U.S. urban cities and less than 0.02 μg per day in rural areas.
Food is the largest potential source of cadmium exposure for the general population. The daily cadmium intake from food in the United States ranges from 10 to 60 μg.
Except in the vicinity of cadmium-emitting industries, the concentration of cadmium in most U.S. drinking-water supplies is less than 1 μg/L. However, concentrations of up to 10 μg/L have been reported in some water supplies. Thus, daily cadmium intake from drinking water is about 2–20 μg, assuming that a person drinks 2 liters of water per day.
Cigarettes are also an important source of cadmium exposure. The amount of cadmium that can be inhaled from smoking one cigarette is 0.1–0.2 μg. Thus, it can be estimated that someone smoking one pack per day will take in 2–4 μg of cadmium per day.
The highest estimated cadmium intake from the zinc cadmium sulfide dispersion tests was 24.4 μg in St. Louis, 14.5 μg in Winnipeg, 6.8 μg in Minneapolis, 1.1 μg in Fort Wayne, and 0.1 μg in Corpus Christi.
The subcommittee concluded that the amounts of cadmium from the zinc cadmium sulfide used in the Army's dispersion tests were well below the amounts at which toxic effects occur. For most of the people living in the most heavily exposed populated area—St. Louis—the highest estimated airborne exposure to cadmium (24.4 μg) was equivalent to what urban residents would typically experience from inhaling air over the course of 1—8 months. For people living in Fort Wayne, the highest estimated exposure to cadmium (1.1 μg) was equivalent to what urban residents would typically experience from inhaling air over the course of 1–11 days. For people living in Minneapolis, the highest estimated exposure to cadmium (6.8 μg) was equivalent to what urban residents would typically experience from inhaling air over the course of 1–10 weeks. As a result, the subcommittee has concluded that given the very small amounts of zinc cadmium sulfide to which people were exposed and the short duration of exposure, it is extremely unlikely that anyone in the test areas