Nasal hyperresponders and atopic subjects report different symptom intensity to air quality: a climate chamber study.

UNLABELLED: Short-term exposure to dust and dust added with beta-(1,3)-d-glucan or aldehydes may cause sensory reactions. In random order, we exposed 36 volunteers in a climate chamber to clean air, office dust, dust with glucan, and dust with aldehydes. Three groups of subjects were exposed, eleven were non-atopic with nasal histamine hyperreactivity, 13 were non-atopic, and 12 were atopic. Subjective ratings of symptoms and general health were registered four times during four 6-h exposure sessions. Six symptom intensity indices were constructed. The nasal hyperreactive group had a high and time-dependent increase of mucous membrane irritations, whereas the atopic group had a low and stable rate of irritations with exposure time, close to the reference group (P = 0.02 for differences between the groups with respect to time under exposure for Weak Inflammatory Responses and P = 0.05 for Irritative Body Perception, significance mainly because of the nasal hyperreactive group). Exposure to dust, with or without glucan or aldehydes, showed increased discomfort measured by the index for Constant Indoor Climate, and dust with glucan had a similar effect for the index for Lower Respiratory Effects. For Psychological and Neurological Effects these were dependent on group affiliation, thus preventing a uniform statement of exposure effects for all three investigated groups. PRACTICAL IMPLICATIONS: Opportunities for identifying persons with high or low sensitivity to low-level exposures are important in preventive medicine and will reduce intra-group variability and thus increase the power of experimental and epidemiological studies searching for correlations between exposures and health effects. The contrast between nasal hyperreactive on one side and atopic and reference subjects on the other side is particularly important. The atopic group indicated a non-homogenous reaction depending on their hyperreactive status, a finding that could be important but needs further confirmation.

Effects on human eyes caused by experimental exposures to office dust with and without addition of aldehydes or glucan.

UNLABELLED: Thirty-six volunteers (in three susceptibility groups: 11 subjects were non-allergic with nasal histamine hypersensitivity, 13 were non-allergic with normal sensitivity, and 12 were pollen allergic with or without nasal hypersensitivity) were exposed for three and a half hours in a climate chamber. Each subject was exposed to clean air (dust 45 +/- 38 microg/m(3) total suspended particle, TSP), house dust at 357 +/- 180 microg/m(3) TSP, house dust 382 +/- 175 microg/m(3) TSP with added glucan (50 ng/m(3)) and house dust 394 +/- 168 microg/m(3) TSP with added aldehydes corresponding to a gaseous phase of 300 microg/m(3) in the air. The study was explorative by nature. No significant effects of exposures as such were seen on break-up time, conjunctival epithelial damage score and Trolox Equivalent Antioxidant Capacity (TEAC) in tear film and subjective ratings. However, in TEAC a significant different time course was seen during exposures to aldehyde-containing dust indicating a subacute and late response to the exposures. Perceived eye irritation increased significantly during exposures to normal dust. The perception ratings were highly correlated, whereas no correlation was found between the subjective responses and the objective measurements. PRACTICAL IMPLICATIONS: The findings indicate that measurement effects on the eyes are rather insensitive measures of short time effects of office dust exposures.

Nasal histamine reactivity among adolescents in a remediated moisture-damaged school--a longitudinal study.

