Geophagy and potential health implications: geohelminths, microbes and heavy metals

The role of geophagy and artisanal gold mining as risk factors for elevated blood lead levels in pregnant women in northwestern Tanzania

Neither artisanal and small-scale gold mining (ASGM) or geophagy practices have received substantial attention related to blood lead levels despite the well documented deleterious effects of lead. This cross-sectional analytical study aimed to document the risk of lead exposure from geophagy and mining-related occupational activities for pregnant women. The study recruited 1056 pregnant women (883 in an ASGM area and 173 in a non-ASGM area) between April 2015 -April 2017. Generalized Linear Model with an identity link function was used to model the association between blood lead levels (BLLs) and geophagy practices and involvement in gold mining. The prevalence of geophagy was 36.2% (95% CI: 33.6, 39.4%) and 6.3% engaged in mining as a primary occupation. Practicing geophagy increased BLLs by 22% (β = 1.22, 95% CI: 1.116, 1.309, p<0.0001). Living in a gold mining area increased BLLs by 33.4% (β = 1.334, 95% CI: 1.2, 1.483, p<0.0001). Having mining as a primary occupation increased BLLs by 1.3% β = 1.013, 95% CI: 0.872, 1.176, p = 0.869) even though the association was not statistically significant. Socioeconomic wealth quantile (β = 1.037, 95% CI: 1.021, 1.054, p<0.001) increased blood lead levels by 3.7%. Developing a comprehensive inventory capturing sources of community-level lead exposure is essential. Further, increasing public health campaigns and education are crucial to limit geophagy practices and to minimize work in gold mining activities during pregnancy.

Prenatal arsenic and mercury levels among women practicing geophagy in areas with artisanal and small-scale gold mining activities, Northwestern Tanzania

BACKGROUND

Artisanal and small-scale gold mining (ASGM) areas potentially pose increased exposure to arsenic and mercury through community contamination, occupations at gold mines, and/or geophagy when soil is locally sourced. This study examined the effects of geophagy, a deliberate soil eating practice, along with community and occupational exposures in ASGM areas on urinary arsenic and blood mercury levels among pregnant women in the Mining and Health Longitudinal Cohort in northwestern Tanzania.

METHODS

Data on maternal arsenic and mercury levels were captured for 1056 pregnant women using an unprovoked morning urine samples and dried blood spots respectively. We used a step-wise generalized linear regression model to retain the most relevant covariates for the model. A generalized linear regression model with identity link function was used to predict the effect of geophagy practices on arsenic and mercury levels separately. The model was adjusted using sociodemographic correlates, including maternal age, education level, whether respondents lived in mining or non-mining area, years of residence, marital status, maternal occupation, individual partner's education, and occupational, and socioeconomic status.

RESULTS

In the adjusted regression model, eating soil during pregnancy increased arsenic concentration by almost 23% (β = 1.229, 95% CI: 1.094, 1.38, p < 0.001) and living in mining areas had a 21.2% (β = 1.212; 95% CI: 1.039,1.414, p = 0.014) increased risk. Geophagy significantly increased mercury levels by 13.3% (β = 1.133, 95% CI: 1.022, 1.257, p = 0.018). Living in areas with ASGM activities was associated with a 142% (β = 2.422, 95% CI: 2.111, 2.776, p < 0.0001) increase in blood mercury.

CONCLUSION

Geophagy practices increased urinary arsenic and blood mercury levels in pregnant women, which was especially true for arsenic when living in areas with ASGM activities. Working in mining = increased risk for blood mercury levels. Community-based environmental health policies should address reductions in occupational and community exposures, along with strategic geophagy reduction interventions.

Geochemical composition and potential health risks of geophagic materials: an example from a rural area in the Limpopo Province of South Africa

Geophagy is a common practice among rural population of the Fetakgomo Tubatse Local Municipality area in the Limpopo Province of South Africa. Although, the practice might be beneficial to the health of the consumers, its negative effects could overshadow the positive effects and might lead to detrimental health issues. The present work sought to investigate the geochemical composition as well as pH and organic matter (OM) content of geophagic materials commonly consumed in the study area. Furthermore, assessment of the potential health risk of the materials on geophagic individuals was also considered. Twelve samples were collected in the study area and analysed by X-ray Fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for major and trace elements composition. The results showed higher concentrations of non-essential elements (e.g., As, Cr, Pb) than the proposed recommended daily standards intake, suggesting a potential health risk. The alkaline nature (pH 6.80 to 9.22) of the studied samples might affect the bioacessibility of some essential elements. Furthermore, the OM content (> 0.7%) observed in some of the studied samples may retain pathogenic micro-organisms detrimental to health. Although As and Cr presented a low bioaccessible fraction (< 16.0%), health risk assessment revealed that their concentrations represented a hazard (HQ > 1) and might induce non-carcinogenic health threats to geophagic individuals. Based on the geochemical analysis, pH and OM content as well as health risk assessment findings, the studied geophagic materials are not considered suitable for human consumption. The practice should therefore be discouraged amongst the population in the study area to avoid possible detrimental health issues.

Heavy metals in edible red soil of the rainbow island in the Persian gulf: Concentration and health risk assessment

Red soil of Hormuz Island has become a tourist attraction and it has various industrial applications. Despite the uncertainty of the health effects, geophagy is one of the common ways of people exposure to the red soil. This soil is widely used as a local spice and plays an important role in the food culture of the region. This study aimed to quantify the level of selected heavy metals (Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, Zn, Ag, Cd, Hg) in the red soil. The content of the metals was measured by ICP-MS (inductively coupled plasma-mass spectrometry). Moreover, risk assessment via heavy metals was carried out by computing the values of Total Hazard Quotient (THQ) and Hazard Index (HI). The results of this study showed that Fe was the most abundant metal among all analyzed metals and the health risk associated with Fe was individually higher than other measured metals. Altough the value for total heavy metals toxicity assessment was found lower than 1 , due to increasing use of red soil as a spice among Hormuz island natives, establishing special industries in order to reducing the amount of heavy metals content in red soil is recommended.

Current status of research and gaps in knowledge of geophagic practices in Africa

This article synthesises current knowledge and identifies research gaps on the still intriguing aspects of the subject of geophagy as practised in Africa. Despite the voluminous research literature that exists on the subject, geophagy in Africa is still a largely misunderstood phenomenon. Although the practice is not confined to any particular age group, race, gender, or geographical region, in Africa it is most commonly recorded among pregnant women and children. Till now, the precise aetiology of geophagy remains obscure; but the practice is thought to have both beneficial effects such as having a role as a nutrient supplement, as well as several demerits. An updated critical review of human geophagy in Africa - with a section on (other) animal geophagy -, highlights several aspects of the practice that need further research. A comprehensive bibliography is assembled, comprising some of the more pertinent and recently published papers (mostly post-dating the year 2005), as well as older seminal works, providing a baseline and robust framework for aiding the search process of Medical Geology researchers and those from allied fields wanting to explore the still poorly understood aspects of geophagy in Africa.

In vitro release of aluminum from the geophagic clay "Chacco" in the Peruvian highlands: Chemical characterization and health risk assessment

In the altiplano zone of Latin America, "Chacco" is one of the clays widely consumed as part of geophagy. The objectives of the study were to chemically characterize "Chacco", determine the zero charge point, evaluate the release of aluminum in vitro, perform the kinetic study and evaluate the health risk. The results by ICP-OES showed that the elements with the highest concentration were Al, Ba, Ca, Fe, K, Mg, Mn, Na, Si, Sr, Ti and Zn. ATR-FTIR analysis showed the presence of Si-O (693 and 990 cm^-1), Al-O (790 cm^-1), Al-Al-OH bending vibration (912 cm^-1), Si-H bond stretching (2100 to 2500 cm^-1) and free -OH groups (3629 cm^-1). SEM-EDX results indicate that Al is one of the main constituents of "Chacco" (7.35 wt%). The pHzpc of "Chacco" was 6.83. In the dissolution profiles, the highest Al release occurred at pH 6.8 and in intestinal juice simulated with pseudo-second order dissolution kinetics. The EDI_Al and EWI_Al were 20.24 and 142.66 respectively, comparing EWI_Al with the PTWI established by JECFA (2 mg/kg bw), it is concluded that the weekly intake of "Chacco" represents an appreciable health risk. There are no reports of the carcinogenic factor of Al, so TR_Al was not calculated.

