Prevalence rate of lead related subjective symptoms in lead workers

Jeong, Du Shin; Kim, Hwa Sung; Ahn, Kyu Dong; Lee, Byung Kook

Abstract

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").