A Study Of The Formal Dehyde Pollution And The Control Method In The Indoor Air Of Northest Normal Univercity

There are many kinds of indoor air pollutions, including the TVOC (suchasformaldehyde, ammonia, benzene) and carbon monoxide, sulphur dioxide, radon,bacteriaetc. Formaldehyde is one of the familiar air pollutions in the newly decorated rooms.Somewood-ply veneers, sawdust-boards, medium-density fiberboards and flake-boards for interiorfittings contain formaldehyde. Even to keep in touch of low dosage of formaldehyde can leadto development of chronic respiratory diseases, and higher concentration will harm nervesystem and liver. The acute melancholia can be caused by long-time living such anenvironment with higher concentration. Institute of International Cancer Research (ICRI) hastreated it as cancer-causing substance. There indicates a year-to-year rapid increase offormaldehyde emission from construction materials, particularly nowadays with a hottendency of interior decoration, the indoor formaldehyde pollution has been drawn greatattention of people concerned.We carried out a serial of experiments for 30 newly-fit houses in Northest NormalUnivercity during a period from 2005 August to2006 February in terms of indoorformaldehyde concentration by means ofinvestigation, sampling, analysis and monitoring,track check especially madefor tensely polluted houses and research and analysis have beendone basedon the results.Newly-decorated houses face serious phenomenon of formaldehyde concentration inNorthest Normal Univercity above the values as specified in standards, 19 out of 30datagroups actually measured exceed the national standards, approximately 63%.The highestgroup comes around 6 times the standard value, average equals to 1.8 times.Through a track monitoring test objects we have found that natural ventilation can realizean express reduction of formaldehyde concentration index, and ventilation improvement canassist dilution, emission and exhaust of formaldehyde from indoors, it is a fact that higher airflow can bring about perfect effects and that proves it is a mostly efficient method of reducingconcentration.We made continuous monitoring work to the Serious Pollution of three rooms in order tostudy the relationship between the whole concentration-reducing course and time only byusing natural ventilation. We have found that during October to November months, the timeof a year in north-eastern areas is in the fall, haven't come yet warm air ,Therefore the indoortemperature ratio is lower, The indoor formal dehyde density lowers more and quickly at thistime. The method of ventilation rise good lower the result of the indoor formaldehyde density.After December, the Temperature of indoor The temperature starts rise because of thewarm air. From an intuitional point of view ventilation can partly decreases concentration butformaldehyde pollution sees a continual emission course,high temperature can aggravateformaldehyde pollution,partially counteracting concentration reduction by ventilation. Itshows that the method of ventilation has its own limitation.In the last monitoring, the indoor formaldehyde density has a clearly reduction, andshorter time with windows and doors open,,the emission and spread of formaldehyde reach arelative state of balance because of low rate of ventilation application, and shorter time withwindows and doors open, with slow emission of formaldehyde.The most important measures to be taken is to avoid introduction of pollution sources offormaldehyde by using as much environment-friendly high-quality materials having no or lowformaldehyde contents as possible for interior decoration, in conformity with related nationalstandards. All governments at all levels should make every effort to timely eliminate andprohibit use of out-of-date construction materials and workmanship.A large-scale development of so-called green construction materials is necessary, thematerials should be made with no poison and pollution and no-harm to human health from agreat large amount of solid-state wastes from industries and residents by meads of cleanproduction techniques with little natural sources. The materials should be of health,environment-friendly and safety type.Such treatment methods for formaldehyde pollution are widely used as chemical reaction,physical adsorption, air negative ion, optical catalysis, and botanical purification etc toefficiently reduce and eliminate the indoor formaldehyde pollution caused by formaldehydeexistence to a certain extent. But the above means and methods are not universal as expectedto be, additional ways should be applied for reduction of formaldehyde concentration. So werecommend that more emphases be made on the treatment of indoor pollution as per a generalprinciple to be followed: "Prevention first, Both prevention and treatment".Scientific and rational interior decoration includes accurate calculation of how muchamount of artificial materials will be used, and reasonable decoration design as well asnon-harm treatment of construction materials,and proper time at which to live in, with allthese measures the indoor formaldehyde pollution can be prevented or minimized from a rootpoint.