Different types of mercury emission (Hg) in the Amazon environrnent have been
contributing to increase the concentration of this metal into the drainage, reaching the aquatic
biota, contaminating the food chain with methyl mercury (MeHg), and increasing human
exposure to mercury. The presence of Hg and MeHg in residente mothers and newborns in
risk area is an important tool for the evaluation of Hg exposure and intoxication of human
populations. In this study, we evaluated Hg exposure levels in mothers and newborns and
performed differential diagnosis with other congenital diseases. The study was realized
between November 2000 and March 2002. AlI adults that participate in this study signed The
Ethical Consent Term in their behalf and in behalf of their children. The data collected
comprised epidemiological and clinical data; sampJes of blood, umbilical cord, placenta, and
hai; (maternal) for Hg analysis; serum for German measles, cytomegalovirus, toxoplasmosis,
and syphilis serological testo A total of 1510 women and the same number of newborn
participated in the study. The mothers were 22 years old (range 12 to 46 years old) and
worked as housewives (61.2%), rural workers (14.8%), and maidservant (10.9%). The mean
Hg leveI in mothers blood was 11.53 !lg/l (0.38 -117.62 !lg/l). The mean Hg leveI in
newborn blood was 16.68 !lg/l (0.35 -126.87 !lg/l). Birth clinical data showed low weight
(7.3%), cyanosis (7.0%), andjaundice (1%); 12.3% ofnewborn required medical Cale. It was
not found statistical difference between clinical data and Hg levels. The correlation among Hg
concentration in newborn and mothers were strongly positive (r = 0.8019; p < 0.001) with a
significant model oflinear regression (r = 0.5283; p < 0.001) in which the maternal Hg leveI
presented positive value for predicting levels in the newborn. The Hg levels found in both
mothers and newborn characterize an exposure similar to those observed in other populations
from the Tapaj?s River basin, with mean levels above the acceptable limits and in some cases
above the internationally established limit of biological tolerance. The variables maternal age
and Hg amount showed good relationship with the Hg levels found in children as predictive
factors of exposure. The Hg concentration in newborn emphasizes the special attention
needed to the process of Hg intra-uterine accumulation, which has potential consequences for
the development of children living in areas polluted by mercury.
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