Effects of lead exposure on blood pressure in 665 lead workers / 公共卫生与预防医学

Objective To investigate the effect of lead exposure on blood pressure of lead workers. Methods A total of 665 lead workers from some lead-acid battery enterprises in Wuhan were selected as the lead exposure group, and 708 ordinary workers without lead exposure were selected as the control group. The blood pressure in the workers of both groups was measured. The blood lead concentrations were measured in the lead-exposed group. The independent samples t-test was used to compare the blood pressure between the two groups. Linear regression model was used to analyze the relationship between the blood lead concentration and the blood pressure in the lead-exposed group. Logistic regression analysis was used to analyze the relationship between the risk of hypertension and blood lead concentration in lead-exposed group. Results The mean values of systolic blood pressure, diastolic blood pressure and pulse in the lead exposure group were significantly higher than those in the control group, and the difference was statistically significant (P0.05). Linear regression analysis revealed that blood lead concentrations were significantly correlated with both systolic and diastolic blood pressure in the lead exposure group. For each increase of 1μg/L of blood lead concentration in the lead exposure group, the systolic blood pressure of lead workers increased by 0.011 mmHg, and the diastolic blood pressure increased by 0.007 mmHg. Logistic regression analysis found that men in the lead-exposed group had a higher risk of hypertension than women. The older the age and the higher the blood lead concentration, the higher the risk of development of hypertension. Conclusion There is a positive correlation between the blood lead concentration and the systolic and diastolic blood pressure in lead workers. The older the lead worker, the higher the risk of developing high blood pressure. The higher the lead concentration in lead workers, the higher the risk of developing high blood pressure.

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.

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.

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.