Humans typically consume less than 100 micrograms of iodine per day. Humans consume on average between 6 and 200 micrograms of selenium per day. In Canada, different variants contain five and 50 micrograms of thimerosal per dose. The EPA's acceptable daily dose is 0.3 micrograms/kg/day. The corresponding limit of blood mercury is 5.8 micrograms per liter. It is present in uranium ores in concentrations of 100 micrograms per metric ton. LD50 of 0.06-0.075 micrograms per g body weight in mice. Humans ingest on average less than 20 micrograms of bismuth per day. Levels of PM in Putuo District reached 726 micrograms per cubic meter. On average, humans ingest about 600 micrograms of tellurium daily. Chromium content of common foods is generally low (1-13 micrograms per serving). One thousand micrograms per day in infants has produced toxicity within one month. Exceeding the Tolerable Upper Intake Level of 400 micrograms per day can lead to selenosis. Humans typically consume several micrograms of thulium per year. The technique can be used on scales from micrograms up to kilograms.