Biomedical subjects

W Bischof

Publications and source records attributed to W Bischof.

At least 19 recordsLinked to original sources

PubMed2005

Self-reported eye symptoms and related diagnostic findings--comparison of risk factor profiles.

UNLABELLED: Profiles of factors affecting self-reported eye symptoms and objectively determined tear film characteristics have been examined and compared using data from 814 office workers. Multiple logistic regression analysis reveals significantly increased risks of subjective perception of eye symptoms for female gender, use of contact lenses and persons with health problems. A reduced break-up time (BUT) depends on personal criteria such as a history of eye disease and female gender. Age under 40 years, high relative humidity and formaldehyde exposure exceeding the 90th percentile are protective regarding BUT. For a thin lipid layer (as an indication of dry eyes) significantly increased risks are detected for high particle load, high endotoxin concentration and female gender. A thick lipid layer (as an indication of inflamed eyes) is significantly associated with a low educational level. The estimation of foam in the medial eye canthus seems to be unsuitable for evaluating indoor problems. The risk factor profiles agree on a few points only. The objectively examined thin lipid layer is the best eye-related indicator of the indoor environment. We therefore conclude that there is a need for the development and application of objective clinical methods for field monitoring in parallel with questioning. PRACTICAL IMPLICATIONS: Self-reported eye symptoms in conjunction with indoor environmental problems should be validated by objective medical examinations such as semi-quantitative estimation of the superficial lipid layer, measurement of the break-up time or assessment of conjunctival epithelial damage. For unbiased proof of environmental impact, personal factors such as acute illness or low job satisfaction should be excluded. As a minimum requirement, measurements of particles, NO(2) and relative humidity (and if possible endotoxin) should be carried out to detect any indoor environmental reason for eye symptoms.

Adult↗

PubMed2004

Comparison of risk factor profiles concerning self-reported skin complaints and objectively determined skin symptoms in German office workers.

The correspondence between impact factor profiles of self-reported skin sensation and of objectively determined skin symptoms was examined using data from the ProKlimA project (1994-1999). A sub-sample of 925 office workers participated in measurements of skin hydration and sebum content and responded to a questionnaire assessing sensory perception. The calculation of multiple logistic regression models revealed a significant increased risk for female sex [Odds ratio (OR): 2.3; confidence interval (CI): 1.4-3.6], poor software (OR: 2.2; CI: 1.3-4.0), unfavorable job characteristics (OR: 1.8; CI: 1.1-2.8), allergic illness (OR: 1.5; CI: 1.1-2.2) and the use of skin cream (OR:2.6; CI: 1.6-4.4) on the subjective perception of skin sensation. Regarding the objective medical examination of the skin humidity a significant increased risk was detected for a high concentration of Total Volatile Organic Compounds (OR: 2.5; CI: 1.3-4.8) and a low relative humidity (OR:1.9; CI: 1.1-3.4). The likewise objectively measured low sebum content is not associated with environmental variables. The impact profiles on subjective vs. objective outcome variables differ in a clear and typical way. Skin related sensory perception is mainly influenced by job-related and personal impacts. Indoor environmental characteristics affect skin hydration. We conclude the need to develop, to adapt and to use objective clinical methods applicable for field monitoring parallel to questioning.

Adult↗

PubMed2004

Exposure to house dust endotoxin and allergic sensitization in adults.

BACKGROUND: It has been suggested that exposure to elevated levels of endotoxin decreases the risk of allergic sensitization. OBJECTIVE: To examine the associations between current exposure to bacterial endotoxin in house dust and allergic sensitization in adults. METHODS: In 1995-1996, we conducted a nested case-control study following a cross-sectional study performed within the European Community Respiratory Health Survey (ECRHS). Data of 350 adults aged 25-50 years was analysed. Allergic sensitization was assessed by measurement of specific immunoglobulin E (IgE) against several inhalant allergens. Living room floor dust samples were taken. The endotoxin content was quantified using a chromogenic kinetic Limulus amoebocyte lysate test. RESULTS: Multiple logistic regression analysis showed a negative association between exposure to house dust endotoxin and severe allergic sensitization. Odds ratios (95% CI) adjusted for place of residence, gender, age, and 'caseness' were 0.80 (0.64-1.00) for sensitization to >/=1 allergen and 0.72 (0.56, 0.92) for sensitization to >/=2 allergens using 3.5 kU/l as a cut-off value for sensitization. With regard to single allergens, the protective effect of endotoxin was strongest for pollen sensitization [aOR (95% CI) = 0.74 (0.58, 0.93)]. CONCLUSION: Our results indicate that current exposure to higher levels of house dust endotoxin might be associated with a decreased odds of allergic sensitization in adults.

