These are the limits for heavy metals in sewage sludge in the EU for the different directives the Eu has in place regarding the regulation of sewage sludge.
European commission
CC BY-SA 4.0
<p>"Disposal and Recycling Routes for Sewage Sludge" part 2 Regulatory report.
</p>
<a rel="nofollow" class="external free" href="https://ec.europa.eu/environment/archives/waste/sludge/pdf/sludge_disposal2.pdf">https://ec.europa.eu/environment/archives/waste/sludge/pdf/sludge_disposal2.pdf</a>