respectively. 4. Simple linear regression of PbB on blood ZPP was statistically significant(P<0.05) and as PbB was 40 ng/dl, blood ZPP was 82.1 ng/dl. 5. While the highest sensitivity and specificity of blood ZPP test to detect lead workers with PbB over 40 ng/dl were observed in the cut-off level of 50 ng/dl and 100 ng/dl of blood ZPP, respectively, the highest validity(sensitivity+specificity) of blood ZPP to detect lead workers with PbB over 40 ng/dl was observed in the cut-off level of around 70 ng/dl of blood ZPP. But even with optimal cut-off level of around 70 ng/dl of blood ZPP, still 25.0% of false negative and 20.7% false positive lead workers were found. As the result of this study, it was suggested that reconsideration of current blood ZPP cut-off of our lead standard from 100 ng/dl to somewhat lower level such as around 70 ng/dl and the inclusion of PbB measurement as a primary screening test for lead workers was highly recommended for the effective prevention of lead workers.

A Study on the Lead Exposure of Workers in Secondary Smelting and Litharge Making Industries / 대한산업의학회지

Two hundred and six male lead workers (86 lead workers from secondary smelting industries and 120 lead workers from litharge making industries) and 212 office workers who were not exposed to lead occupationally were studied to investigate the effect of lead on the health of lead workers in high risk operation to lead. Blood lead (PbB), zinc protoporphyrin in whole blood (ZPP), delta-aminolevulinic acid in urine (ALAU), Hematocrit (Hct) and hemoglobin (Hb) were selected as an index of lead exposure. Questionnaires of 15 lead related symptoms were provided to all study subject and filled up by themselves and reconfirmed the symptom answers by interviewing medical doctor. While the mean value of PbB, ZPP and ALAU of lead workers in secondary smelting industries were 62.7+/-14.6 microgram/dl, 103.1+/-60.5 microgram/dl and 7.4+/-10.3 mg/liter, those of lead workers in litharge making industries were 58.8+/-14.1 microgram/dl, 74.2+/-45.2 microgram/dl and 5.3+/- 7.9 mg/liter respectively, and there were statistically significant difference of mean values between two groups. Simple linear regression analysis of PBB on ZPP and ALAU shoved the steeper slope in secondary smelting industries than litharge making industries. Higher symptom prevalence rates of lead exposed group were observed in lead colic related symptom (S4) and neuromuscular symptoms compared with non-exposed workers. The prevalence of neuromuscular symptoms only showed dose-response relationship by the increase of PBB and ZPP. But more statistical significances were observed in neuromuscular symptoms by the increase of PBB than ZPP. On stepwise multiple regression using total symptom score as a dependent variable and PBB, ZPP, ALAU, Hct, Hb, age and work duration as a independent variables only ZPP and age contributed to the lead related symptoms.

Follow-up Management State of Lead Battery Workers in Periodic Health Examination / 예방의학회지

To evaluate the follow-up management state and related factor of lead battery workers in periodic health examination as part of program of group occupational health service, author studied 293 workers with questionnaire on knowledge of results and follow-up management state and related factors, and compared the responses to their periodic health examination result charts. The results were as follows: 1. 252(86%) workers responsed that they had received the health examination result chart, but only 116(39.6%) workers responsed that they had been educated or explained about the result of health examination, and 11(57.9%) workers among 19 workers with non-occupational disease D, 101(44.3%) workers among 228 workers with non-occupational disease C, and 19(28.4%) workers among 67 workers with occupational disease C knew accurately their health examination results. 2. 78(24.8%) of the workers responsed that they had follow-up management, and contents of follow-up management were follow-up(36.6%), out-patient treatment(31%), change worksite(8.5%), temporary retirement(7.0%) and others(16.9%). 3. Most of the workers responsed that the health examination were necessary, but three-fourths of the workers responsed that the health examination had been superficial or that they didn't know. 4. In this study, follow-up management show significant association with only explanation or education about health examination result chart.