Optimization of Carboniferous Egyptian Kaolin Treatment for Pharmaceutical Applications

This paper quantitatively determines the occurrences of potentially toxic elements in Carboniferous kaolin in southwestern Sinai, Egypt. This research describes, in detail, the experimental treatment optimization to be used in pharmaceutical applications. The concentrations of As, Co, Ni, Pb, and V in these kaolin deposits exceed the Permitted Concentrations of Elemental Impurities for oral use in pharmaceutical applications. Herein, six desorbing agents (acetic acid, citric acid, DTPA, EDDS, EDTA, and NTA) were utilized as extracting solutions in batch-wise extractions to select the proper reagents. Parameters such as the pH, the mixing speed and time, and the solid–solution ratio were varied to optimize the extraction conditions. The findings indicate that citric acid and EDTA were effective in the removal of the aforementioned elements. The results reveal that the optimum removal of potentially toxic elements from kaolin can be achieved using citric acid and EDTA concentrations of 0.2 M and 0.1 M, respectively, for the treatment of 5 g of kaolin, under a pH of 4 for citric acid, and a pH of 10 for EDTA. The ideal mixing speed and time are 500 rpm and 6 h, respectively. Using 1:10 S/L of citric acid and EDTA showed removal rates of 100% for all the investigated PTEs. We recommend this treatment for different kinds of kaolin showing various degrees of contamination.

Evolution of Hydraulic Conductivity of Unsaturated Compacted Na-Bentonite under Confined Condition-Including the Microstructure Effects

Compacted bentonite is envisaged as engineering buffer/backfill material in geological disposal for high-level radioactive waste. In particular, Na-bentonite is characterised by lower hydraulic conductivity and higher swelling competence and cation exchange capacity, compared with other clays. A solid understanding of the hydraulic behaviour of compacted bentonite remains challenging because of the microstructure expansion of the pore system over the confined wetting path. This work proposed a novel theoretical method of pore system evolution of compacted bentonite based on its stacked microstructure, including the dynamic transfer from micro to macro porosity. Furthermore, the Kozeny–Carman equation was revised to evaluate the saturated hydraulic conductivity of compacted bentonite, taking into account microstructure effects on key hydraulic parameters such as porosity, specific surface area and tortuosity. The results show that the prediction of the revised Kozeny–Carman model falls within the acceptable range of experimental saturated hydraulic conductivity. A new constitutive relationship of relative hydraulic conductivity was also developed by considering both the pore network evolution and suction. The proposed constitutive relationship well reveals that unsaturated hydraulic conductivity undergoes a decrease controlled by microstructure evolution before an increase dominated by dropping gradient of suction during the wetting path, leading to a U-shaped relationship. The predictive outcomes of the new constitutive relationship show an excellent match with laboratory observation of unsaturated hydraulic conductivity for GMZ and MX80 bentonite over the entire wetting path, while the traditional approach overestimates the hydraulic conductivity without consideration of the microstructure effect.

Soil-Transmitted Helminthic Infections and Geophagia among Pregnant Women in Jimma Town Health Institutions, Southwest Ethiopia

Background

Pregnancy is a key step for human's reproduction and continuity of generation. Pregnant women are among at risk groups for the infection of soil-transmitted helminths (STHs). STHs are highly prevalent in low- and middle-income countries due to the deprived environmental sanitation and personal hygiene. Eating soil (geophagia) is also commonly practiced by pregnant women, particularly in developing countries. The aim of this study was to determine the prevalence of STHs and geophagia, and to assess associated factors among pregnant women in Jimma, Southwest Ethiopia.

Methods

A cross sectional study was conducted among 407 pregnant women attending antenatal care (ANC) at different health facilities located in Jimma Town. Data related to sociodemographic and geophagia practice was collected using a structured questionnaire and STH infections status was determined by using McMaster technique.

Results

A total of 407 pregnant women were included in this study. The overall prevalence of any STHs was 19.7% (80/407). Ascaris lumbricoides was the most prevalent 45(56.2%), followed by Trichuris trichiura 19(23.8%) and hookworms 12(15%). There were 4(5%) of double infection with A. lumbricoides and T. trichiura. Overall, 71 (17.4%) of the pregnant women responded to practice geophagia. STHs infection was significantly higher among geophagic pregnant women (p<0.01) and pregnant women who practiced geophagia were 3 times more likely (OR 2.9, 95% CI 1.3–4.2) to have the STHs compared to non-geophagic. Out of those who claimed soil eating habits, 59.1% preferred reddish soil type. Geophagia practice was significantly higher during the third trimester as compared to first and second (p<0.05).

Conclusion

Geophagia is a risky behavior and this study showed a significant association of geophagia practice with STH infections, although the causal relation could not be established.

Geophagic clay around Uteh-Uzalla near Benin: mineral and trace elements compositions and possible health implications

Geophagic clay consumption, which is an age-long cultural practice by humans and animals in many parts of the world, and particularly in Nigeria, may have long time health effects on the consumers. This is particularly so because of the relatively high concentration of harmful minerals and toxic elements. This study sought to determine the mineralogical and trace element compositions of geophagic clay in Uteh-Uzalla area, which is underlain by the Benin Formation of Oligocene to Miocene age, in order to evaluate the potential health risk associated with the consumption of the clay. Sixteen clay samples were collected from mine face profiles of an open pit, analysed for mineral and trace element compositions, using x-ray diffraction technique and ultra-trace inductively coupled plasma mass spectrometry (ICP-MS) methods, respectively. The mean mineral concentration in % includes kaolinite, quartz and smectite (64.88, 19.98, and 9.54), respectively, among other minerals. And the mean concentrations in mg/kg for Cu (15.0), Pb (14.4), Zn (30.9), Co (8.9), Mn (39.4) and Th (10.5) among other elements were found in the clay. From the trace elements results when compared with health risk indices by Agency for Toxic Substances and Diseases Registry (ATSDR): Minimum Risk Level, recommended daily intake and estimated daily intake, it was found that the elements are far above the daily oral intake requirement. Also, considering the relatively low pH (acidic) values that were exhibited by the clays, harmful minerals and elements contained in the clay may be bioavailable in the internal system among those who are frequently involved in the consumption of the clay.

Geophagic practice in Mashau Village, Limpopo Province, South Africa

Large quantities of earth materials are consumed daily in Mashau Village; nonetheless, this practice had not been studied. Furthermore, the motivations for this geophagic behaviour in the study area were unclear. Thus, questionnaires were distributed to 200 participants in the study area with the aim of generating data on the motivations of and potential medical conditions associated to this practice. About 91% of the participants were geophagists, of which 98.5% were female. Craving was found to be the main reason (73.9%) why people of the Mashau communities consume soil. The majority of the geophagists in Mashau craved for the soil upon seeing it (31.2%), during pregnancy (22.5%) and when experiencing sleeplessness (21%). About 60% of the geophagists had chronic illnesses, and they were diagnosed with headaches (31.6%), low haemoglobin level (29.9%), constipation (18.8%), iron deficiency (12.0%) and high blood pressure (7.7%). There is a concern that the soil from the study area may be adversely affecting individuals ingesting these soils. Since females mostly reported practicing geophagia, counselling and education of women and girls would be a useful public health measure. Soil characterisation and beneficiation for healthy geophagic practices should also be carried out at Mashau Village.

