RESUMEN
Polychlorinated biphenyl (PCB) contamination of buildings continues to pose an exposure threat, even decades after their application in the form of calks and other building materials. In this research, we investigate the ability of clothing to sorb PCBs from contaminated air and thereby influence exposure. The equilibrium concentration of PCB-28 and PCB-52 was quantified for nine used clothing fabrics exposed for 56 days to air in a Danish apartment contaminated with PCBs. Fabric materials included pure materials such as cotton and polyester, or blends of polyester, cotton, viscose/rayon, and/or elastane. Air concentrations were fairly stable over the experimental period, with PCB-28 ranging from 350 to 430 ng/m3 and PCB-52 ranging from 460 to 550 ng/m3 . Mass accumulated in fabric ranged from below detection limits to 4.5 mg/g of fabric. Cotton or materials containing elastane sorbed more than polyester materials on a mass basis. Mass-normalized partition coefficients above detection limits ranged from 105.7 to 107.0 L/kg. Clothing acts as a reservoir for PCBs that extends dermal exposure, even when outside or in uncontaminated buildings.
Asunto(s)
Vestuario , Bifenilos Policlorados/química , Adsorción , Aire/análisis , Contaminación del Aire Interior , Humedad , Bifenilos Policlorados/análisis , Temperatura , Textiles/análisisRESUMEN
Several studies have reported poor indoor air quality (IAQ) in day care centers (DCCs), and other studies have shown that children attending them have an increased risk of respiratory and gastrointestinal infections. The aim of this study was to investigate whether there is an association between ventilation in DCCs and sick leave among nursery children. Data on child sick leave within an 11-week period were obtained for 635 children attending 20 DCCs. Ventilation measurements included three proxies of ventilation: air exchange rate (ACR) measured with the decay method, ACR measured by the perfluorocarbon tracer gas (PFT) method, and CO2 concentration measured over a 1-week period. All but two DCCs had balanced mechanical ventilation system, which could explain the low CO2 levels measured. The mean concentration of CO2 was 643 ppm, exceeding 1000 ppm in only one DCC. A statistically significant inverse relationship between the number of sick days and ACR measured with the decay method was found for crude and adjusted analysis, with a 12% decrease in number of sick days per hour increase in ACR measured with the decay method. This study suggests a relationship between sick leave among nursery children and ventilation in DCCs, as measured with the decay method.
Asunto(s)
Contaminación del Aire Interior/estadística & datos numéricos , Guarderías Infantiles/estadística & datos numéricos , Exposición a Riesgos Ambientales/estadística & datos numéricos , Estado de Salud , Ventilación/estadística & datos numéricos , Preescolar , Femenino , Humanos , Masculino , Ausencia por Enfermedad/estadística & datos numéricosRESUMEN
UNLABELLED: The Dampness in Buildings and Health study (DBH) started in the year 2000 in Värmland, Sweden, with a baseline questionnaire sent to all children (n = 14,077) aged 1-6. Five years later, a follow-up questionnaire was sent to the children who were 1-3 years at baseline. A total of 4779 children participated in both the baseline and the follow-up studies and constitute the study population in this cohort study. The aim of this study was to examine the association between exposure to PVC-flooring in the child's and parent's bedroom in homes of children aged 1-3 and the incidence of asthma, rhinitis, and eczema during the following 5-year period. Adjusted analyses showed that the incidence of asthma among children was associated with PVC-flooring in the child's bedroom (AOR 1.52; 95% CI 0.99-2.35) and in the parent's bedroom (1.46; 0.96-2.23). The found risks were on borderline of significance and should therefore be interpreted with caution. There was further a positive relationship between the number of rooms with PVC-flooring and the cumulative incidence of asthma. PVC-flooring was found to be a stronger risk factor for incident asthma in multifamily homes when compared with single-family houses and in smoking families compared with non-smoking families and in women. PRACTICAL IMPLICATIONS: These longitudinal data from the DBH study found an association between the presence of PVC-flooring in the home and incident asthma in children. However, earlier results from the DBH study have shown that PVC-flooring is one important source for phthalates in indoor dust, and exposure to such phthalates was found to be associated with asthma and allergy among children. This emphasizes the need for prospective studies that focus on the importance of prenatal and neonatal exposure to phthalates in the development of asthma and allergy in children.
Asunto(s)
Asma/epidemiología , Eccema/epidemiología , Pisos y Cubiertas de Piso , Ácidos Ftálicos/toxicidad , Rinitis Alérgica Perenne/epidemiología , Asma/etiología , Preescolar , Estudios de Cohortes , Eccema/etiología , Femenino , Humanos , Incidencia , Lactante , Masculino , Cloruro de Polivinilo , Rinitis Alérgica Perenne/etiología , Suecia/epidemiologíaRESUMEN
UNLABELLED: The concentration of nitric oxide (NO) in exhaled and aspirated nasal air was used to objectively assess human response to indoor air pollutants in a climate chamber exposure experiment. The concentration of NO was measured before exposure, after 2, and 4.5 h of exposure, using a chemiluminescence NO analyzer. Sixteen healthy female subjects were exposed to two indoor air pollutants and to a clean reference condition for 4.5 h. Subjective assessments of the environment were obtained by questionnaires. After exposure (4.5 h) to the two polluted conditions a small increase in NO concentration in exhaled air was observed. After exposure to the reference condition the mean NO concentration was significantly reduced compared to pre-exposure. Together these changes resulted in significant differences in exhaled NO between exposure to reference and polluted conditions. NO in nasal air was not affected by the exposures. The results may indicate an association between polluted indoor air and subclinical inflammation. PRACTICAL IMPLICATIONS: Measurement of nitric oxide in exhaled air is a possible objective marker of subclinical inflammation in healthy adults.
Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Óxido Nítrico/análisis , Contaminantes Atmosféricos/metabolismo , Pruebas Respiratorias , Espiración/fisiología , Humanos , Óxido Nítrico/metabolismoRESUMEN
We examined the amount of fat that can be forced into the circulation by compression of femora and of heads of the tibia in the very moment of injury. By fractures of diaphyses no considerable reduction of the intraosseous space was achieved and no fat was expelled through the foramina nutritia before the hard cortical bone was splintered. However, considerable amounts of fat were expelled into veins, when the epiphyses of the femora or when the head of the tibia was compressed from medially and from laterally. Even by a purely manual compression some fat was forced to leave the spongiosa by the foramina nutritia. This is explained by the higher elasticity of the spongious bone, permitting a marked space reduction by compression even before a fracture sets in. The mechanism resembles the procedure of opacification of veins by contrast media, injected into the bone cavity under pressure. The significance of these findings for the pathogenesis of clinical fat embolism is discussed.