Acute effects of exposure to vapors of 3-methyl-1-butanol in humans.

UNLABELLED: The secondary alcohol 3-methyl-1-butanol (3MB, isoamyl alcohol) is used, for example, as a solvent in a variety of applications and as a fragrance ingredient. It is also one of the microbial volatile organic compounds (MVOCs) found in indoor air. There are little data on acute effects. The aim of the study was to assess the acute effects of 3MB in humans. Thirty healthy volunteers (16 men and 14 women) were exposed in random order to 1 mg/m(3) 3MB or clean air for 2 h at controlled conditions. Ratings with visual analogue scales revealed slightly increased perceptions of eye irritation (P = 0.048, Wilcoxon) and smell (P < 0.0001) compared with control exposure. The other ratings were not significantly affected (irritation in nose and throat, dyspnea, headache, fatigue, dizziness, nausea, and intoxication). No significant exposure-related effects were found in blinking frequency, tear film break-up time, vital staining of the eye, nasal lavage biomarkers, lung function, and nasal swelling. In conclusion, this study suggests that 3MB is not a causative factor for health effects in damp and moldy buildings. PRACTICAL IMPLICATIONS: 3-Methyl-1-butanol (3MB) is one of the most commonly reported MVOCs in damp and moldy buildings and in occupational settings related to agriculture and composting. Our study revealed no irritation effects at 1 mg/m3, a concentration higher than typically found in damp and moldy buildings. Our study thus suggests that 3MB is not a causative factor for health effects in damp and moldy buildings.

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

UNLABELLED: 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.

Acute effects of exposure to 1 mg/m(3) of vaporized 2-ethyl-1-hexanol in humans.

The objective was to assess acute effects from controlled exposure of volunteers to 2-ethyl-1-hexanol, a volatile organic compound that is often found in indoor air. Sixteen males and fourteen females were in random order exposed to 1 mg/m(3) of vapors of 2-ethyl-1-hexanol or to clean air (control exposure) in an exposure chamber during 2 h at rest. The subjects performed symptom ratings on Visual Analog Scales. During exposure to 2-ethyl-1-hexanol subjective ratings of smell and eye discomfort were minimally but significantly increased. Ratings of nasal irritation, throat irritation, headache, dyspnoea, fatigue, dizziness, nausea, and intoxication were not significantly affected. No exposure-related effects on measurement of blinking frequency by electromyography, measurement of the eye break-up time, vital staining of the eye, nasal lavage biomarkers, transfer tests, spirometric and rhinometric measures were seen. No differences in response were seen between sexes or between atopics and non-atopics. Practical Implications It is important to assess acute effects in volatile organic compounds like 2-ethyl-1-hexanol. 2-ethyl-1-hexanol is often found in indoor air generated by degradation of plastic building materials or in new buildings. There are associations between 2-ethyl-1-hexanol in indoor air and respiratory effects, eye irritation, headache, and blurred vision. A controlled chamber exposure study in acute effects was performed. In conclusion, this study showed weak subjective symptom of irritation in the eyes.

Bias in height and weight reported by Swedish adolescents and relations to body dissatisfaction: the COMPASS study.

OBJECTIVE: To assess the size of biases in self-reported height, weight in a large sample of adolescents with special attention to possible effects of body dissatisfaction and to assess how such biases may influence estimates of overweight and obesity. DESIGN: Cross-sectional study. SETTING: Unselected population from Southwestern parts of Stockholm County, Sweden. SUBJECTS: Two-thousand seven hundred and twenty-six boys and girls, 15 years of age. METHODS: Data were collected by a questionnaire answered by adolescents and a physical examination made by trained study nurses. A validated physical appearance scale and body silhouettes were embedded into the questionnaire. RESULTS: Obese boys under-reported their weight (5.2 kg) (95% confidence intervals (CI) 3.7; 6.6) more than obese girls (3.8 kg) (95% CI 1.8; 5.8). Agreement between self-reported and measured body mass index (BMI)-categories (obese, overweight and non-overweight/obese) as estimated by weighted kappa was 0.77 (95% CI 0.72; 0.82) for girls and 0.74 (95% CI 0.70; 0.79) for boys. For obese girls and boys sensitivity of self-reports were 0.65 (95% CI 0.47; 0.79) and 0.52 (95% CI 0.38; 0.66). Boys with low scores on the physical appearance scale under-reported their weight and BMI more than those with high scores. Boys and girls who wished to be leaner under-reported their weight and BMI more than subjects who were satisfied with their body size (P<0.05). CONCLUSION: Thirty-five percent of obese girls and 48% of obese boys would remain undetected from self-reported data. Boys and girls who were dissatisfied with their physical appearance or size under-reported their weight more than satisfied subjects.