Cadmium and lead in geophagic clay consumed in Southern Nigeria: health risk from such traditional nutraceutical

Geophagy is a cultural behavior, based on the recurrent intentional eating of clay soil, that is raising increasing concern as it implies multidimensional (space, time) potential risk of serious adverse health effects. This study investigated the level of toxic metals (Cd and Pb) in 20 Nigerian geophagic clays intended for both local consumption and distribution to the West Africa market. After sampling in 4 open markets in southern Nigeria (Akwa Ibom, Abia, Rivers, Imo), samples were subjected to digestion, ashing and analysis. The Pb levels in all samples exceeded the WHO/FAO maximum permissible limit of 0.1 mg kg^-1 whereas 16% exceeded the Cd limit of 0.3 mg kg^-1. The estimated daily intake of Pb for all samples ranged from 0.0032-0.0286 mg kg_bw^-1 day^-1 to 0.0024-0.0215 mg kg_bw^-1 day^-1 for children and adults, respectively. The estimated daily intakes for Cd ranged from bdl (below detection limit)-0.0010 mg kg_bw^-1 day^-1 to bdl-0.0028 mg kg_bw^-1 day^-1 for children and adults, respectively. In both cases, the WHO/FAO provisional Tolerable Weekly Intake is exceeded through the ingestion of these soils. Our results confirm health risks related to the geophagic practices, its role in exceeding health guidelines when considering aggregate exposure in the Nigerian scenario and body burden in developing organisms, young women, women at fertile age, and pregnant women. We discuss how geophagists consider clays as traditional nutraceuticals and how clarifying the nutraceutical role of geophagy could facilitate risk communication. Geophagic products are implicitly or explicitly marketed as dietary supplements, and as such they should be regulated (1) by labeling, and prohibition of scientifically unfounded health claims and (2) by safety standards before marketing. This is particularly critical when clays originate from countries living rapid, unplanned and uncontrolled development and dumped, like Nigeria.

"Back to Eden": An explorative qualitative study on traditional medicine use during pregnancy among selected women in Lusaka Province, Zambia

BACKGROUND AND PURPOSE

No qualitative study on traditional medicine use among Zambian pregnant women has ever been conducted. Accordingly, this study was performed to explore the perceptions, motivations and experiences of Zambian women with regard to traditional medicine use during pregnancy.

MATERIALS AND METHODS

In-depth, semi-structured interviews were conducted in June/July 2019 with 8 adult women residing in Lusaka, Zambia, who used traditional remedies during their pregnancies, and who were recruited through purposive and snowball sampling.

RESULTS

Reported reasons behind traditional medicine use during pregnancy included labour induction, prevention of childbirth complications in case of sexual infidelity by either spouse, and prevention and/or treatment of anaemia. In addition, family members and faith leaders played an important role in influencing traditional medicine use.

CONCLUSION

Multiple, interconnecting factors influence traditional medicine use among pregnant women in Lusaka, Zambia. Traditional medicine use during pregnancy will likely continue to be widespread across Zambia.

Herbal medicine use among pregnant women attending antenatal clinics in Lusaka Province, Zambia: A cross-sectional, multicentre study

BACKGROUND AND PURPOSE: The study of herbal medicine (HM) use which is related to maternal health, a public health priority in many sub-Saharan African countries including Zambia, has been limited. Accordingly, we aimed to determine the prevalence and patterns of HM use during pregnancy in Lusaka Province, Zambia.

MATERIALS AND METHODS

A survey-based (interviewer-administered), cross-sectional, multicentre study was conducted in 446 adult pregnant women attending antenatal clinics in June/July 2019.

RESULTS

Overall, 57.8% of participants reported using HM during their current pregnancy, with a mean of 2.0 ± 1.5 remedies/woman. Logistic regression analysis showed that HM use was significantly associated with HM use in prior pregnancies (p < 0.001) and willingness to use HM in the future (p < 0.001). The most commonly used herbs were lemon for nausea/vomiting and common cold, soybean to boost energy, ginger for common cold and nausea/vomiting, and Aloe vera for skin care. The perceived safety of HM (37.6%) and its complementary action with conventional medicines (35.3%) were the main reasons for HM use.

CONCLUSION

HM use among pregnant women attending antenatal clinics in Lusaka Province, Zambia is common, and a wide range of herbs is used.

Health Risk Evaluation of Trace Elements in Geophagic Kaolinitic Clays within Eastern Dahomey and Niger Delta Basins, Nigeria

The deliberate consumption of earthly materials is a universally recognised habit with health benefits and risks to those that practice it. Thirteen (13) samples comprising of six (6) Cretaceous and seven (7) Paleogene/Neogene geophagic kaolinitic materials, respectively, were collected and analysed for trace element concentrations (V, Cr, Co, Ni, Zn, Pb, and Fe), and possible risk on consumers' health. The trace element compositions were obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and X-ray fluorescence spectrometry (XRF) analytical methods. Based on their average concentrations, Fe > V > Cr > Ni > Zn > Pb > Cu > Co and Fe > V > Cr > Zn > Cu > Pb > Ni > Co for the Cretaceous and Paleogene/Neogene geophagic clays, respectively. Iron concentrations were significantly higher in Paleogene/Neogene geophagic clays than in Cretaceous geophagic clays. The nutritional value of Cu and Zn were lower whereas, Cr and Fe were higher than the recommended dietary intake. The index of geoaccumulation (0 < Igeo ≤ 1) showed that the geophagic materials were uncontaminated to moderately contaminated by the trace elements. The overall hazard indices (HI) for non-carcinogenic effects showed that the geophagic clays pose threat to children (HI > 1) and no threat to adults (HI < 1) health. However, the carcinogenic risk indices (CRI) for Cr, Ni, and Pb were within acceptable cancer risks (10-6 < CRI < 10-4) for children and adults. Hence, based on the trace element s HI and CRI, this study concluded that the consumption of Cretaceous and Paleogene/Neogene geophagic kaolinitic clays poses no risks to adult health but children might suffer health risk if the geophagic clays are not beneficiated before ingestion.

Clay Ingestion During Pregnancy Among Black African Women in a North London Borough: Understanding Cultural Meanings, Integrating Indigenous and Biomedical Knowledge Systems

Findings from this qualitative audit conducted in a North London Borough among Black African women show that clay ingestion during pregnancy is a cultural phenomenon embedded in indigenous knowledge (IK). Reasons for clay ingestion include curbing morning sickness, nausea, satisfying cravings, "mineral deficiency" and other life sustaining beliefs. However, Public Health practitioners' top down approach and response which considers the practice as "dangerous" and potentially harmful to the health of the woman and unborn child with midwives and General Practitioner doctors called upon to discourage it, risks alienating the target population. Furthermore, within such a top down framework, opportunities to integrate biomedical science and indigenous knowledge systems are potentially missed. The use of culturally sensitive Public health interventions which consider a community approach, while attempting to integrate these two knowledge systems through further research is likely to bear more fruits.

Prevalence of geophagy and knowledge about its health effects among native Sub-Saharan Africa, Caribbean and South America healthy adults living in France

Geophagy is widespread among women from Sub-Saharan Africa, South America and the Caribbean and may persist in western countries. This practice may be associated with adverse effects such as anaemia, constipation or intestinal occlusion. We aimed to determine the prevalence of geophagy and the level of knowledge about its health effects among healthy adults originating from these countries and attending a travel medicine and international vaccination consultation in France. Among 101 travellers enrolled in the study, 83 (82.1%) were born in Sub-Saharan Africa and 13 (12.8%) in South America or the Caribbean. The mean duration of residence in France was 15.6 ± 10.4 years. Previous or current geophagy was present in 42 travellers [previous geophagy in 31 (30.7%) and current consumption in 11 (10.9%)]; 38 (90.5%) were women. The rate of awareness of harmful effects of geophagy as the risk of iron-deficient anaemia (18.8%) and soil-transmitted intestinal parasitic infections (11.9%) was low overall. Women with previous or current geophagy more often had history of iron therapy compared to those who never consumed, both during pregnancy (50.0 versus 14.3%; p = 0.0009) and outside pregnancy (47.4 versus 2.8%; p < 0.0001). Despite a long period of residence in France, geophagy was still a current practice among 10.9% of Sub-Saharan, South American and Caribbean travellers, who are poorly informed of its harmful effects. Therefore, specific information tailored to Sub-Saharan, South American and Caribbean about the risks of geophagy should be implemented in western countries.Level of evidence Level V, descriptive cross-sectional survey.

