Water
Moderate burden — Harvested Rainwater adds a moderate, reducible exposure.
Roof-collected rainwater used for drinking.
Each driver rated 0 (none) to 10 (worst)
Evidence strength: moderate · Detox Score = 100 − hazard×4.6 − exposure×3.4 − persistence×2.6, clamped 1–100.
A Detox Score of 51 places harvested rainwater in the Moderate band. The persistence rating is the standout concern here — these compounds linger in the body and environment for years. A widely reported analysis in Environmental Science & Technology found PFAS in rainwater samples worldwide at levels exceeding some drinking-water guideline values, alongside whatever the roof surface contributes. Rainwater remains fine for irrigation.
Harvested Rainwater has a Detox Score of 51 out of 100 (Moderate burden), which means it adds a moderate, reducible exposure. A widely reported analysis in Environmental Science & Technology found PFAS in rainwater samples worldwide at levels exceeding some drinking-water guideline values, alongside whatever the roof surface contributes. Rainwater remains fine for irrigation.
A lower-exposure swap for harvested rainwater is: Keep rainwater for the garden; drink filtered mains water. A widely reported analysis in Environmental Science & Technology found PFAS in rainwater samples worldwide at levels exceeding some drinking-water guideline values, alongside whatever the roof surface contributes. Rainwater remains fine for irrigation.