Adult↗

PubMed2004

Levels and predictors of endotoxin in mattress dust samples from East and West German homes.

UNLABELLED: East-West differences in prevalence of asthma and allergies were suggested to be associated with lifestyle factors. To describe endotoxin levels in mattress dust samples from East and West German homes collected approximately 10 years after reunification. To identify factors that may account for an East-West difference. Dust was collected from mattresses of 2157 infants and 2108 mothers living in Leipzig (former East Germany) and Munich (West Germany). Endotoxin was measured using a chromogenic kinetic Limulus amoebocyte lysate test. Data on bedding, dwelling, and housing characteristics, and occupants' behavior were collected using a self-administered questionnaire. Endotoxin levels were significantly higher in Leipzig compared with Munich for the infants' mattresses but not for the mothers' mattresses. Apart from this, predictors for the mothers' and the infants' mattresses were very similar. Pet-ownership and contact with animals outside the home were most influential. Endotoxin levels in mattress dust were highest in summer and increased with the number of persons living in the household. The overall percentage of variability in endotoxin levels explained by these factors was low. Endotoxin levels were associated with lifestyle factors discussed within the framework of the hygiene hypothesis. None of these factors explains the difference in infant's mattress dust endotoxin between Leipzig and Munich or could be used as a surrogate for endotoxin. PRACTICAL IMPLICATIONS: Endotoxin levels in mattress dust are associated with a number of factors discussed in the framework of the hygiene hypothesis; among other things they are associated with pet-ownership, contact with pets and number of persons living in the home. However, none of these factors and not even a combination of factors explains the variability of endotoxin levels between homes.

Adult↗

PubMed2003

The effect of storage on allergen and microbial agent levels in frozen house dust.

BACKGROUND: House dust samples collected for exposure studies are often stored for variable time periods until analysis. However, there is currently no information on the effects of dust storage on the content of biocontaminants. Therefore, associations were analysed between the levels of mite allergens (Der p 1, Der f 1), cat allergen (Fel d 1) and microbial components (endotoxin, beta(1-->3)-glucan) on the one hand and the storage duration of dust samples at -20 degrees C on the other hand. METHODS: Within the framework of a study on the influences of INdoor factors and Genetics on Asthma (INGA), dust samples were collected from living room floors between June 1995 and August 1998 and extracted according to a standardized protocol. The concentrations of Der p 1, Der f 1, Fel d 1 and beta(1-->3)-glucan were determined with specific enzyme immunoassays. Endotoxin content was quantified using a chromogenic kinetic Limulus amoebocyte lysate (LAL) test. All concentrations were expressed per gram of dust RESULTS: Dust samples (n = 1236) were obtained from 655 homes in Hamburg, Hettstedt, Zerbst and Bitterfeld. Storage duration (range 8-298 days) was grouped into four categories ( 120 d). After adjustment for city of residence and season of dust sampling, means ratios comparing categories 2-4 to the first category were not statistically significant for Der p 1, Der f 1, endotoxin and beta(1-->3 glucan). However, Fel d 1 concentrations significantly declined with increased storage times of dust samples. CONCLUSIONS: Storage of house dust at -20 degrees C for up to 10 months has no effect on mite allergen, endotoxin and beta(1-->3)-glucan levels. A potential loss of Fel d 1 during storage of frozen dust samples needs further investigations by repeated measurements of allergen in identical dust samples.

Air Pollution, Indoor↗

PubMed2003

'EUROPART'. Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects.

