A new study has reported that cumulative lead exposure, typically in a community setting, may adversely impact a women's cognition in her later years.
The study, supported by the National Institute of Environmental Health Sciences, was conducted with a view to examine biomarkers of lead exposure in relation to performance on cognitive tests given to older women.
Lead exposure is measured in two ways-blood lead level, which is a reading of recent lead dosage; and bone lead level, which is a cumulative measure of lead exposure over many years.
The current study involved the assessment of bone lead levels in the tibia and the patella.
The researchers said that the analysis of all cognitive tests combined showed that levels of all three lead biomarkers were associated with worse cognitive performance, with the association between bone lead and letter fluency scoring dramatically different from the other bone lead/cognitive score associations.
They said that even though the levels of patella and blood lead were linked with worse cognitive function, their findings were statistically significant only for tibia lead, which typically reflects longer-ago exposures than patella lead.
Based on their observations, the researchers came to the conclusion that lead exposures in the distant past might be more important than relatively recent exposures in influencing cognitive function in older women.
"The identification of modifiable risk factors for cognitive decline may provide important clues for delaying or even preventing dementia," wrote first author Jennifer Weuve and colleagues.
The study has been published in the journal Environmental Health Perspectives (EHP).
The journal's editor-in-chief, Dr. Hugh A. Tilson, said: "Findings in this study are important because of their long-range consequences on the public health of an aging generation. Impaired cognition and cognitive decline in older women are associated with heightened risks of dementia, physical disability, hospitalisation and reduced quality of life in later years."