Determinants of arsenic metabolism: blood arsenic metabolites, plasma folate, cobalamin, and homocysteine concentrations in maternal-newborn pairs.
BACKGROUND
In Bangladesh, tens of millions of people have been consuming waterborne arsenic for decades. The extent to which As is transported to the fetus during pregnancy has not been well characterized.


OBJECTIVE
We therefore conducted a study of 101 pregnant women who gave birth in Matlab, Bangladesh.


METHODS
Maternal and cord blood pairs were collected and concentrations of total As were analyzed for 101 pairs, and As metabolites for 30 pairs. Maternal urinary As metabolites and plasma folate, cobalamin, and homocysteine levels in maternal cord pairs were also measured. Household tube well-water As concentrations exceeded the World Health Organization guideline of 10 microg/L in 38% of the cases.


RESULTS
We observed strong associations between maternal and cord blood concentrations of total As (r = 0.93, p < 0.0001). Maternal and cord blood arsenic metabolites (n = 30) were also strongly correlated: in dimethylarsinate (DMA) (r = 0.94, p < 0.0001), monomethylarsonate (r = 0.80, p < 0.0001), arsenite (As(+3)) (r = 0.80, p < 0.0001), and arsenate (As(+5)) (r = 0.89, p < 0.0001). Maternal homocysteine was a strong predictor of %DMA in maternal urine, maternal blood, and cord blood (beta = -6.2, p < 0.02; beta = -10.9, p < 0.04; and beta = -13.7, p < 0.04, respectively). Maternal folate was inversely associated with maternal blood As(5+) (beta = 0.56, p < 0.05), and maternal cobalamin was inversely associated with cord blood As(5+) (beta = -1.2, p < 0.01).


CONCLUSIONS
We conclude that exposure to all metabolites of inorganic As occurs in the prenatal period.
Hall
Marni
M
Department of Environmental Health Sciences, Columbia University Medical Center, New York, New York 10032, USA.
Gamble
Mary
M
Slavkovich
Vesna
V
Liu
Xinhua
X
Levy
Diane
D
Cheng
Zhongqi
Z
van Geen
Alexander
A
Yunus
Mahammad
M
Rahman
Mahfuzar
M
Pilsner
J Richard
JR
Graziano
Joseph
J
D000328:Adult; D001151:Arsenic / Q000097:blood* / Q000378:metabolism / Q000652:urine; D020261:Arsenic Poisoning / Q000097:blood* / Q000652:urine; D001459:Bangladesh; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D014805:Vitamin B 12 / Q000097:blood; D014881:Water Supply / Q000032:analysis
D015415:Biomarkers; D006710:Homocysteine; D005492:Folic Acid; D001151:Arsenic; D014805:Vitamin B 12