This document discusses past, present, and future exposures from natural elements. It presents at a global symposium on soil pollution in Rome, Italy. While mean soil concentrations have more than doubled for some elements like rhodium and rhenium due to sludge amendment over the past 100 years, the effects on the environment are difficult to establish but likely at higher local concentrations. All data has uncertainty and requires verification.

1. Past, present and future
exposures from natural elements
Presentation at
GLOBAL SYMPOSIUM ON SOIL POLLUTION
| FAO HQ | Rome, Italy, 2-4 May 2018
Gunnar Bengtsson
gunnarbengt@telia.com

2. 2

12. Conclusions
•Mean soil conc. now and 100 years sludge amendment
> doubled for Rh, Re,
•Effects on environment at higher local concentrations
likely but hard to establish
•All data uncertain and need verification