Environmental Engineering Reference
In-Depth Information
and topical application. Milk fluoridation has been shown to be effective in the
prevention of dental caries, but to be clinically effective, it must be freshly
prepared and consumed immediately. The use of table salt containing fluoride
has been proposed by the Pan American Health Organization in areas lacking
fluoridated community water supplies. Oral hygiene, including at least daily teeth
brushing, consumption of fewer sweets, followed by water rinse or drink, is also
basic to caries reduction.
Hypothermia
The maintenance of a normal body temperature at or near 98.4
◦
F(37
◦
C) is
necessary for proper body function. When the body core temperature drops to
95
◦
F(35
◦
C) or below, the vital organs (brain, heart, lungs, kidneys) are affected,
causing what is known as hypothermia. There were 7,450 deaths from hypother-
mia reported between 1976 and 1985. In 2001, Montana had a death rate from
hypothermia of 1.08 per 100,000, which is nearly fives time greater than the
overall U.S. rate.
78
Rectal temperature measurement is necessary to get a correct
reading. Special “hypothermia thermometers” for accurate reading are available.
Predisposing conditions for hypothermia include old age, poor housing, inade-
quate clothing, poverty, lack of fuel, illness, cold weather, alcohol, and drugs.
Proper body temperature requires a balance between body heat generated and
heat loss. Bald people lose a great deal of heat; fat people are better insulated
and lose less heat on a weight - body surface basis. Disease and drugs, including
alcohol, affect heat loss. Wind and dampness increase coldness. The maintenance
of warmth and comfort is related to the prevailing temperature, building design
and construction, clothing, heating and cooling facilities, and food consumed and
also to air movement, radiant heat, relative humidity, the tasks performed, and
the age and health status of individuals. At greater risk are babies and the elderly,
particularly those already suffering from an acute or chronic illness. Provision
for heating and cooling above and below that temperature is recommended. Lack
of adequate housing and acute alcohol intoxication are the principal causes of
death, as well as advanced age and adverse social and economic circumstances
(homelessness).
Signs of hypothermia are bloated face, pale and waxy skin or pinkish color,
drowsiness, low blood pressure, irregular and slow heart beat, shallow very slow
breathing, trembling of leg, arm, or side of body, and stiff muscles. People should
stay indoors when the windchill index is
20
◦
F(
29
◦
C) and below.
−
−
High Environmental Temperatures
Heat waves have been associated with marked increases in morbidity and mortal-
ity in the United States, but these deaths are largely preventable. Heat disorders
include heatstroke, heat exhaustion, heat cramps, and heat rash. Heatstroke, when
one's core temperature exceeds 105
◦
F (40.5
◦
C), is the most serious. The mea-
sures that have been shown to be effective to reduce heat stress include the
following:
