Testing Your Comprehension
Environmental health hazards can be physical, chemical, biological, or cultural.
Infectious disease is the worst of the biological health hazards, and causes more human deaths
than any other environmental health hazard. It is a problem that can grow over time, is communicable,
and can be understood only in the context of complex interrelationships among technology, land use,
Exposure to lead, asbestos, radon, and PBDEs occurs primarily indoors. Lead exposure can
occur though contamination of water flowing through older pipes with lead solder, or by ingestion of
paint containing lead. Both of these uses have been largely discontinued, and in older homes, can be
abated. Asbestos was a commonly used insulating material, and can be inhaled if the material is
disturbed. This use has also been largely discontinued, and old asbestos insulation can be removed by a
qualified contractor. Radon is a naturally occurring radioactive gas that, in certain geological areas, can
seep into the basements of homes and accumulate there. When inhaled it increases the risk of lung
cancer. If the basement is both sealed and well ventilated, radon levels can be kept very low. PBDEs
(polybrominated diphenyl ethers) are used as flame retardants in many consumer products. They are
environmentally persistent, are bioaccumulated, and appear to be endocrine disruptors. Little has been
done to address this situation in the United States.
Concern over pesticides in the United States has been growing since
in 1962. Carson argued that DDT was harmful to the health of people, wildlife, and ecosystems. DDT
use was subsequently banned in the United States, although it is still produced domestically, sold
abroad, and used abroad.