Journal article
Associations of a toenail metal mixture with attention and memory in the Gulf long-term follow-up (GuLF) study
The Science of the total environment, Vol.935, 173387
07/2024
DOI: 10.1016/j.scitotenv.2024.173387
PMCID: PMC11170656
PMID: 38788945
Abstract
Research on metal-associated neurodegeneration has largely focused on single metals. Since metal exposures typically co-occur as combinations of both toxic and essential elements, a mixtures framework is important for identifying risk and protective factors. This study examined associations between toenail levels of an eight-metal mixture and attention and memory in men living in US Gulf states.
We measured toenail concentrations of toxic (arsenic, chromium, lead, and mercury) and essential (copper, manganese, selenium, and zinc) metals in 413 non-smoking men (23–69 years, 46 % Black) from the Gulf Long-Term Follow-Up (GuLF) Study. Sustained attention and working memory were assessed at the time of toenail sample collection using the continuous performance test (CPT) and digit span test (DST), respectively. Associations between toenail metal concentrations and performance on neurobehavioral tests were characterized using co-pollutant adjusted general linear models and Bayesian Kernel Machine Regression.
Adjusting for other metals, one interquartile range (IQR) increase in toenail chromium was associated with a 0.19 (95 % CI: −0.31, −0.07) point reduction in CPT D Prime score (poorer ability to discriminate test signals from noise). One IQR increase in toenail manganese was associated with a 0.20 (95 % CI, −0.41, 0.01) point reduction on the DST Reverse Count (fewer numbers recalled). Attention deficits were greater among Black participants compared to White participants for the same increase in toenail chromium concentrations. No evidence of synergistic interaction between metals or adverse effect of the overall metal mixture was observed for either outcome.
Our findings support existing studies of manganese-related memory deficits but are some of the first to show chromium related attention deficits in adults. Longitudinal study of cognitive decline is needed to verify chromium findings. Research into social and chemical co-exposures is also needed to explain racial differences in metal-associated neurobehavioral deficits observed in this study.
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•Toenail chromium inversely associated with sustained attention.•Toenail manganese inversely associated with working memory.•Greater attention deficits at lower chromium levels for Black vs White participants.•Future mixtures research should investigate social and chemical co-exposures.
Details
- Title: Subtitle
- Associations of a toenail metal mixture with attention and memory in the Gulf long-term follow-up (GuLF) study
- Creators
- Joyce J.Y. Lin - Johns Hopkins UniversityJordan R. Kuiper - Milken InstituteAisha S. Dickerson - Johns Hopkins UniversityJessie P. Buckley - University of North Carolina at Chapel HillHeather E. Volk - Johns Hopkins UniversityDiane S. Rohlman - University of IowaKaitlyn G. Lawrence - National Institute of Environmental Health SciencesW. Braxton Jackson - Social and Scientific Systems (United States)Dale P. Sandler - National Institute of Environmental Health SciencesLawrence S. Engel - University of North Carolina at Chapel HillAna M. Rule - Johns Hopkins University
- Resource Type
- Journal article
- Publication Details
- The Science of the total environment, Vol.935, 173387
- DOI
- 10.1016/j.scitotenv.2024.173387
- PMID
- 38788945
- PMCID
- PMC11170656
- NLM abbreviation
- Sci Total Environ
- ISSN
- 0048-9697
- eISSN
- 1879-1026
- Publisher
- Elsevier B.V
- Language
- English
- Electronic publication date
- 05/23/2024
- Date published
- 07/2024
- Academic Unit
- Public Health Administration; Occupational and Environmental Health; International Programs; Injury Prevention Research Center
- Record Identifier
- 9984630751402771
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