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Geophagia is the craving for non-food substances and commonly practiced among pregnant women and children. Consumption of geophagic clay samples can have serious implications on the health of the consumers as a result of the presence of toxic metals such as Pb, As, Hg and Cd. This study sought to determine the levels of heavy metals in the studied geophagic clay samples and to determine the potential risks of heavy metals as cumulative carcinogenic and non-carcinogenic risks to the health of the consumers via oral (ingestion) and dermal exposure routes. A total of thirty (30) white clay samples were analysed using Niton Thermo scientific XRF Analyser (Mobile Test S, NDTr-XL3t-86956, com 24). The clay samples were found to contain essential elements such as Ca, Fe, K and Zn as well as toxic metals such as As and Pb. There were isolated cases of the presence of Hg and all samples had Cd levels below detection. Health risk indices such as hazard quotient and cancer risk were calculated and the results indicated that consumers are likely to suffer from cancer through ingestion of geophagic clay. Bioaccessibility studies were done on zinc and it did not indicate any potential toxicity due to zincs essential nature. The levels of heavy metals in some of the geophagic clay consumed by some residents in the Kumasi were high compared to the Permitted Maximum Tolerable Daily Intake (PMTDI) by (WHO/FAO) and may pose potential health threat over time. Keywords: Geophagia, White clay, Heavy metals, Health risk assessment, Permitted maximum tolerable daily intake

Geophagia is an ancient practice subject to many prejudices. Recent animal experiments have shed light on its causes and consequences. Geophagia, a form of pica, may be induced by various factors. Clay, the material preferentially ingested by geophagic subjects, interacts with the food bolus and the digestive mucosa. Its capacity to form colloids and to adsorb and exchange ions results in both beneficial and harmful effects. In a less civilized age, the ingestion of clay may have reinforced digestive barriers against alkaloids and toxins, conferring a selective advantage on individuals practicing geophagia. However, in the modern Western world, complex interactions of clay with metals and ions are likely to generate low-level poisoning and deficiencies, potentially damaging the health of geophagic individuals and their offspring.

Members of the animal kingdom, including humans, can ingest soil either involuntarily or deliberately, the latter practice being known as geophagy or geophagia. This paper briefly documents the often significant quantities of soil that can be consumed, but discusses in detail the importance of this ingestion in supplying mineral nutrients and potentially harmful elements (PHEs) to consumers of earth materials. Whilst geophagia is recognised as a multi-causal behaviour, a prevalent explanation is the ‘nutritional hypothesis’ where the deliberate consumption of soil is attributed to an attempt to regulate a mineral nutrient imbalance such as sodium deficiency. When soils encounter digestive fluids, chemical elements can be solubilised and are potentially available for absorption, sometimes to an extent where toxicity symptoms are evident. In grassland agricultural systems, two main pathways of chemical elements are recognised, the soil–plant–animal flow being complemented by the more direct soil–animal transfer of mineral nutrients and PHEs. In locations where the pasture herbage absorbs very low concentrations of chemical elements relative to the soil content, ingested soil particles can often be observed to be the major source of mineral nutrients/PHEs consumed by livestock. However, further research is required in quantifying the bioaccessibility – defined as the fraction that is soluble in the gastrointestinal tract and is potentially available for absorption – of soil-elements to animals. In this respect, regarding human nutrition, for more than a decade considerable work has been undertaken on the development of in vitro bioaccessibility tests (IVBA) that can rapidly and inexpensively estimate this portion of chemical elements from ingested soils. Work to date has demonstrated that significant amounts of some mineral nutrients, especially iron, can be bioaccessible to humans, as can quantities of PHEs such as lead. Paradoxically, some ingested soils can also result in mineral nutrient deficiency problems in humans and other members of the animal kingdom attributable, for example, to the adsorptive properties of earth materials that can effectively bind chemical elements.

It is first article that reviews the literature on the problem of disorders of malnutrition among Saharawi children. Most of the studies reveal problems mainly of celiac disease, goiter, geophagia, undernutrition, wasting, stunting, overweight, scurvy, rickets and iron-deficiency anaemia.