UNLABELLED: In a previous study, in the spring of 1995, we found that teachers, who had been working for several years in a moister-damaged school, 1 year after the renovation still reported a higher frequency of complaints and symptoms and showed significantly higher mucosal histamine reactivity compared with teachers in a control school, although the school seemed to be properly renovated. A longitudinal study of 90 randomly selected senior high school students entering the two schools was initiated to exclude or verify if the indoor air still exerted an irritant effect on the upper airways of an earlier unexposed group. The students went through a nasal histamine provocation test and answered a questionnaire on three occasions, in 1995, 1996 and 1997. No significant differences in the nasal histamine provocation curves for the students at the target school and those at the control school could be shown from start to endpoint of the study period. Neither was there any differences concerning perceived indoor air or mucosal symptoms between the target and the control group and technical measurements showed no noteworthy differences between the two schools. In conclusion, this study indicates that based on both technical and objective medical measures, the current indoor air in the remediated moisture-damaged school does not exert an irritant effect on the upper airway mucosa of the students. A 2-year follow-up of the teachers showed a decreased reactivity to histamine, giving further support to this statement. The increased mucosal reactivity observed among the teachers is probably a result of the previous long-term exposure to building dampness. No differences were seen between atopic and non-atopic students. PRACTICAL IMPLICATIONS: Persistent symptoms and increased nasal mucosal reactivity among personnel in a remediated damp building does not necessary imply an inadequate renovation. A longitudinal study with registration of subjective (questionnaires) and objective (nasal histamine reactivity) data of an earlier unexposed group residing in the same building further contributes to the evaluation whether the renovation was successful or not.

Eye trigeminal sensitivity, tear film stability and conjunctival epithelium damage in 182 non-allergic, non-smoking Danes.

UNLABELLED: The population distributions of CO(2)-induced irritation sensitivity in the eyes (COI), tear film stability (break-up time, BUT), and epithelium damage (ED) and the relation of these to basic potential confounders were assessed in an age- and gender-stratified random sample of citizens in Aarhus County, Denmark. One hundred eighty-two non-allergic, non-smoking persons participated. A general health questionnaire and an indoor air questionnaire was filled out before the measurements. The BUT was non-normally distributed, as was COI at 16% CO(2) and single ED-scores. However, COI average for all levels was normally distributed and the total score for ED was only marginally deviating. BUT decreased, the threshold to CO(2) increased, and irritation intensity at CO(2) eye exposure decreased with increasing age. ED was increased among women. There were no internal relations between the three measures, but reduced BUT was seen among subjects rating high levels of exposure to dust, electrostatic fields, and dry air. ED decreased by perceived unpleasant odors and increased with experiences of high temperatures. CO(2) sensitivity increased by perceived draught, dry air, and noise exposure prior to measurements. Selection bias cannot be excluded and the results may therefore not be truly representative of the general population. However, the results may be used as reference data for future use of measurements of break-up time, epithelium defects, and CO(2) sensitivity of the eyes in the indoor air. PRACTICAL IMPLICATIONS: The most direct implication is that results can be used as reference level for measurements in problem buildings and for individual measurements. The reference can also be used in research and the other results as basis for future hypotheses and for support of existing hypotheses.

Nasal mucosal histamine reactivity among young students and teachers, having no or prolonged exposure to a deteriorated indoor climate.

BACKGROUND: In a study performed in the spring of 1995, we found a significantly greater nasal mucosal histamine reactivity among teachers, who had worked for several years in a recently renovated moisture-damaged school, than in those in a control school. In the present study we investigated the students who begun their high-school studies at both schools in the autumn of 1995 and compared them with the teachers as regards mucosal reactivity, atopy and symptoms. METHODS: Twenty-eight teachers in the target school, 18 teachers in the control school and 45 students from each school underwent a nasal histamine provocation test and a skin-prick test. They also answered a standardized questionnaire. RESULTS: The teachers in both schools had more marked nasal mucosal histamine reactivity at the lowest provocation concentrations than the students. The histamine provocation curve of the target school teachers had consistently higher values than that of the students (P = 0.0001), but its slope and shape were similar (P = 0.15), while the slope of the provocation curve of the control school teachers was flatter. However, there was only a borderline significance in this respect compared to the students (P = 0.07). Teachers with a dry and crusty appearance of the nasal mucosa on anterior rhinoscopy reacted more strongly to histamine provocation than those without this finding (P = 0.0004). There was a significantly higher frequency of skin-prick test positivity (SPT+) among the students (P = 0.03). There were no significant differences in nasal mucosal histamine reactivity between atopic and non-atopic subjects out of pollen season. CONCLUSIONS: Teachers had a significantly greater mucosal histamine reactivity than the students, whereas the latter had a significantly higher frequency of atopy. These results are compatible with an age-related pattern of mucosal reactivity. A crusty appearance of the nasal mucosa seems to predispose to an increase in histamine reactivity. There were no significant differences according to histamine reactivity between atopic and non-atopic subjects.

