Page 380 - Environment: The Science Behind the Stories

(c) Biological hazard

(a) Physical hazard (b) Chemical hazard (d) Cultural hazard
Figure 14.2 Environmental health hazards come in four types. The sun’s ultraviolet radiation is an
example of a physical hazard (a). Excessive exposure increases the risk of skin cancer. Chemical hazards
(b) include both synthetic and natural chemicals. Much of our exposure comes from pesticides and household
chemical products. Biological hazards (c) include diseases and the organisms that transmit them. Some
mosquitoes are vectors for pathogenic microbes, including those that cause malaria. Cultural or lifestyle hazards
(d) include the behavioral decisions we make, as well as the socioeconomic constraints forced on us. Smoking
is a lifestyle choice that raises one’s risk of lung cancer and other diseases.

buildings to resist damage, and governments and individu- occurs through a vector, an organism (such as a mosquito)
als can create and rehearse emergency plans to prepare for a that transfers the pathogen to the host. Infectious diseases
quake’s aftermath. such as malaria, cholera, tuberculosis, and influenza (flu) are
Some common practices make us vulnerable to certain major environmental health hazards, especially in developing
physical hazards. Clearing forests from slopes makes land- nations with widespread poverty and few resources for health
slides more likely, for instance, and channelizing rivers pro- care. As with physical and chemical hazards, it is impossi-
motes flooding in some areas while preventing it in others ble for us to avoid risk from biological agents completely, but
(p. 418–420). We can reduce risk from such hazards by through monitoring, sanitation, and medical treatment we can
improving our forestry and flood control practices and by reduce the likelihood and impacts of infection.
regulating development in areas prone to floods, landslides,
fires, or coastal waves. Cultural hazards Hazards that result from our place of
residence, our socioeconomic status, our occupation, or our
Chemical hazards Chemical hazards include many of behavioral choices can be thought of as cultural hazards or
the synthetic chemicals that our society manufactures, such as lifestyle hazards. We can minimize or prevent some of these
pharmaceuticals, disinfectants, and pesticides (Figure 14.2b). cultural or lifestyle hazards, whereas others may be beyond
Some substances produced naturally by organisms (such our control. For instance, choosing to smoke cigarettes, or CHAPTER 14 • Envi R onm E n TA l H EA lTH A nd T o xi C ology
as venoms) also can be hazardous, as can many substances living or working with people who smoke, greatly increases
that we find in nature and then process for our use (such as our risk of lung cancer (Figure 14.2d). Choosing to smoke is
hydrocarbons, lead, and asbestos). Following our overview a personal behavioral decision, but exposure to secondhand
of environmental health, much of this chapter will focus on smoke in the home or workplace may be beyond one’s con-
chemical health hazards and the ways we study and regulate trol. The influences of personal choices and “forced” deci-
them. sions on health can also apply to diet and nutrition, workplace
hazards, drug use, criminal behavior, and one’s primary mode
Biological hazards Biological hazards result from eco- of transportation. As advocates of environmental justice
logical interactions among organisms (Figure 14.2c). When we (pp. 158–159) argue, health factors such as living near toxic
become sick from a virus, bacterial infection, or other patho- waste sites or working with pesticides without proper training
gen, we are suffering parasitism (p. 97) by other species that and safeguards are often correlated with socioeconomic dep-
are simply fulfilling their ecological roles. This is what we call rivation. In general, the fewer economic resources or political
infectious disease. Some infectious diseases are spread when clout one has, the harder it is to avoid cultural hazards and
pathogenic microbes attack us directly. With others, infection environmental health risks. 379

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