Geophagy in India: a qualitative exploratory study on motivation and perception of female consumers

BACKGROUND

Geophagy, the consumption of soil, is well documented in Africa and other continents, but is rarely investigated in Asia and even less so in India. The main aim of this exploratory qualitative study was therefore to understand the motivation for clay consumption, the social perception of the habit, the mode and quantity of consumption, as well as subjectively perceived effects of clay consumption in Himachal Pradesh, North India.

METHODS

We conducted semi-structured interviews with 27 female geophagists aged 18-80 years.

RESULTS

We could show that geophagy exists across all ages and social groups. The main type of consumed soil is yellow clay used for house wall plastering. Geophagy is usually practised because of a craving for soil despite various fears of negative health effects. It is normally done secretly and under-reported to local doctors. The most common self-reported positive effect of geophagy was the feeling of relief. Geophagy was generally considered as harmful to health and various complaints were associated with it. It is not practised because of food shortages or as a remedy. On the contrary, it is generally seen as an addiction detrimental to health.

CONCLUSIONS

Awareness of geophagy has to be ameliorated in the Indian population and specifically among health workers to improve support for affected individuals. Geophagy should be routinely included in national antenatal care guidelines.

Investigating the association between stress. Anxiety and geophagy among pregnant women in mwanza, Tanzania

Geophagy, the craving and intentional consumption of soil, is common especially among pregnant women in some low- and middle-income settings. Soils may contain a variety of non-nutritive components such as heavy metals and microbes or substances that interfere with gastrointestinal absorptive processes, posing health risks to pregnant women. Several hypotheses regarding the practice have been proposed but very few have examined the role of maternal stress. The practice of geophagy may help to alleviate stress or anxiety during gestation from perceived dietary or other pregnancy-related concerns. In this study, we evaluated several measures of maternal stress (general anxiety, Pregnancy-Related Anxiety Scores (10-item revised), and Perceived Stress Scores) and other covariates in relation to geophagic behaviour in early pregnancy in 227 women (12-19 weeks gestation) recruited from two hospitals in the Nyamagana district of Mwanza City, Tanzania. Geophagy was reported by 24.7% of the pregnant women. Using LASSO regression, self-reported treatment of nausea or vomiting during pregnancy (adjusted OR = 3.12, 95%CI: 1.43 to 6.83), paternal education level (adjusted OR = 2.79, 95%CI: 1.32 to 5.87 for primary or lower education level), antenatal hospital site (adjusted OR = 3.71, 95%CI: 1.78 to 7.75), prescription drug use prior to pregnancy (adjusted OR = 1.76, 95%CI: 0.87 to 3.56) and general anxiety (feeling worried, tense or anxious in the past four weeks) (adjusted OR = 1.81, 95%CI: 0.88 to 3.72) were associated with geophagic behaviour. Given that relatively little has been done to examine geophagy in relation to the public health risk it may pose to pregnant women, these findings suggest the need for further investigations regarding maternal stress.

High prevalence of kaolin consumption in migrant women living in a major urban area of France: A cross-sectional investigation

Geophagia is a feeding behavior involving the regular intake of soil, including clay-like kaolin. Frequent in Africa, kaolin consumption is associated with heavy metal intoxication, iron and other micronutrient deficiencies, geohelminth infection and inactivation of concomitantly taken drugs. It is expected that this practice would be imported into an asylum country during the immigration process. To confirm this hypothesis, a single center, cross-sectional study was conducted at the University Hospital of Nantes, France, whose main objective was to assess whether the prevalence of kaolin consumers was high in a migrant population living in a large French metropolitan area (the city of Nantes). Each woman consulting for the first time at the Medical and Psychosocial Gynecology Obstetric Unit during the inclusion period ranging from January 1, 2017, to July 1, 2017, was asked for consent to be included in the study. The main outcome was the proportion of positive answers regarding consumption of kaolin within the last twelve months, with its 95% confidence interval (CI). A logistic regression was performed to identify drivers of consumption, and a clustering approach was conducted to identify profiles of consumers. A total of 284 women were included in the study, of whom 110 (38.7%) were pregnant. Our main finding was a 14.1% (95% CI: 10.5-18.6) prevalence of clay consumers. Second, the characteristic most strongly associated with consumption was Central or West Africa origin (adjusted Odds Ratio (aOR) = 52.7; 95% CI: 13.7-202.2). Finally, 60% of consumers showed signs of addictive-like phenomena, and three profiles were identified, depicting a continuum of patients in regard to their control over their kaolin consumption. Our results suggest that kaolin consumption is frequent in particular subpopulations of migrants. This warrants further study of the clinical consequences of kaolin consumption and its associated addictive-like symptoms.

The sources and chemical content of edible soil sticks sold in markets in Tanzania: a cross-sectional analytical study

Geophagy, or eating soil, is common in various countries including Tanzania. Studies have reported on the levels of different chemicals in consumed soil, some of which can be harmful to the health of individuals practicing geophagy. Dried soil sticks for eating, referred to as pemba, are commercially available in many markets in sub-Saharan Africa, but few studies have established the sources of the soils. The purpose of the current study was to: (1) systematically document the sources of the soils used in pemba commonly sold in regional markets throughout Tanzania using a global positioning system (GPS) to establish the supply chain flow of pemba to markets, and (2) assess the chemical element content of the soil sources for both water-extractable chemical element (WEC) and total chemical element (TC) contents. Surveys were conducted at regional markets across mainland Tanzania to identify the sources of soils commonly used in commercially available soil sticks. Then, soil samples were collected from identified sources in 12 regions across Tanzania and analyzed for WEC and TC content using an inductively coupled plasma mass spectrometry laboratory technique. Mining of the pemba soil was localized in 12 regions. Analysis of the supply chain flow revealed a well-established distribution network that ensured transportation and marketing of the soil sticks to regions throughout the country. WEC and TC of essential and trace elements (Ca, Fe, K, Mg, Na, Mn, Co, Cr, V, Mo, Cu, and Zn) and toxic elements (Al, As, Ba, Cd, Ni, and Pb) were detected at varying concentrations. Most of the trace and toxic elements were above the normal range, based on the oral maximum tolerable limits designated by the World Health Organization and US Agency for Toxic Substance and Disease Registry. This is the first study in Tanzania to document and examine the source soil locations for commercially available soil sticks at the macroscale across the entire country. The findings suggest that geophagy could be a significant exposure pathway for toxic elements.

Pica in end-stage chronic kidney disease: Literature review

Pica is an individual entity in the patient with chronic kidney disease (CKD), which phenomenon has not been widely studied despite the high reported prevalence. Moreover, pica complications (anemia, altered electrolytes, poor absorption of micro and macronutrients and malnutrition) could be exacerbated in CKD and limit the quality of renal replacement therapy. The intake of non-caloric and non-nutritional substances could be harmful and cause effects on satiety and metabolic / electrolyte imbalance and modify the biocompatibility of micronutrients, toxins and pathogens worsening health status. In daily practice, pica could be under-reported because patient's shame to recognize it, or fear that such behavior influences their treatment. Additionally, clinicians who not investigate the presence of pica or its complications contribute to the lack of information about the magnitude and relevance of this problem in CKD.

