Annoyance and performance of three environmentally intolerant groups during experimental challenge with chemical odors

OBJECTIVES: This study investigated exposure- and subject-related determinants of annoyance and performance during the chemical odor provocation of healthy persons with self-reported environmental annoyance. METHODS: Persons with self-reported annoyance attributed to (i) chemicals or smells (smell-annoyed, SA, N=29), (ii) electrical equipment (electrically annoyed, EA, N= 16), and (iii) both smells and electricity (generally annoyed, GA, N=39) were, together with referents (N=54), challenged with n-butyl acetate in an exposure chamber at levels far below the threshold values for neurotoxic effects and trigeminal irritation. A sequence of three air concentrations, 0.37, 1.5, and 6 ppm (1.8, 7.1, and 28 mg/m3) was used, counterbalanced within groups, together with intermittent periods of room air between each exposure level. The response measures comprised ratings of annoyance and smell intensity and reaction-time tests. RESULTS: Only the GA group showed clearly elevated ratings of smell annoyance, mucous membrane irritation, and fatigue, as well as longer reaction times, compared with the referents, in response to the challenge. No group difference was found for the smell-intensity ratings. During intermittent periods without exposure, only the GA group maintained higher ratings for mucous membrane irritation and fatigue. Reaction time and all the rating dimensions showed a positive relationship with momentary n-butyl acetate concentration, while cumulative exposure had a more limited impact on the ratings and reaction time. A suggestion effect by the chamber environment before exposure could not be demonstrated. CONCLUSIONS: The results suggest that self-reported annoyance generalized to both electrical equipment and smells is a better predictor of chemical intolerance than self-reported annoyance to smells only.     

Annoyance and performance during the experimental chemical challenge of subjects with multiple chemical sensitivity

OBJECTIVES: This study explored the subjective reactions and psychological test performance of smell-intolerant subjects during consecutive challenges to chemicals with contrasting neurotoxic properties. METHODS: Women with symptoms compatible with multiple chemical sensitivity (N=10) and healthy referents (N=20) were individually challenged in an exposure chamber. All the subjects attended two separate 2-hour sessions of exposure to n-butyl acetate and toluene, in counterbalanced sequence. After an initial phase without exposure, air concentrations were increased in steps ranging from 3.6 to 57 mg/m3 for n-butyl acetate and from 11 to 180 mg/m3 for toluene. The response measures comprised ratings of annoyance and smell intensity and also neurobehavioral test performance. RESULTS: Both groups showed an increase in annoyance ratings and a decrease in test performance in the initial unexposed chamber phase and also in the first phase of the chemical exposure, these results indicating slight immediate expectancy or "suggestion" effects. During the six chamber phases, the ratings of mucous membrane irritation and fatigue showed a steeper increase in the group with multiple chemical sensitivity than among the referents, while the ratings of smell intensity and smell annoyance were similar in the two groups. A reduction in test performance was observed during the chamber phases, particularly in the group with multiple chemical sensitivity. No relation was found between the ratings or performance and chemical substance. CONCLUSIONS: Stronger immediate expectancy or "suggestion" reactions than normal did not characterize the group with multiple chemical sensitivity. This group showed a stronger than normal gradual build-up of fatigue, mucous membrane irritation, and reduced performance during chemical exposure. The results offer the most support to an irritative basis for multiple chemical sensitivity.     

Time courses of sensory irritations due to 2-butanone and ethyl benzene exposure: influences of self-reported multiple chemical sensitivity (sMCS)

