SBS symptoms in relation to dampness and ventilation in inspected single-family houses in Sweden.

PURPOSE: To investigate the relationships between symptoms compatible with the sick building syndrome (SBS) in adults and building dampness and ventilation in single-family houses. METHODS: Within the Swedish BETSI study, a national sample of single-family houses were inspected by professional building experts, and adults living in the houses answered a questionnaire on SBS. Relationships between building factors and SBS were analysed using logistic regression. RESULTS: Of the respondents, 23% reported having had weekly SBS symptoms during the last three months. A large proportion of houses exhibited building or construction problems. In total, 40% of houses had dampness problems in the foundation, and this was related to a higher prevalence of both mucous and dermal symptoms, and any SBS symptoms. Furthermore, high air humidity was related to more symptoms, with the relationship with absolute humidity being stronger than that with relative humidity or moisture load. Symptoms were also more prevalent in houses with a high U value, reflecting a poor thermal insulation. Compared to natural ventilation, living in a house with mechanical supply and exhaust ventilation was related to a lower prevalence of general symptoms and any SBS symptoms, but there were only weak associations between measured air exchange rate and symptoms. CONCLUSIONS: A large proportion of single-family houses have dampness problems in the foundation, and pollutants may enter the living space of the house and affect the health of the occupants. Furthermore, absolute air humidity should be measured more often in indoor air studies.

A new multiple regression model to identify multi-family houses with a high prevalence of sick building symptoms "SBS", within the healthy sustainable house study in Stockholm (3H).

PURPOSES: The aim was to develop a new model to identify residential buildings with higher frequencies of "SBS" than expected, "risk buildings". METHODS: In 2005, 481 multi-family buildings with 10,506 dwellings in Stockholm were studied by a new stratified random sampling. A standardised self-administered questionnaire was used to assess "SBS", atopy and personal factors. The response rate was 73%. Statistical analysis was performed by multiple logistic regressions. RESULTS: Dwellers owning their building reported less "SBS" than those renting. There was a strong relationship between socio-economic factors and ownership. The regression model, ended up with high explanatory values for age, gender, atopy and ownership. Applying our model, 9% of all residential buildings in Stockholm were classified as "risk buildings" with the highest proportion in houses built 1961-1975 (26%) and lowest in houses built 1985-1990 (4%). CONCLUSION: To identify "risk buildings", it is necessary to adjust for ownership and population characteristics.

Acute health effects on planters of conifer seedlings treated with insecticides.

OBJECTIVES: The aim of this study was to assess acute health effects on planters caused by planting conifer seedlings treated with two insecticides, with active ingredients imidacloprid and cypermethrin, in comparison with untreated seedlings. METHODS: The investigation was a double-blind crossover study, which included a follow-up of 19 planters over a 3-week period. During Week 1, the 19 planters handled untreated conifer seedlings while they planted imidacloprid- and cypermethrin-treated seedlings during study Week 2 and 3, respectively. Signs and symptoms of acute health effects were documented by a questionnaire, administered by the field staff, during these 3 weeks. Inflammation markers in the nasal mucous membrane were also measured as an objective test. Exposure to cypermethrin was further assessed by measuring 3-phenoxybenzoic acid (3-PBA) in urine. No validated biomarker was available to assess internal exposure to imidacloprid. RESULTS: No clear, acute adverse health effects could be found in planters during the week of exposure to conifer seedlings treated with imidacloprid (Merit Forest) or cypermethrin (Forester), as compared to during the week of planting untreated seedlings. During the week of cypermethrin exposure, the individuals had 3-PBA values that were 12-54% higher (P < 0.05), depending on the worker, than those observed during the untreated week. There were no statistically significant correlations between the raised levels of 3-PBA and self-reported health problems. These results have been obtained during planting in late summer/early autumn and with good use of protective clothing. CONCLUSIONS: No clear, acute adverse health effects could be found in planters after exposure to conifer seedlings treated with imidacloprid (Merit Forest) or cypermethrin (Forester), as compared with planting untreated seedlings. The metabolite, 3-PBA, was found in low levels in urine and was increased after exposure to cypermethrin. However, no clear relationships could be found between exposure and reported symptoms or between elevated 3-PBA levels and reported symptoms.

Ocular, airway, and dermal symptoms related to building dampness and odors in dwellings.

The authors examined the relationship between symptoms of Sick Building Syndrome and reports of building dampness and odors. Two hundred thirty-one multifamily buildings built prior to 1961 in Stockholm, Sweden, contained a total of 4,815 dwellings. The authors selected these buildings for study by stratified random sampling. Occupants answered a postal questionnaire that assessed weekly symptoms, personal factors, population density in each apartment, water leakage in the preceding 5 yr, different types of odors, and signs of high indoor air humidity. The response rate was 77%. Independent information on building characteristics was gathered from the building owners and the central building register in Stockholm. Multiple logistic-regression analysis was applied and odds ratios were calculated, with adjustments for age, gender, current smoking, hay fever, population density, type of ventilation, and ownership of the building. In total, 22% reported at least 1 sign of dampness, and 32% reported odor in the dwelling. Condensation on windows, high air humidity in the bathroom, moldy odor, and water leakage were reported from 6.8%, 8.8%, 5.7%, and 13% of the dwellings, respectively. A combination of odor and signs of high humidity was related to an increased occurrence of all symptoms (odds ratios = 2.2-3.6). Similar findings were observed for a combination of odors and a history of water leakage in the past 5 yr (odds ratios = 1.2-4.4). Symptoms increased with the number of signs of dampness. The study indicated that dampness in dwellings, with emissions of odorous compounds, are associated with an increase in symptoms consistent with Sick Building Syndrome.