Geophagia, the deliberate consumption of rocks, soil, or clay, is prevalent in developing countries, particularly sub-Saharan Africa. Health risks associated with this behavior include parasitosis, heavy metal poisoning, nutrient deficiencies, and poor birth outcomes. This pilot study was designed to reduce geophagic practices and improve nutrition among rural Kenyan women.The researchers used snowball sampling to recruit participants (n = 135; aged 15-49 years) from low socioeconomic areas who consumed geophagic materials. Interviews were carried out before and after a nutrition intervention implemented by trained community health volunteers.Nutrition education focusing on geophagia significantly (P .001) decreased the practice in 77% of participants. Postintervention interviews also demonstrated substantial improvement in understanding the concept of making half the plate vegetables using the healthy plate model.Nutrition education can be useful for reducing geophagia (a largely ignored, unsafe dietary behavior) and enhancing nutritional knowledge in African women.

Little is known about the relationship between soil biological function and the physical and chemical characteristics of soil-feeding termite nests in the Lope tropical rainforest (Gabon). We compared nine soil-feeding termite nests of Cubitermes of different ages (fresh to mature to old) and six surrounding soils that originated from three forests differing with respect to age and vegetative cover according to 14 physical and chemical variables and acid (pH 4) and alkaline (pH 9) phosphatase activities. Physical and chemical variables of the studied samples were influenced by the three factors tested: (1) forest age, (2) termite activity (nest versus soil), (3) termite nest age. Soils from the gallery forest were strongly discriminated from all the other soils studied notably due to their high organic matter contents. All mature nests showed significant increases in K, P, clay and fine silt, pH, and cationic exchange capacity compared to soils. Some nests also had increased amounts of organic matter and larger water retention capacities. Moreover, we observed that with age the termite nests possessed decreased values of these variables from fresh to mature to old. Likewise, phosphatase activities also differed according to the three factors tested. Due to its high organic matter contents, the highest phosphatase activities were noted in the gallery forest. Within each forest, phosphatase activities decreased in mature nests compared to soils and tended to be higher in fresh nests compared to mature nests. These differences might be due to an inhibition by high inorganic P contents, as mature nests were enriched in this element and to the quality of organic matter as nests are built with termite faeces. Termite activity has an important role in influencing physical and chemical variables and phosphatase activities.

Geophagia, the intentional and repeated ingestion of soil material, is a complex eating behaviour with incomprehensible aetiology. It is generally assumed that geophagia may help supplement mineral nutrients and thus should not be dissuaded, particularly in subsistence communities. This is largely based on the assumption that a large proportion of mineral nutrients in geophagic materials is potentially available for absorption in the body. We tested this hypothesis on five soils collected from geophagia-prevalent communities by using an in vitro soil ingestion simulation test that is broadly similar to the gastrointestinal (GI) tract. The results show that, despite the soils being rich in mineral nutrients, soil ingestion, inadvertent or through geophagia can potentially reduce the absorption of already bioavailable nutrients, particularly micronutrients such as Fe, Cu and Zn. These in vitro findings, while disagreeing with the commonly held view of geophagia as a source of nutrient supplementation, are consistent with micronutrient deficiency problems observed in clinical nutrition studies conducted amongst geophagic populations. The work also showed that, in some cases, the ingested soils may become a source of Ca, Mg and Mn, although it is not clear why other similar soils should not release any of these mineral nutrients.

Ce travail analyse les transformations qui conduisent à augmenter le contenu en phosphore inorganique (Pi) assimilable du sol suite à l'ingestion d'un ferralsol par le ver géophase #Pontoscolex corethrurus$. Le contenu en phosphore total, inorganique et organique d'échantillons de sol témoin, de sol non-ingéré mais incubé et de déjections de surface a été mesuré. Le phosphore extractible par NaHCO3 et NaOH a été dosé dans des échantillons ayant préalablement subi un fractionnement granulométrique (plus de 20, 2-20 et moins de 2 micromètres). La teneur en phosphore total est la même dans le sol témoin, le sol non-ingéré et les déjections ; la réhumectation du sol et l'ingestion du sol par le ver diminuent la teneur en phosphore organique et augmentent la teneur en phosphore inorganique. La teneur en argile des déjections (19.7%) est significativement supérieure à celle de l'échantillon témoin (9,1%). Les turricules ont une teneur en phosphore inorganique extractible par NaHCO3 significativement supérieure à celle du sol non-ingéré (5,04 micromètres Pi/g sol contre 3,17). La même tendance est observée dans l'extrait NaOH (45,8 micromètres Pi/g sol dans les déjections contre 27,4 dans le sol non-ingéré). Les phosphates dans les déjections sont essentiellement concentrés dans les fractions granulométriques fines (0-2 micromètres) (8.3% des phosphates extraits contre 61% pour le sol non-ingéré). Ces modifications résultent de l'ingestion sélective par le ver de particules fines et de la minéralisation partielle du phosphore organique. (Résumé d'auteur)

