Physical Stress of Lotus Growers and Their Health Control. Assessment of Cardiovascular Overload / 日本農村医学会雑誌

ABSTRACT

During winter months, lotus growers have to harvest edible roots, waist-deep in the muddy fields. In addition to such an external factor as the cold, physical labor involved is so hard that a level of stress is considered high, especially on the cardiovascular system. In this study, we examined how hard the labor is on the cardiovascular system, based on the measurements of hemodynamic parameters taken in the fields while farmers were working. The subjects were comprised of a total of 18 lotus growers-11 men and 7 women-aged between 41 and 66 years (mean 56.7 years old). During a week before the measurement was performed, a physical examination and an anaerobic threshold (AT) test were given. In the field, each examinee carried an ambulatory electrocardiograph with him or her and levels of blood Pressure (BP), heart rate (HR), and blood saturation-O<SUB>2</SUB> (SO<SUB>2</SUB>) were measured. During work, the heart rate was elevated significantly, but did not exceed the evaluated maximum heart rate in every case. Immediately after the work, the HR returned to the level measured before the work began. No significant fluctuation was noted in BP, pressure-rate-products (PRP) and SO<SUB>2</SUB> even during the work. Any sign associated with ischemia was not observed on ECG, either. Soon after the work began, the blood pressure level tended to lower in women compared with that in men and the PRP did not rise in women so much as it did in the opposite sex. However, in two elderly subjects of over 60 years, arrhythmia was noted along with the elevation of blood pressure soon after the stop of the work. These results showed that harvesting lotus roots did not bring about marked changes in the hemodynamic parameters and that the caraiovascular load was slight. However, an adequate health control system should be worked out for the lotus growers of advanced age over 60.