The individually different effects of exposure to comparable levels of chemicals might be partly explained by dissimilar response sensitivity towards chemicals. Multiple chemical sensitivity (MCS) might be the clinical endpoint of this altered sensitivity. Concerning a subclinical range of chemical sensitivity, 'challenge studies' with people reporting chemical sensitivity are needed to improve the knowledge about such differences. The chemical and general environmental sensitivity questionnaire (CGES) is a standardized screening tool for the selection of this group. In the present study 24 healthy male volunteers, half of them classified as sMCS-subjects, were experimentally exposed to 2-butanone and ethyl benzene at different levels (TLV-level vs. odor threshold). The strength of self-reported sensory irritations (nasal and ocular) and symptoms of bad smell were assessed, prior, during, and after the 4 hours of exposure. The time courses of sensory irritations were affected by sMCS. Across all exposure periods sMCS-subjects showed increasing symptom scores while control-subjects did not. Symptoms of bad smell were affected by three exposure-related factors (substance, level, duration) without any additional influence from the sMCS factor. Starting from these results it could be concluded that the time-depending influence of reported chemical sensitivity is most prominent for subjective data of sensory irritations.     

From chemosensory thresholds to whole body exposures—experimental approaches evaluating chemosensory effects of chemicals

Objectives: To ensure safety and health the avoidance of adverse chemosensory effects is essential at workplaces where volatile chemicals are used. The present study describes psychophysical approaches that provide information for the evaluation of such effects. Methods: By means of a modified staircase procedure the odor (OT) and irritation thresholds (IT) of 15 irritants were determined. These basic chemosensory properties, confining the chemosensory effect range, were investigated in a random sample of 144 persons stratified for gender and age. Those irritants exhibiting high chemosensory potency were selected for the second psychophysical part of the study. Forty-eight persons, again stratified for gender and age, rated the intensity of 13 trigeminal and olfactory perceptions elicited by nine ascending concentrations of the irritants, ranging from the odor to the irritation threshold of the respective substances. Results: Across the investigated chemicals the transition from concentrations eliciting pure olfactory stimulation (OT) to trigeminal stimulation (IT) differed markedly. The carboxylic acids yielded narrow ranges from odor to irritation thresholds, while for the amines (cyclohexylamine, dimethylamine, and trimethylamine) and the esters (ethyl formate and ethyl acetate) these ranges were somewhat wider. The two chemosensory thresholds of ethyl acrylate and ammonia were farthest from each other. Gender and age had only weak impact on the chemosensory thresholds. At present, the results of the intensity ratings could be given for six substances. Among them, the rated pungency for cyclohexylamine, formic acid, and ethyl acetate increased strongest across the nine applied concentrations. Conclusions: By means of these psychophysical approaches a diverse class of chemicals can be described and compared with respect to their chemosensory potency. This information can be used twofold (a) for the evaluation of existing studies reporting sensory irritations and (b) for the design of experimental exposure studies.     

Acute sensory irritation from exposure to isopropanol (2-propanol) at TLV in workers and controls: objective versus subjective effects

OBJECTIVES: Phlebotomists occupationally exposed to isopropanol (IPA) (2-propanol) and na?ve controls (n = 12 per group) were exposed to the time-weighted average threshold limit value of 400 p.p.m. IPA for 4 h in an environmental chamber to investigate: (i) acute effects of sensory irritation using subjective health symptom reports and objective, physiological end-points; and (ii) differences in measured effects in relation to exposure history. METHODS: Before, during and after exposure subjects gave self-reports of health complaints. During exposure subjects rated the intensity of the odor, sensory irritation and annoyance. Objective end-points of ocular hyperemia, nasal congestion, nasal secretion and respiration were obtained at various times before, during and after exposure. Results were compared with exposure to phenylethyl alcohol (PEA), a negative control for irritation, and to clean air (CA), a negative control for odor and irritation, using a within-subjects design. RESULTS: Significantly higher intensity ratings of odor, irritation and annoyance were reported during the exposure to IPA, when compared with exposure to CA or PEA. Nevertheless, the overall level of reported sensory irritation to IPA was low and perceived as 'weak' on average. Health symptom ratings were not significantly elevated for IPA as compared with PEA or CA exposure. The only physiological end-point that showed a change exclusively in the IPA condition was respiration frequency: relative to baseline, respiration frequency increased in response to IPA in both groups. No differences were encountered between the occupationally exposed and the control groups. CONCLUSIONS: The increase in respiration frequency in response to IPA may reflect either a reflexive change due to sensory irritation (an autonomic event) or a voluntary change in breathing in response to perception of an unpleasant, solvent-like odor (a physiological event caused by cognitive mediation). Our findings on objective end-points, including nasal and ocular sensory irritation, did not confirm subjective irritation reports. Irritation reports and odor intensity decreased, rather than increased, over time, lending credence to the cognitive argument and suggesting that the elevated subjective responses to IPA may be mediated by responses to its odor.     