The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers (called EUROPART) by reviewing papers identified in Medline, Toxline, and OSH. Studies dealing with dermal effects or cancer or specifically addressing environmental tobacco smoke, house dust-mite, cockroach or animal allergens, microorganisms and pesticides were excluded. A total of 70 papers were reviewed, and eight were identified for the final review: Five experimental studies involving mainly healthy subjects, two cross-sectional office studies and one longitudinal study among elderly on cardiovascular effects. From most studies, no definite conclusions could be drawn. Overall, the group concluded that there is inadequate scientific evidence that airborne, indoor particulate mass or number concentrations can be used as generally applicable risk indicators of health effects in non-industrial buildings and consequently that there is inadequate scientific evidence for establishing limit values or guidelines for particulate mass or number concentrations.

Air Pollution, Indoor↗

PubMed2003

Early endotoxin exposure and atopy development in infants: results of a birth cohort study.

BACKGROUND: Exposure to endotoxin in childhood is currently discussed to protect from the development of allergic diseases. OBJECTIVE: To study the effect of early endotoxin exposure on incidence of atopic sensitization, atopic dermatitis and wheezing until the age of 2 years in infants with different risk status in terms of parental atopy. METHODS: Data of 1942 infants of an ongoing birth cohort study were analysed by logistic regression. Endotoxin was measured in settled dust of the mothers' mattresses at infants' age of 3 months. Data on allergic symptoms and physicians' diagnoses were gathered by questionnaire. Sensitization to common food and inhalant allergens was assessed by specific serum IgE. RESULTS: High endotoxin levels increased the risk of repeated wheeze [adjusted odds ratio (OR) for 4th exposure quartile (Q4) 1.52, 95% confidence interval (CI) 1.08-2.14], but were associated with neither sensitization to food allergens nor atopic dermatitis. Stratification by parental atopy showed that there was an association of endotoxin exposure with incidence of repeated wheeze as well as with sensitization to inhalant allergens (P for trend = 0.008 and 0.044, respectively) only in infants with parental atopy, with the highest risk in the 4th exposure quartile (repeated wheeze: ORQ4 1.77, 95% CI 1.14-2.73; sensitization to inhalant allergens: ORQ4 1.69, 95% CI 0.70-4.11). CONCLUSION: Early endotoxin exposure in terms of mattress dust endotoxin levels seemed to increase the risk of atopic reactions to inhalant allergens at the age of 2 years, especially in infants at risk due to parental atopy. Our data disagree with an early protective effect of endotoxin on atopy development until the age of 2 years.

Bedding and Linens↗

PubMed2003

Repeated measurements of allergens and endotoxin in settled house dust over a time period of 6 years.

BACKGROUND: Studies investigating the effect of exposure to indoor allergens and endotoxin on human respiratory health usually take dust samples only at one single point of time and consider them to be representative for the indoor biocontaminant burden during a time period of several years. This singly measured biocontaminant concentration is related to adverse respiratory outcomes such as asthma, wheeze or others. OBJECTIVE: We analysed two repeated measurements of mite and cat allergens in mattress and living room floor dust as well as endotoxin concentrations in living room floor dust. The repeated samples were taken over a time period of about 6 years. We investigated the repeatability over time of their concentrations by determining correlation coefficients and computing within- and between-home variance components. METHODS: Our analysis was based on the population of a study on Indoor Factors and Genetics in Asthma (INGA) being carried out in 1995/96 and followed up in 2000/01. Complete data were available from 152 participants. RESULTS: The measured allergen concentrations were low and a considerable percentage of the values was below the limit of detection. The crude Spearman's rank correlation coefficients between the two measurements taken in 1995/96 and 2000/01 ranged from 0.32 to 0.61 for the dust mites allergens, from 0.21 to 0.44 for cat allergen and from 0.35 to 0.51 for endotoxin. Correlations were higher if measurements were performed on the same floor or the same mattress at both sampling time-points. The within-home variance for all measured biocontaminant concentrations was of about the same order as the between-home variance. CONCLUSION: For studies like ours with low allergen and endotoxin concentrations, the repeatability of these concentrations over a time period as long as 6 years is low and a single measurement does not accurately reflect the true long-term exposure in the homes.

