No consistent risk factor pattern for symptoms related to the sick building syndrome: a prospective population based study

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

Effects of occupant behaviors on perceived dormitory air quality and sick building syndrome symptoms among female college students

We performed a cross-sectional survey of 2143 female students in a university in Tianjin, China regarding perceived air quality (PAQ) and sick building syndrome (SBS) symptoms in the student dormitory. The prevalence of general, mucosal, and skin symptoms was 22.1%, 21.9%, and 26.3%, respectively. The three most prevalent PAQ complaints were "dry air" (48.9% often), "stuffy odor" (18.2%), and "other unpleasant odors" (5.1%), and they were significant risk factors for 11-12 out of 12 SBS symptoms (adjusted odds ratios [AOR]: 1.6-5.8). Survey data of 1471 undergraduates, whose dorms were of uniform layout and furnishing, were used to further investigate the influences of occupancy level and occupant behaviors on PAQ and SBS symptoms. Frequent use of air freshener/perfume was a significant risk factor for "dry air," less frequent room cleaning and higher occupancy density were significant risk factors for "stuffy odor," and less natural ventilation was a significant risk factor for both "stuffy odor" and "pungent odor." These factors were also significantly associated with some SBS symptoms. In particular, the use of air freshener/perfume exhibited a significant dose-response pattern with "fatigue" (sometimes: AOR 1.3; often: AOR 2.0) and with "irritated, stuffy, or runny nose" (sometimes: AOR 1.6; often: AOR 2.2).

Common mental disorders through the eyes of German employees: attributed relevance of work-related causes and prevention measures assessed by a standardised survey

PURPOSE

Common mental disorders (CMDs) are becoming increasingly relevant in the working world. Numbers of risk factors have been confirmed by mostly correlative cross-sectional studies. Comprehensive and effective prevention is urgently needed. There is little knowledge about employees' own perceptions on causes of CMDs and prevention measures. Therefore, a survey was conducted in 2016.

METHODS

A standardised instrument was developed for an online survey in a commercial access panel, targeted employees in different job types. We assessed two outcomes: perceived relevance of (1) work-related demands to the development of CMDs, and (2) prevention approaches in the workplace and on individual and societal levels. Possible predictive aspects were analysed exploratively by multivariate linear regression analysis.

RESULTS

The response rate was 75% (n = 610). Job types were categorised as "blue", "grey" and "white-collar" workers (n = 193, 169, 248). The majority of respondents rated both outcomes consistently as "quite" or "very relevant"; societal prevention strategies were more relevant for non-white-collar workers. Perceived relevance of individual predisposition to develop a CMD was the strongest predictor for both outcomes, indicating the perception that people with higher personal vulnerability might suffer a higher strain from work-related risk factors than others.

CONCLUSION

We assume that participants in our survey judged the relevance of work-related causes of CMDs independently of their own workload. The perceived relevance of prevention measures in different areas is consistent with official guidelines. A possible selection bias due to characteristics of access panel collectives and own direct or indirect experiences with CMD should be critically questioned.

Self-reported health and comfort in 'modern' office buildings: first results from the European OFFICAIR study

In the European research project OFFICAIR, a procedure was developed to determine associations between characteristics of European offices and health and comfort of office workers, through a checklist and a self-administered questionnaire including environmental, physiological, psychological, and social aspects. This procedure was applied in 167 office buildings in eight European countries (Portugal, Spain, Italy, Greece, France, Hungary, the Netherlands, and Finland) during the winter of 2011-2012. About 26 735 survey invitation e-mails were sent, and 7441 office workers were included in the survey. Among respondents who rated an overall comfort less than 4 (23%), 'noise (other than from building systems)', air 'too dry', and temperature 'too variable' were the main complaints selected. An increase of perceived control over indoor climate was positively associated with the perceived indoor environment quality. Almost one-third of office workers suffered from dry eyes and headache in the last 4 weeks. Physical building characteristics were associated with occupants' overall satisfaction (acoustical solutions, mold growth, complaints procedure, cleaning activities) and health (number of occupants, lack of operable windows, presence of carpet and cleaning activities). OFFICAIR project provides a useful database to identify stressors related to indoor environmental quality and office worker's health.

Effect of Traffic Exposure on Sick Building Syndrome Symptoms among Parents/Grandparents of Preschool Children in Beijing, China

INTRODUCTION

Sick building syndrome (SBS) includes general, mucosal and skin symptoms. It is typically associated with an individual's place of work or residence. The aim of this study was to explore the effect of traffic exposure on SBS symptoms in Beijing, China.