A study on lead exposure indices of male workers exposed to lead less than 1 year in storage battery industries / 예방의학회지

This study intended to obtain an useful information for health management of lead exposed measuring the lead exposure indices and workers and determine biological monitoring interval in early period of exposure by work duration in all male workers (n=433 persons) exposed less than 1 year in 6 storage battery industries and in 49 males who are not exposed to lead as control. The examined variables were blood lead concentration(PBB), Zinc-protoporphyrin concentration(ZPP), Hemoglobin(HB) and personal history; also measured lead concentration in air(PBA) in the workplace. According to the geometric mean of lead concentration in the air, the factories were grouped into three categories: A; When it is below 0.05mg/m3, B; When it is between 0.05 and 0.10mg/m3, and C; When it is above 0.10mg/m3. The results obtained were as follows: 1. The means of blood lead concentration(PBB), ZPP concentration and hemoglobin(HB) in all male workers exposed to lead less than 1 year in storage battery industries were 29.5+/-12.4 microgram/100ml, 52.9+/-30.0 microgram/100ml and 15.2+/-1.1 gm/100ml. 2. The means of blood lead concentration(PBB), ZPP concentration and hemoglobin(HB) in control group were 5.8+/-1.6 microgram/100ml, 30.8+/-12.7 microgram/100ml and 15.7+/-1.6 microgram/100ml, being much lower than that of study group exposed to lead. 3. The means of blood lead concentration and Zpp concentration among group A were 21.9+/-7.6 microgram/100ml, 41.4+/-12.6 microgram/100ml; those of group B were 29.8+/-11.6 microgram/100ml, 52.6+/-27.9 microgram/100ml; those of group C were 37.2+/-13.5 microgram/100ml, 66.3+/-40.7 microgram/100ml. Significant differences were found among three factory group(P<0.01) that was classified by the geometric mean of lead concentration in the air, group A being the lowest. 4. The mean of blood lead concentration of workers who have different work duration(month) was as follows; when the work duration was 1-2 month, it was 24.1+/-12.4 microgram/100ml,; When the work duration was 3-4 month, it was 29.2+/-13.4 microgram/100ml; and it was 28.9+/-34.5 microgram/100ml for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 5. The mean of ZPP concentration of workers who have different work duration(month) was as follows; When the work duration was 1 2 month, it was 40.6 18.0 g/100ml, When the work duration was 3-4 month, it was 53.4+/-38.4 microgram/100ml; and it was 51.5+/-60.4 microgram/100ml for the workers who had longer work duration than other. Significant differences were found among work duration group(P<0.05). 6. Among total workers(433 person), 18.2% had PBB concentration higher than 40 microgram/100ml and 7.1% had ZPP concentration higher than 100 microgram/100ml; In workers of factory group A, those were 0.9% and 0.0%; In workers of factory group B, those were 17.1% and 6.9%; In workers of factory group C, those were 39.4% and 15.4%. 7. The proportions of total workers(433 person) with blood lead concentration lower than 25 microgram/100ml and ZPP concentration lower than 50 microgram/100ml were 39.7% and 61.9%, respectively; In workers of factory group A, those were 65.5% and 82.3%; In workers of factory group B, those were 36.1% and 60.2%; In workers of factory group C, those were 19.2% and 43.3%. 8. Blood lead concentration (r=0.177, P<0.01), ZPP concentration (r=0.135, P<0.01), log ZPP (r=0.170, P<0.01) and hemoglobin (r=0.096, P<0.05) showed statistically significant correlation with work duration (month). ZPP concentration (r=0.612, P<0.01) and log ZPP(r=0.614, P<0.01) showed statistically significant correlation with blood lead concentration. 9. The slopes of simple linear regression between work duration(month, independent variable) and blood lead concentration(dependent variable) in workplace with low air concentration of lead was less steeper than that of poor working condition with high geometric mean air concentration of lead. The study result indicates that new employees should be provided with biological monitoring including blood lead concentration test and education about personal hygiene and work place management within 3~4 month.