Allergens↗

PubMed2002

Ventilation and health in non-industrial indoor environments: report from a European multidisciplinary scientific consensus meeting (EUROVEN).

Scientific literature on the effects of ventilation on health, comfort, and productivity in non-industrial indoor environments (offices, schools, homes, etc.) has been reviewed by a multidisciplinary group of European scientists, called EUROVEN, with expertise in medicine, epidemiology, toxicology, and engineering. The group reviewed 105 papers published in peer-reviewed scientific journals and judged 30 as conclusive, providing sufficient information on ventilation, health effects, data processing, and reporting, 14 as providing relevant background information on the issue, 43 as relevant but non-informative or inconclusive, and 18 as irrelevant for the issue discussed. Based on the data in papers judged conclusive, the group agreed that ventilation is strongly associated with comfort (perceived air quality) and health [Sick Building Syndrome (SBS) symptoms, inflammation, infections, asthma, allergy, short-term sick leave], and that an association between ventilation and productivity (performance of office work) is indicated. The group also concluded that increasing outdoor air supply rates in non-industrial environments improves perceived air quality; that outdoor air supply rates below 25 l/s per person increase the risk of SBS symptoms, increase short-term sick leave, and decrease productivity among occupants of office buildings; and that ventilation rates above 0.5 air changes per hour (h-1) in homes reduce infestation of house dust mites in Nordic countries. The group concluded additionally that the literature indicates that in buildings with air-conditioning systems there may be an increased risk of SBS symptoms compared with naturally or mechanically ventilated buildings, and that improper maintenance, design, and functioning of air-conditioning systems contributes to increased prevalence of SBS symptoms.

Air Pollution, Indoor↗

PubMed2002

Predictors of high endotoxin concentrations in the settled dust of German homes.

Endotoxin concentrations in settled house dust were measured within the collaborative study named INGA (Indoor Exposure and Genetics in Asthma) together with other asthma-related indoor factors in 405 randomly selected homes in two German cities. Endotoxin was assayed using the quantitative kinetic chromogenic Limulus Amebocyte Lysate (LAL) method. The mean concentration of 2,274 ng endotoxin/g dust in living rooms is about two orders of magnitude below mean occupational exposure (e.g. agriculture). Endotoxin concentrations are higher in old buildings (means ratio = (MR) 1.52, 95% C.I.: 1.14; 2.04), and in the lower storey of the dwelling (MR = 1.30, 95% C.I.: 1.04; 1.62). Furthermore, higher endotoxin concentrations are associated with longer occupancy in the apartment (MR = 1.63, 95% C.I.: 1.21; 2.18), high utilisation of the apartment during the sampling period (MR = 2.52, 95% C.I.: 1.42; 4.47), infrequent vacuum cleaning of the carpets (MR = 1.67; 95% C.I.: 1.10; 2.54), an indifferent attitude to ventilation (MR = 1.37; 95% C.I.: 1.03; 1.82), keeping cats (MR = 1.91; 95% C.I.: 1.43; 2.55) and dogs (1.57; 95% C.I.: 1.08; 2.30), as well as the occurrence of mice (MR = 1.39; 95% C.I.: 1.00; 1.93). The season and indoor climate (operative temperature and relative humidity) did not effect endotoxin concentration. These results indicate that high endotoxin concentration in settled dust is an indicator of poor hygienic conditions in homes.

Adult↗

PubMed2002

Allergens and endotoxin on mothers' mattresses and total immunoglobulin E in cord blood of neonates.