Slowly decreasing mucosal hyperreactivity years after working in a school with moisture problems.

In our first study in 1995, teachers, who had worked in a water-damaged school for more than 5 years, were tested for nasal histamine reactivity by rhinostereometry. They were found to have significantly increased reactivity compared with teachers in a school without these indoor-climate problems. This finding could not be explained by differences in atopy or other personal characteristics. In this 2-year follow-up study (1995-97), 26 of 28 teachers in the target school and all 18 teachers in the control school, who participated in the initial study, accepted to take part. They were tested with the same histamine provocation procedure and answered the same questionnaire as 2 years earlier. Technical measurements of temperature, relative humidity, dust, carbon dioxide, formaldehyde and total volatile organic compounds (TVOC) were carried out in both schools during the time period between the two test occasions. In this provocation test, the teachers from the repaired water-damaged school still demonstrated an increased reactivity to histamine compared with the teachers in the control school, but the difference between the growth curves of the provocation tests was less than in 1995. Teachers in the target school still complained about the indoor air quality more than their colleagues, although the complaints were less common. No major differences were observed in the technical investigation between the two schools and the measurements were all within values usually seen in schools in northern countries. Our conclusion is that the observed nasal mucosal hyperreactivity among the teachers in the renovated water-damaged school seems to persist over years and only slowly decrease even after successful remedial measures have been taken.

Nasal hyperreactivity among teachers in a school with a long history of moisture problems.

Upper airway symptoms have frequently been reported in people working or residing in damp buildings. However, little information has been available on objective pathophysiologic findings in relation to these environments. Twenty-eight teachers, who had worked for at least five years in a recently renovated school that had had severe moisture problems for years, were randomly selected for this study. Eighteen teachers, who had worked in another school that had no moisture problems, were randomly selected to serve as the control group. Although remedial measures had been taken, an increase in the prevalence of mucous membrane irritations was still reported by the teachers in the target school. We used a nasal challenge test with three concentrations of histamine (1, 2 and 4 mg/mL). Recordings of swelling of the nasal mucosa were made with rhinostereometry, a very accurate optical non-invasive method. The growth curves of mucosal swelling induced by the three concentrations of histamine differed significantly between the two groups (p < 0.01). The frequencies of atopy, evaluated with the skin-prick test, were almost identical in both groups. The study indicates that long-term exposure to indoor environments with moisture problems may contribute to mucosal hyperreactivity, of the upper airways. Such hyperreactivity also seems to persist for at least one year after remedial measures have been taken.

The eye irritation and odor potencies of four terpenes which are major constituents of the emissions of VOCs from Nordic soft woods.

Eye goggles were used to estimate human thresholds for sensory eye irritation from four monoterpenes: (+)3-carene, (-)limonene and (+)alpha-pinene and (rac)alpha-terpineol all known as air pollutants emitted from wood. Only a ranking of the irritation thresholds relative to that of n-butanol is given. The measurements showed that the thresholds for eye irritation of the terpenes ranged from subthreshold to below 1,250 mg/m3. It appears that the irritation of 3-carene and limonene in contrast to the expectations was of the same size as or less than that of n-butanol. Too few subjects reported eye-irritation for alpha-pinene and alpha-terpineol to allow estimates of thresholds of these compounds which therefore have much less irritative potency than n-butanol, 3-carene, and limonene. The measurements of one terpene alcohol do not support the hypothesis that monoterpene alcohols, would have lower eye irritation threshold than monoterpene hydrocarbons. The sequence from strongest odorant to weakest was alpha-terpineol, 3-carene, n-butanol, limonene and alpha-pinene. In conclusion, the tested terpenes can probably be ruled out as cause of acute eye irritation indoors. The measured odor thresholds did not deviate from the few values reported in the literature.