METHODS

From January to May, 2011, recruitment occurred at kindergartens in 11 districts in Beijing. Self-administered questionnaires were distributed by teachers to legal guardians of children and then returned to teachers. The questionnaire asked them to recall the presence of 12 SBS symptoms from the previous three months. Living near a highway or main road (within 200 meters) was used as a proxy for traffic exposure. Multivariable logistic regression was used to test the association between traffic exposure and a higher number of SBS symptoms, controlling for key covariates.

RESULTS

There were 5487 valid questionnaires (65.0% response rate). Univariate analysis showed that living near a main road or highway (OR = 1.40), female gender (OR = 1.44), and environmental tobacco smoking (ETS) (OR = 1.13) were significant risk factors for general symptoms. Grandparent's generation (OR = 0.32) and home ownership (owner vs. renter) (OR = 0.89) were significant protective factors. The adjusted odds ratio (aOR) for the association between living close to a highway and general symptoms remained significant in the multivariable model (aOR = 1.39; 95% CI = 1.21: 1.59). ORs and aORs were similar for mucosal and skin symptoms.

CONCLUSIONS

This study found traffic exposure to be significantly associated with SBS symptoms. This finding is consistent with current literature that indicates an association between adverse health effects and living near highway or main road.

Work-related symptoms in indoor environments: a puzzling problem for the occupational physician

PURPOSES

People who work indoors often manifest symptoms related to the work environment. Sick building syndrome (SBS) is a condition closely associated with sealed, air-conditioned workplaces and is especially frequent in countries with a cold climate. However, it is also present in Mediterranean countries where artificial ventilation accompanies the natural one. The significance of personal factors, air quality perception, and psychosocial work conditions in relation to SBS and other work-related symptoms needs to be clarified.

METHODS

Workers from 28 companies in the Latium region of Italy were invited to answer a questionnaire during their routine medical examination at the workplace. A total of 4,029 out of 4,129 took part in the survey, giving a response rate of 97.6 %.

RESULTS

A high percentage of workers (31.9 %) reported symptoms related to work, and two-thirds of the employees (65.4 %) complained of environmental problems. In logistic regression models, personal factors (gender, smoking habit, age, and atopy), anxiety and depression, environmental discomfort and job strain were associated both with symptoms of SBS and other work-related symptoms. There was a significant association between the perception of stuffy air, dry air, and electricity and cases of SBS. Some associations between symptoms and the work environment lacked biological plausibility.

CONCLUSIONS

The occupational physician's task is to systematically monitor workers' symptoms and their perception of the work environment in order to analyze this relationship and indicates the best mode of preventing illness/discomfort. This paper provides a method and reference values.

Odors and sensations of humidity and dryness in relation to sick building syndrome and home environment in Chongqing, China

The prevalence of perceptions of odors and sensations of air humidity and sick building syndrome symptoms in domestic environments were studied using responses to a questionnaire on the home environment. Parents of 4530 1–8 year old children from randomly selected kindergartens in Chongqing, China participated. Stuffy odor, unpleasant odor, pungent odor, mold odor, tobacco smoke odor, humid air and dry air in the last three month (weekly or sometimes) was reported by 31.4%, 26.5%, 16.1%, 10.6%, 33.0%, 32.1% and 37.2% of the parents, respectively. The prevalence of parents’ SBS symptoms (weekly or sometimes) were: 78.7% for general symptoms, 74.3% for mucosal symptoms and 47.5% for skin symptoms. Multi-nominal regression analyses for associations between odors/sensations of air humidity and SBS symptoms showed that the odds ratio for “weekly” SBS symptoms were consistently higher than for “sometimes” SBS symptoms. Living near a main road or highway, redecoration, and new furniture were risk factors for perceptions of odors and sensations of humid air and dry air. Dampness related problems (mold spots, damp stains, water damage and condensation) were all risk factors for perceptions of odors and sensations of humid air and dry air, as was the presence of cockroaches, rats, and mosquitoes/flies, use of mosquito-repellent incense and incense. Protective factors included cleaning the child’s bedroom every day and frequently exposing bedding to sunshine. In conclusion, adults’ perceptions of odors and sensations of humid air and dry air are related to factors of the home environment and SBS symptoms are related to odor perceptions.