False-positive Ascaris suum egg counts in pig faeces are frequently observed under both experimental and natural conditions. Data from 12 experiments with A. suum infections in pigs were summarized and showed that the percentage of false-positive faecal samples ranged from 4 to 36%. False-positive egg count values varied greatly between pigs and experiments (range 20-1060 eggs per gram faeces). Indoor experiments with pigs housed groupwise in pens generally produced more and higher false-positive egg counts, which may reflect differences in surface area and hence exposure to infective eggs, compared with pasture experiments. The positive predictive value (the number of pigs diagnosed positive by faecal sample that actually harboured worms) was low for indoor experiments (45%) compared with pasture experiments (89%). Differences in design for indoor experiments, such as floor type and use of bedding material, did not influence the positive predictive value (44-47%). A positive correlation was found (r = 0.56, P < 0.05) between faecal egg counts of true-positive and false-positive pigs that were penned together. The results of this survey strongly support previous suggestions that false-positive A. suum egg counts in pigs are the result of coprophagia in indoor experiments and coprophagia/geophagia in pasture experiments. False-positive A. suum egg counts in pig faeces may vary greatly in prevalence and magnitude, and depend in part on management/housing factors.

An extensive survey was conducted during 1992–1993 in the Varanasi region to identify the most common species of earthworms which could be utilized for improving soil fertility and garbage decomposition. Eleven species of earthworms (Metaphire posthuma, Lampito mauritii, Eutyphoeus incommodus, Eutyphoeus nicholsoni, Eutyphoeus waltoni, Octochaetona surensis, Ramiella bishambari, Drawida calebi, Glyphidrilus sp., Dichogaster bolaui and Amynthas morrisi) were identified for the first time from this region. Among these L. mauritii, E. incommodus, E. nicholsoni, O. surensis and D. bolaui were very common and abundant species in each of the habitats sampled. D. bolaui, L. mauritii and E. incommodus were identified as major potential species and results suggest utilization of these species in soil fertility programmes.

Individuals of Pontoscolex corethrurus Muller, a geophagous tropical earthworm, were fed with two soils that have P-sorption contrasting characteristics. Water-soluble and exchangeable-P contents increased significantly in casts produced after ingestion of the low P-sorption soil, meaning that an important change occurred in the P-sorption complex. This increment was maintained for 4 days of cast aging and it could be ascribed to changes in the sorption reactive surfaces induced by competition for sorbing sites between orthophosphate and carboxyl groups of a (mucus-produced) glycoprotein. The increment in P availability in casts derived from the higher P-sorption soil decreased after 96 h perhaps due to an aging effect. The results presented, coupled with the high population of Pontoscolex corethrurus recorded in natural grasslands and cultivated agroecosystems suggest that these earthworms could be important in affecting P cycling in humid tropical soils.

As an eating disorder, pica may be manifested by ingestion of food or nonfood items, although various sources continue to present definitions of only selected forms. Many substances have been identified among a wide range of pica practicers; selected substances have been labeled as specific phagias, but among forms of pica, plumbophagia as a source of lead poisoning probably poses the greatest health threat to children, whereas geophagia is probably the most universal form of pica, especially among children. In addition to the value of averting the devastating effect of some forms of pica, the condition also offers promise as an early marker for iron deficiency. However, unless clinicians develop an open, nonjudgmental inquiry strategy, the practice is likely to be concealed, negating the route to appropriate assessment and treatment.

We investigated geophagia in the black population of rural Holmes County, Mississippi. Twenty-five sources of geophagical clays were located and most of the sources are associated with rural settlements throughout the county. Clays are taken from subsurface soil horizons, and all but one of the sources come from the upland portion of the county. Geophagia occurs among 57% of women and 16% of children of both sexes, but it is not found among adult males or adolescents. Average daily consumption of clay is 50 g. Our data indicate geophagia is not correlated with hunger, anemia, or helminthic problems, but it may contribute to the common problem of hypertension. Geophagia has been suggested as one of the factors leading to hyperka- lemia, but our data do not Support this notion. Am. I Cuts.Nutr. 32: 2 129-2135, 1979. Geophagia, the deliberate consumption of

The syndrome of dwarfism, hypogonadism, iron-deficiency anemia and geophagia, first reported in 1960 from Iran, was thought to be limited to males. In 1971-1972 two females with the same clinical features were observed over a 14-month period. The anemia responded rapidly to iron. Growth and sexual development occurred promptly when 120 mg of zinc sulfate was administered daily in conjunction with a well-balanced diet and iron supplement. This diet prior to the addition of zinc sulfate, resulted in gradual but much slower growth and sexual development. Observations in these two patients provide confirmation of the occurrence of human zinc deficiency in females, which responds to large doses of zinc salt.

