The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1937-04-22
Keeping Up
WMit|6Seienfe
&SeAn@M2erse
Clue in Geography
to Tooth Decay
Found by Research
Effects of Latitude
and Drinking Water

Baltimore.-Dentists seeking
ways to prevent carries or tooth
decay took a lesson in geogra-
ply at the meeting here of the
International Association for
Dental Research.
Latitude, hardness of drinking wa
ter and nearness to mining regions
all seem to have an effect on tooth
decay, DR.. Clarence A. Mills, pro-
lessor of experimental medicine at
the University of Cincinnati, told the
dentists.
The amount of tooth decay in
American school children increases
steadily throughout the United
States as the distance from the trop-
les increases, DR.. Mills said. The
increase is roughly Is more decayed
teeth per 100 children for each add
ed degree of latitude, cor well over
200 per cent from Gulf to Cana
dian border"
Effects of Ultraviolet Light.
DR.. Mills explains this as being
due to the decreased amount of ul-
tra-violet light reaching inhabitants
of the more northern ATTITUDES. The
only exception to the increase Of
tooth decay toward the north is
found in the northern plains section,
where the sunlight is more plenti-
full than in other northern regions of
the country. The part played by ul-
tra-violet light in stimulating devel-
opment of strong bones and teeth
has already been shown, DR.. Mills
pointed out.
Hard water is good for the teeth,
even though it makes dishwashing,
laundering and other household
chores more difficult and presents a
serious problem to factories. DR..
Mills found almost 80 per cent more
carries among the children of cities
using river and lake water than
among those using water from wells
or springs, even though the mean
latitude of the two groups was the
same. The reason for this, he be-
lieves, is the degree of hardness of
the water. His data show that car
les diminishes as hardness in
creases. Animal studies have al
ready shown that the calcium and
magnesium supply in the drinking
water and food affect bone and tooth
formation and tooth decay.
Carries and Soil Teaching.
Another relation between geogra-
ply and tooth decay is the finding
that children living near the head
waters of a river have less carries
than those living near the same riv-
er's mouth. This is probably related
to soil teaching, DR.. Mills suggests.
A high carries rate is found in min
ing regions in Pennsylvania and on
down the Ohio river. This may be
accounted for by the millions of tons
of sulphuric acid which seep each
year from the mines into PennSyl-
vania streams and on down the
Ohio. Besides corroding boilers,
metal pipes and river craft, DR..
Mills believes this acid may lead
to tooth decay in persons drinking
the water. Sulphuric acid will lib
crate calcium from bones and teeth
in large amounts, studies on lead
poisoning treatment have shown.
This point and possible relation
between amount of tooth decay and
amount of oxidized sulphur from
coal combustion in the air of smoky
cities need to be investigated fur
Their, DR.. Mills suggested.
Exploring geographers know that
primitive people usually have good
teeth until they come in contact with
civilization, and that one of the first
articles of trade brought to such
peoples is salt. Laboratory scien-
lists know that when animal diets
contain large amounts of salt, cal
cium and phosphorus, important
bone constituents, are excreted from
the body in larger amounts. Re-
calling these two facts, DR.. Mills
made rough survey of salt use
and tooth decay. He found that chill
dren and adults who salt their food
heavily have more decayed teeth.