Perceived odor and irritation of isopropanol: a comparison between naïve controls and occupationally exposed workers

OBJECTIVES: To assess sensory irritation levels from isopropanol (IPA) unconfounded by subjective evaluations of odor for comparison against the recommended exposure limits (400 ppm threshold limit value (TLV); American Conference of Governmental Industrial Hygienists). METHOD: The lateralization method was used to assess intra-nasal irritation thresholds for IPA, while odor detection thresholds were also measured. Thresholds for 1-butanol and phenyl ethyl alcohol (PEA) were obtained as positive and negative irritant controls. To compare potency and hedonic characteristics, subjects provided subjective ratings of odor, irritation and annoyance intensity for three concentrations of each chemical. Workers occupationally exposed to IPA ( n=26) were compared with previously unexposed controls ( n=26). RESULTS: The (geometric) mean odor detection threshold for IPA was slightly higher among exposed workers than controls (39 ppm vs. 11 ppm). Lateralization thresholds measuring intra-nasal irritation were elevated when compared with controls (6,083 ppm in exposed workers vs. 3,361 ppm in na?ve controls), with a significantly higher proportion of phlebotomists being unable to lateralize the maximum concentration regarded as safe, than controls. Calculations of the 6th percentile for lateralization thresholds revealed that 95% of the sample did not experience sensory irritation below 512 ppm. Thus, while odor detection thresholds were well below the current recommended exposure limits, the irritation thresholds were well above these values. The odor, irritation and annoyance from IPA was perceived, on average, as between weak and almost strong, from lowest to highest concentration. CONCLUSIONS: The results indicate that current exposure guidelines would be adequately protective of the acute adverse effect of nasal sensory irritation, as operationally defined by the intra-nasal lateralization threshold. Exposures to higher concentrations should perhaps be evaluated on the basis of existing knowledge about systemic, rather than local (e.g., irritation), toxic effects. IPA appears to be a weak sensory irritant and occupational exposure to IPA appears to elicit small changes in sensitivity that do not generalize to other odorants (e.g., PEA and 1-butanol) and are likely to be reversible.     

Examination of the influence of personal traits and habituation on the reporting of complaints at experimental exposure to ammonia

Objective: The aim of the study is to examine the impact of personal traits and habituation on the intensity of self reported health symptoms and complaints. Methods: Forty-three healthy male volunteers were exposed to ammonia vapours in concentrations of 0, 10, 20, 20/40, and 50 ppm on five consecutive days. To explore a possible influence of habituation on the perception of symptoms, the study group was divided into 30 men who were not familiar with the smell of ammonia, and ten participants regularly exposed to ammonia at the workplace. The perceived acute health symptoms and self-reported changes of well-being were assessed by the German version of a questionnaire of the Swedish Performance Evaluation System (SPES). Personal traits were ascertained with the positive and negative affectivity schedule (PANAS) and the Freiburger Persönlichkeits Inventar (FPI). Results: There are significant associations between personal traits and the amount of complaints. Subjects with high positive affectivity report less respiratory and irritative complaints, whereas persons with negative affectivity report significantly more olfactory and respiratory symptoms. In general, the strength of these correlations decreases with higher exposure levels. At ammonia concentration above 20 ppm, these associations were no more statistically significant. During the daily exposures, the score of symptoms did not vary significantly. The perceived intensity of health symptoms and annoyance increased with the concentration of ammonia, while the self-reported dimensions of well-being decreased. Workers familiar with the smell of ammonia vapours reported less symptoms compared to naïve subjects. Conclusions: Habituation to ammonia vapours as well as personal traits influence the reporting of complaints particularly at low exposure. Both factors should be considered in the examination of chemosensory irritative compounds.     

