RESUMEN
@#Abstract: Objective In order to understand the radon exposure level of homes in Chongqing, this survey was carried out on the indoor radon concentration in 38 districts and counties of Chongqing. Methods According to the population ratio of every 100 000 people, one monitoring site was arranged, and the number of parallel samples was 10% of the distribution sites. The monitoring sites covered 38 districts and counties in Chongqing. A total of 1 019 residential monitoring sites in 38 districts and counties in Chongqing were measured with radon accumulation detectors from July 2020 to June 2021. Results The five districts/counties in Chongqing having the highest average concentration of residential radon in the year were Xiushan County 78.8 Bq/m3, Qianjiang District 78.0 Bq/m3, Yubei District 73.9 Bq/m3, Youyang County 71.4 Bq/m3 and Shapingba District 69.8 Bq/m3. The five districts/counties with the lowest mean concentration of indoor radon were 37.6 Bq/m3 in Zhongxian County, 36.4 Bq/m3 in Changshou District, 33.7 Bq/m3 in Kaizhou District, 33.2 Bq/m3 in Liangping District and 27.3 Bq/m3 in Wushan County. The concentration levels of radon in four seasons were 46.0 Bq/m3, 53.4 Bq/m3, 45.1 Bq/m3 and 59.5 Bq/m3, respectively. The concentration of radon was higher in Summer and Winter, and lower in Spring and Autumn, and the difference of concentration among four seasons was statistically significant (P<0.001). The radon concentration of newly built buildings after 2017 was relatively high, up to 61.8 Bq /m3, but there was no statistical significance in radon concentration in different building ages (P>0.05). The concentration of radon in rooms of buildings with less than 10 floors was higher, up to 63.2 Bq /m3, and there were significant differences in radon concentration among rooms of different floors (P<0.05). The average annual radon concentration in houses in Chongqing was about (51.6±19.5) Bq/m3, and the average annual effective dose of inhaling radon and its progeny by house-related people was about (1.38±0.52) mSv. Conclusion The average annual radon concentration level of houses in Chongqing is within the standard limit value recommended by China, but the prevention and control of radon should be strengthened.
RESUMEN
Background: Orientation is a significant factor in architectural design that may affect well-being. Body direction does not change during sleeping, and sleeping is sensitive and affected by environmental factors. Aims: This neuroarchitecture study aimed to assess the effects of bed orientation on sleep quality to enhance bedroom design. Materials and Methods: To do so, the effects of earth's electromagnetic field (EMF) on sleep electroencephalography (EEG) signals were evaluated using signal processing techniques. In this cross-sectional study, a total of 21 healthy volunteer participants slept for two consecutive naps, at two rooms with identical interior design and different bed orientations, toward and against earth's EMF in a sleep clinic. Statistical Analysis: In this experiment, discrete wavelet transform extracted five subfrequencies of EEG data as delta, theta, alpha, beta1, and beta2. In addition, the energy signals were computed by measurement of wave frequencies. The mean total sleep time was 1.63 h in North–South (N-S) earth's EMF orientation and 1.38 h in the other direction. Results: t-test results showed significant changes in delta, theta, and alpha frequencies in terms of bed orientation. There was a significant result in the alpha energy ratio over the whole signal energy. Furthermore, there were increases in the average energy of delta, theta, and alpha bands in N-S versus East–West (E-W) bed directions. Conclusions: This study indicated that sleep in N-S direction could be more beneficial than E-W and the sleep EEG signals can be sensitive to earth's EMF. The results show the importance of considering orientation in bedroom design and its benefits on inhabitants' well-being.