The current authors examined whether mite and cat allergen and bacterial endotoxin levels in dust of the mothers' mattresses were associated with cord blood immunoglobulin (Ig)E (CB-IgE) levels in newborns. Data from 1,332 term and normal weight neonates, from an ongoing birth cohort study, influences of life-style related factors on the immune system and the development of allergies in childhood (LISA), with complete information on exposure to biocontaminants in mattress dust and CB-IgE were analysed. Two thirds of CB-IgE were undetectable (<0.35 kU x L(-1)). Thus, 0.35 and 0.45 kU x L(-1) (4th quartile) were chosen as cut-offs. Nonparametric smoothing (generalised additive models) showed statistically significant confounder-adjusted associations between elevated CB-IgE levels (> or = 0.45 kU x L(-1)) and log-transformed exposures to cat (linear), mite (inverse u-shaped), and endotoxin (u-shaped). After adjustment for covariables, elevated CB-IgE levels (logistic regression using the 1st-4th quartiles of exposure) were positively associated with high cat-allergen exposure and medium exposure to mite allergen, but were inversely associated with exposure to endotoxin. The associations were similar, but somewhat weaker, when 0.35 kU x L(-1) was used as cut-off. These results, showing an association between prenatal allergen and endotoxin exposures and immunoglobulin E production, suggest that the development of foetal immune responses may be affected.

Allergens↗

PubMed2001

Why do women suffer from sick building syndrome more often than men?--subjective higher sensitivity versus objective causes.

Office workers often report so-called sick building syndrome (SBS) symptoms affecting the skin, mucous membranes and nervous system. The recurring higher prevalence of SBS in women was investigated using questionnaire and ergonomic data from the German ProKlimA-Project. The hypothesis that working conditions and job characteristics for women are inferior to those of men was tested for groups of risk factors. Finally, gender-specific multiple logistic regression models were compared. It was found that 44.3% of women (n = 888) and 26.2% of men (n = 576) suffer SBS with significant differences between men and women for many variables. Considering sub-groups--supposing the same circumstances in psycho-social and work-related conditions--gender-specific SBS prevalence rates differ as for the whole sample, e.g. 35.9% of women with the most favourable job characteristic suffer SBS (men: 19.4%), 53.0% of women with the most unfavourable job characteristic suffer SBS (men: 33.3%). These results show that women suffer more SBS than men independent of personal, most work-related and building factors. Multiple logistic models define self-reported acute illness, job satisfaction, software quality and job characteristics as significant gender-independent risk factors. Number of persons/room, self-reported allergy and smoking are characteristic female risk factors. Age is a significant risk factor only in men.

Adult↗

PubMed2001

Pets and vermin are associated with high endotoxin levels in house dust.

BACKGROUND: Previous studies have shown that the risk for allergic sensitization is lower in children who grew up on farms and in young adults who were exposed to dogs in early childhood. A higher microbial exposure in general and in particular to endotoxin in early childhood might contribute to this lower risk of atopy. OBJECTIVE: We examined whether the presence of pets or vermin in the home is associated with higher endotoxin concentrations in settled house dust. METHODS: House dust was sampled in a standardized manner on the living room floors of 454 homes of German children aged 5-10 years (participation rate 61%). Endotoxin was assessed with a quantitative kinetic chromogenic Limulus Amebocyte Lysate (LAL) method. Associations between endotoxin levels, pets and vermin are presented as ratios of the crude and confounder adjusted geometric means (means ratios) in the category of study vs. a reference category using multiple linear regression models. RESULTS: Endotoxin concentrations in living room floor dust sampled in homes without pets and vermin were lower (1246 ng per square meter, 1519 ng endotoxin/g dust, n = 157) than those sampled in homes with pets or vermin (2267 ng per square meter, 2200 ng endotoxin/g dust, n = 296). After adjustment for city of residence, season of dust sampling, age of the building and story of the dwelling, means ratios for endotoxin expressed per gram of dust were statistically significantly increased for dog (1.64, 95% CI 1.09-2.46), for cat (1.50, 95% CI 1.03-2.18) and for cockroach (3.01, 95% CI 1.37-6.60), whereas no major statistically significant associations were found for other pets, ants and mice. CONCLUSION: Keeping a dog or a cat in the home is consistent with higher exposure to endotoxin and might therefore contribute to the lower risk of atopy in later life.

Air Pollution, Indoor↗

PubMed2001

Exposure to endotoxin decreases the risk of atopic eczema in infancy: a cohort study.

