Section 3: Chemical Hazards What are toxic and hazardous chemicals? What are some possible impacts from chemical hazards? Are hormonally active agents a human health threat? Why do scientists no so little about the impacts of chemicals on human health? Is pollution prevention the answer?

What are toxic and hazardous chemicals? Toxic Chemical: a chemical that can cause temporary or permanent harm or death. Hazardous Chemical : can harm humans because it is flammable or explosive.

Types of Toxic Agents Mutagen: causes changes to ones DNA. Teratogens: chemicals that cause birth defects to fetus or embryo. (alcohol) Carcinogens: cause cancer (growth of cancerous tumors)

Impacts of Chemicals on Humans Chemicals may also impact: Immune system (arsenic, dioxin) Nervous System (neurotoxins, brain, spinal cord, etc.) Endocrine System (levels of hormones)

Hormonally Active Agents Exposure to low level certain synthetic chemicals may disrupt a bodies hormone levels Endocrine disrupters or hormonally active agents  So called, gender benders

Establishing Guilt Is Difficult Under current laws, most chemicals are considered innocent until proven guilty. “Toxicologist know a great deal about a few chemicals, a little about many, and nothing about most.”

Establishing Guilt Is Difficult U.S. National Academy of Sciences estimates that only 10% of the 80,000 chemicals in commercial use have been tested for toxicity. Why? Not required (considered innocent) Lack of funds, personnel, facilities Expensive Difficult to test interactions

Pollution Prevention Model Where do we go from here? We do not know much about all of the chemicals inside us, around us Eliminating them mean other problems Some say Pollution Prevention,

Pollution Prevention Model Precautionary Principle: where there is plausible, but incomplete scientific evidence of significant harm we need to take action to reduce the risk. “Better Safe Than Sorry”

Pollution Prevention Model First: new chemical technologies would be considered harmful until studies say otherwise. Second: existing chemicals that appear to be harmful would be removed from use.