- A Good Overview (though slightly back-dated): Quantitative assessment of worldwide contamination of air, water and soil by trace metals 
- A summary of Pollutants from the EPA 
- MCL: 5 ppb
- MCLG: 5 ppb
- Known Carcinogen
- Cadmium Contamination Sites
- Ishihara01 pmid=11376862
- Heavy Metal Limits
- Staessen JA, Lauwerys RR, Ide G, Roels HA, Vyncke G, and Amery A. . pmid:7911869.
- Satarug S, Baker JR, Urbenjapol S, Haswell-Elkins M, Reilly PE, Williams DJ, and Moore MR. . pmid:12505433.