[Effect of occupational combined exposure of chromium and iron on erythrocyte metabolism].
OBJECTIVE
To investigate the effect of combined occupational exposure of chromium and iron on erythrocyte metabolism, and the possible mechanism.


METHODS
A total of 115 chromate production workers were selected in a chemical factory of Jinan as exposure group, Dec, 2008, and 60 healthy residents from a community which was far away from the factory were enrolled as control group. Environmental concentrations of chromium and iron were collected by filter membrane sampling and determined. The peripheral blood of subjects were collected for determination of chromium, iron, copper in whole blood and folate, vitamin B₁₂ in serum, mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) and correlation analysis was conducted.


RESULTS
The median (quartile interval) concentration of air-chromium and air-iron in workplace were 9.0 (10.5) and 11.2 (10.1) µg/m³, respectively, which were significantly higher than that of the control (0.1 (0.1) and 7.2 (2.5) µg/m³) (all P values < 0.01). Blood-chromium and blood-iron of the exposed group were 15.5 (14.1) µg/L and (895.1 ± 90.2) mg/L, which were significantly higher than the counterpart of the control (3.6(2.0) µg/L, (563.7 ± 49.3) mg/L) (all P values < 0.01). Serum folate ((6.9 ± 2.5) µg/L), serum vitamin B₁₂ ((396.4 ± 177.0) µg/L) and blood copper ((777.6 ± 103.5) µg/L) of the exposed group were all significantly lower comparing to the control group ((558.0 ± 330.8), (8.1 ± 3.8), (812.1 ± 94.6) µg/L) (all P values < 0.05). The relationships between blood chromium and serum folate, serum vitamin B₁₂ were statistical significant (r = -0.319 and -0.293, P < 0.01). Both serum vitamin B₁₂ and blood copper correlated with mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) (r = -0.223, -0.242, -0.261, -0.292, all P values < 0.01).


CONCLUSIONS
Combined chromium and iron exposure existed in the workplace. Adverse effect of Chromium on human erythrocyte may via folate and vitamin B₁₂ metabolism, while iron may via copper metabolism.
Department of Occupational and Environmental Health Sciences, School of PuBlic Health, Peking University, Beijing 100191, China.
Qin
Q
Qian
Tian-cheng
TC
Wang
Yan-shuang
YS
Song
Li
L
Wang
Yu-hui
YH
Li
Shan-fa
SF
Yu
Ji
J
Zhang
Yan-hui
YH
Ma
Ning
N
Zhang
Jing-wen
JW
Zhou
Lan-zheng
LZ
Liu
Lei
L
Yan
Guang
G
Jia
D000395:Air Pollutants, Occupational; D002840:Chromates / Q000009:adverse effects*; D002857:Chromium / Q000009:adverse effects; D003300:Copper / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism*; D005492:Folic Acid / Q000097:blood; D006801:Humans; D007501:Iron / Q000009:adverse effects*; D016273:Occupational Exposure / Q000032:analysis; D014805:Vitamin B 12 / Q000097:blood
D000395:Air Pollutants, Occupational; D002840:Chromates; D002857:Chromium; D003300:Copper; D005492:Folic Acid; D007501:Iron; D014805:Vitamin B 12