Study on the lead exposure of workers in a litharge making industry / 예방의학회지

In order to investigate the level of lead exposure of workers in litharge making industry and to evaluate how lead exposure, personal habit such as smoking and drinking affect the prevalence of lead related symptoms and other study variables, we investigate 114 workers(24 office workers and 90 lead exposed workers) in a litharge making industry. Study variables chosen were blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), Hemoglobin(Hb), hematocrit (Hct), SGOT and SGPT. symptom questionnaires which had 15 lead exposure related symptoms were provided to all workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The mean value of PbB, ZPP and SGOT in lead exposed group were higher than those of non-exposed group, and there were no differences of means in other study variables. 2. The smoking and drinking rate of study subjects were 65.8% and 71.0% as a whole. Smoking rates were lower in non-exposed group than exposed group, but drinking rate were not. 3. There were no differences of mean values of study variables between smoker and non-smoker in non-exposed and exposed group, but there was a difference of mean value of SGOT between drinker and non-drinker in lead exposed group. 4. while the symptom prevalence of lead exposed group were higher in neuromuscular category than non-exposed group, those of non-exposed group were higher or same with exposed group in gastrointestinal and general symptom category. 5. The symptom prevalence of smoker were higher than non-smoker regardless of exposure. 6. The symptom prevalence of drinker were only higher in gastrointestinal symptom category than non-drinker. 7. In multiple stepwise regression analysis of lead related symptoms as dependent variable and blood lead, smoking habit, drinking habit and work duration as independent variables, drinking habit contributed to the gastrointestinal symptom category, whereas blood lead and smoking contributed to the neuromuscular symptom category. For the total symptoms work duration and smoking habit contributed significantly.

A study on renal function indices in lead exposed male workers / 예방의학회지

The influence of lead exposure on renal function was studied. Eighty nine lead exposed workers who worked in 2 storage battery factories, and seventy one control workers were chosen for this study. Blood lead(pbB) and zinc protoporphyrin in whole blood(ZPP) were selected as indicators of lead exposure. As indicators of renal function, urinary N-acetyl-beta-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(S-Cr), total protein in urine(U-Tp),and serum uric acid(S-Ua) were selected. The results obtained were as follows: 1. while the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of NAG, U-TP, BUN and S-Cr of renal function indicators of exposed were also significantly different from non-exposed but their mean values were all within normal limits. 2. BUN, logarithmic U-TP, logarithmic NAG and S-Cr showed statistically significant correlation with pbB. 3. The proportion of workers whose values of renal function indicators were over the normal limits(NAG7.5 U/g cr; U-TP 10.9mg/dl; BuN20 mg/dl; S-Cr1.2 mg/dl; S-Ua7.0 mg/dl) by the level of lead absorption in terms of pbB and ZPP were calculated. The proportion of workers with over the normal limits of U-TP among total workers showed the dose-response relationship. when age is adjusted, U-TP showed significantly strong dose-response relationship with the level of pbB and ZPP.

A Study on Urinary N-acetyl-beta-D-glucosaminidase Activities of Office Workers in a Certain Industrial Complex Area / 예방의학회지

In order to identify the necessary information of biochemical indices for renal effect of lead for the early detection in medical surveillance of lead worker, the reference values of urinary N-acetyl-beta-D-glucosaminidase(NAG) activities were studied with 205 office workers in one industrial complex area who were not exposed to lead occupationally. While study variables selected for lead exposure were blood lead (pbB), blood zinc protoporphyrin(ZPP) and delta-aminolevulinic acid (DALA) in urine, those for renal effect were urinary N-acetyl-beta-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(cr), serum uric acid (Ua), and urinary total protein (U-Tp). The results obtained were as follows: 1. The mean values of blood lead, ZPP and DALA in all subjects were 14.39+/-4.02 microgram/dl, 21.61+/-8.00 microgram/dl, and 2.73+/-0.90 microgram/l respectively. 2. The mean value of urinary NAG activities in all subjects was 3.51+/-2.01 U/l. The mean value of urinary NAG activities, which calculated from NAG activities divided by urinary creatinine concentration (CNAG), was 5.42+/-5.53 U/g creatinine and logarithmic normal distributed. 3. The reference value of urinary NAG activity was 12.06 U/g creatinine (95% CI=10.57-14.76U/g creatinine). 4. Logarithmic CNAG(r=0.781 P<0.01), U-TP(r=0.670 p<0.01) and ZPP (r=0.172 p<0.05)showed statistically significant correlation with CNAG.

