| 1. |
|
|
| 2. |
- Bornehag, Carl-Gustaf, et al.
(author)
-
The association between asthma and allergic symptoms in children and phthalates in house dust : a nested case-control study
- 2004
-
In: Journal of Environmental Health Perspectives. - : National Institute of Environmental Health Sciences (NIEHS). - 0091-6765 .- 1552-9924. ; 112:14, s. 1393-1397
-
Journal article (peer-reviewed)abstract
- Global phthalate ester production has increased from very low levels at the end of World War II to approximately 3.5 million metric tons/year. The aim of the present study was to investigate potential associations between persistent allergic symptoms in children, which have increased markedly in developed countries over the past three decades, and the concentration of phthalates in dust collected from their homes. This investigation is a case-control study nested within a cohort of 10,852 children. From the cohort, we selected 198 cases with persistent allergic symptoms and 202 controls without allergic symptoms. A clinical and a technical team investigated each child and her or his environment. We found higher median concentrations of butyl benzyl phthalate (BBzP) in dust among cases than among controls (0.15 vs. 0.12 mg/g dust). Analyzing the case group by symptoms showed that BBzP was associated with rhinitis (p = 0.001) and eczema (p = 0.001), whereas di(2-ethylhexyl) phthalate (DEHP) was associated with asthma (p = 0.022). Furthermore, dose-response relationships for these associations are supported by trend analyses. This study shows that phthalates, within the range of what is normally found in indoor environments, are associated with allergic symptoms in children. We believe that the different associations of symptoms for the three major phthalates-BBzP, DEHP, and di-n-butyl phthalate-can be explained by a combination of chemical physical properties and toxicologic potential. Given the phthalate exposures of children worldwide, the results from this study of Swedish children have global implications.
|
|
| 3. |
|
|
| 4. |
- Marston, H. F., et al.
(author)
-
Challenges in the modelling of scale formation and decarburisation of high carbon, special and general steels
- 2004
-
In: Ironmaking & steelmaking. - : Informa UK Limited. - 0301-9233 .- 1743-2812. ; 31:1, s. 57-65
-
Journal article (peer-reviewed)abstract
- The oxygen bearing gases of the atmosphere in a reheating furnace oxidise the feedstock producing scale on the surface of the metal and, for high carbon steels, cause decarburisation of the surface layers. Modelling of these effects has to take into account the competitive nature of the two processes, scale formation and decarburisation, and complications that arise from changes in the controlling mechanism. Initially, the rate of scale formation may be controlled by effects in the gas phase, or nucleation of scale on the metal surface. Subsequently, scale growth is influenced by the gas composition and may be disturbed by the accumulation of oxidation products at the scale-metal interface. Voids and cracks within the scale may either inhibit solid state diffusion within the scale or provide channels for oxidising gas to access the scale-metal interface, For decarburisation, complications arise if a ferrite rim creates a step in the carbon profile or if retention of carbon monoxide within the scale provides a thermodynamic barrier to the reaction. This paper considers these complications and how they may be handled in mathematical models.
|
|