No effect of aircraft crash near South Limburg (the Netherlands) on self-perceived health, but an increase in perceived environmental nuisance by the inhabitants

OBJECTIVE: To investigate the influence of an aircraft crash near the South of Limburg, the Netherlands, on the perceived physical and psychological health and annoyance of local residents. DESIGN: Controlled, blinded, follow-up questionnaire survey. METHOD: Three months before an aircraft crash occurred, randomly selected local residents and control subjects who lived approximately 20 km from the crash site were asked to complete a health questionnaire. The study was repeated one year after the crash. The aim of the survey was not mentioned in the questionnaire. The questionnaire asked about demographic features, physical health, psychological health and environmental nuisance. In the first survey, 544/926 (59%) questionnaires were successfully returned, and after the disaster this figure was 677/900 (75%). Linear regression modelling was used to check whether or not any differences in outcome were due to confounding demographic variables. RESULTS: There was no significant difference in the perceived physical and psychological health of local residents before and after the aircraft crash. A year after the crash, the nuisance level of aircraft noise reported by local residents had markedly increased. Aircraft noise was the major cause of disturbance. More than 1 in 3 residents perceived daily aircraft noise as a nuisance compared with 1 in 6 before the crash. The scores of local inhabitants for annoyance due to aircraft odour and dust doubled after the crash. Compared with control subjects, local inhabitants scored more than 20 times higher for annoyance due to aircraft odour and 40 times higher for annoyance due to dust. The reported nuisance caused by road traffic noise, odour and dust also increased, although to a lesser extent. CONCLUSION: Health was not influenced by the aircraft crash. A year after the crash, there was a strong drop in tolerance of aircraft nuisance. There was also a reduction in the tolerance of comparable nuisance due, for example, to road traffic, although this change was less marked.     

Neurobehavioral effects during experimental exposure to 1-octanol and isopropanol

OBJECTIVES: The study examined acute neurobehavioral effects provoked by controlled exposure to 1-octanol and isopropanol among male volunteers. METHODS: In a 29-m3 exposure laboratory, 24 male students (mean age 25.8 years) were exposed to 1-octanol and isopropanol. Each substance was used in two concentrations (0.1 and 6.4 ppm for 1-octanol; 34.9 and 189.9 ppm for isopropanol:). In a crossover design, each subject was exposed for 4 hours to the conditions. Twelve subjects reported enhanced chemical sensitivity; the other 12 were age-matched controls. At the onset and end of the exposures neurobehavioral tests were administered and symptoms were rated. RESULTS: At the end of the high and low isopropanol exposures the tiredness ratings were elevated, but no dose-dependence could be confirmed. For both substances and concentrations, the annoyance ratings increased during the exposure, but only for isopropanol did the increase show a dose-response relation. The subjects reported olfactory symptoms during the exposure to the high isopropanol and both 1-octanol concentrations. Isopropanol provoked no sensory irritation, whereas high 1-octanol exposure slightly enhanced it. Only among the subjects with enhanced chemical sensitivity were both 1-octanol concentrations associated with a stronger increase in annoyance, and lower detection rates were observed in a divided attention task. CONCLUSIONS: Previous studies reporting no neurobehavioral effects for isopropanol (up to 400 ppm) were confirmed. The results obtained for 1-octanol lacked dose-dependency, and their evaluation, is difficult. The annoying odor of 1-octanol may mask sensory irritation and prevent subjects with enhanced chemical sensitivity from concentrating on performance in a demanding task.     

Odour annoyance in a residential area near a papermill.