Healing and edible clays: a review of basic concepts, benefits and risks

The use of clay by humans for medicinal and wellness purposes is most probably as old as mankind. Within minerals, due to its ubiquitous occurrence in nature and easy availability, clay was the first to be used and is still used worldwide. Healing clays have been traditionally used by man for therapeutic, nutritional and skin care purposes, but they could impart some important health and skin care risks. For instance, clay particles could adsorb and make available for elimination or excretion any potential toxic elements or toxins being ingested or produced, but they could adsorb and make available for incorporation, through ingestion or through dermal absorption, toxic elements, e.g. heavy metals. Edible clays, a particular case of healing clays, have been traditionally used by man for nutritional and therapeutic purposes. Geophagy, the deliberate soil eating, earth eating, clay eating and pica (medical condition or eating disorder shown by individuals addicted to eat earth substances), has been observed in all parts of the world since antiquity, reflecting cultural practice, religious belief and physiological needs, be they nutritional (dietary supplementation) or as a remedy for disease. This paper pretends to review historical data, basic concepts and functions, as well as benefits and risks of the use of healing clays, in general, for therapeutic and cosmetic purposes, and of edible clays, in particular, for therapeutic purposes.

Consequences of prenatal geophagy for maternal prenatal health, risk of childhood geophagy and child psychomotor development

OBJECTIVE

To investigate the relationship between prenatal geophagy, maternal prenatal haematological indices, malaria, helminth infections and cognitive and motor development among offspring.

METHODS

At least a year after delivery, 552 of 863 HIV-negative mothers with singleton births who completed a clinical trial comparing the efficacy of sulfadoxine-pyrimethamine and mefloquine during pregnancy in Allada, Benin, responded to a nutrition questionnaire including their geophagous habits during pregnancy. During the clinical trial, helminth infection, malaria, haemoglobin and ferritin concentrations were assessed at 1st and 2nd antenatal care visits (ANV) and at delivery. After the first ANV, women were administered daily iron and folic acid supplements until three what? post-delivery. Singleton children were assessed for cognitive function at age 1 year using the Mullen Scales of Early Learning.

RESULTS

The prevalence of geophagy during pregnancy was 31.9%. Pregnant women reporting geophagy were more likely to be anaemic (AOR = 1.9, 95% CI [1.1, 3.4]) at their first ANV if they reported geophagy at the first trimester. Overall, prenatal geophagy was not associated with maternal haematological indices, malaria or helminth infections, but geophagy during the third trimester and throughout pregnancy was associated with poor motor function (AOR = -3.8, 95% CI [-6.9, -0.6]) and increased odds of geophagous behaviour in early childhood, respectively.

CONCLUSIONS

Prenatal geophagy is not associated with haematological indices in the presence of micronutrient supplementation. However, it may be associated with poor child motor function and infant geophagy. Geophagy should be screened early in pregnancy.

Geophagic earths consumed by women in western Kenya contain dangerous levels of lead, arsenic, and iron

OBJECTIVES

Geophagy is commonly reported by pregnant women and children, yet its causes and consequences remain poorly understood. Therefore, we sought to determine if geophagy could contribute micronutrients and/or be a source of heavy metal exposure by examining the elemental composition of earths consumed in Kakamega, Kenya.

METHODS

Ten samples of earths commonly consumed during pregnancy were collected by study enumerators and analyzed using inductively coupled plasma-atomic emission spectroscopy. Samples were either collected at markets or from walls of participants' homes, based on where participants reported most commonly sourcing their consumed earths.

RESULTS

Based on estimated intakes (40 g/day), all samples had lead levels that exceeded the provisional maximum tolerable daily intake, and one sample exceeded the threshold for arsenic. Further, estimated intakes of iron for all samples were at least 8.9 times higher than the established threshold. Elemental concentrations were also compared by the site of sample collection (market vs. household wall); market samples had significantly higher iron concentrations and lower calcium concentrations than wall samples.

CONCLUSIONS

Geophagic earths in Kakamega may be harmful because of dangerously high levels of lead, arsenic, and iron. The prevalence of geophagy among vulnerable populations underscores the importance of understanding its causes and consequences for accurate public health messaging.

Child soil ingestion in rural Ghana - frequency, caregiver perceptions, relationship with household floor material and associations with child diarrhoea

OBJECTIVES

The objectives of this work were to evaluate (i) the prevalence and frequency of caregiver-reported soil ingestion by children, (ii) whether household flooring material in the bedroom (earth vs. concrete) affected caregiver-reported soil ingestion, (iii) whether caregiver-reported soil ingestion was associated with caregiver-reported diarrhoea and (iv) caregivers' perceptions of their children ingesting soil.

METHODS

We conducted 309 household surveys in northern Ghana, including 529 children under five (249 children aged 6-36 months), and measured faecal contamination in soil from 31 households.

RESULTS

Among all children, 15% were reported to have directly ingested soil in the past week, including 28% of children aged 6-36 months. Among children reported to have ingested soil, the median frequency was 14 times in the past week, and the median amount of soil ingested each time was half a handful. There was no association between household floor material and whether the caregiver observed a child directly ingesting soil. After adjusting for household floor material and other potential confounding variables, caregiver-reported soil ingestion was associated with caregiver-reported diarrhoea for children under five [adjusted odds ratio (adj. OR) = 3.13, 95% confidence interval (CI) 2.76-3.55] and children aged 6-36 months (adj. OR = 2.61, 95% CI 2.01-3.39). Approximately 83% of caregivers whose children ingested soil reported they thought it was unsafe and were more likely to report stopping their child from ingesting soil, but these responses did not affect the quantity of soil ingested.

CONCLUSIONS

Our results suggest direct soil ingestion is associated with diarrhoea independent of household floor material, and separate interventions may be necessary to prevent exploratory soil ingestion.

Chronic arsenicosis and cadmium exposure in wild snowshoe hares (Lepus americanus) breeding near Yellowknife, Northwest Territories (Canada), part 1: Evaluation of oxidative stress, antioxidant activities and hepatic damage

Previous gold mining activities and arsenopyrite ore roasting activities at the Giant mine site (1948 to 2004) resulted in the release of high amounts of arsenic and trace metals into the terrestrial and aquatic ecosystems of Yellowknife, Northwest Territories, Canada. While elevated levels of arsenic has been consistently reported in surface soils and vegetation near the vicinity of the Giant mine area and in surrounding locations, systematic studies evaluating the overall health status of terrestrial small mammals endemic to the area are lacking. The purpose of this present study was to evaluate and comparatively assess the biochemical responses and histopathological effects induced by chronic arsenic and cadmium exposure in wild snowshoe hares breeding near the city of Yellowknife, specifically around the vicinity of the abandoned Giant mine site and in reference locations. Analysis included measurement of total arsenic and cadmium concentration in nails, livers, kidneys, bones, stomach content of hares, in addition to histopathological evaluation of hepatic and ocular lesions. Biochemical responses were determined through measurement of lipid peroxidation levels and antioxidant enzymes activities (catalase, superoxide dismutase, glutathione peroxidase, and glutathione disulfide). The results revealed that arsenic concentration was 17.8 to 48.9 times higher in the stomach content, and in the range of 4 to 23 times elevated in the nails of hares from the mine area compared to the reference location. Arsenic and cadmium levels were also noted to be increased in the bones, renal and hepatic tissues of hares captured near the mine area compared to the reference site. Specifically, hares from the mine area showed nail cadmium levels that was 2.3 to 17.6 times higher than those from the reference site. Histopathological examination of the eyes revealed no specific ocular lesions, such as lens opacity (cataracts) or conjunctivitis; however, hares from both locations exhibited hepatic steatosis (fatty liver change). Lipid peroxidation levels were relatively increased and accompanied with reduced antioxidant enzyme activities in hares from the mine area compared to the hares from the reference site. The results of this preliminary study suggest that the snowshoe hares breeding near the vicinity of Yellowknife, including near the Giant mine area have been chronically exposed to elevated levels of arsenic and cadmium, which consequently led to the increased levels of oxidative stress and perturbation of antioxidant defense system in exposed animals. The results of this present study constitute the first observation of chronic arsenicosis in wild small mammal species in Canada.

An analysis of human exposure to trace elements from deliberate soil ingestion and associated health risks

Fifty-seven samples of soils commonly ingested in South Africa, Swaziland, Democratic Republic of Congo (DRC), and Togo were analyzed for the concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) and their bioaccessibility in the human gastrointestinal tract. Bioaccessibility values were used to calculate daily intake, and hazard quotient of each trace element, and chronic hazard index (CHI) of each sample. Carcinogenic risk associated with As and Ni exposure were also calculated. Mean pseudo-total concentrations of trace elements in all samples were 7.2, 83.3, 77.1, 15.4, 28.6, 24.9, 56.1, 2.8, and 26.5 mg/kg for As, Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb, respectively. Percent bioaccessibility of Pb (13-49%) and Zn (38-56%) were highest among trace elements studied. Average daily intake values were lower than their respective reference doses for ell elements except for Pb in selected samples. Samples from DRC presented the highest health risks associated with trace element exposure with most of the samples having CHI values between 0.5 and 1.0. Some samples had higher than unacceptable values of carcinogenic risk associated with As and Ni exposure. Results indicate low trace element exposure risk from ingesting most of the soil samples.

Geophagy during pregnancy: Is there a health risk for infants?

Prenatal lead exposure is a public health concern. Geophagy, the practice of soil eating, is documented for pregnant women of sub-Saharan Africa to treat pregnancy-related malaise. The soils however can contain substantial amounts of lead. In an exploratory study on 48 mother-child pairs in the Democratic Republic of Congo, we found striking site-specific differences in prenatal lead exposure, i.e., higher lead levels at Kisangani than at Isiro. Kisangani women consumed 1/ more often soil during the first trimester of pregnancy as well as 2/ a different type of soil compared to Isiro women (P<0.05). We conclude geophagy may be a potential source of prenatal lead exposure.

Soil Ingestion is Associated with Child Diarrhea in an Urban Slum of Nairobi, Kenya

Diarrhea is a leading cause of mortality in children under 5 years of age. We conducted a cross-sectional study of 54 children aged 3 months to 5 years old in Kibera, an urban slum in Nairobi, Kenya, to assess the relationship between caregiver-reported soil ingestion and child diarrhea. Diarrhea was significantly associated with soil ingestion (adjusted odds ratio = 9.9, 95% confidence interval = 2.1-47.5). Soil samples from locations near each household were also collected and analyzed for Escherichia coli and a human-associated Bacteroides fecal marker (HF183). Escherichia coli was detected in 100% of soil samples (mean 5.5 log colony forming units E. coli per gram of dry soil) and the Bacteroides fecal marker HF183 was detected in 93% of soil samples. These findings suggest that soil ingestion may be an important transmission pathway for diarrheal disease in urban slum settings.

Geophagy in Northern Uganda: Perspectives from Consumers and Clinicians

The etiology and health consequences of geophagy are still poorly understood. The consumed soil, individual motives, consumption habits, and the clinical perspective of geophagy in northern Uganda were examined. A total of 50 semistructured interviews (17 pregnant, eight nonpregnant women, 10 men, and 15 health-care professionals) were conducted. Our results suggest that geophagy is not limited to pregnancy and can also be found among nonpregnant women and men. During gestation, excessive amounts of various soil types are consumed and can replace food at times. Nonpregnant women and men consume less soil and stick to one type. When pregnant, craving and alleviating gastrointestinal upset are the main motives. In men, the main reasons for geophagy were craving, hypersalivation, and natural stimulants. If soil is craved, it can show similarities to a dependency syndrome. When picked up in childhood, geophagy is more likely to be continued throughout life. The consumption habits differ and thereby vary in their possible implications on health. Our findings suggest that men should be included in further studies. Especially nurses from the antenatal care are exposed to geophagists; however, no national guidelines exist for geophagy. Further research is necessary to create guidelines to be included in medical training and practice.

Unsafe Child Feces Disposal is Associated with Environmental Enteropathy and Impaired Growth

OBJECTIVE

To investigate the relationship between unsafe child feces disposal, environmental enteropathy, and impaired growth, we conducted a prospective cohort study of 216 young children in rural Bangladesh.

STUDY DESIGN

Using a prospective cohort study design in rural Bangladesh, unsafe child feces disposal, using the Joint Monitoring Program definition, was assessed using 5-hour structured observation by trained study personnel as well as caregiver reports. Anthropometric measurements were collected at baseline and at a 9-month follow-up. Stool was analyzed for fecal markers of environmental enteropathy: alpha-1-antitrypsin, myeloperoxidase, neopterin (combined to form an environmental enteropathy disease activity score), and calprotectin.

FINDINGS

Among 216 households with young children, 84% had an unsafe child feces disposal event during structured observation and 75% had caregiver reported events. There was no significant difference in observed unsafe child feces disposal events for households with or without an improved sanitation option (82% vs 85%, P = .72) or by child's age (P = .96). Children in households where caregivers reported unsafe child feces disposal had significantly higher environmental enteropathy scores (0.82-point difference, 95% CI 0.11-1.53), and significantly greater odds of being wasted (weight-for-height z score <-2 SDs) (9% vs 0%, P = .024). In addition, children in households with observed unsafe feces disposal had significantly reduced change in weight-for-age z-score (-0.34 [95% CI -0.68, -0.01] and weight-for-height z score (-0.52 [95% CI -0.98, -0.06]).

CONCLUSION

Unsafe child feces disposal was significantly associated with environmental enteropathy and impaired growth in a pediatric population in rural Bangladesh. Interventions are needed to reduce this high-risk behavior to protect the health of susceptible pediatric populations.

Interpreting habits in a new place: Migrants' descriptions of geophagia during pregnancy

BACKGROUND AND INTRODUCTION

Previous studies of soil eating, or geophagia, among pregnant women in sub-Saharan Africa indicate the practice is widespread. Various explanations have been explored to explain the global phenomenon of soil eating, with the most compelling explanation focused on clay's ability to prevent or treat intestinal infection. The urban South African context for clay eating is not well understood. This paper explores clay consumption amongst pregnant migrants who are nationals of countries where clay consumption may be common.

METHODS

I conducted in-depth interviews with a purposively selected group of Somali, Congolese, and Zimbabwean women (n = 23). Interviews included questions broadly related to maternal and infant nutrition. In addition, I conducted nine focus group discussions (n = 48) with adult Somali, Congolese (DRC), and Zimbabwean men (N = 3) and women (N = 6), segregated by country of origin and gender. This paper focuses specifically on responses related to geophagia.

RESULTS

While Somali women did not report consuming clay or charcoal, Congolese and Zimbabwean participants self-reported commonly consuming clay during pregnancy, and at times also when not pregnant. Despite having heard public health messaging that discouraged the practice, participants largely did not describe this consumption in terms of health, but rather in terms of craving and habit. Participants described continued consumption of clay in South Africa, and the only reason for ceasing consumption was in cases of severe constipation.

DISCUSSION

The widespread consumption of clay soil by Congolese and Zimbabwean women during pregnancy may be a mechanism through which identity was reasserted and reproduced in a foreign country. Participants' emphasis on clay consumption seemed related to the absence or expense of other craved foods, and perhaps also to feelings of loss in Cape Town.

Preeclampsia and toxic metals: a case-control study in Kinshasa, DR Congo

BACKGROUND

Preeclampsia is frequent in Kinshasa (Democratic Republic of Congo), especially during the dry season. We tested whether preeclampsia was associated with exposure to environmental metals.

METHODS

Using a case-control design, 88 women hospitalized with preeclampsia (cases) and 88 healthy pregnant women from the antenatal clinic (controls) were included in the study; 67 and 109 women were enrolled during the rainy and dry season, respectively. The concentrations of 24 elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) in 24-h urine collections. Differences in the urinary excretion of metals were investigated between cases and controls, and the interaction with season was assessed.

RESULTS

Cases and controls were well matched regarding age, parity and duration of pregnancy. In controls, the urinary concentrations of most elements were substantially higher than reference values for adults from industrially developed countries, e.g. for lead: geometric mean (GM) 8.0 μg/L [25(th)-75(th) percentile 3.1-13.8]. The daily urinary excretions of 14 metals were significantly higher in women with preeclampsia than in control women, e.g. for lead: GM 61 μg/day (25(th)-75(th) percentile 8-345) in women with preeclampsia vs 9 μg/day (25(th)-75(th) percentile 3-21) in controls (p < 0.001). A significant interaction was found between season and preeclampsia for several elements, with higher urinary excretions in preeclamptic women than controls during the dry season, but not during the rainy season.

CONCLUSIONS

This study revealed not only that women with preeclampsia excrete higher amounts of several toxic metals, especially lead, than control women, but also that this excretion exhibits seasonal variation, thus possibly explaining the high incidence and seasonal variation of preeclampsia in Kinshasa. Although the exact sources of this exposure are unknown, these findings underscore the need for preventing environmental exposures to lead and other toxic metals.

Heavy metal intoxication compromises the host cytokine response in Ascaris Suum model infection

Lead (Pb), Cadmium (Cd) and Mercury (Hg) are recognized for their deleterious effect on the environment and immunity where subsequently compromised immune response affects the susceptibility to the potential parasitic infections. This study examined the host cytokine response after heavy metal intoxication (Pb, Cd, and Hg) and subsequent Ascaris suum infection in BALB/c mice. Pb modulated murine immune response towards the Th2 type of response (delineated by IL-5 and IL-10 cytokine production) what was also dominant for the outcome of A. suum infection. Chronic intoxication with Pb caused a more intensive development of the parasite infection. Cd stimulated the Th1 immune response what was associated with increase in IFN-γ production and reduction of larvae present in the liver of intoxicated mice. The larval burden was also low in mice intoxicated with Hg. This was probably not related to the biased Th1/Th2 type of immune response, but rather to the bad host conditions caused by mercury toxicity and high level of pro-cachectic cytokine TNF-α.

Fecal Markers of Environmental Enteropathy are Associated with Animal Exposure and Caregiver Hygiene in Bangladesh

Undernutrition is estimated to be an underlying cause of over half of all deaths in young children globally. There is a growing body of literature suggesting that increased exposure to enteric pathogens is responsible for environmental enteropathy (EE), a disorder associated with impaired growth in children. To determine if household unsanitary environmental conditions were significantly associated with EE and stunting in children, we conducted a cohort of 216 children (≤ 30 months) in rural Bangladesh. Stool was analyzed for four fecal markers of EE: alpha-1-antitrypsin, myeloperoxidase, and neopterin combined to form an EE disease activity score, and calprotectin. We observed a significant association between having an animal corral in a child's sleeping room and elevated EE scores (1.0 point difference, 95% confidence interval [CI]: 0.13, 1.88) and a two times higher odds of stunting (height-for-age z-score < -2) (odds ratio [OR]: 2.53, 95% CI: 1.08, 5.43) after adjusting for potential confounders. In addition, children of caregivers with visibly soiled hands had significantly elevated fecal calprotectin (μg/g) (384.1, 95% CI: 152.37, 615.83). These findings suggest that close contact with animals and caregiver hygiene may be important risk factors for EE in young children. These findings are consistent with the hypothesis that unsanitary environmental conditions can lead to EE in susceptible pediatric populations.

A Comparative Analyses of Granulometry, Mineral Composition and Major and Trace Element Concentrations in Soils Commonly Ingested by Humans

This study compared the granulometric properties, mineralogical composition and concentrations of major and trace element oxides of commonly ingested soils (geophagic soil) collected from different countries with a view of understanding how varied they may be in these properties and to understand the possible health implications of ingesting them. Soil samples were collected from three different countries (South Africa, Swaziland and Democratic Republic of Congo (DRC)) and their granulometric properties, concentrations of major and trace element oxides as well as mineralogical composition determined. Differences were observed in the granulometric properties of geophagic soil from the three different countries with most of them having <20% clay content. The soils also showed varied degrees of weathering with values of Chemical Index of Alteration (CIA) and Chemical Index of Weathering (CIW) being between 60% and 99.9% respectively. The mineral assemblages of the soils from South Africa and Swaziland were dominated by the primary minerals quartz and feldspar whereas soils from DRC had more of kaolinite, a secondary mineral than primary minerals. Soils from DRC were associated with silt, clay, Al₂O₃, and CIA unlike most samples from South Africa which were associated with SiO₂, sand, K₂O, CaO, and MgO. The soils from Swaziland were closely associated with silt, H₂O and Fe₂O₃(t). These associations reflect the mineralogy of the samples. These soils are not likely to serve as nutrient supplements because of the low concentrations of the nutrient elements contained. The coarse texture of the samples may also result in dental destruction during mastication. Sieving of the soils before ingestion to remove coarse particles is recommended to reduce the potential health threat associated with the ingestion of coarse-textured soils.

Determination of metal ion contents of two antiemetic clays use in Geophagy

Nausea is usually associated with early to late stages of pregnancy. Geophagy-deliberate consumption of soil is a common method of managing gravidae-induced discomfort. To control nausea, pregnant women in Nigeria commonly eat baked clay called "Eko" and another type of clay that induces buccal constriction called "Omumu". The metal contents in Eko and Omumu, digested under different pH conditions (acidic, alkaline and neutral), were investigated using Inductively Coupled Plasma Optical Emission Spectroscopy (ICPS-OES). We identified and quantitate the elements present and speculate on their potential impact on maternal and fetal health upon gestational exposure beyond the acceptable exposure levels and the Millennium Contaminant Level Goals (MCLG) set by the United States Environmental Protection Agency (USEPA). Specifically, our result indicates unacceptably high levels of aluminum in Eko and Omumu (>10-fold greater than the highest desirable levels set by the USEPA). The aluminum concentrations were influenced by the pH condition in which the samples were digested. Dietary exposure to aluminum at such high levels may be deleterious to maternal health and fetal development. Therefore consumption of Eko and Omumu as an antidote to reduce nausea during pregnancy should be discouraged. Future studies are planned to investigate specific impacts on fetal and maternal health and likely teratogenicity in rodent models.

Geophagy is associated with environmental enteropathy and stunting in children in rural Bangladesh

There is a growing body of literature indicating an association between stunting and environmental enteropathy (EE), a disorder thought to be caused by repeated exposures to enteric pathogens. To investigate the relationship between exposure to enteric pathogens through geophagy, consumption of soil, EE, and stunting, we conducted a prospective cohort study of 216 children under 5 years of age in rural Bangladesh. Geophagy was assessed at baseline using 5 hour structured observation and caregiver reports. Stool was analyzed for fecal markers of intestinal inflammation: alpha-1-antitrypsin, myeloperoxidase, neopterin (all three combined to form an EE disease activity score), and calprotectin. Eighteen percent of children had observed geophagy events by structured observation and 28% had caregiver reported events in the past week. Nearly all households had Escherichia coli (97%) in soil, and 14% had diarrheagenic E. coli. Children with caregiver-reported geophagy had significantly higher EE scores (0.72 point difference, 95% confidence interval [CI]: 0.01, 1.42) and calprotectin concentrations (237.38 μg/g, 95% CI: 12.77, 462.00). Furthermore, at the 9-month follow-up the odds of being stunted (height-for-age z-score < -2) was double for children with caregiver-reported geophagy (odds ratio [OR]: 2.27, 95% CI: 1.14, 4.51). These findings suggest that geophagy in young children may be an important unrecognized risk factor for EE and stunting.

