CrVI exposure and biomarkers: Cr in erythrocytes in relation to exposure and polymorphisms of genes encoding anion transport proteins.
A total of 195 subjects, including 141 exposed workers and 54 farmers, were recruited in China to evaluate the usefulness of chromium (Cr) in erythrocytes as a biomarker of exposure to CrVI. The levels of Cr in red blood cells (RBC) were remarkably elevated even in a group of workers routinely exposed to CrVI as low as 5-15 microg m(-3) and showed a significant exposure-response trend over the exposure range from 0.002 to 1152 microg m(-3) (p <0.0001). Multiple linear regression analyses indicated that age and cigarette smoke were not associated with Cr in RBC. However, female subjects had lower Cr in RBC compared with their male counterparts for about the same exposure levels (p <0.05). The genotypes of band III, which encodes for anion transport protein and may regulate CrO4(-2) across cell membranes, were also identified and included for analysis. The ratios of Cr in RBC to CrVI exposure were higher in subjects with a wild genotype than in those who had heterozygous or homozygous variant alleles. However, the difference was not statistically significant probably due to the limited number of participating subjects. In addition, 15 of the 141 workers were selected for multiple exposure monitoring and blood sample collections to evaluate the inter- and intraindividual variations of Cr in RBC. Compared with the personal exposure levels, Cr in RBC had small intraindividual variations with a reliability coefficient of 0.88. The study suggests that Cr in RBC may serve as a sensitive and reliable biomarker for long-term exposure to CrVI.
Qu
Qingshan
Q
Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA. qingshan@env.med.nyu.edu
Li
Xiaomei
X
An
Feiyun
F
Jia
Guang
G
Liu
Lanzeng
L
Watanabe-Meserve
Hiroko
H
Koenig
Karen
K
Cohen
Beverly
B
Costa
Max
M
Roy
Nirmal
N
Zhong
Mianhua
M
Chen
Lung Chi
LC
Liu
Suhua
S
Yan
Lei
L
D027321:Anion Transport Proteins / Q000235:genetics*; D001483:Base Sequence; D015415:Biomarkers / Q000097:blood*; D002857:Chromium / Q000097:blood* / Q000633:toxicity*; D003367:Cotinine / Q000652:urine; D003404:Creatinine / Q000652:urine; D017931:DNA Primers; D006801:Humans; D016273:Occupational Exposure; D011110:Polymorphism, Genetic; D012680:Sensitivity and Specificity; D012907:Smoking; D011795:Surveys and Questionnaires
D027321:Anion Transport Proteins; D015415:Biomarkers; D017931:DNA Primers; D002857:Chromium; D003404:Creatinine; D003367:Cotinine