Indoor air pollutants in office environments: assessment of comfort, health, and performance

Concentrations of volatile organic compounds (VOCs) in office environments are generally too low to cause sensory irritation in the eyes and airways on the basis of estimated thresholds for sensory irritation. Furthermore, effects in the lungs, e.g. inflammatory effects, have not been substantiated at indoor relevant concentrations. Some VOCs, including formaldehyde, in combination may under certain environmental and occupational conditions result in reported sensory irritation. The odour thresholds of several VOCs are low enough to influence the perceived air quality that result in a number of acute effects from reported sensory irritation in eyes and airways and deterioration of performance. The odour perception (air quality) depends on a number of factors that may influence the odour impact. There is neither clear indication that office dust particles may cause sensory effects, even not particles spiked with glucans, aldehydes or phthalates, nor lung effects; some inflammatory effects may be observed among asthmatics. Ozone-initiated terpene reaction products may be of concern in ozone-enriched environments (≥0.1mg/m(3)) and elevated limonene concentrations, partly due to the production of formaldehyde. Ambient particles may cause cardio-pulmonary effects, especially in susceptible people (e.g. elderly and sick people); even, short-term effects, e.g. from traffic emission and candle smoke may possibly have modulating and delayed effects on the heart, but otherwise adverse effects in the airways and lung functions have not been observed. Secondary organic aerosols generated in indoor ozone-initiated terpene reactions appear not to cause adverse effects in the airways; rather the gaseous products are relevant. Combined exposure to particles and ozone may evoke effects in subgroups of asthmatics. Based on an analysis of thresholds for odour and sensory irritation selected compounds are recommended for measurements to assess the indoor air quality and to minimize reports of irritation symptoms, deteriorated performance, and cardiovascular and pulmonary effects.

The prevalence and incidence of sick building syndrome in Chinese pupils in relation to the school environment: a two-year follow-up study

There are few incidence studies on sick building syndrome (SBS). We studied two-year change of SBS in Chinese pupils in relation to parental asthma/allergy (heredity), own atopy, classroom temperature, relative humidity (RH), absolute humidity (AH), crowdedness, CO₂, NO₂, and SO₂. A total of 1993 participated at baseline, and 1143 stayed in the same classrooms after two years. The prevalence of mucosal and general symptoms was 33% and 28% at baseline and increased during follow-up (P < 0.001). Twenty-seven percent reported at least one symptom improved when away from school. Heredity and own atopy were predictors of SBS at baseline and incidence of SBS. At baseline, SO₂ was associated with general symptoms (OR=1.10 per 100 μg/m³), mucosal symptoms (OR=1.12 per 100 μg/m³), and skin symptoms (OR=1.16 per 100 μg/m³). NO₂ was associated with mucosal symptoms (OR=1.13 per 10 μg/m³), and symptoms improved when away from school (OR=1.13 per 10 μg/m³). Temperature, RH, AH, and CO₂ were negatively associated with prevalence of SBS. Incidence or remission of SBS was not related to any exposure, except a negative association between SO₂ and new skin symptoms. In conclusion, heredity and atopy are related to incidence and prevalence of SBS, but the role of the measured exposures for SBS is more unclear.

PRACTICAL IMPLICATIONS

We found high levels of CO₂ indicating inadequate ventilation and high levels of SO₂ and NO₂, both indoors and outdoors. All schools had natural ventilation, only. Relying on window opening as a tool for ventilation in China is difficult because increased ventilation will decrease the level of CO₂ but increase the level of NO₂ and SO₂ indoors. Prevalence studies of sick building syndrome (SBS) might not be conclusive for causal relationships, and more longitudinal studies on SBS are needed both in China and other parts of the world. The concept of mechanical ventilation and air filtration should be introduced in the schools, and when planning new schools, locations close to heavily trafficked roads should be avoided.

[Variations of indoor environment and the prevalence of sick house syndrome over three-year period in detached houses in Sapporo]

OBJECTIVES

The purpose of this study was to investigate annual variations in indoor environmental chemical, fungal and dust mite allergen levels, with regards to variations in sick house syndrome (SHS) symptoms over a three-year period.

METHODS

Detached houses were randomly selected from a building plan approval application, and a questionnaire survey was conducted in 2003 in Sapporo, Japan. Indoor environmental measurements and a self-administered questionnaires survey were conducted on the selected houses in 2004, 2005 and 2006. The same protocol was used for the three-year period to measure the levels of chemicals, fungi and dust mite allergens. A personal questionnaire to assess SHS was distributed to all inhabitants of the dwellings along with one questionnaire to assess housing characteristics.

