Arsenic (As)
Heavy Metal · measured in mg/L
A naturally occurring metalloid that dissolves into groundwater from certain rock formations, and is also introduced by some agricultural and industrial activity.
Common sources
Natural geological deposits (especially in private wells), historic pesticide/herbicide use, mining runoff, and some industrial discharge.
Health risks
Chronic ingestion is linked to skin lesions and skin cancer, and increased risk of bladder, lung, and other internal cancers; the International Agency for Research on Cancer classifies arsenic as a Group 1 (known) human carcinogen. It is also associated with cardiovascular disease and developmental effects.
Sources & further reading
- WHO — Arsenic Fact Sheet
- EPA — Basic Information about Arsenic in Drinking Water
- Smith AH et al. (1992), 'Cancer risks from arsenic in drinking water', Environmental Health Perspectives, 97:259-267
- IARC Monographs — Arsenic and Arsenic Compounds, Volume 100C
How ClearDive rates severity
Readings are bucketed for map color-coding using thresholds referenced from EPA regulatory limits where available. This is a simplified public-awareness scale, not a substitute for certified lab analysis.
How to test for it
Field arsenic test kits (strip-based, ~30 min) give a screening estimate; confirm with certified lab ICP-MS testing, particularly for private wells which are not covered by EPA's regulated public water testing.