Page 4: Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Chromium
Canadian Exposure
Recent analyses of self-selected Canadian diets (including drinking water) found the mean dietary intake of chromium to be approximately 0.055 mg/day, with a range of approximately 0.01 to 0.16 mg/day.Footnote 18 Studies in the United States have estimated the mean daily intake to be 0.06 to 0.09 mg.Footnote 19,Footnote 20 All these values are significantly lower than earlier estimates of approximately 0.2 mg/day,Footnote 13,Footnote 21 possibly as a result of improvements in analytical techniques.Footnote 18,Footnote 22
Assuming daily water consumption to be 1.5 LFootnote 23 and the average chromium concentration of Canadian drinking water to be 0.002 mg/L, the average daily intake of chromium from drinking water would be 0.003 mg per person. This value compares well with U.S. estimates of 0.004 to 0.005 mg.Footnote 11,Footnote 24 Chromium intake from food is substantially higher than that from drinking water; the mean total daily intake of chromium from water would be roughly 10 percent of the total dietary intake estimated above.
If the concentration of chromium in air in Canada is assumed to be 0.000015 mg/m3 Footnote 25 and an individual's daily respiratory volume to be 20 m3, then the daily intake of chromium from air would be 0.0003 mg. One U.S. estimate of the daily intake of chromium from air is 0.00028 mg.Footnote 24 The U.S. National Academy of Sciences has estimated this quantity to be only 0.00004 to 0.00008 mg.Footnote 26 Chromium is also present in cigarettes.Footnote 27
Based on the above considerations, the total daily intake of chromium from food, air, and water would be about 0.06 mg. Intake for smokers may be higher because of the presence of chromium in cigarettes.