So found a study by the New York State Health Department that showed a relative doubling of exposures in children in 2006-2007, compared with 1993-1994, that could be attributed to renovation and repair of older homes.
In two-thirds of the cases, parents did the home-renovation work themselves. The activities most often associated with lead exposure were sanding and scraping and paint removal.
A 1997 study by the health department identified home repairs, renovations, and painting as a major contributor to cases of lead exposure in children. The study emerged from statewide data (excluding New York City) from 1993-1994.
The current study, published in the Jan. 30 issue of Morbidity and Mortality Weekly Report, updated the earlier study with data from 2006-2007.
Since 1993, New York has required blood lead testing of all children at ages one and two years. During 2006 and 2007, the state health department conducted 972 environmental investigations related to blood lead levels of at least 20 Âµg/dL. That compared with 4,608 investigations during 1993-1994.
The relative proportion of exposures attributable to home renovation and repair doubled from 6.9% in 1993-1994 to 14.3% during 2006-2007.
However, the total number of exposures related to home renovation and repairs declined by 56% between the two periods (320 to 139), consistent with the nationwide decline in exposures linked to lead-based paint from an estimated 64 million in 1990 to 38 million in 2000.
Of 972 New York children with blood lead levels of at least 20 Âµg/dL, home renovation, repair, and painting accounted for 139 (14.3%) of presumed sources of exposure, reported investigators at the state health department and colleagues at the CDC.
"Children living in homes built before 1978 . . . that are undergoing renovation, repair, and painting activities should be considered at high risk for elevated blood lead levels, and appropriate precautions should be taken to prevent exposure," the authors concluded.
Blood lead levels of at least 10 Âµg/dL have been associated with adverse behavioral and developmental outcomes. Environmental and medical interventions are recommended at levels â‰¥20 Âµg/dL. However, no blood lead level is considered safe, the authors noted.
The 139 cases linked to home renovation and repair included 63 (45%) children with blood lead levels of 20 to 24 Âµg/dL, 24 (17%) with levels of 25 to 29 Âµg/dL, and 52 (38%) with levels â‰¥30 Âµg/dL. About 70% of the children were ages one to two.
The 139 children lived in 131 homes, all but one of which was built before 1978. More than 40% of the homes were located in urban areas, 28% in suburbs, and 30% in rural areas.
Despite a dramatic reduction in potentially dangerous lead exposures, an estimated 250,000 children remain at high risk for exposure, according to a report from the Environmental Protection Agency.
The exposure risk is greatest in houses built before 1950, when paint contained higher levels of lead, the New York and CDC investigators noted. That risk raises particular concern in New York, which has the nation's largest number (3.3 million) and proportion (43%) of pre-1950 housing units.
- Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco