How much soil do young children ingest: An epidemiologic study

Ingestion of soil may be a potentially important pathway of exposure to environmental pollutants. Although several studies have estimated soil ingestion in children, data on ingestion in adults are sparse. The purposes of this study were to estimate soil ingestion in children aged 3 to 8 years and their parents, identify factors associated with increased ingestion, and compare ingestion rates within the same family. Food/liquid, excreta, and soil/dust samples were collected for the mother, father, and participant child for 11 consecutive days in 19 families. Soil ingestion was estimated using a mass balance approach. Soil ingestion levels in children were similar to those reported previously, whereas adult estimates were somewhat higher than previous estimates. Children's eating of dirt and parents' occupational contact with soil were associated with increased ingestion. Within families, soil ingestion levels in children and adults were not correlated, although this analysis was based on fewer than 19 participant families. Children's mean soil ingestion rates ranged from 37 to 207 mg/day depending on the tracer, with the highest values based on titanium as a tracer. Adult mean soil ingestion rates ranged from 23 to 625 mg/day depending on the tracer, with the highest value based on titanium as a tracer. Soil ingestion rate estimates were more variable in adults than in children.

Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Soil ingestion in children and adults in the same family

Davis

Mirick

2005

“…2,69,75 According to the literature, children in general ingest about 50 mg/day house dust during the summer and 100 mg/day during the winter, when they spend more time indoors. 57,58 In the case of pica behavior (eating of non-nutritive substances), uptake can reach up to 2--30 g/day. 2 Adults usually incorporate only 0.6 mg house dust per day, mainly because of dust settled on food and all kinds of surfaces combined with occasional hand to mouth contacts.…”

Section: Resultsmentioning

confidence: 99%

Bioaccessibility of pesticides and polychlorinated biphenyls from house dust: in-vitro methods and human exposure assessment

Ertl¹,

Butte

2012

Semi-volatile chemicals like pesticides and polychlorinated biphenyls (PCB) tend to accumulate in house dust. This may result in residues of some parts per million (p.p.m.), closely associated with health impairments and diseases like cancer. To explain these associations, we must establish whether a relevant absorption from house dust into human organisms occurs, and most crucially the release of chemicals, that is, their bioaccessibility. Digestive as well as dermal bioaccessibilities were examined using in-vitro methods. On average, the digestive bioaccessibility was B40% for the pesticides and B60% for the PCB. The dermal penetration availability reached B60% for the pesticides and B70% for the PCB (percentages of the concentrations in the dust). Based on the bioaccessibility, an estimate of internal exposure was calculated and expressed as percentages of acceptable or tolerable daily intake (ADI/TDI) values. Exposure via the respiratory tract proved to be very low. Exposure via the digestive tract had maximum values of 4% for pesticides and 12% for PCB. Dermal exposure was much higher. Even for average concentrations in house dust (E0.5 p.p.m.), children exposed to DDT and PCB showed up to 300% of the ADI/TDI values, and adults about 60%. With high concentrations of contaminants in house dust, the maximum doses absorbed through the skin reached 5000%.

“…For example, the median soil ingestion levels reported by different investigators range from 11 to 618 mg/day for US children and from 1 to 77 mg/day for adults (Binder et al, 1986;Clausing et al, 1987;Calabrese and Stanek, 1991;Calabrese et al, 1989aCalabrese et al, , 1989bThompson and Burmaster, 1991). These values were based upon studies of US adults and children.…”

Section: Pb Exposures Via Three Major Pathwaysmentioning

confidence: 99%

High lead exposures resulting from pottery production in a village in Michoacán State, Mexico

Hibbert

Bai

Navia³

et al. 1999

This paper reports findings from a screening study conducted to examine potential lead (Pb) exposures in residents of a Mexican village where Pb oxide continues to be used in ceramic pottery production. Extremely high Pb concentrations were measured in personal and indoor air samples, household surface dust samples, and household soil samples. Personal air Pb concentrations for workers performing pottery firing and glazing were up to 454 g/m 3 . Results from indoor air samples indicate that airborne Pb concentrations were lower during nonglazing period compared to the glazing period. Soil Pb concentrations measured in 17 homes ranged from 0.39 to 19.8 mg/g. Dust Pb loading on surfaces of household items, hands, and clothes of a worker ranged from 172 to 33 060 g/f t 2 . Pb content as high as 2.4 g/g was found in a bean stew cooked in a pot made in the village. Based on these Pb concentrations measured in multiple media and data adapted for exposure contact rates, we have made rough estimates of Pb exposures via inhalation, soil/dust ingestion, and food ingestion. Estimated total daily Pb intake, on average, is 4.0 mg for adults and 3.4 mg for children living in the village. In the total daily intake, a greatest fraction may be contributed by food ingestion and another significant fraction may come from soil/dust ingestion for the children. Although the sample size is small, these measurements indicate a very significant public health problem for the village residents and a large number of other similar communities in Mexico. (It was estimated that there are approximately 1.5 million glaze potters.) The Pb exposure is implicated in a number of pervasive health problems in the region, and is the cause for national and international attention. Several recommended solutions to this problem range from personal protection and behavioral changes to introduction of alternative glazes.