Chiaradia M, Gulson B L, MacDonald K
CSIRO/dEM, North Ryde, NSW, Australia.
Occup Environ Med. 1997 Feb;54(2):117-24. doi: 10.1136/oem.54.2.117.
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.
评估铅锌铜矿的含铅粉尘进入员工住宅的途径，以及对儿童血铅浓度（PbB）的影响。
获取了来自一座铅锌铜矿的6名员工（及其子女）的8名儿童的静脉血和环境样本（吸尘器灰尘、室内降尘累积物、水、油漆）中的高精度铅同位素和铅浓度数据。将这些数据与来自同一城市职业未暴露对照家庭的11名儿童的结果进行比较。
吸尘器灰尘中铅的中位数（范围）浓度为470（21 - 1300）ppm。在矿山员工的住宅中，吸尘器灰尘所含的矿山铅比例高于三个月期间累积的降尘所测得的空气中颗粒物。土壤中铅的中位数（范围）浓度为30（5 - 407）ppm，未显示出任何矿山铅的迹象。矿山员工的血铅含量在7至25微克/分升之间，且通常以矿山铅为主（> 60%）。矿山员工子女的平均（标准差）血铅浓度为5.7（1.7）微克/分升，而对照儿童为4.1（1.4）微克/分升（P = 0.02）。所有儿童的血铅浓度始终< 10微克/分升，这是澳大利亚国家卫生与医学研究委员会为所有澳大利亚人设定的目标。一些对照儿童的血铅浓度高于矿山员工的子女，可能是由于接触含铅油漆，因为对照儿童的八所房屋中有六所房龄超过50年。在矿山员工的八名儿童中，有五名儿童血铅的> 20%来自铅矿。然而，在矿山员工子女的其他三个案例中，他们的血铅来自矿山铅以外的来源（油漆、汽油、背景来源）。
即使矿山员工的住宅不在矿山所在地，也可能被矿山铅污染。矿山到住宅途径的划定表明，铅可能通过工人的衣服、鞋子、头发、皮肤以及某些情况下的机动车辆进入住宅。在一个案例中，从一名矿山员工衣服上抖落的灰尘含铅量为3000 ppm，且100%为矿山铅。考虑到矿山员工为尽量减少铅带入家中所采取的预防措施，住宅的不同程度污染出乎意料。尽管矿山员工的八名儿童中有五名血铅中矿山铅含量> 20%，但没有一名儿童的血铅浓度超过澳大利亚国家卫生与医学研究委员会设定的10微克/分升的目标。事实上，对照家庭中的一些儿童血铅浓度高于矿山员工的子女。在两个案例中，这归因于对油漆的异食癖习惯。矿山员工子女和对照儿童的血铅浓度与铅的来源无关。矿山员工子女血铅浓度较低可能反映了矿山粉尘在0.1 M盐酸中的溶解度相对较低（< 40%）、行为因素（例如有限的口接触活动）或饮食因素。
