Contamination of houses by workers occupationally exposed in a lead-zinc-copper mine and impact on blood lead concentrations in the families.
- 1 February 1997
- journal article
- case report
- Published by BMJ in Occupational and Environmental Medicine
- Vol. 54 (2), 117-124
- https://doi.org/10.1136/oem.54.2.117
Abstract
To evaluate the pathway of leaded dust from a lead-zinc-copper mine to houses of employees, and the impact on blood lead concentrations (PbB) of children. High precision lead isotope and lead concentration data were obtained on venous blood and environmental samples (vacuum cleaner dust, interior dustfall accumulation, water, paint) for eight children of six employees (and the employees) from a lead-zinc-copper mine. These data were compared with results for 11 children from occupationally unexposed control families living in the same city. The median (range) concentrations of lead in vacuum cleaner dust was 470 (21-1300) ppm. In the houses of the mine employees, vacuum cleaner dust contained varying higher proportions of mine lead than did airborne particulate matter measured as dustfall accumulated over a three month period. The median (range) concentrations of lead in soil were 30 (5-407) ppm and these showed no evidence of any mine lead. Lead in blood of the mine employees varied from 7 to 25 micrograms/dl and was generally dominated by mine lead (> 60%). The mean (SD) PbB in the children of the mine employees was 5.7 (1.7) micrograms/dl compared with 4.1 (1.4) micrograms/dl for the control children (P = 0.02). The PbB of all children was always < 10 micrograms/dl, the Australian National Health and Medical Research Council goal for all Australians. Some of the control children had higher PbB than the children of mine employees, probably from exposure to leaded paint as six of the eight houses of the control children were > 50 years old. In five of the eight children of mine employees > 20% of PbB was from the lead mine. However, in the other three cases of children of mine employees, their PbB was from sources other than mine lead (paint, petrol, background sources). Houses of employees from a lead mine can be contaminated by mine lead even if they are not situated in the same place as the mine. Delineation of the mine to house pathway indicates that lead is probably transported into the houses on the clothes, shoes, hair, skin, and in some cases, motor vehicles of the workers. In one case, dust shaken from clothes of a mine employee contained 3000 ppm lead which was 100% mine lead. The variable contamination of the houses was not expected given the precautions taken by mine employees to minimise transportation of lead into their houses. Although five out of the eight children of mine employees had > 20% mine lead in their blood, in no case did the PbB of a child exceed the Australian National Health and Medical Research Council goal of 10 micrograms/dl. In fact, some children in the control families had higher PbB than children of mine employees. In two cases, this was attributed to a pica habit for paint. The PbB in the children of mine employees and controls was independent of the source of lead. The low PbB in the children of mine employees may reflect the relatively low solubility (bioavailability) of the mine dust in 0.1 M hydrochloric acid (< 40 %), behaviour--for example, limited mouthing activity--or diet.Keywords
This publication has 16 references indexed in Scilit:
- Sources of lead in soil and dust and the use of dust fallout as a sampling mediumScience of The Total Environment, 1995
- Paint as a source of recontamination of houses in urban environments and its role in maintaining elevated blood leads in childrenScience of The Total Environment, 1995
- Lead Bioavailability in the Environment of Children: Blood Lead Levels in Children Can Be Elevated in a Mining CommunityArchives of environmental health, 1994
- New Ceramics-Related Industry Implicated in Elevated Blood Lead Levels in ChildrenArchives of environmental health, 1987
- Indirect Exposures: The Significance of Bystanders at Work and at HomeAihaj Journal, 1986
- Transmission of occupational disease to family contactsAmerican Journal of Industrial Medicine, 1986
- Home lead-work as a potential source of lead exposure for childrenInternationales Archiv für Arbeitsmedizin, 1983
- Lead exposure among 3-year-old children and their mothers living in a pottery-producing areaInternationales Archiv für Arbeitsmedizin, 1983
- Application of lead isotopes and trace elements to mapping black shales around a base metal sulphide depositJournal of Geochemical Exploration, 1977
- Lead Poisoning in Children of Lead WorkersNew England Journal of Medicine, 1977