P. Langlois et al., BLOOD LEAD LEVELS IN TORONTO CHILDREN AND ABATEMENT OF LEAD-CONTAMINATED SOIL AND HOUSE-DUST, Archives of environmental health, 51(1), 1996, pp. 59-67
South Riverdale in Toronto, Canada, underwent a lead-abatement program
. In 1988, lead-contaminated soil was replaced at 970 properties, and
in 1989, professional housecleaning for lead removal was conducted in
717 households. The effect of ''abatement'' on blood lead levels in yo
ung children was investigated. Data were analyzed from 12 cross-sectio
nal blood-screening surveys that were conducted during an 8-y period i
n South Riverdale and in two comparison areas. Responses regarding beh
avioral, household, lifestyle, neighborhood, and environmental factors
, all of which were gleaned from associated questionnaires, were also
analyzed. Response rates varied between 32% and 75%. During the years
between 1984 and 1992, blood lead decreased in all study areas. There
appeared td be a minimal blood lead level of 2-3 mu g/dl for urban Ont
ario children who were less than 6 y of age. The significant differenc
e between South Riverdale and the control areas disappeared by 1992. A
lthough abatement activity in South Riverdale was associated with an a
ccelerated decline in blood lead levels, it was difficult to distingui
sh this from effects of decreased Toronto air lead levels or decreased
smelter emissions. Within South Riverdale, abatement appeared to be a
ssociated with a slower decline in blood lead levels over time, likely
the result of selection bias, soil mixing, or recontamination from th
e smelter. No difference was observed between the separate effects of
housecleaning or soil replacement. The findings could neither strongly
support nor refute beneficial effects of abatement.