Comparison of Renal Function Indices Between Occupationally lead Exposed Females and Healthy Non-exposed Females / 대한산업의학회지

This study was to investigate the effect of lead on the selected clinical renal function in female lead workers. The 123 female lead workers from 9 lead industry and 177 females who were not occupationally exposed were examined. Females who had history of renal disease or oral medication were excluded. Blood lead, zinc protoporhphyrin in blood, delta-aminolevulinic acid and haemoglobin were examined as of lead exposure indices and blood urea nitrogen, serum creatinine, serum uric acid and urine protein were examined as of renal function indices. Mean concentration of lead were 40.7(+/-13.02)ug/dl for lead workers and 10.7(+/-3.56)ug/dl for non-lead workers. Differences between lead workers and non-lead workers in blood lead, zinc protoporhphyrin in blood and delta-aminoleuvulinic acid were statistically significant. There were significant differences between lead workers and non-lead workers in blood urea nitrogen, serum creatinine, serum uric acid except urine protein but their mean concentrations were all within normal limits. Serum creatinine and urine protein were not increasing according to the increasing blood lead. When cut off points of 20mg/dl in blood urea nitrogen, 1.2mg/dl in serum creatine, 7.0mg/dl in serum uric acid, 8.0mg/dl in urine protein and 40ug/dl in blood lead, 100ug/dl in zinc-protoporhphyrin in blood, 7.0mg/l in delta-aminoleuvulinic acid were accepted, comparison between frequencies of blood urea nitrogen, serum creatine, serum uric acid, urin protein by the level of blood lead, zinc-protoporhphyrin in blood and delta-aminoleuvulinic acid respectively was not statistically different. There were no dose-repsonse relationships in risk ratios by the level of blood lead and zinc-protoporphyrin in blood respectively. In summary, there were no significant effect of lead on the selected clinical renal function among the female lead workers at level of blood lead 40ug/dl that is the permissible level of lead poisoning in Korea.

Prevalence rate of lead related subjective symptoms in lead workers / 예방의학회지

The relationship between lead related subject symptoms and lead exposure indices was studied in 435 male lead workers in thirteen lead using industries. 212 male office workers who were not exposed to lead occupationally were also studied as a control group. Fourteen lead related symptoms were selected. They were further subdivided into 4 sub-symptom groups such as 1) gastrointestinal, 2) neuromuscular and joint 3) constitutional, and 4) psychological symptoms. Symptom questionnaires were provided to the workers and filled up by themselves and reconfirmed by interviewer(doctor). The test used for the evaluation of lead exposure were blood lead (PbB), zinc protoporphyrin in whole blood(ZPP), hemoglobin(Hb), hematocrit(Hct), delta-aminolevulinic acid in urine(DALA). The results obtained were as follows; 1. The higher prevalence rate in the sub-group of neuromuscular and joint symptoms was observed in occupationally lead exposed subjects than non-exposed subjects. Among the sub-groups, the most frequent symptom was "numbness of finger, hands of feet", and the prevalence of the symptom of "arthralgia", "weakness of fingers, hands or feet" and "myalgia" were higher in order. 2. While the symptom which showed the biggest difference of prevalence rate among the 14 symptoms between exposed and non-exposed subjects was "numbness of fingers, hands or feet" , the symptom which showed the highest prevalence rate was "feeling tired generally" in exposed and non-exposed subjects, but no statistical difference of symptom prevalence were observed. 3. In total study population, PbB and ZPP had dose-response relationship with 4 symptoms of neuromuscular and joint symptoms ("numbness of finger, hands or feet", "arthralgia", "weakness of fingers, hands or feet" and "myalgia") and one symptom of gastrointestinal group("intermittent pains in lower abdomen"). 4. In lead exposed workers, only neuromuscular and joint symptoms group showed dose-response relationship with PbB and ZPP. 5. In lead exposed workers, the prevalence rate of overall symptoms of lead workers with age below 39 years was higher than that of lead workers with age above 40. While neuromuscular and joint symptoms group had a dose-response relationship with PbB in former group, it had a dose-response relationship with ZPP in latter group. 6. Age adjusted odds ratios of symptoms of non-exposed with exposed and odds ratios of low exposed with high exposed workers showed the dose-response relationship of lead exposure with neuromuscular and joint symptoms group("numbness of fingers, hands or feet", "arthralgia", "weakness of fingers, hands or feet" and "myalgia") and gastrointestinal symptoms group("intermittent pains in lower abdoman").