고온 및 저온작업환경 근무자의 여름철 땀분비에 관한 실험적 연구

Abstract

[영문]

[한글]

열순화는 수동적인 혹은 능동적인 가열에 의한 체온상승에 적응하기 위한 생리적 기능

의 하나이다. 열순화의 중요한 기전으로서 땀분비에 의한 열손실의 증가를 들 수 있다.

여러 학자들이 열순화 과정을 연구하기 위하여 10일 정도의 단기간 고온 노출로써 인위

적인 순화를 일으켜 관찰한 결과 땀분비 증가, 피부 및 직장온도의 증가폭 감소, 심박동

수 증가폭 김소 및 땀의 Na**+ 농도 감소 등을 보고하였다.

땀분비에는 계절적인 변화가 있어서 여름에 땀분비량이 증가하고 땀의 Na**+ 농도는 감

소한디고 보고되어 있으나 Hori등(1976; 1980)에 의하면 열순화가 잘 되어 있는 사람은

여름철에도 땀분비량이 증가하지 않는다고 하였다.

저자는 고온작업환경에 의해 장기간 열순화가 되어 있는 용해직 근무자 10명과 저온작

업환경에서 일하는 냉동실 근무자 12명을 대상으로 여름철인 7월에 건구온도 46℃, 습구

온도 37℃(상대습도 : 50%)되는 Environ-Room에서 한시간 동안 땀을 분비케 하고, 땀분비

량, 땀의 Na**+ 농도, 피부 및 직장온도, 심박동수, 24시간 뇨중 NaCl 배설량을 측정하고

같은 방법으로 상온직업환경 근무자인 청소직 근무자 12명의 성적과 비교하여 다음과 같

은 결과를 얻었다.

1. 모든 실험군에서 시간이 경과할수록 땀분비율이 올라가서 30∼45분에 최고에 달하고

이후 감소하는 경향을 보였다. 한시간 땀분비량에 있어 저온작업환경군과 대조군 간에는

차이가 없었고 고온작업환경군에서는 땀분비량이 현저히 증가하였다.

2. 땀의 Na**+ 농도는 고온작업환경군에서 땀분비량이 현저히 많음에도 불구하고 가장

낮았다.

3. 피부온도는 첫 30분에 급격히 증가하였고 이후 서서히 증가하여 1시간 땀분비 후 그

증가폭은 고온작업환경군에서 의의있게 작았다.

4. 직장온도는 모든 군에서 서서히 증가하였고 1시간 땀분비 후 그 증가폭은 약 1℃로

서 각 실험군간에 유의한 차이는 없었다.

5. 심박동수는 각 실험군에서 점차 증가하였으나 그 증가폭에 있어 각 실험군간에 의의

있는 차이는 없었다.

6. 24시간 뇨중 NaCl 배설량은 고온작업환경군에서 약간 많은 경향이었으나 각 실험군

간에 유의한 차이는 없었다.

이상의 결과로 보아 장기간 고온작업환경에서 일한 용해직 근무자들이 대조군과 저온작

업환경군에 비해 열순화가 잘 되어 있으며, 이에 따라 고온노출시 많은 땀분비율의 증가

와 땀의 Na**+ 농도 감소, 그리고 피부온도 증가폭의 감소를 보였다고 추측된다.

An Experimental Study on the Sweat Secretion of Furnace and Freezer Workers in

Summer

Hye Won Cheon

Department of Medical Science The Graduate School, Yonsei University

(Directed by Professor Sungnack Lee, M.D.)

Heat acclimatization is characterized by improved responsiveness on heat

dissipating function. The primary adaptive change is an increased sweating and

evaporative efficiency.

After 10 to 20 days heat acclimatization, the following physiological changes

were reported by Fox et al (1963): increased sweat production, lowered pulse rate,

lowered skin and deed body temperatures, and less discomfort during heat exposure.

These adaptive changes disappear within several weeks after cessation of heat

exposure.

It is well recognized that the sweating reaction of humans is influenced by

different climates. Many investigators reported that sweat rate is higher, salt

concentration in sweat is lower and the latent period of sweating is shorter in

summer than in winter.

On the other hand, Kuno(1956) reported that tropical natives sweat less and

slower than Japanese and the salt concentration in the sweat in the tropical

natives is much lower than that in Japanese.

The purpose of this experiment is twofold. The first is to evaluate the

physiological changes during heat exposure in the hot environmental workers who are

occupationally acclimatized to heat for long years. The second is to compare this

evaluation to changes in normal and the cold environmental groups: physiological

changes measured in all groups were sweat secretion rate, sodium concentration in

sweat, skin and rectal temperatures, pulse rate, and the amount of NaCl excreted in

24-hour urine.

Ten furnace workers working at 38℃, 12 freezer workers working at -20℃, and 12

control subjects working at room temperature were selected for each experimental

group.

The experiment was performed in July during the summer season. An "Environ-Room"

(db 46℃, wb 37℃: Lab line lnsc. Int. Melrose Park III) was used for the sweat

secretion test. Sweat was collected on both forearms with a sweat collector

designed by Sato and Dobson(1969) every 15 minutes for 1 hour (mg/4.91㎠). Sodium

concentration in sweat was analized with a flame photometer (mEq/l). Skin and

rectal temperatures were measured with a telethermometer and a indwelling rectal

probe. Radial pulse rates were counted every 15 minutes. Twenty four hour urine was

collected to measure the amount of excreted sodium choloride.

Summary and conclusion :

1. During the experiment, sweat secretion in all groups increased until

45minutes, and decreased for the following 15 minutes. There was no significant

difference in the amount of sweat from the right and the left forearms. The amount

of sweat increased more markedly in the hot environmental group

(338.85mg/4.91㎠/hour) than in the otter groups (control group:

183.25mg/4.91㎠/hour, cold environmental group: 188.50mg/4.91㎠/hour).

2. The sodium concentration in sweat was markedly lower in the hot environmental

group (56.3mEq/l) than in the other two groups (cold environmental group:

67.7mEq/l, control group: 71.4mEq/l), while its sweat rate was the highest among

the three groups.

3. The increment of skin temperature in the hot environmental group was

aignificantly lower (3.3℃) than in the control group (3.9℃) and the cold

environmental group (4.2℃).

4. The increment of rectal temperature showed no statistical significance among

the three groups.

5. The amount of NaCl excreted in the 24-hour urine is relatively higher in the

hot environmental group but there was no statistical significance among the three

groups.

6. Heart rates increased in all the three groups without any significant

difference.

It is, therefore, concluded that the furnace workers are more acclimatized to

heat stimuli than freezer workers and control group, resulting in higher sweat

rate, lower sodium concentration in sweet, and less increment of skin temperature

after heat exposure.