Data from: Variation in thyroid hormone levels is associated with elevated blood mercury levels among artisanal small-scale miners in Ghana

Background: Mercury can be very toxic to human health even at low dose of
exposure. Artisanal small-scale miners (ASGMs) use mercury in gold
production, hence are at risk of mercury-induced organ dysfunction. Aim:
We determined the association between mercury exposure, thyroid function
and work-related factors among artisanal small-scale gold miners in
Bibiani-Ghana. Method: We conveniently recruited 137 consenting male gold
miners at their work site in Bibiani-Ghana, in a comparative
cross-sectional study. Occupational activities and socio-demographic data
of participants were collected using a questionnaire. Blood sample was
analysed for total mercury and thyroid hormones. Results: Overall, 58.4%
(80/137) of the participants had blood mercury exceeding the occupational
exposure threshold (blood mercury ≥5μg/L). T3(P<0.0001) and
T4(P<0.0001) were significantly reduced among the exposed group
compared to the non-exposed. TSH showed no significant variation between
the exposed and non-exposed groups. Longer work duration (≥5years), gold
amalgamation, gold smelting and sucking of excess mercury with the mouth
were associated with increased odds of mercury exposure. Blood mercury
showed negative correlation with T3(r = -0.29, P<0.0001), and T4(r
= -0.69, P<0.0001) and positive correlation with work duration (r =
0.88, P<0.001). Even though a positive trend of association between
blood mercury and TSH levels was recorded, it was not significant (r =
0.07, P = 0.4121). Conclusion: Small scale miners in Bibiani are exposed
to mercury above the occupational threshold which may affect thyroid
hormone levels.