A cohort study on blood zinc protoporphyrin concentration of workers in storage battery factory / 예방의학회지

To investigate the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, the blood zinc protoporphyrin(ZPP) concentrations of 131 workers ( 100 exposed subjects and 31 controls ) of a newly established battery factory were analyzed. They were measured in every 3 months up to 18 months. Air lead concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean blood ZPP concentration of the controls was 16.45+/-4.83 microgram/dashliter at the preemployment examination and slightly increased to 17.77+/-5.59 microgram/dashliter after 6 months. Mean blood ZPP concentration of the exposed subjects who were employed before the factory was in operation (Group A) was 17.36+/-5.20 microgram/dashliter on employment and it was increased to 23.00+/-13.06 microgram/dashliter after 3 months. The blood ZPP concentration was increased to 27.25+/-6.40 microgram/dashliter on 6 months (p<0.01) after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between 25.48 microgram/dashliter and 26.61 microgram/dashliter in the subsequent 4 results. Mean blood ZPP concentration of the exposed subjects who were employed after the factory had been in operation but before the intervention program was initiated (Group B) was 14.34+/-6.10 microgram/dashliter on employment and it was increased to 28.97+/-7.14 microgram/dashliter (p<0.01) in 3 months later(1 month after the intervention). The values of subsequent 4 tests were maintained between 26.96 microgram/dashliter and 27.96 microgram/dashliter. Mean blood ZPP concentration of the exposed subjects who were employed after intervention program had been started (Group C) was 21.34+/-5.25 microgram/dashliter on employment and it was gradually increased to 23.37+/-3.86 microgram/dashliter (p<0.01) after 3 months, 23.93+/-3.64 microgram/dashliter after 6 months, 25.50+/-3.01 microgram/dashliter (p<0.01) after 9 months, and 25.50+/-3.10 microgram/dashliter after 12 months. Workplaces were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were 0.365 microgram/m4, and after the intervention the levels were decreased to 0.216 microgram/m4 and 0.208 microgram/m4 in follow-up test. The Pb-A of part II which was resulted in lower value than part I was decreased from 0.232 microgram/m4 to 0.148 microgram/m4, and 0.120 microgram/m4 after the intervention. The Pb-A of part III was tested after the intervention and resulted in 0.124 microgram/m4 in January 1988 and 0.081 microgram/m4 in August 1988. The Pb-A of part IV was also tested after the intervention and resulted in 0.110 microgram/m4 in August 1988. There was no consistent relationship between Pb-A and blood ZPP concentration. The blood ZPP concentration of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. The blood ZPP concentration of the workers in the part of the lowest Pb-A increased more rapidly. The blood ZPP concentration of the group C workers was the highest in part III. These findings suggest that the intervention in personal hygiene is more effective than environmental intervention, and it should be carried out from the first day of employment and to both the exposed subjects, blue color workers and the controls, white color workers.

Exposed level of workers in the factory next to a led recycling factory / 예방의학회지

The purpose of this study was to determine whether workers at a factory next to a lead recycling factory in Pusan, were affected by lead contamination. The mean air lead concentration of lead recycling factory was 0.21mg/m3(TWA=0.05mg/m3). Thirty-nine male workers of Factory A, Cr. plating factory next to the lead recycling factory were exposed group and a comparison group, 62 male workers of Factory B were selected from another Cr. plating factory about 8.5km away from lead recycling factory. Air lead concentration of each workplace was checked for 4 times from August 5 to August 20 in 1995 by low volume air sampler. Each subject was interviewed about age, life-style, smoking, work history, and residence etc, and venous blood was drawn for lead measurement by graphite furnace atomic absorption spectrometry. We have observed that air lead concentration and blood lead concentration of Factory A was higher than Factory B(2.6 +/- 1.6 Vs. 1.2 +/- 0.2 microgram/m3, 14.9 +/- 1.6 Vs. 12.2 +/- 1.6 microgram/dl). We believe that other environmental lead sources such as transportation and residence did not affect air lead and blood lead concentration differences of both factory. We concluded that high air lead and blood lead concentration of Factory A were caused by lead contamination generated by the neighboring lead recycling factory.