A papermill in a small town has for many years caused a lot of odour annoyance. Odour exposures were determined by odour emission measurements and dispersion calculations. Odour exposure on immission level was determined by the use of a trained sniffing team. Odour annoyance was determined by panellists using a diary four times a day during a six week period. The odour annoyance was calculated as an Odour Annoyance Index. Distinction was made between different types of odours (rotten, wood). The relation between odour annoyance and the direction of wind and the distance of the observations from the source is presented. The relations between two dispersion models, the measured immission by the sniffing team and the odour annoyance, as determined by the panellists, are presented. Results: The relations between the distance from the source and the odour annoyance is strong. The relation between the direction of wind and the odour annoyance is also strong. A trend is shown between the odour annoyance and the immission level determined by the sniffing team. A strong correlation is found between the exposure calculated with the dispersion models and the measurements by the sniffing team.     

Passive smoking: Irritating effects of the total smoke and the gas phase

Summary In a ventilated climatic chamber 32 subjects (in groups of two or three) were exposed in one experiment to the total sidestream smoke of cigarettes and in another experiment to the gas phase of cigarette smoke, which was obtained by filtering out the particulate matter. The degree of air pollution corresponded to 10 ppm CO in both experiments. The concentrations of the particulate matter, CO, NO, NO₂ and HCHO were recorded. With a questionnaire, we determined the degree of annoyance and of subjective irritations of the eyes, nose and throat; eye blink rate was measured, as an objective indicator of eye irritation.Both exposures of air pollution produced nearly the same degree of annoyance, which indicates that the gas phase is to a large extent responsible for the annoyance due to cigarette smoke. On the other hand the objective and subjective eye irritation was very much lower with the gas phase than with the total smoke. This indicates that the particulate phase is to a very large extent responsible for the irritating effects.     

Odour annoyance and physical symptoms among residents living near waste treatment centres

Waste treatment processes produce odours and biological emissions to the environment, but their health effects are controversial. The aim of our study was to assess odour-associated self-reported physical symptoms among residents living near waste treatment centres. The study was conducted in the surroundings of five large-scale Finnish waste treatment centres with composting plants. In 2006, 1142 randomly selected residents living within 1.5, 3.0 and 5.0 km of these centres were interviewed by telephone. A questionnaire with 102 items asked about respondent's personal characteristics, odour exposure and symptoms during the preceding 12 months. Physical symptoms were analysed by distance to the waste treatment centre and by the respondent's perception and annoyance of waste treatment odour. The residents who were classified as “annoyed of the odour” reported following physical symptoms more than the others did: unusual shortness of breath (OR 1.5, 95% CI 1.0–2.2), eye irritation (1.5, 1.1–2.1), hoarseness/dry throat (1.5, 1.1–2.0), toothache (1.4, 1.0–2.1), unusual tiredness (1.5, 1.1–2.0), fever/shivering (1.7, 1.1–2.5), joint pain (1.5, 1.1–2.1) and muscular pain (1.5, 1.1–2.0). Moreover, the ORs for almost all other physical symptoms were elevated among the annoyed respondents. Reported odour annoyance near the waste treatment centres showed an association with many physical symptoms among residents living in the neighbouring areas.     

Community reappraisal of the perceived health effects of a petroleum refinery

This paper presents results from a study of the community health impacts of a petroleum refinery in Oakville, Ontario in Canada. The research is informed by the environmental stress and coping literatures and the focus is on community reappraisal of the refinery's impacts before and after the implementation of a substantive odour reduction initiative on the part of the refinery operators. Community health surveys were conducted in 1992 (n = 391) and 1997 (n = 427) to examine changes in odour perception and annoyance and self-reported health status attributable to the odour reduction plan. The findings reported here suggest an on-going process of cognitive reappraisal, whereby negative perceptions and concerns decreased between 1992 and 1997. Irrespective of this positive reappraisal of the refinery efforts, those living close to the refinery continue to report negative health impacts. A strong mediating effect of odours on the refinery exposure-symptom reporting relationship was confirmed by our results. While the relationship between odour perception and symptom reporting indicates the importance of odour perception and annoyance as the principal mechanism mediating ill-health reporting, the plausibility of other causal pathways is recognized. Residents' sensitivity to the negative effects of the refinery on their health and the health of their children suggests a psychosocial reaction to the environmental stress associated with perceived and actual refinery emissions.     