RESULTS

In 2004, 2005 and 2006, the owners of 104, 64 and 41 houses, respectively, agreed to participate in this study. Forty-one houses and the 127 inhabitants who participated in this three-year survey period were included in the analysis to evaluate the associations between differences in environmental measurements and SHS. The levels of formaldehyde, acetone, toluene, Alternaria and Cladosporium tended to decrease, whereas those of limonene and Aspergillus tended to increase over the three-year period. Increasing levels of Cryptococcus and the dampness index in individual houses correlated with increasing SHS symptom scores in the inhabitants after mutual adjustment.

CONCLUSIONS

Although the average levels of chemicals and fungi were relatively low, the results show the relationship between annual variations in indoor environmental measurements and variations in SHS symptom scores.

Sick building syndrome in relation to domestic exposure in Sweden - A cohort study from 1991 to 2001

Background: Most studies on sick building syndrome (SBS) are cross-sectional and have dealt with symptoms among office workers. There are very few longitudinal cohort studies and few studies on SBS in relation to domestic exposures. The aim of this study was to investigate changes in SBS symptoms during the follow-up period and also to investigate changes in different types of indoor exposures at home and relate them to SBS symptoms in a population sample of adults from Sweden. We also wanted to investigate if there was any seasonal or regional variation in associations between exposure and SBS. Methods: A random sample of 1,000 people of the general population in Sweden (1991) was sent a self administered questionnaire. A follow-up questionnaire was sent in 2001. Results: An increased risk for onset of any skin symptoms (risk ratio (RR) 2.32, 1.37—3.93), mucosal symptoms (RR 3.17, 1.69—5.95) or general symptoms (RR 2.18, 1.29—3.70) was found for those who had dampness or moulds in the dwelling during follow-up. In addition people living in damp dwellings had a lower remission of general symptoms and skin symptoms. Conclusions: Dampness in the dwelling is a risk factor for new onset of SBS symptoms. Focus on indoor environment improvements in dwellings can be beneficial both for the inhabitants and the general population. Reducing dampness in buildings is an important factor for reducing SBS symptoms in the general population.

Indoor environment in dwellings, asthma, allergies, and sick building syndrome in the Swedish population: a longitudinal cohort study from 1989 to 1997

OBJECTIVES

To investigate changes of sick building syndrome (SBS) and different types of indoor exposures at home over an 8-year follow-up period (1989-1997), and onset of SBS symptoms in relation to size of residence town and education level.

METHODS

A random sample (0.1%) of the population in a 3-county region in Sweden, initially aged 20-65 years (n = 466). In total, 348 (75%) answered the postal follow-up questionnaire.

RESULTS

Water leakage during the last year had decreased from 11.2 to 4.8% visible indoor mould had decreased from 4.7 to 1.6%, and any sign of building dampness decreased from 16.1 to 9.5%. The prevalence of current smoking had decreased from 30 to 19%. Smokers at baseline reported more onset of SBS symptoms than non-smokers. Furthermore, remission from mucosal symptoms was less likely in subjects that were tobacco smoker. Subjects with any indoor painting during follow-up period reported more onset of SBS symptoms, and those with intermediate education level had more onset of skin symptoms.

CONCLUSION

Smoking and indoor painting could be predictors of new onset of SBS symptoms. Focus on indoor environment in Sweden the last decades may have resulted in environmental improvements in the dwellings, which can be beneficial both for the inhabitants and for the future public health.

Regional differences in residential environments and the association of dwellings and residential factors with the sick house syndrome: a nationwide cross-sectional questionnaire study in Japan

This study was conducted to clarify regional differences in residential factors and the association of those factors with dwellings having sick house syndrome (SHS) problems. The survey was conducted in six areas of northern and southern Japan. In terms of regional differences, dampness was not as severe in the dwellings in Sapporo as compared with that in areas in the south. SHS was defined using five categories of nasal, throat and respiratory, skin and general symptoms, which appeared frequently or not frequently and improved upon leaving the home. The dampness index was estimated by the sum of the presence of several indicators: condensation on the window panes and/or wall, visible mold growth, moldy odor, slow-drying wet towels in the bathroom, and water leakage. The dwellings where inhabitants showed any symptoms of SHS comprised 3.7% of all surveyed dwellings. We found significant associations between SHS and dampness index, odors, and stuffiness of the air. For dampness, the adjusted odds ratio (OR) increased with increased dampness index, adjusting for the age of the house, pets indoors, stuffiness of the air, and odors. These results showed an increased risk when several dampness indicators appeared simultaneously.