BACKGROUND: Previous studies have shown a protective effect of early exposure to cats and dogs on the development of atopic eczema, asthma, allergic rhinitis, and atopic sensitization in later life. In particular, a higher microbial exposure to endotoxin in early childhood might contribute to this effect. OBJECTIVE: We examined the associations between bacterial endotoxin in house dust and atopic eczema, infections, and wheezing during the first year of life in an ongoing birth cohort study (LISA). METHODS: Data of 1884 term and normal-weight neonates with complete information on exposure to biocontaminants and confounding variables were analyzed. House dust from the mothers' and the children's mattresses was sampled 3 months after birth. Endotoxin content was quantified by using a chromogenic kinetic limulus amoebocyte lysate test. RESULTS: During the first 6 months of life, the risk of atopic eczema was significantly decreased by endotoxin exposure in dust from mothers' mattresses in the fifth quintile (odds ratio [OR], 0.50; 95% CI, 0.28-0.88), whereas the risk was increased for respiratory infections (OR, 1.69; 95% CI, 1.25-2.28) and cough with respiratory infection, bronchitis, or both (OR, 1.73; 95% CI, 1.28-2.33). The risk of wheezing was also significantly increased during the first 6 months of life (OR, 2.37; 95% CI, 1.40-4.03). For the entire first year of life, these associations attenuated, except for the risk of wheezing, which remained significant (OR, 1.60; 95% CI, 1.10-2.30). CONCLUSION: Our findings support the hygiene hypothesis that exposure to high concentrations of endotoxin very early in life might protect against the development of atopic eczema within the first 6 months of life, along with an increased prevalence of nonspecific respiratory diseases.

Air Pollution, Indoor↗

PubMed2001

Eye- and skin symptoms in German office workers--subjective perception vs. objective medical screening.

The question of whether perceived sensation correlates with medical tests was examined using data from the ProKlimA project (1994-1999) in which sensory perception and medical examination of Sick Building Syndrome related complaints were examined in 14 office buildings across Germany. Within the ProKlimA study, a subsample of 817 persons participated in ophthalmological examinations; dermatological tests were conducted on 925 persons using serni quantitative dermatological methods. Participants of both sub-samples responded to a questionnaire assessing sensory perception over 6 sub-scales (eyes, skin nose, mouth, throat and nervous systems) consisting of 9 to 11 items per sub-scale. Non-parametric analysis revealed a significant association between medical tests of symptoms and self-reported complaints regarding skin/eyes. Break up time, a measure of tear film stability, appeared to be the best indicator for self-reported eye complaints. In terms of skin symptoms, low sebaceous secretion and/or low stratum corneum hydration was associated significantly with increased skin complaints. But not all items of the sensory perception modules reflected the medical diagnoses in the same way. For instance the items "rough skin" and "dry skin" described the medical diagnosis "low sebum content" better than "irritated skin", "rash" or "spotty skin". However, sensory perception modules differed in their relationship to medical tests, so that questionnaires may be used as indicators not as substitutes for medical test data. The choice of method has to be determined by the purpose of the research project.

Environment, Controlled↗

PubMed2001

Respiratory symptoms in relation to indoor exposure to mite and cat allergens and endotoxins. Indoor Factors and Genetics in Asthma (INGA) Study Group.

