18 research outputs found
Common Household Chemicals and the Allergy Risks in Pre-School Age Children
The risk of indoor exposure to volatile organic compounds (VOCs) on allergic airway diseases in children remains unknown.We examined the residential concentrations of VOCs, emitted from building materials, paints, furniture, and other lifestyle practices and the risks of multiple allergic diseases as well as the IgE-sensitization in pre-school age children in Sweden.In a case-control investigation (198 case children with asthma and allergy and 202 healthy controls), air samples were collected in the room where the child slept. The air samples were analyzed for the levels of eight classes of VOCs.A natural-log unit of summed propylene glycol and glycol ethers (PGEs) in bedroom air (equal to interquartile range, or 3.43 - 15.65 Âľg/m(3)) was associated with 1.5-fold greater likelihood of being a case (95% CI, 1.1 - 2.1), 1.5-fold greater likelihood of asthma (95% CI, 1.0 - 2.3), 2.8-fold greater likelihood of rhinitis (95% CI, 1.6 - 4.7), and 1.6-fold greater likelihood of eczema (95% CI, 1.1 - 2.3), accounting for gender, secondhand smoke, allergies in both parents, wet cleaning with chemical agents, construction period of the building, limonene, cat and dog allergens, butyl benzyl phthalate (BBzP), and di(2-ethylhexyl)phthalate (DEHP). When the analysis was restricted to the cases, the same unit concentration was associated with 1.8-fold greater likelihood of IgE-sensitization (95% CI, 1.1 - 2.8) compared to the non-IgE sensitized cases. No similar associations were found for the other classes of VOCs.We propose a novel hypothesis that PGEs in indoor air exacerbate and/or induce the multiple allergic symptoms, asthma, rhinitis and eczema, as well as IgE sensitization respectively
Profiles of Volatile Biomarkers Detect Tuberculosis from Skin
Tuberculosis (TB) is an infectious disease that threatens >10Â million people annually. Despite advances in TB diagnostics, patients continue to receive an insufficient diagnosis as TB symptoms are not specific. Many existing biodiagnostic tests are slow, have low clinical performance, and can be unsuitable for resource-limited settings. According to the World Health Organization (WHO), a rapid, sputum-free, and cost-effective triage test for real-time detection of TB is urgently needed. This article reports on a new diagnostic pathway enabling a noninvasive, fast, and highly accurate way of detecting TB. The approach relies on TB-specific volatile organic compounds (VOCs) that are detected and quantified from the skin headspace. A specifically designed nanomaterial-based sensors array translates these findings into a point-of-care diagnosis by discriminating between active pulmonary TB patients and controls with sensitivity above 90%. This fulfills the WHO's triage test requirements and poses the potential to become a TB triage test
Modeling Ozone Removal to Indoor Materials, Including the Effects of Porosity, Pore Diameter, and Thickness
We develop an ozone
transport and reaction model to determine reaction
probabilities and assess the importance of physical properties such
as porosity, pore diameter, and material thickness on reactive uptake
of ozone to five materials. The one-dimensional model accounts for
molecular diffusion from bulk air to the airâmaterial interface,
reaction at the interface, and diffusive transport and reaction through
material pore volumes. Material-ozone reaction probabilities that
account for internal transport and internal pore area, Îł<sub>ipa</sub>, are determined by a minimization of residuals between
predicted and experimentally derived ozone concentrations. Values
of Îł<sub>ipa</sub> are generally less than effective reaction
probabilities (Îł<sub>eff</sub>) determined previously, likely
because of the inclusion of diffusion into substrates and reaction
with internal surface area (rather than the use of the horizontally
projected external material areas). Estimates of Îł<sub>ipa</sub> average 1 Ă 10<sup>â7</sup>, 2 Ă 10<sup>â7</sup>, 4 Ă 10<sup>â5</sup>, 2 Ă 10<sup>â5</sup>, and 4 Ă 10<sup>â7</sup> for two types of cellulose
paper, pervious pavement, Portland cement concrete, and an activated
carbon cloth, respectively. The transport and reaction model developed
here accounts for observed differences in ozone removal to varying
thicknesses of the cellulose paper, and estimates a near constant
Îł<sub>ipa</sub> as material thickness increases from 0.02 to
0.16 cm
Equal abundance of summertime natural and wintertime anthropogenic Arctic organic aerosols
Aerosols play an important yet uncertain role in modulating the radiation balance of the sensitive Arctic atmosphere. Organic aerosol is one of the most abundant, yet least understood, fractions of the Arctic aerosol mass. Here we use data from eight observatories that represent the entire Arctic to reveal the annual cycles in anthropogenic and biogenic sources of organic aerosol. We show that during winter, the organic aerosol in the Arctic is dominated by anthropogenic emissions, mainly from Eurasia, which consist of both direct combustion emissions and long-range transported, aged pollution. In summer, the decreasing anthropogenic pollution is replaced by natural emissions. These include marine secondary, biogenic secondary and primary biological emissions, which have the potential to be important to Arctic climate by modifying the cloud condensation nuclei properties and acting as ice-nucleating particles. Their source strength or atmospheric processing is sensitive to nutrient availability, solar radiation, temperature and snow cover. Our results provide a comprehensive understanding of the current pan-Arctic organic aerosol, which can be used to support modelling efforts that aim to quantify the climate impacts of emissions in this sensitive region