A dog's tale: soil ingestion by a canine

Area of Science:

• Environmental Science
• Toxicology
• Animal Science

Background:

• Soil ingestion is a known exposure route for environmental contaminants in humans, particularly children.
• Limited quantitative data exists on soil ingestion rates in domestic animals.
• Domestic animals may be exposed to soil-borne contaminants through geophagia.

Purpose of the Study:

• To quantitatively estimate the daily soil ingestion rate in a pet dog.
• To compare canine soil ingestion rates with those reported for children.
• To assess the implications of high soil ingestion in pets for contaminant exposure.

Main Methods:

• A single Irish Setter was studied over three consecutive days.
• Soil ingestion was estimated using a soil tracer-based mass-balance methodology.
• Eight different soil tracers (Al, Si, Ti, Y, Zr, La, Ce, Nd) were employed for quantitative estimation.

Main Results:

• High agreement was observed among the eight tracers used to estimate soil ingestion.
• The estimated daily soil ingestion rate for the dog ranged from approximately 10 to 20 g/day.
• This rate is several hundred-fold higher than the soil ingestion reported for an average child (30-50 mg/day).

Conclusions:

• Pet dogs exhibit significantly higher soil ingestion rates compared to children.
• The high soil ingestion rate in dogs warrants further investigation into soil and dust ingestion in domestic animals and wildlife.
• Evaluating soil ingestion in pets is crucial for understanding potential exposure to environmental contaminants.