Asthma, allergy and eczema among adults in multifamily houses in Stockholm (3-HE study)--associations with building characteristics, home environment and energy use for heating.

Risk factors for asthma, allergy and eczema were studied in a stratified random sample of adults in Stockholm. In 2005, 472 multifamily buildings (10,506 dwellings) were invited (one subject/dwelling) and 7,554 participated (73%). Associations were analyzed by multiple logistic regression, adjusting for gender, age, smoking, country of birth, income and years in the dwelling. In total, 11% had doctor's diagnosed asthma, 22% doctor's diagnosed allergy, 23% pollen allergy and 23% eczema. Doctor's diagnosed asthma was more common in dwellings with humid air (OR = 1.74) and mould odour (OR = 1.79). Doctor's diagnosed allergy was more common in buildings with supply exhaust air ventilation as compared to exhaust air only (OR = 1.45) and was associated with redecoration (OR = 1.48) and mould odour (OR = 2.35). Pollen allergy was less common in buildings using more energy for heating (OR = 0.75) and was associated with humid air (OR = 1.76) and mould odour (OR = 2.36). Eczema was more common in larger buildings (OR 1.07) and less common in buildings using more energy for heating (OR = 0.85) and was associated with water damage (OR = 1.47), humid air (OR = 1.73) and mould odour (OR = 2.01). Doctor's diagnosed allergy was less common in buildings with management accessibility both in the neighbourhood and in larger administrative divisions, as compared to management in the neighbourhood only (OR = 0.49; 95% CI 0.29-0.82). Pollen allergy was less common if the building maintenance was outsourced (OR = 0.67; 95% CI 0.51-0.88). Eczema was more common when management accessibility was only at the division level (OR = 1.49; 95% CI 1.06-2.11). In conclusions, asthma, allergy or eczema were more common in buildings using less energy for heating, in larger buildings and in dwellings with redecorations, mould odour, dampness and humid air. There is a need to reduce indoor chemical emissions and to control dampness. Energy saving may have consequences for allergy and eczema. More epidemiological studies are needed on building management organization.

Rhinitis, asthma and respiratory infections among adults in relation to the home environment in multi-family buildings in Sweden.

Risk factors for rhinitis, asthma and respiratory infections in the home environment were studied by a questionnaire survey. Totally 5775 occupants (≥ 18 years old) from a stratified random sample of multi-family buildings in Sweden participated (46%). 51.0% had rhinitis in the last 3 months (current rhinitis); 11.5% doctor diagnosed asthma; 46.4% respiratory infections in the last 3 months and 11.9% antibiotic medication for respiratory infections in the last 12 months. Associations between home environment and health were analyzed by multiple logistic regression, controlling for gender, age and smoking and mutual adjustment. Buildings constructed during 1960-1975 were risk factors for day time breathlessness (OR = 1.53, 95%CI 1.03-2.29). And those constructed during 1976-1985 had more current rhinitis (OR = 1.43, 95%CI 1.12-1.84) and respiratory infections (OR = 1.46, 95%CI 1.21-1.78). Cities with higher population density had more current rhinitis (p = 0.008) and respiratory infections (p<0.001). Rented apartments had more current rhinitis (OR = 1.23, 95%CI 1.07-1.40), wheeze (OR = 1.20, 95%CI 1.02-1.41), day time breathlessness (OR = 1.31, 95%CI 1.04-1.66) and respiratory infections (OR = 1.13, 95%CI 1.01-1.26). Living in colder parts of the country was a risk factor for wheeze (p = 0.03) and night time breathlessness (p = 0.002). Building dampness was a risk factor for wheeze (OR = 1.42, 95%CI 1.08-1.86) and day time breathlessness (OR = 1.57, 95%CI 1.09-2.27). Building dampness was a risk factor for health among those below 66 years old. Odor at home was a risk factor for doctor diagnosed asthma (OR = 1.49, 95%CI 1.08-2.06) and current asthma (OR = 1.52, 95%CI 1.03-2.24). Environmental tobacco smoke (ETS) was a risk factor for current asthma (OR = 1.53, 95%CI 1.09-2.16). Window panel condensation was a risk factor for antibiotic medication for respiratory infections (OR = 1.41, 95%CI 1.10-1.82). In conclusion, rhinitis, asthma and respiratory infections were related to a number of factors in the home environment. Certain building years (1961-1985), building dampness, window panel condensation and odor in the dwelling may be risk factors.