Effects of bioaerosol polluted outdoor air on airways of residents: a cross sectional study

Background: Bioaerosol pollution of workplace and home environments mainly affects airways and mucous membranes. The effect of environmental outdoor residential bioaerosol pollution, for example, livestock holdings, farming, and waste disposal plants, is unclear.

Aims: To investigate the perceived health of residents living in areas with measurable outdoor bioaerosol pollution (for example, spores of Aspergillus fumigatus and actinomycetes), and effects of accompanying odours.

Methods: In a cross sectional study, double blinded to ongoing microbial measurements, doctors collected 356 questionnaires from residents near a large scale composting site, and from unexposed controls in 1997. Self reported prevalence of health complaints during the past year, doctors' diagnoses, as well as residential odour annoyance were assessed. Microbiological pollution was measured simultaneously in residential outdoor air.

Results: Concentrations of >10⁵ colony forming units of thermophilic actinomycetes, moulds, and total bacteria/m³ air were measured 200 m from the site, dropping to near background concentrations within 300 m. Positive adjusted associations were observed for residency within 150–200 m from the site versus unexposed controls for self reported health complaints: "waking up due to coughing", odds ratio (OR) 6.59 (95% confidence interval (CI) 2.57 to 17.73); "coughing on rising or during the day", OR 3.18 (95% CI 1.24 to 8.36); "bronchitis", OR 3.59 (95% CI 1.40 to 9.4); and "excessive tiredness", OR 4.27 (95% CI 1.56 to 12.15). Reports of irritative airway complaints were associated with residency in the highest bioaerosol exposure, 150–200 m (versus residency >400–500 m) from the site, and period of residency more than five years, but not residential odour annoyance. Lifetime prevalence of self reported diseases did not differ with exposure.

Conclusions: Bioaerosol pollution of residential outdoor air can occur in concentrations found in occupational environments. For the first time residents exposed to bioaerosol pollution were shown to report irritative respiratory complaints similar to mucous membrane irritation independently of perceived odours.

     

Trait anxiety and modeled exposure as determinants of self-reported annoyance to sound, air pollution and other environmental factors in the home

Objectives We examined to what degree annoyance ratings to noise, air pollution and other common environmental factors in the home environment could be considered to mirror personality disposition in terms of habitual anxiety level and, when appropriate, objectively modeled noise and nitrogen emission (NOx). Methods A trait anxiety scale was introduced in a cross-sectional public health survey with 2,856 respondents. Of these, 705 had self-reported asthma and the rest constituted gender-matched referents. Annoyance to ten specific factors in the residential environment, mainly focusing on source-specific noise and air pollution, was assessed on a six-point likert scale. A-weighted energy equivalent continuous sound pressure level during a full day (24 h; L _Aeq,24) as well as annual average NOx levels (μg/m³) at the residential address were modeled with high resolution, using a road data base and a detailed emission data base for NOx. Results The two most prevalent complaints were annoyance to traffic noise and sounds from neighbors, which was reported by about 8% of the participants. Unadjusted logistic regression analyses using the continuous trait anxiety score as a predictor showed positive associations with ratings of annoyance from total traffic noise, sounds from neighbors, sound from ventilation, exhaust fumes from traffic, sounds from other installations, and vibrations from traffic (ORs between 1.37 and 2.14). Modeled noise and NOx exposure were positively related with annoyance to traffic noise and exhaust fumes, respectively. Adjustment of the trait anxiety scores for other individual characteristics and potential determinants did not change the overall pattern of results. Conclusion Trait anxiety scores were often mirrored in ratings of annoyance, which suggests caution when using annoyance reports either as a surrogate measure for environmental exposure on the individual-level in epidemiologic studies or when studying the moderating effects of annoyance on health outcomes.     

