kinds and how serious they will be. Those factors include the toxicity of the substance, the dose (how much), the duration (how long), the pathway or route by which you are exposed (breathing, eating, drinking, or skin contact), the other chemicals to which you are exposed, and your individual characteristics, such as age, sex, nutritional status, family traits, and state of health.
Although more is known about some related chemicals, it is not well known how the compound zinc cadmium sulfide could affect people's health. There is little information on the toxicity of zinc cadmium sulfide in experimental animals. We do know that animals that were fed massive amounts of zinc cadmium sulfide one time did not show any ill health effects. We also know that zinc cadmium sulfide does not irritate rabbits' skin or eyes.
Information is not available on whether particles of zinc cadmium sulfide that might become lodged in your lungs for a long time are harmful. The subcommittee has recommended that research be done to find out whether those particles might break down in the lungs into toxic materials that could enter the bloodstream. The Army is now doing the recommended research.
Cadmium is the most toxic component of zinc cadmium sulfide. Zinc cadmium sulfide cannot be more toxic than soluble cadmium compounds, so toxicologic assessment assuming soluble cadmium compounds represents the worst-case scenario.
Cadmium is a natural component of the earth's crust. All soils and rocks, including coal, have some cadmium in them. Humans are exposed to cadmium naturally through water, air, food, soil, and house dust. Cadmium enters the air from the burning of coal and household waste. In the United States, mean concentrations of cadmium in ambient air range from less than 0.001 μg/m3 in remote areas to 0.005–0.04 μg/m3 in urban areas. Atmospheric concentrations of cadmium are generally highest in the vicinity of cadmium-emitting industries such as smelters, municipal incinerators, or fossil-fuel combustion facilities. Measurements of atmospheric cadmium up to 7 μg/m3 have been reported in these industrial types of areas in the United States. Cadmium intake from air is estimated to be 0.1–0.8 μg per day in typical