Effect of Kaolin Consumption on Serum Heavy Metal Levels of Pregnant Women

Abstract

Geophagy is the consumption of earth materials across several cultures in many continents. For various reasons, consumption of kaolin is common among pregnant women in Nigeria. This earth material is known to contain heavy metals. This study was carried out to determine the effect of kaolin consumption on some heavy metal levels in pregnant women attending antenatal clinic in a Teaching Hospital in the south east Nigeria. A total of eighty pregnant women recruited for this study were grouped as follows; Group 1, (30 geophagic pregnant women within the first trimester). Group 2 (30 geophagic pregnant women within the second trimester) and Group 3 (20 non-geophagic pregnant women that served as control) Subjects in Groups 1 and 2 were subdivided into three based on the quantity of kaolin consumed per week, Group A (100 g/week), group B (150 g/week) and group C (200 g/week). Preliminary analysis of the heavy metal contents of kaolin was carried out. After two weeks of kaolin consumption, the serum levels of lead, arsenic, cadmium and mercury of the subjects were determined. The mean concentrations of lead (0.347 ± 0.12), arsenic (0.354 ± 0.15), cadmium (0.209 ± 0.11) and mercury (0.029 ± 0.02) in the kaolin exceeded the maximum permissible concentrations in food. The concentration of lead increased significantly (p < 0.05) in the first and second trimester pregnant women on 150 and 200 g of kaolin per week. There was a significant (p < 0.05) increase in the concentration of arsenic and cadmium in the second trimester women who consumed 200 g of kaolin per week. These results indicate that unregulated consumption of kaolin in pregnancy increases the serum level of the heavy metals and may be a risk factor for lead toxicity with its attendant complications in the infants.