PRACTICAL IMPLICATIONS

To evaluate the associations of residential environments and Sick House Syndrome (SHS), this cross-sectional questionnaire study was conducted on 2297 dwellings in six areas in Japan from 2003 to 2004. The dwellings where inhabitants showed any of nasal, throat and respiratory, skin and general symptoms comprised 3.7% of all surveyed dwellings, and an increased risk for SHS was found when several dampness indicators, 'condensation', 'visible mold growth', 'moldy odor', 'slow drying wet towels in the bathroom' and 'water leakage', appeared simultaneously.

Structural equation analysis of the causal relationship between health and perceived indoor environment

OBJECTIVES

To explore the temporal relationship and reversed effects between health and perception of the indoor environment using structural equation models.

METHODS

The study was a two-phase prospective questionnaire study with a cross-lagged design. Altogether 1,740 adults participated on both occasions.

RESULTS

The perceived indoor environment had only weak effects on health at follow-up. However, the results strongly indicated a reversed effect that health problems may lead to increased complaints about the indoor environment.

CONCLUSIONS

Structural equation models are powerful analytical tools for disentangling the effects of a specific variable on another in high dimensional data with complex patterns of associations. The analyses confirmed the results of our previous logistic regression analysis about the strong reversed effect. Hence, it is probable that a reversed effect between health and complaints about the indoor environment exists.

The dichotomy of relative humidity on indoor air quality

Dry and irritated mucous membranes of the eyes and airways are common symptoms reported in office-like environments. Earlier studies suggested that indoor pollutants were responsible. We have re-evaluated, by review of the literature, how low relative humidity (RH) may influence the immediately perceived indoor air quality (IAQ), including odour, and cause irritation symptoms (i.e. longer-term perceived IAQ). "Relative humidity" were searched in major databases, and combined with: air quality, cabin air, dry eyes, formaldehyde, inflammation, mucous membranes, offices, ozone, pungency, sensory irritation, particles, precorneal tear film, sick building syndrome, stuffy air, and VOCs. The impact of RH on the immediately and longer-term perceived IAQ by VOCs, ozone, and particles is complex, because both the thermodynamic condition and the emission characteristics of building materials are influenced. Epidemiological, clinical, and human exposure studies indicate that low RH plays a role in the increase of reporting eye irritation symptoms and alteration of the precorneal tear film. These effects may be exacerbated during visual display unit work. The recommendation that IAQ should be "dry and cool" may be useful for evaluation of the immediately perceived IAQ in material emission testing, but should be considered cautiously about the development of irritation symptoms in eyes and upper airways during a workday. Studies indicate that RH about 40% is better for the eyes and upper airways than levels below 30%. The optimal RH may differ for the eyes and the airways regarding desiccation of the mucous membranes.

The sick building syndrome: a chicken and egg situation?

OBJECTIVES

To examine the temporal relationship and specificity between self-reports on the indoor environment at work and symptoms that are traditionally connected with the sick building syndrome (SBS).

METHODS

This questionnaire study used a prospective full panel design as regards self-reports on exposure and outcome. At the baseline, the sample comprised 2,164 adults selected randomly from the general population. Of these 1,402, who were still working and living in the same place, completed a second questionnaire a year later. Health measures were symptoms that are traditionally connected with the SBS, as well as some "dummy" symptoms that hardly can be causally related to the indoor environment. The associations between self-reports on the indoor environment and these symptom groups were assessed both in cross-sectional and longitudinal analyses, the latter examining the normal direction that exposure leads to symptoms as well as the reverse order: that symptoms lead to perceived exposure.

RESULTS

In cross-sectional analyses, the indoor environment factors were associated equally with SBS symptoms and with "dummy" symptoms. In longitudinal analyses, only few of the indoor environment factors predicted the development of any of the symptom groups. However, both the SBS symptoms and the "dummy" symptoms were risk factors for beginning to report exposures in the indoor environment.

CONCLUSIONS

Symptoms predict future reports on exposures in the indoor environment indicating that it is difficult to determine what existed first: the outcome or the exposure. In addition, the perceived indoor environment is associated not only with the traditional SBS symptoms, but also with symptoms that cannot be physiologically linked to the indoor environment. These results suggest that there is a risk of reporting bias when assessing non-specific symptoms. Thus, many of the associations found in previous cross-sectional studies on SBS symptoms and indoor environment factors may possibly be explained by reporting bias.