Page 405 - Environment: The Science Behind the Stories

Testing Your Comprehension

1. What does the field of environmental health cover? and contrast the processes of bioaccumulation and
2. In what way is disease the greatest hazard that people biomagnification.
face? What kinds of interrelationships must environmen- 7. What are epidemiological studies, and what is their value?
tal health experts study to learn about how diseases affect Are there any disadvantages to epidemiological studies?
human health? 8. Why are animals used in laboratory experiments in toxi-
3. Where does most exposure to lead, asbestos, radon, and cology? Explain the dose-response curve. Why is a sub-
PBDEs occur? How has each been addressed? stance with a high LD considered safer than one with a
50
4. Briefly comment on the research to determine the toxicity low LD ?
50
of bisphenol-A (BPA). Also, explain why this topic repre- 9. What factors may affect an individual’s response to a
sents a challenge to scientific integrity and credibility and toxic substance? Why is chronic exposure to toxic agents
the implications for national and international policies on often more difficult to measure and diagnose than acute
this compound that depend on the research. exposure? What are synergistic effects, and why are they
5. List and describe the general categories of toxic sub- difficult to measure and diagnose?
stances described in this chapter. 10. How do scientists identify and assess risks from sub-
6. How do toxic substances travel through the environment, stances or activities that may pose health threats?
and where are they most likely to be found? Describe

Seeking Solutions

1. Describe some environmental health hazards that you 5. THINK IT THROUGH You are the parent of two young
think you may be living with indoors. How do you think children, and you want to minimize the environmental
you may have been affected by indoor or outdoor hazards health risks your kids are exposed to. Name five steps that
in the past? How could you best deal with these hazards you could take in your household and in your daily life
in the future? that would minimize your children’s exposure to environ-
2. Do you feel that laboratory animals should be used in mental health hazards.
experiments in toxicology? Why or why not? 6. THINK IT THROUGH You work for a public health organ-
3. Why has research on endocrine disruption spurred so ization and have been asked to educate the public about
much debate? What steps do you think could be taken to bisphenol A and to suggest ways to minimize exposure
help establish greater consensus among scientists, indus- to the chemical. You begin by examining your lifestyle
try, regulators, policymakers, and the public? and finding ways to use alternatives to BPA-containing
products. Create a list of five ways you are exposed daily
4. Describe differences in the policies of the United States to bisphenol A, and then list approaches that would avoid
and the European Union toward the study and manage- or minimize these exposures. Do these steps require more
ment of the risks of synthetic chemicals. Which do you time and/or money? What are some costs of embracing
believe is better, the policies of the United States or those these changes? What would you tell an interested person
of the European Union, and why?
about bisphenol A as it relates to human health?

Calculating Ecological footprints

In 2007, the last year the U.S. EPA reported data on pesti- insecticides, fungicides, herbicides, rodenticides, repellants,
cide use, Americans used 1.13 billion pounds of pesticide and disinfectants. They are used by farmers, governments,
active ingredients, and world pesticide use totaled 5.21 billion industries, and individuals. In the table, calculate your share
pounds of active ingredients. In that same year, the U.S. pop- of pesticide use as a U.S. citizen in 2007 and the amount used
ulation was 302 million, and the world’s population totaled by (or on behalf of) the average citizen of the world.
404 6.63 billion. Pesticides include hundreds of chemicals used as

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