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Powdered lead oxide (Pb 3 O 4 ) is used in the wooden-boat repair industry as a constituent of the caulking material. This study compared skin lead of household members of caulkers' and control homes, and examined the relationship of household member's skin lead with household floor lead loading (FLL) and dust lead content (DLC). FLL and DLC were measured in 67 caulkers' houses and 46 nearby houses with no known lead exposure. In each household, wipe specimens of skin lead were obtained from one selected family member. Hand lead loading (HdLL) and foot lead loading (FtLL) were significantly higher in family members of caulkers than controls (geometric mean 64.4 vs. 36.2 μ g m -2 ; p=0.002 and 77.8 vs 43.8 μ g m -2 ; p=0.002, respectively). This pattern mirrored FLL and DLC, which were also higher in caulkers' than in control houses (geometric mean 109.9 vs. 40.1 μ g m -2 ; p<0.001 and 434.8 vs 80.8 μ g g -1 ; p<0.001, respectively). Multiple linear regression modelling revealed FLL to be a better predictor than DLC for HdLL in all age groups and for FtLL in adult family members. In conclusion, skin lead levels are elevated in family members living in a lead-exposed worker's house and are related to the levels of household lead contamination.

A new dust-collecting device was developed to assess surface lead loading rates in houses in communities contaminated with lead oxide dust used for caulking in nearby boat-repair yards. The device consists of two small glass sheets with total area of 1,200 cm(2) placed in two plastic trays suspended from the ceiling in the house for 3 months before wiping and sending the dust specimen for determination of lead content using flame atomic absorption spectrophotometry. After a pilot trial in four households, further data were collected from 43 matched pairs of boat-caulkers' and neighboring control households. All devices were retained in the house for 3 months without any complaint. Static measurements of lead dust levels were also assessed in all households. The values significantly discriminated high from low lead exposure households (p = 0.015) and provided good correlations with floor lead loading (Spearman rank correlation coefficient, r = 0.39 to 0.62) and dust lead content (r = 0.53 to 0.64). This sampling method is an alternative to others which consume more household space or require a longer collection period.

Relative Contribution of Potential Modes of Surface Dust Lead Contamination in the Homes of Boatyard Caulkers: Orrapan UNTIMANON, et al. Bureau of Occupational and EnvironmentalDiseases, Ministry of Public Health, ThailandObjectives: The aim of this study was to quantify the relative contributions to surface lead contamination of boat-caulkers' houses of three contamination modes, namely "take-home" lead from the caulker, "natural" spatial dispersal from boatyard to household and "redistribution" of accumulated lead-laden dust within the house. Methods: Boat-caulkers' houses situated in areas surrounding boat repair yards were recruited. Caulkers' houses that were located close together were divided into location-matched pairs, within which one was randomly assigned to be given a cleaning and designated a CL house, and the other was to be left uncleaned and designated a NCL house. Geographically isolated caulker's houses were randomly assigned to one of the two categories. The nearest non-boatyard worker's house (NB) was additionally recruited for each set. The surface lead loading rate (SLLR), defined as the mass of lead deposited in dust per unit area of surface per unit time, was measured over a period of 3 mo in all houses, and the data were modeled using linear mixed effects regression. Results: Adjusted values of SLLR differed only slightly between CL and NCL houses (0.96 to 1.02 times) but were between 1.65 and 2.03 times higher in CL and NCL houses than in NB houses depending on proximity to the boatyard and between 2.12 and 2.61 times higher in houses within one km of a boatyard than in more distant houses depending on category of house. Conclusions: Newly deposited dust lead likely resulted from the take-home and spatial dispersion modes. The contribution of

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