Effect of nocturnal road traffic noise exposure and annoyance on objective and subjective sleep quality

BackgroundVarious epidemiological studies have found an association between noise exposure and sleep quality, but the mediating role of annoyance is unclear for this association.ObjectivesTo investigate the effects of both objectively modeled road traffic noise exposure as well as noise annoyance on subjective and objective sleep quality measures.Methods1375 randomly selected participants from Basel, Switzerland, were enrolled in a questionnaire survey in 2008 with follow-up one year later (1122 participants). We assessed sleep quality by using a standardized sleep disturbance score, as well as the level of annoyance with road traffic noise at home. Objective sleep efficiency data was collected in a nested diary study by means of actigraphy from 119 subjects for 1551 nights. Residential nocturnal exposure to road traffic noise was modeled using validated models. Data were analyzed with random intercept mixed-effects regression models.ResultsIn the main study, self-reported sleep quality was strongly related to noise annoyance (p for trend <0.001) but only moderately correlated with modeled noise exposure (p = 0.07). In the nested diary study objectively measured sleep efficiency was not related to annoyance (p = 0.25) but correlated with modeled noise exposure (p = 0.02). Strikingly, noise induced decreased sleep efficiency was even more significant for study participants who were not annoyed with traffic noise (p = 0.001).ConclusionsThis study indicates that effects of nocturnal traffic noise on objective sleep quality are independent of perceived noise annoyance, whereas the association between self-reported sleep quality and noise is mediated by noise annoyance.     

Effects of an external exposure to 200 ppm methyl ethyl ketone on nasal mucosa in healthy volunteers

OBJECTIVES: To investigate the effects of an acute exposure to 200 ppm methyl ethyl ketone on the nasal mucosa of healthy volunteers. METHODS: Nineteen healthy non-smoking men were exposed to 200 ppm methyl ethyl ketone and to a sham exposure in an exposure chamber, using a cross-over design. Mucociliary transport time was determined with the saccharine test. Interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor-alpha (TNFalpha) were measured in nasal secretions. Subjective symptoms were assessed by questionnaire. RESULTS: Mucociliary transport time was significantly higher (660 vs. 600 s (medians), P = 0.01) after solvent exposure. Concentrations of IL-1beta and IL-8 were insignificantly elevated after exposure (IL-1beta: 83.8 pg/ml vs. 48.1 pg/ml, medians, P = 0.11; IL-8: 14471 pg/ml vs. 11080 pg/ml, P = 0.12), whereas those of IL-6 and TNFalpha remained unchanged. Subjects did not feel any irritation of nasal mucosa. CONCLUSION: Concentrations of organic solvents not exceeding their MAK values can cause subclinical rhinitis. The secretion of proinflammatory cytokines and impairment of mucociliary transport can explain the development of clinical rhinitis in highly exposed subjects.     

Annoyance due to air pollution in Europe

BACKGROUND: Annoyance due to air pollution is a subjective score of air quality, which has been incorporated into the National Environmental monitoring of some countries. The objectives of this study are to describe the variations in annoyance due to air pollution in Europe and its individual and environmental determinants. METHODS: This study took place in the context of the European Community Respiratory Health Survey II (ECRHS II) that was conducted during 1999-2001. It included 25 centres in 12 countries and 7867 randomly selected adults from the general population. Annoyance due to air pollution was self-reported on an 11-point scale. Annual mean mass concentration of fine particles (PM(2.5)) and its sulphur (S) content were measured in 21 centres as a surrogate of urban air pollution. RESULTS: Forty-three per cent of participants reported moderate annoyance (1-5 on the scale) and 14% high annoyance (> or =6) with large differences across centres (2-40% of high annoyance). Participants in the Northern European countries reported less annoyance. Female gender, nocturnal dyspnoea, phlegm and rhinitis, self-reported car and heavy vehicle traffic in front of the home, high education, non-smoking and exposure to environmental tobacco smoke were associated with higher annoyance levels. At the centre level, adjusted means of annoyance scores were moderately associated with sulphur urban levels (slope 1.43 microg m(-3), standard error 0.40, r = 0.61). CONCLUSIONS: Annoyance due to air pollution is frequent in Europe. Individuals' annoyance may be a useful measure of perceived ambient quality and could be considered a complementary tool for health surveillance.     

