referaty.sk – Všetko čo študent potrebuje
Ľubomíra
Utorok, 9. augusta 2022
Indoor air pollution
Dátum pridania: 21.11.2002 Oznámkuj: 12345
Autor referátu: aradvan
 
Jazyk: Angličtina Počet slov: 2 077
Referát vhodný pre: Stredná odborná škola Počet A4: 7.5
Priemerná známka: 2.98 Rýchle čítanie: 12m 30s
Pomalé čítanie: 18m 45s
 

Reducing indoor burning processes and smoking are important measures to prevent sick building syndrome.

Volatile Organic Compounds
Volatile organic compounds are now a major source of air pollution in Europe. They are as much a part of the air we breathe as oxygen, nitrogen and carbon dioxide. Indoors, a VOC has been defined as any organic substance that can release vapor to the atmosphere with the potential of causing effects at low concentration. The United Nations Economic Commission for Europe, considering the outdoors has said that VOCs are all organic compounds of anthropogenic nature other than methane that are capable of producing photochemical oxidants by reactions with nitrogen oxides in the presence of sunlight. Among the apparently limitless number of organic chemical compounds that exist there, is a large number that is commonly found in the built environment. They are there either because we put them there, for example emissions from vehicles and number of solvents we use, or are present incidentally as a component of something else such as plasticisers and natural products like pinene in wood.
Outdoor air, exactly emissions from vehicle exhausts are the major source of VOCs in urban life in Europe. There has been a qualitative change in environmental VOCs in recent years as vehicle fuels have changed dramatically with the introduction of unleaded petrol.
Sources of VOCs in indoor air are numerous and can be summarized as follows: building materials, solvents and adhesives, environmental tobacco smoke, cooking and outdoor sources.
Since by definition VOCs are present in the air, the only effective route into the body is by inhalation, although a number of compounds are absorbed through the skin. This is a less effective route and the only that is one for all practical purposes insignificant. The health risks associated with exposure to VOCs can be divided into four main categories: acute effects, carcinogenicity, neurobehavioral effects and nephrotoxic effects. Emission of formaldehyde depends on finishing of surfaces, as the used material plays a primary role in formaldehyde emission. We certificate products with emission not exceeding 60 g.m-3. Certified materials were: particleboards, boards based on wood, wall-papers, carpets, textile floor coverings and related products. Concentration of formaldehyde emitted from 10 material samples fluctuates in between 16 - 100 g.m-3 , see figure 2.

Figure 2.
 
späť späť   1  |  2  |   3  |  4  |  5  |  ďalej ďalej
 
Copyright © 1999-2019 News and Media Holding, a.s.
Všetky práva vyhradené. Publikovanie alebo šírenie obsahu je zakázané bez predchádzajúceho súhlasu.