Low presence of potentially toxic elements in Singapore urban garden soils

Urban Farm DB summary

Researchers assessed pseudo-total concentrations of cadmium, copper, lead and zinc in soils from community gardens, public parks and woodlands across Singapore, comparing them to risk guidelines and using lead isotope analysis to trace contamination sources. All measured concentrations were below thresholds considered to represent substantial risk, garden soils were largely equivalent in concentration to parks and woodlands though geographic distribution varied, lead sources were both anthropogenic and natural with spatial variability inconsistent with a single point source, and a correlation between copper and zinc suggested a shared source such as road traffic or atmospheric deposition; the study did not assess bioavailability or bioaccessibility of these elements, which it noted would be needed for a fuller risk assessment at sites with higher contamination.