RESUMEN
Objective: We conducted a clinical study to investigate the effects of a combination of wooden interior and indirect lighting in the bedroom on improving sleep quality and attenuating fatigue. Design: Eleven healthy male subjects, whose Pittsburgh Sleep Quality Index (PSQI) scores were ≥ 6, participated in a 3-way crossover trial. Subjects rested from 21:00 to 22:00 under a combination of wooden interior and indirect lighting, indirect lighting, or direct lighting, went to bed at 22:00, and awoke at 6:00. We evaluated sleep quality by the St. Mary's Hospital Sleep Questionnaire (SMHSQ), autonomic nervous function by the Active Tracer, sleepiness and fatigue sensation by the Visual Analogue Scale (VAS), and performance by the Advanced Trail Making Test (ATMT). Results: The combination of wooden interior and indirect lighting improved early morning awakening, nocturnal awakening, and satisfaction with sleep according to the SMHSQ, activated the parasympathetic nerve system at bedtime according to the Active Tracer, and attenuated sleepiness and fatigue sensation at the time of awakening according to the VAS; moreover, it improved work performance according to the ATMT. Conclusion: These results show that the combination of wooden interior and indirect lighting produces a suitable bedroom environment that improves sleep quality and attenuates fatigue.
RESUMEN
<b>Objective</b>:<br>A rapid rise in blood pressure (BP) in the early morning is called morning BP surge and is known to be related to the onset of cerebrovascular or cardiovascular diseases. Exposure to cold temperature aggravates this condition. However, few studies have investigated the relationship between morning BP surge and bedroom temperature (BT). This study examined the effectiveness of a comfortable BT for mitigating morning BP surge.<br><b>Methods</b>:<br>In this study, five healthy male university students (22.8±0.4 years old with BMI 21.7±1.3Kg/m<sup>2</sup>) volunteered to be subjects. The relative humidity in the bedroom was controlled to 50%, and the BT was set at 10°C and 250°C for two test conditions. From 0:00 to 8:00am, a Portapres Model-2 was used to measure BP continually at each beat. The average BP and heart rate (HR) from 2:00 and 4:00am were used as the baseline BP and HR. The changing rates of BP and HR from 4:00 to 7:30, the time and the BP value when BP started to rise, the time and the BP value when the BP reached the maximum, the BP value at the time of waking, and the time and rate of increase of BP until it reached the peak at temperatures of 10°C and 25°C were compared by means of the Wilcoxon signed ranking test.<br><b>Results</b>:<br>The BP before waking started to rise later at 25°C than that at 10°C. BP rose more slowly at the higher BT than at the lower BT, especially 30 minutes after waking. At the lower BT, BP rose almost linearly, and the maximum rising rates were 37% (153.3mmHg) for systolic BP and 54% (97.6mmHg) for diastolic BP. At the higher BT of 25°C, however, BP reached the first peaks about 20 minutes after waking/getting up, and then remained stable. The maximum rising rate was 30% (14.2mmHg) for systolic BP and 33% (86.5mmHg) for diastolic BP. At the higher BT, BP reached the maximum value 40 minutes later for systolic BP and 60 minutes later for diastolic BP. At the lower BT, systolic BP exceeded the normal range, reached 140mmHg 35 minutes after getting up, remained stable for 55 minutes, and then rose to the maximum value of 153.3mmHg. In contrast, at the higher BT, the first peak of BP was significantly lower than that at the lower BT. Furthermore, the differences in BP between the first peak of BP and the BP value at the time of staring to rise and between the first peaks and the BP value at the time of waking up were significantly lower at the higher BT than those at the lower BT. The rising rates of BP from the time when BP started to rise and from the time of waking until reaching the maximum value were significantly lower at the higher BT than those at the lower BT.<br><b>Conclusions</b>:<br>These results suggest that the margin of the rise in BP, the rising rate of BP, and the peak value of BP in the early morning are significantly lower at a BT of 25°C than those at a BT of 10°C. They also suggest that sleeping at a comfortable BT, especially during winter, may suppress morning hypertension or morning BP surge and indirectly prevent the onset of cerebrovascular and cardiovascular disease as well as related deaths. Although the subjects in this study were healthy young men, it was considered that the benefit of sleeping in warm bedroom for preventing morning BP surge may be increased for the elderly who are highly likely to have already suffered from such underlying diseases as hypertension.