Dust from Zambian smelters: mineralogy and contaminant bioaccessibility

Metal smelting is often responsible for local contamination of environmental compartments. Dust materials escaping from the smelting facilities not only settle in the soil, but can also have direct effects on populations living close to these operations (by ingestion or inhalation). In this particular study, we investigate dusts from Cu-Co metal smelters in the Zambian Copperbelt, using a combination of mineralogical techniques (XRD, SEM/EDS, and TEM/EDS), in order to understand the solid speciation of the contaminants, as well as their bioaccessibility using in vitro tests in simulated gastric and lung fluids to assess the exposure risk for humans. The leaching of metals was mainly dependent on the contaminant mineralogy. Based on our results, a potential risk can be recognized, particularly from ingestion of the dust, with bioaccessible fractions ranging from 21 to 89% of the total contaminant concentrations. In contrast, relatively low bioaccessible fractions were observed for simulated lung fluid extracts, with values ranging from 0.01% (Pb) up to 16.5% (Co) of total contaminant concentrations. Daily intakes via oral exposure, calculated for an adult (70 kg, ingestion rate 50 mg dust per day), slightly exceeded the tolerable daily intake limits for Co (1.66× for fly ash and 1.19× for slag dust) and occasionally also for Pb (1.49×, fly ash) and As (1.64×, electrostatic precipitator dust). Cobalt has been suggested as the most important pollutant, and the direct pathways of the population's exposures to dust particles in the industrial parts of the Zambian Copperbelt should be further studied in interdisciplinary investigations.

Bacterial diversity in soil from geophagic mining sites in the Qwa-Qwa region of South Africa

Geophagia is practised in many parts of the world and can be associated with medicinal treatments, ceremonial events and spiritual behaviours/practices. This is the first report on a systematic investigation and description of the bacterial diversity in soil regularly ingested by geophagic individuals using a culture-independent method. Diversity in 17 different mining sites was investigated using denaturing gradient gel electrophoresis. Genetic material from Pantoea, Stenotrophomonas, Listeria, Rhodococcus and Sphingomonads was present in most of the soil samples. Species from these genera are recognised, potential or immerging human pathogens, and are of special interest in immune-compromised individuals. Other genera able to produce a variety of bacteriocins and antimicrobial/antifungal substances inhibitory towards food borne pathogens (Dactylosporangium and Bacillus) and able to degrade a range of environmental pollutants and toxins (Duganella and Massilia) were also present. These essential insights provide the platform for adjusting culturing strategies to isolate specific bacteria, further phylogenetic studies and microbial mining prospect for bacterial species of possible economic importance.

Geophagy practices and the content of chemical elements in the soil eaten by pregnant women in artisanal and small scale gold mining communities in Tanzania

BACKGROUND

Geophagy, a form of pica, is the deliberate consumption of soil and is relatively common across Sub-Saharan Africa. In Tanzania, pregnant women commonly eat soil sticks sold in the market (pemba), soil from walls of houses, termite mounds, and ground soil (kichuguu). The present study examined geophagy practices of pregnant women in a gold mining area of Geita District in northwestern Tanzania, and also examined the potential for exposure to chemical elements by testing soil samples.

METHOD

We conducted a cross sectional study using a convenience sample of 340 pregnant women, ranging in age from 15-49 years, who attended six government antenatal clinics in the Geita District, Tanzania. Structured interviews were conducted in June-August, 2012, to understand geophagy practices. In addition, soil samples taken from sources identified by pregnant women practicing geophagy were analysed for mineral element content.

RESULTS

Geophagy was reported by 155 (45.6%) pregnant women with 85 (54.8%) initiating the practice in the first trimester. A total of 101 (65%) pregnant women reported eating soil 2 to 3 times per day while 20 (13%) ate soil more than 3 times per day. Of 155 pregnant women 107 (69%) bought pemba from local shops, while 48 (31%) consumed ground soil kichuguu. The estimated mean quantity of soil consumed from pemba was 62.5 grams/day. Arsenic, chromium, copper, iron, manganese, nickel and zinc levels were found in both pemba and kichuguu samples. Cadmium and mercury were found only in the kichuguu samples. Based on daily intake estimates, arsenic, copper and manganese for kichuguu and copper and manganese for pemba samples exceed the oral Minimum Risk Levels designated by the U.S. Agency for Toxic Substance and Disease Registry.

CONCLUSION

Almost 50% of participants practiced geophagy in Geita District consistent with other reports from Africa. Both pemba and kichuguu contained chemical elements at varying concentration, mostly above MRLs. As such, pregnant women who eat soil in Geita District are exposed to potentially high levels of chemical elements, depending upon frequency of consumption, daily amount consumed and the source location of soil eaten.

Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans) in traditional clay products used during pregnancy

Geophagy, the practice of consuming clay or soil, is encountered among pregnant women in Africa, Eastern Asia and Latin America, but also in Western societies. However, certain types of clay are known to contain high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The aim of this study was to determine the PCDD/F contents of orally consumed clays purchased from Dutch and African markets. Congener patterns were compared with those of pooled human milk samples collected in eight African countries, to investigate a possible relationship with clay consumption. From the Dutch market thirteen clay products were examined, seven of African and six of Suriname origin. From seven African countries, twenty clay products were collected. All 33 clay products were screened with a cell-based bioassay and those showing a high response were analyzed by GC/HRMS. High PCDD/F concentrations were measured in three clay products from the Dutch market, ranging from 66 to 103 pg TEQ g(-1), whereas clay products from African countries were from 24 to 75 pg TEQ g(-1). Patterns and relatively high concentrations of PCDD/Fs in human milk samples from the Democratic Republic of the Congo and Côte d'Ivoire suggest a relationship with the consumption of contaminated clay. Frequent use of PCDD/F contaminated clay products during pregnancy may result in increased exposure of the mother and subsequently the developing fetus and new-born child. The use of these contaminated clays during pregnancy should be carefully considered or even discouraged.

Human geophagia, calabash chalk and undongo: mineral element nutritional implications

The prime aim of our work is to report and comment on the bioaccessible concentrations – i.e., the soluble content of chemical elements in the gastrointestinal environment that is available for absorption – of a number of essential mineral nutrients and potentially harmful elements (PHEs) associated with the deliberate ingestion of African geophagical materials, namely Calabash chalk and Undongo. The pseudo-total concentrations of 13 mineral nutrients/PHEs were quantified following a nitric-perchloric acid digestion of nine different Calabash chalk samples, and bioaccessible contents of eight of these chemical elements were determined in simulated saliva/gastric and intestinal solutions obtained via use of the Fed ORganic Estimation human Simulation Test (FOREhST) in vitro procedure. The Calabash chalk pseudo-total content of the chemical elements is often below what may be regarded as average for soils/shales, and no concentration is excessively high. The in vitro leachate solutions had concentrations that were often lower than those of the blanks used in our experimental procedure, indicative of effective adsorption: lead, a PHE about which concern has been previously raised in connection with the consumption of Calabash chalk, was one such chemical element where this was evident. However, some concentrations in the leachate solutions are suggestive that Calabash chalk can be a source of chemical elements to humans in bioaccessible form, although generally the materials appear to be only a modest supplier: this applies even to iron, a mineral nutrient that has often been linked to the benefits of geophagia in previous academic literature. Our investigations indicate that at the reported rates of ingestion, Calabash chalk on the whole is not an important source of mineral nutrients or PHEs to humans. Similarly, although Undongo contains elevated pseudo-total concentrations of chromium and nickel, this soil is not a significant source to humans for any of the bioaccessible elements investigated.