trail , canada , has been the site of an active lead / zinc smelter for nearly a century . since 1991 , 
 the trail community lead task force has carried out blood lead screening , case management , education programs targeted at early childhood groups and the general community , community dust abatement , exposure pathways studies , and remedial trials . from 1989 through 1996 , 
 average blood lead levels of children tested for the first time declined at an average rate of 0.6 microg / dl / year , while blood lead levels in canadian children not living near point sources appeared to be leveling off following the phase - out of leaded gasoline . 
 since there was no concurrent improvement in local environmental conditions during this time , it is possible that the continuing decline in trail blood lead levels has been at least partly due to community - wide intervention programs . 
 one year follow - up of children whose families received in - home educational visits , as well as assistance with home - based dust control measures , found that these specific interventions produced average blood lead changes of + 0.5- -4.0 microg / dl , with statistically significant declines in 3 years out of 5 . 
 education and dust control , particularly actions targeted toward higher risk children , appear to have served as effective and appropriate interim remedial measures while major source control measures have been implemented at the smelter site.imagesfigure 1figure 2