The authors investigated the relationship between respiratory symptoms in adults and exposure to mite and cat allergens, the role of endotoxins in house dust, the effects of mixtures of several allergens, and interactions between allergen exposure and allergic sensitization. Within a nested case-control study, 405 subjects aged 25-50 yrs from two German cities answered a standardized questionnaire. Allergen-specific immunoglobulin-E was measured. Dust samples were taken from the subjects' homes to determine exposure to mite (Dermatophagoides pteronyssinus antigen 1 Der p 1) and (D. farinae antigen 1 Der f l) and cat (cat antigen d1 Fel d 1) allergen and endotoxin content in settled house dust. Exposure to Der f 1 and Der p 1 plus Der f 1 >10 microg x g(-1) of mattress dust, respectively, increased the risk of wheeze and breathlessness (odds ratios (OR): 4.04, 95% confidence interval (CI): 1.53-10.64, OR: 2.78, 95% CI: 1.06-7.28). Fel d 1 >8 microg x g(-1) was positively associated with cough at night (OR: 2.74, 95%, CI: 1.22-.17), noteworthy also in the nonsensitized subjects. Subjects exposed to elevated concentrations of more than one allergen had an up to seven-fold increase in the risk of respiratory symptoms, compared to nonexposed subjects. Sensitized subjects exposed to elevated concentrations of Der f 1 or Fel d 1 were found to have the highest risk of asthma attacks and respiratory symptoms. No statistically significant association was found between exposure to endotoxins and respiratory health. Indoor exposure to Dermatophagoides farinae antigen 1 and cat antigen d1 is a risk factor for respiratory symptoms in adults, and for cat antigen d 1 even in nonsensitized subjects. The risk is increased if subjects are exposed to a mixture of allergens or if they are sensitized in addition to high exposure.

Adult↗

PubMed2001

Beta(1-->3)-glucan in house dust of German homes: housing characteristics, occupant behavior, and relations with endotoxins, allergens, and molds.

beta(1-->3)-Glucans are potent proinflammatory agents that have been suggested to play a role in indoor-related respiratory health effects. The aim of this study was to assess whether beta(1-->3)-glucan concentrations in house dust are correlated with levels of endotoxins, allergens, and culturable mold spore counts in house dust. Further, the associations of beta(1-->3)-glucan with housing characteristics and occupant behavior were assessed. beta(1-->3)-Glucan was measured in settled house dust from living room floors of 395 homes of two German cities, Erfurt and Hamburg, with a specific enzyme immunoassay. Concentrations ranged from below the limit of detection to 19,013 microg/m(2) (22,588 microg/g dust). Concentrations per square meter were found to be correlated with endotoxins, mite and cat allergens, and culturable mold spores. Correlations were weaker when concentrations were expressed per gram of dust, indicating that variance in concentrations of all factors is largely determined by the amount of dust sampled. Associations between beta(1-->3)-glucan, housing characteristics, and occupant behavior were found for concentrations per square meter but not for concentrations per gram of dust. The following characteristics were associated with a significant increase in beta(1-->3)-glucan levels: carpets in the living room [means ratio (MR) = 1.9-2.1], keeping a dog inside (MR = 1.4), use of the home by four or more persons (MR = 1.4), use of the living room for > 180 hr/week (MR = 2.1), lower frequency of vacuum cleaning (MR = 1.6-3.0) and dust cleaning (MR = 1.2 and 1.4, respectively), and presence of mold spots during the past 12 months (MR = 1.4). We conclude that that the amount of dust sampled can be used as a proxy for hygiene and that beta(1-->3)-glucan concentrations per square meter are related to the amount of dust sampled.

Air Pollution, Indoor↗

PubMed2000

Indoor viable mold spores--a comparison between two cities, Erfurt (eastern Germany) and Hamburg (western Germany).

BACKGROUND: In eastern Germany, the prevalence of allergies is lower than in western Germany for both children and adults. Several reasons for this fact have been discussed, although it is still not completely understood. One purpose of the epidemiologic study "Indoor and genetic factors in asthma and allergy" (INGA) is to compare exposure to mold spores in two German cities. Therefore, 405 homes in Erfurt (east) and Hamburg (west) were visited twice by trained investigators between June 1995 and May 1997. METHODS: Samples of settled dust were taken by vacuuming from the carpet in the living room. Sieved house dust was diluted and plated on DG18 agar. The analyses were carried out in duplicate in the same laboratory. RESULTS: No significant difference could be shown for the total and for single genera (Alternaria, Aspergillus, Cladosporium, and Penicillium) in concentration of spores of viable fungi in settled house dust between Erfurt and Hamburg. Seasonal variation of the mold picture, with highest values in August, could be identified both indoors and outdoors. CONCLUSIONS: Because outdoor concentration is the main influence on indoor concentration of mold spores from June to October, we recommend sampling from November to May to evaluate exposure to indoor mold spores.

Adult↗