PMID- 9172087
OWN - NLM
STAT- MEDLINE
DCOM- 19970725
LR  - 20190914
IS  - 1076-2752 (Print)
IS  - 1076-2752 (Linking)
VI  - 39
IP  - 5
DP  - 1997 May
TI  - Curvilinear relationship between blood lead level and reaction time. Differential 
      association with blood lead fractions derived from exogenous and endogenous 
      sources.
PG  - 426-31
AB  - Prior studies demonstrate an inconsistent relationship between occupational 
      inorganic lead exposure and simple reaction time (SRT) performance. In this 
      study, we administered a computerized SRT test to 78 currently employed lead 
      smelter workers and then investigated the relationship between different measures 
      of blood lead and components of SRT performance. The measures of blood lead 
      included current blood lead (PbB) and mathematically derived blood lead fractions 
      from the environment (PbB-env) and from bone (PbB-bn). Measures of SRT 
      performance, obtained from 44 trials with interstimulus intervals (ISIs) ranging 
      from 1 to 10 seconds, included median SRT (SRT-md), mean SRT for ISIs between 1 
      and 5 seconds (SRT-1-5), and mean SRT for ISIs between 6 and 10 seconds 
      (SRT-6-10). Multiple regression analysis after adjustment for age and education 
      revealed a curvilinear relationship between PbB and SRT-md. As PbB increased from 
      0 to 30 micrograms dl-1, SRT-md decreased, and only with PbB levels above 30 
      micrograms dl-1 did SRT-md increase. PbB terms accounted for 13.7% of the 
      variance in this SRT measure (P < 0.01). The longer ISI variable, SRT-6-10, was 
      found to be more strongly related to PbB, to have lesser variability across ISIs, 
      and to be unrelated to age. Additional multiple regression analysis to examine 
      the relationship between components of SRT and the PbB fractions, PbB-env and 
      PbB-bn, showed only PbB-env to account for significant variance in SRT-md, 
      (14.4%, P < 0.01), SRT-1-5 (9.7%, P < 0.03), and SRT-1-6 (15%, P < 0.01). We 
      conclude that the relationship between PbB and SRT is U-shaped, that the SRT 
      measure SRT-6-10 has properties that make it the preferred measure of SRT 
      performance in future studies, and finally that only PbB-env, and not PbB-bn, is 
      related to components of SRT.
FAU - Bleecker, M L
AU  - Bleecker ML
AD  - Center for Occupational and Environmental Neurology, Baltimore, MD 21211, USA.
FAU - Lindgren, K N
AU  - Lindgren KN
FAU - Tiburzi, M J
AU  - Tiburzi MJ
FAU - Ford, D P
AU  - Ford DP
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Occup Environ Med
JT  - Journal of occupational and environmental medicine
JID - 9504688
RN  - 2P299V784P (Lead)
SB  - IM
MH  - Adult
MH  - Environmental Monitoring/methods
MH  - Factor Analysis, Statistical
MH  - Humans
MH  - Lead/*adverse effects/*blood/metabolism
MH  - Linear Models
MH  - Male
MH  - Middle Aged
MH  - Occupational Exposure/*adverse effects
MH  - Reaction Time/*drug effects
MH  - Regression Analysis
MH  - *Welding
EDAT- 1997/05/01 00:00
MHDA- 1997/05/01 00:01
CRDT- 1997/05/01 00:00
PHST- 1997/05/01 00:00 [pubmed]
PHST- 1997/05/01 00:01 [medline]
PHST- 1997/05/01 00:00 [entrez]
AID - 10.1097/00043764-199705000-00008 [doi]
PST - ppublish
SO  - J Occup Environ Med. 1997 May;39(5):426-31. doi: 
      10.1097/00043764-199705000-00008.