The significance of pica and geophagia as a public health problem is well known. The objective radiographic diagnosis of geophagia depends on the abnormal opacification of the bowel as an immediate manifestitation of the condition. The chance of detectability of geophagia is highest in the colon and can be improved by using low penetration films, particularly for smaller amounts of ingested clay. Other radiologic changes frequently associated with the prolonged practice of geophagic are an atonic pattern of the colon, secondary radiographic changes due to iron-deficiency anemia and bone-age retardation. The occurrences of intestinal obstruction due to pica in the presence of preexisting bowel stricture is demonstrated.

Geophagia, in the form of clay-eating, is often observed during pregnancy in the human population. The intent of this study was to determine the effects of kaolin (clay) ingestion on the maternal blood and embryonic development of the pregnant rat. Thirty-six Sprague-dawley female rats were divided into three groups: control diet, 20% kaolin diet, and iron-supplemented 20% kaolin diet. The diets were fed 37 to 68 days, 69 to 95 days, and 96 to 117 days prior to fertilization, and the same diets were fed for the duration of the gestation period. The rats fed the kaolin diet exhibited significant reductions in hemoglobin, hematocrit, and red blood cell levels, thus indicating maternal anemia. There was also a significant reduction in the birth weight of the pups born to kaolin fed rats. The kaolin fed rats receiving an iron supplement maintained hematocrit, hemoglobin, red blood cell levels, and pup weight within the normal range.

Two experiments investigating the effects of motion sickness on pica (the consumption of non-nutritive substances) are reported. In the first experiment rats subject to rotational stimulation subsequently engaged in geophagia (clay consumption). In the second experiment use of a conditioned aversion paradigm confirmed that the method of rotational stimulation used in the first experiment causes motion sickness in rats. The results of these experiments indicate that simple gastrointestinal malaise in the absence of a deficiency state or acute toxemia will elicit pica. It is suggested that gastrointestinal distress may be a significant factor in the etiology of pica and its relationship to other causes of pica is discussed.

Soil-feeding termites ingest humified, organic-rich soil. The soil faeces are used for nest construction and mounds of two species of Cubitermes contained more soil, clay, exchangeable Ca and Mg, available P, total N and organic C than adjacent topsoil. Available P increased by 1.4–6.0 times. Mounds of a plant-debris feeding termite, Trinervitermes , contained significantly more of these fractions, with the exception of available P, than adjacent topsoil. The modification of Trinervitermes mounds by Cubitermes resulted in a 2-fold increase in available P, whereas organic C remained the same and N increased by 1.5-times. The relatively large increase in available P resulting from soil feeding termites could be attributed to the high pH regime in their hind-guts.

Zinc deficiency associated with nutritional dwarfism was reported from Egypt in 1963. The conclusions drawn from that study were based on biochemical changes in zinc metabolism plus zinc supplementation studies. The dwarfs were of varying ages and were affected in varying degrees of severity. This syndrome, which is common in the Middle East, has been extensively investigated in Iran where its clinical features were reported in detail in 1961. Our study was designed prospectively to give oral zinc supplementation under controlled conditions. A major factor in the etiology of this syndrome is the village diet which consists largely, and sometimes exclusively, of whole meal wheat bread. This contains a high level of phytate which binds zinc and makes it unavailable. Geophagia, which was present in all subjects, may be a factor in the pathogenesis. The subjects of this report are fifteen men who were rejected at the Iranian Army induction center because of "malnutrition," and two women. A unique feature was that all were nineteen or twenty years of age. They were studied for six to twelve months. One group was given a well-balanced nutritious diet containing ample animal protein plus a placebo capsule. A second group was given the same diet plus a capsule of zinc sulfate daily containing 27 mg of elemental zinc. A third group was given the diet alone without additional medication for six months, followed by the diet plus the administration of zinc sulfate. Assignment to groups was by random selection. Although the development in subjects receiving the diet alone was slow, the effect on height increment and onset of sexual function was strikingly enhanced in those receiving zinc capsules as a supplement. The differences were significant statistically (p