Relationship Between The Biological Lead Exposure Indices And Air Lead Concentrations Measured By Personal Air Samplers / 예방의학회지

This study was carried out to evaluate the relationship between the biological lead exposure indices and air lead concentrations measured by personal air samplers. The 72 occupationally lead exposed workers were observed and the biological lead exposure indices chosen for this study were blood lead(PuB), urine lead(PbU), zinc protoporphyrin in whole blood(ZPP), gamma-aminolevulinic acid in urine(ALAU), gamma-aminolevulinic acid dehydratase activity(ALAD), coproporphyrin in urine(CPU) and hemoglobin(Hb). The workers were divided into four groups by air lead concentrations: Group I; under 0.05 mg/m3, Group II; 0.05-0.10 mg/m3, Group III; 0.10-0.15 mg/m3 and Group IV; and over 0.15 mg/m3. For evaluation the relationship between the biological lead exposure indices and air lead concentrations was used as correlation coefficients. The results obtained were as follows: 1. In Group I, II, III and IV, the mean value of PbB were 25.45+/-1.84 microgram/dl, 27.87+/-3.53 microgram/dl, 31.21+/-1.76 microgram/dl and 47.02+/-13.96 microgram/dl. Between Group IV and other groups showed statistically significant difference(p<0.05). 2. There was an increasing tendency of PbB, PbU, ALAU and ZPP according to the increase the mean air lead concentration, while ALAD has decreasing tendency. CPU and Hb did not show any constant tendency. 3. Correlation coefficients between PbB, PbU, ZPP, ALAU, ALAD, CPU, Hb and air lead concentration were 0.95, 0.83, 0.89, 0.72, -0.83, 0.51 and -0.45 respectively, and regression coefficient between PbB(Y) and PbA(X) was Y=126.8746X+16.9996(P<0.01).

Cohort Observation of Blood Lead Concentration of Storage Battery Workers / 예방의학회지

To assess the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, 156 workers (116 exposed subjects and 40 controls) of a newly established battery factory were examined for their blood lead concentration (Pb-B) in every 3 months up to 18 months. Air lean concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean Pb-B of the controls was 21.97 +/- 33.6 microgram/dl at the preemployment examination and slightly increased to 22.75 +/- 3.38 microgram/dl after 6 months. Mean Pb-B of the workers who were employed before the factory was in operation (Group A) was 20.49 +/- 3.84 microgram/dl on employment and it was increased to 23.90 +/- 5.30 microgram/dl after 3 months <(P<0.01). Pb-B was increased to 28.84 +/- 5.76 microgram/dl 6 months after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between 26.83 microgram/dl and 28.28 microgram/dl in the subsequent 4 tests. Mean Pb-B of the workers who were employed after the factory had been operation but before the intervention program was initiated (Group B) was 16.58 +/- 4.53 microgram/dl before the exposure and it was increased to 28.82 +/- 5.66 microgram/dl (P<0.01) in 3 months later (1 month after the intervention). The values of subsequent 4 tests remained between 26.46 and 28.54 microgram/dl. Mean Pb-B of the workers who were employed after intervention program had been started (Group C) was 19.45 +/- 3.44 microgram/dl at the preemployment examination and gradually increased to 22.70 +/- 4.55 microgram/dl after 3 months (P<0.01), 23.68 +/- 4.18 microgram/dl after 6 months, and 24.42 +/- 3.60 microgram/dl after 9 months. Work stations were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were 0.365 mg/m3, and after intervention the levels were decreased to 0.216 mg/m3 and 0.208 mg/m3 in follow-up tests. The Pb-A of part II was decreased from 0.232 mg/m3 to 0.148 mg/m3, and 0.120 mg/m3 after the invention. Pb-A of part III and IV was tested only after intervention and the Pb-A of part III were 0.124 mg/m3 in January 1988 and 0.081 mg/m3 in August 1988. The Pb-A of part IV, not stationed at one place but moving around, was 0.110 mg/m3 in August 1988. There was no consistent relationship between Pb-B and Pb-A. Pb-B of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. Pb-B of the workers in the part of the lowest Pb-A increased more rapidly. Pb-B of group C workers was the highest in part I and the lowest in part IV. These findings suggest that Pb-B is more valid method than Pb-A for monitoring the health of lead workers and intervention in personal hygiene is more effective than environmental intervention.