Open AccessNeurocognitive function in relation to blood lead among young men prior to chronic occupational exposure
Author(s) -
CaiGuo Yu,
WenYi Yang,
Nelly D. Saenen,
FangFei Wei,
Zhenyu Zhang,
Blerim Mujaj,
Lutgarde Thijs,
Yingmei Feng,
Tim S. Nawrot,
Jan A. Staessen
Publication year - 2019
Publication title -
scandinavian journal of work, environment and health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.621
H-Index - 103
eISSN - 1795-990X
pISSN - 0355-3140
DOI - 10.5271/sjweh.3798
Subject(s) - confidence interval , neurocognitive , stroop effect , medicine , confounding , demography , psychology , audiology , cognition , psychiatry , sociology
Objectives Higher than contemporary exposure levels and advanced age of study participants have limited the interpretation of previous studies relating neurocognitive function to lead exposure. We reassessed this association in young American men prior to chronic occupational exposure at lead recycling plants, using baseline measurements of the Study for Promotion of Health in Recycling Lead (NCT02243904). Methods We administered the Stroop test (ST) and the digit-symbol test (DST) to 339 men (mean age, 28.6 years; participation rate 82.7%). Whole blood lead (BL) was determined by inductively coupled plasma mass spectrometry and related ST and DST test results using multivariable-adjusted regression. Results Average values were 4.26 μg/dL for BL, 1624 ms and 1474 ms for mean reaction time in incongruent and congruent ST trials, and 109 sec for mean total latency in DST. The number of participants with fully correct answers amounted to 281 (82.9%) and 334 (98.5%) in incongruent and congruent ST trials, respectively, and to 198 (58.4%) in the DST. In multivariable-adjusted analyses, there was no association between cognitive performance and BL except for a weak but opposite association in DST; for a 10-fold BL increment, mean total latency was 5.4% (95% confidence interval, -0.4‒11.5%; P=0.066) higher, whereas the error score was 42% (-10‒69%; P=0.096) lower. To exclude an effect of the cumulative lead dose, sensitivity analyses restricted to workers <40, 35 and 30 years were confirmatory. Conclusions At the exposure levels in our current study, we failed to demonstrate a consistent inverse association of BL with neurocognitive performance in young American men.