A cross-sectional analytical study of geophagia practices and blood metal concentrations in pregnant women in Johannesburg, South Africa

Abstract

Background. Geophagia, a form of pica, has been shown to be widely practised in sub-Saharan Africa, especially among pregnant women. Objective. To assess the prevalence of geophagia and examine exposure to selected metals and associated risk factors in women attending an antenatal clinic at Rahima Moosa Mother and Child Hospital, Johannesburg, South Africa, during June and July 2010. Methods. We conducted a cross-sectional study on a convenience sample of 307 pregnant women, ranging in age from 18 to 46 years. Structured interviews were conducted to understand geophagia practices. Blood samples were collected to determine haemoglobin values and concentrations of arsenic, cadmium, mercury and lead. Statistical analyses using the χ 2 test, Wilcoxon's rank-sum test and logistic regression analyses were performed as appropriate. Results. Mean parity was 1.4 and the mean (standard deviation) gestational age 30.3 (6.0) weeks. Geophagia was reported by 60 women (19.5%), and the majority purchased soil from street vendors (83.3%). The prevalence of anaemia in the study sample was 16.9% (95% confidence interval 13.1 -21.6%). Geophagic women had significantly higher blood lead levels than non-geophagic women (2.1 v. 1.4 µg/dl; p<0.001). Anaemia, the use of African traditional medicines and craving of non-nutritive substances in a previous pregnancy were associated with geophagia. Conclusions. Geophagia is practised by a considerable proportion of pregnant women in Johannesburg, especially migrant women. Greater vigilance in respect of pica, especially geophagia, may be needed as part of antenatal care programmes to avoid potentially detrimental health effects of the practice.

Assessment of Haemoglobin Status and Transplacental Transport of Lead and Calcium During Geophagy

“…Rate of consumption that varied during pregnancy from daily to casual, with occasional or casual consumption dominating is consistent with [39]. Geophagy has been reported amongst different professions [39], and it is observed not to be linked to any specific profession like in this study.…”

“…Studies have confirmed that geophagy during pregnancy is linked to nausea or vomiting associated with morning sickness [37], taste [37][38] influence from others [39][40] and therapeutic where clay or soil is considered like a medicament [39]. Rate of consumption that varied during pregnancy from daily to casual, with occasional or casual consumption dominating is consistent with [39].…”

“…Ranges (Table 4) also indicate high anemia amongst kaolin consumers compared to previous and nonconsumers of kaolin. High prevalence of anemia in pregnant women, especially migrant women practicing geophagia in Johannesburg has been found [39], confirming that kaolin consumption can negatively affects Hb level of the body. These findings also coincide with those of the previous authors [60][61][62] that revealed a positive correlation between kaolin consumption and anemia.…”

The relation between pica and iron deficiency in children in Zanjan, Islamic Republic of Iran: a case-control study

“…Pica may have consequences like gastrointestinal disturbances; lead, mercury or arsenic intoxication; parasitic infestation; or potassium abnormalities (8). The frequency of pica varies from place to place, however, it appears to be more common in children, women, black people, people residing in rural areas and pregnant women (9). Its frequency in the United States of America ranges from 4% among men to 68% in pregnant women and 18.5% in children (10).…”

Effects of Geophagy on Hemoglobin Level and Iodine Absorption /Assimilation in Albino Rats

“…Although there exist beliefs about the nutritional benefits and detoxifying effects of geophagia [1] some reports indicate that ingestion of soil causes anemia [2][3]. Others present contrary view of no association between geophagia and anemia [4].…”