The Relationship between Occupational Lead Exposure and Minor Hearing Impairment / 대한산업의학회지

In this study the relationship between occupational lead exposure and minor hearing impairment was investigated in a cross-sectional design with 50 lead exposed workers from January to April 1994, The data were collected from the interview with the structured questionnaire which included sociodemographic variables and medical histories especially ear disease and occupational histories. Lead exposure indices which were blood lead, urine lead, zinc protoporphyrin in urine, and delta-aminolevulinic acid in urine were analyzed, Also study subjects were examined pure-tone hearing test. The results were as follows ; 1. There were significant differences in lead indices between lead-exposed workers and non-exposed workers. 2. The duration of lead exposure did not affect the hearing impairment among lead exposed workers. 3. Minor hearing impairment were higher in lead-exposed workers than non-exposed workers, but there were not statisticatly significant. The result from this study indicated that lead exposed workers should be monitored to prevent hearing impairment and would be needed health education.

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.