Prevalence and risk factors for self-reported odour intolerance: the Skövde population-based study

Objectives: The present study was performed to determine the prevalence of odour intolerance in adults with respect to both self-reported general intolerance and affective and behavioural consequences. Furthermore, we aimed to relate odour intolerance to explanatory variables and risk factors. Method: This is a cross-sectional, population-based epidemiological study. A random sample of 1900 inhabitants from the age of 20, stratified for age and gender, were recruited. Subjects were invited for clinical examinations that included questions about general odour intolerance, respiratory symptoms and smoking habits, as well as a smell identification test. The chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) was used to quantify affective and behavioural consequences. Results: In total 1387 volunteers (73% of the sample) were investigated. The overall prevalence of self-reported general odour intolerance was 33% (95% confidence interval (CI): 30–36%), with problems mainly from the upper respiratory tract. The prevalence of affective and behavioural consequences of odour intolerance (CSS-SHR score 43) was 19% (95% CI: 15–22%). The risk for the latter condition was increased in women compared with men (odds ratio = 2.3: 95% CI: 1.5–3.6), but no increased risk was found related to current smoking or impaired sense of smell. Conclusion: This study demonstrates that intolerance to odours is a widespread problem in society, and that it is about twice as common in women than in men.     

The influence of cognitive bias on the perceived odor, irritation and health symptoms from chemical exposure

 Objective: Responses to volatile chemicals are often subjective and variable, both over time and across individuals. Although variability can derive from differences in individual olfactory sensitivity, the response to a chemical stimulus is also influenced by the complex environment surrounding the exposure, which can include the perceiver’s cognitive state. To explore the role of cognitive bias in chemical exposures, we evaluated whether information about the consequences of exposure to acetone could influence ratings of odor and irritation during exposure and/or the frequency or intensity of reported health symptoms following exposure. Methods: Ninety adults (mean age 33.7, range 25–64) with no history of occupational exposure to solvents, were exposed to 800 ppm acetone in a chamber for 20 min. To control for non-specific responses to the odor of acetone, the subjects were also exposed for 20 min to 200 ppm phenylethyl alcohol (PEA), a nonirritant volatile chemical that produces a distinct odor but does not elicit irritation in the vapor phase. Subjects were assigned to one of three groups (n=30/group); each group was given either a positive, negative or neutral bias towards the consequences of exposure to the chemicals in the study. During exposure, subjects rated the intensity of odor and irritation; following exposure, they completed symptom questionnaires. Results: During the 20-min exposure to acetone, the positive bias group exhibited the most adaptation to its odor and the lowest perceived irritation; following exposure they reported the fewest health symptoms. In contrast, the negative bias group rated higher levels of odor intensity and, on average, reported the most overall irritation; following exposure they reported significantly more health symptoms than the other groups. None of the demographic variables studied (e.g., age, gender, race, smoking status) were predictive of the response to odor or irritation. The perceived irritancy of acetone was well predicted by a linear combination of the perceived odor of acetone and the perceived irritation from PEA (the nonirritant), r ²=0.73. Conclusions: The results provide strong evidence that both the perceived odor and cognitive expectations about a chemical can significantly affect how individuals respond to it. Moreover, because naive control subjects appear to exhibit extreme variation in their cognitive evaluations of chemical effects, there may be limited value in using non-exposed controls to assess the irritancy of chemicals for worker populations. Received: 7 May 1996/Accepted: 20 September 1996