m71.    What chemicals pose a danger?

Atmospheric emissions of lead from human sources are 28 times greater than those from natural sources. Yearly, 12,000 to 16,000 American children under age 9 are treated for acute lead poisoning and about 200 die. Eighty-eight percent of all children in the U.S. under age 6 have unsafe blood levels of lead that may retard their mental, physical, and emotional development.

Dioxins are a family of 75 different chlorinated hydrocarbons. TCDD (2,3,7,8-Tetrachlorodibenzo-p-Dioxin) and other dioxins result from burning of chlorine-containing wastes in municipal and hazardous waste incinerators and cement kilns; chlorine bleaching of pulp and paper; the manufacture of certain herbicides, many plastics, and many chlorinated hydrocarbon chemicals. TCDD does indeed cause cancer in humans but, unlike most carcinogens, does not damage DNA. Americans routinely eat food containing 7-120 times more TCDD than EPA considers safe.  

e10.    Why do organisms become extinct?

e14.    What are the basic components of life?

e17.    How do organisms use matter?

e20.    What are environmental hazards and risks?

g16.    What is matter?

g19.    Where do you find air pollution?