Significance of humidity and temperature on skin and upper airway symptoms.

The objective of the present study was to assess the effect of absolute and relative humidity, temperature and humidification on workers' skin and upper airway symptoms, and perceptions in the office environment. Associations between physical factors, and symptoms and perceptions were assessed in logistic regression models. At temperatures between 18 and 26 degrees C, relative humidity of 17-40%, and absolute humidity of 3.3-5.6 g H2O/kg air, skin symptoms and nasal dryness and congestion were alleviated by both kinds of humidity. Pharyngeal dryness increased when temperatures rose and was alleviated with a rise in relative humidity. Eye symptoms showed no dependence on humidity. Any kind of humidity increased odor sensation. Stuffiness increased when the air was humidified. In non-humidified conditions (21.3-22.7 degrees C, 20.0-31.7%, 3.3-5.6 g H2O/kg air), skin and nasal symptoms showed no association with humidity or temperature. Pharyngeal dryness diminished when humidity rose. In addition, the association between humidity and odor disappeared. In humidified conditions (21.5-23.7 degrees C, 26.6-41.2%, 4.2-7.0 g H2O/kg air), nasal dryness and congestion were alleviated by both absolute and relative humidity, and odor perception increased. Skin dryness and rash, pharyngeal dryness, and nasal dryness and congestion are alleviated in higher humidity. Steam humidification results in a risk for increased perception of odor and stuffiness.

Comparison of uterine and spiral artery blood flow in women with unexplained and tubal infertility.

OBJECTIVE: To evaluate the possible difference in uterine and spiral artery impedance to blood flow among women with unexplained and tubal infertility during spontaneous and gonadotropin-stimulated cycles. METHODS: We prospectively compared uterine and spiral artery pulsatility index and peak systolic velocity in a longitudinal study in women with either unexplained infertility (n = 20) or tubal infertility (n = 18). Measurements of uterine and spiral artery impedance were taken on days 11-12, 16-17 and 21-23 of the spontaneous cycle and on days 1, 5 and 10 during gonadotropin stimulation. In addition, measurements were taken on the days of oocyte pick-up and embryo transfer. RESULTS: A clinical pregnancy was achieved in 8/20 (40%) women with unexplained and 6/18 (33.3%) women with tubal infertility with in-vitro fertilization treatment. There were no differences in the uterine artery pulsatility index or peak systolic velocity during the spontaneous or the in-vitro fertilization cycle between the two groups. The impedance to blood flow in the uterine or spiral artery did not differ between women conceiving with in-vitro fertilization-embryo transfer and those who did not. However, the spiral artery pulsatility index on the 5th day of gonadotropin stimulation was significantly lower among women with unexplained infertility (0.96 +/- 0.25) compared to women with tubal infertility (1.24 +/- 0.30; P < 0.05), but on the other days of gonadotropin stimulation the spiral artery pulsatility index and peak systolic velocity were similar. CONCLUSIONS: Impaired uterine or spiral artery blood flow is not an important factor in unexplained infertility.

Effects of temperature and humidification in the office environment.

In this investigation, the authors evaluated the relationship between temperature and (a) Sick Building Syndrome symptoms and (b) workers' perceptions of air dryness in environments with and without humidification. The authors studied the average intensity of symptoms and perceptions of dry air relative to room temperature in humidified and nonhumidified conditions. During the 6 wk of the experiment, 2 wings of the building were humidified one-by-one for 1 wk, followed by a week without humidification. A total of 230 daily questionnaires were completed during the nonhumidified period, and 233 were completed during the humidified period. The results were analyzed with linear regression analysis, and the average intensity of dryness symptoms and sensations of dryness increased with each unit increase in temperature above 22 degrees C, both in the humidified and nonhumidified conditions. Sick Building Syndrome symptoms increased relative only to temperature during the period of no humidification. In conclusion, temperatures above 22 degrees C caused increased dryness symptoms and a sensation of dryness, independent of humidification. The overall intensity of Sick Building Syndrome symptoms increased only when indoor air was not humidified.

Humidification and perceived indoor air quality in the office environment.

OBJECTIVE: To evaluate the effect of humidification on the odour, acceptability, and stuffiness of indoor air. METHODS: In a six period cross over trial at the Pasila Office Center, Helsinki, the air of two wings of the building in turn were ventilated with air of 30%-40% humidity. A third wing served as a non-humidified control area. The quality of indoor air was assessed weekly by a panel containing 18 to 23 members. The intraindividual differences in the ratings for odour, stuffiness, and acceptability between humidified and non-humidified wings were used to assess the effect of humidification. The roles of sex, current smoking, and age as potential effect modifiers were assessed by comparing the mean intraindividual differences in ratings between the groups. RESULTS: Humidified air was found to be more odorous and stuffy (paired t test P = 0.0001) and less acceptable than the non-humidified air (McNemar's test P < 0.001). The differences in odour and stuffiness between humidified and non-humidified air were greater for women and for non-smokers, and greatest differences were in the youngest age group, and least in the oldest age group. The differences were not significant. CONCLUSIONS: An untrained panel of 20 members is able to differentiate a slight malodour and stuffiness in indoor air. The results suggest that steam air humidification decreases the perceived air quality. This effect is strongest in women and young subjects.

The effect of air humidification on symptoms and perception of indoor air quality in office workers: a six-period cross-over trial.

The objective of this study was to evaluate the effect of air humidification on (a) the dryness of the skin and mucosa, (b) allergic and asthmatic reactions, and (c) the perception of indoor air quality. A total of 290 office workers at the Pasila Office Center were included in a six-period cross-over trial. One wing of the building was operated with 30-40% humidification, and the other wing operated under conditions of no air humidification (relative humidity from natural conditions was 20-30%). The length of each study period was 1 work wk. The workers were instructed to keep a structured daily diary of their symptoms, their perception of the indoor air, and potential determinants of the symptoms. A total of 211 (72.6%) workers who returned at least two weekly diaries, and who had experienced both humidified and nonhumidified conditions, were included in the analyses. The primary outcome--dryness symptom score--was characterized by dryness, irritation or itching of the skin and eyes, dryness or irritation of the throat, and nasal dryness. Means of the daily symptom scores and perception ratings during the humidified and nonhumidified periods were calculated for each participant, and intraindividual differences in the means were used to assess the effect of air humidification. The dryness symptom score was significantly smaller during the humidified phase than during the reference phase (paired t test; p less than .05). Allergic symptoms that were considered as a separate outcome, a sensation of dryness, and draft were also significantly less frequent during the humidification phase (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)