School of Medicine Publications and Presentations
Document Type
Article
Publication Date
12-4-2020
Abstract
Objectives Lead exposure causes neurocognitive dysfunction in children, but its association with neurocognition in adults at current occupational exposure levels is uncertain mainly due to the lack of longitudinal studies. In the Study for Promotion of Health in Recycling Lead (NCT02243904), we assessed the two-year responses of neurocognitive function among workers without previous known occupational exposure newly hired at lead recycling plants.
Methods Workers completed the digit-symbol test (DST) and Stroop test (ST) at baseline and annual follow-up visits. Blood lead (BL) was measured by inductively coupled plasma mass spectrometry (detection limit 0.5 μg/ dL). Statistical methods included multivariable-adjusted mixed models with participants modelled as random effect.
Results DST was administered to 260 participants (11.9% women; 46.9%/45.0% whites/Hispanics; mean age 29.4 years) and ST to 168 participants. Geometric means were 3.97 and 4.13 μg/dL for baseline BL, and 3.30 and 3.44 for the last-follow-up-to-baseline BL ratio in DST and ST cohorts, respectively. In partially adjusted models, a doubling of the BL ratio was associated with a 0.66% [95% confidence interval (CI) 0.03–1.30%; P=0.040] increase in latency time (DST) and a 0.35% (95% CI ‑1.63–1.63%; P=0.59) decrease in the inference effect (ST). In fully adjusted models, none of the associations of the changes in the DST and ST test results with the blood lead changes reached statistical significance (P≥0.12).
Conclusions An over 3-fold increase in blood lead over two years of occupational exposure was not associated with a relevant decline in cognitive performance.
Recommended Citation
Yu Y-L, Thijs L, Saenen N, Melgarejo JD, Wei D-M, Yang W-Y, Yu C-G, Roels HA, Nawrot TS, Maestre GE, Staessen JA, Zhang Z-Y. Two-year neurocognitive responses to first occupational lead exposure. Scand J Work Environ Health – online first. doi:10.5271/sjweh.3940
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication Title
Scandinavian Journal of Work, Environment & Health
DOI
10.5271/sjweh.3940
Academic Level
faculty
Mentor/PI Department
Neuroscience
Comments
Copyright (c) Scandinavian Journal of Work, Environment & Health