Environmental Heavy Metals Exposure: Effects on Development of Heart Failure in Nigeria

Background: Despite indications that environmental heavy metals; Lead (Pb), Arsenic (As), Cadmium (Cd) and Mercury (Hg) exposure may play important role in the pathogenesis of Cardiovascular diseases and thus heart failure, it has not been investigated in Black-African human population from a developing economy like Nigeria.

Objective: The aim of this study is to determine the role of blood Lead, Arsenic, Cadmium and Mercury in development of Heart failure.

Materials and Methods: Blood Pb, As, Cd and Hg levels were determined by Atomic Absorption Spectrophotometry (AAS) in 40 patients with heart failure and 40 control subjects.

Results: There were significant increases in Blood Arsenic (0.1082±0.058µg/dl versus 0.0072±0.015µg/dl, p=0.000), Pb (13.17±2.72µg/d versus 9.21±2.12µg/dl, p=0.000) and Cd(0.132±0.054µg/dl versus 0.087±0.029µg/dl, p=0.005) respectively, but no significant difference in blood Hg(0.85±0.55µg/dl versus 0.78±0.16µg/dl, p=0.593) and BMI(28.54±4.99 versus 26.98±3.30, p=0.289) respectively in all patients with heart failure compared to all controls. Comparison of the heavy metals (As, Pb, Cd and Hg) in male patients with heart failure versus female patients with heart failure shows no significant difference(P>0.05) in each case. There was positive correlation of blood Pb with Cd(r=0.474, p=0.036) and Hg( r=0.492, p=0.028) in all patients with heart failure, but there was no significant correlation of blood lead (Pb) with blood As(r=0.088, P=0.712) and BMI (r= -0.104, P=0.490) respectively).

It therefore appears that increases in blood levels of As, Pb and Cd due to environmental exposure may in part contribute to the development of heart failure in this environment. Thus, strict measures should be applied by the policy makers to reduce heavy metals pollution in Nigeria.