Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants.
Scientists in china have developed a passive air sampler that can be used for monitoring common indoor air pollutants. Air quality is currently an important topic in China, with air pollution rivaling food safety and clean drinking water as a key theme for Chinese lawmakers. The quality of indoor air can be just as compromised as the outside. Nowadays, people spend a large amount of their time indoors so it is important to be able to accurately measure indoor air quality. Read the full article about this newly developed air testing device here: “Measuring indoor air pollution” Chemistry World.
Passive sampling techniques are preferred over active ones, as they are low-cost, do not require a power supply and can be left for long-term, large-scale sampling. Zhang used hydrophobic silica zeolites as adsorbents in the samplers as they have a large capacity for adsorbing BTX and are compatible with thermal desorption, the method used to transfer the samples from the sampler to the gas chromatography-mass spectrometry machine.
The Tsinghua Passive Diffusive Sampler (THPDS), made by Yinping Zhang and colleagues at Tsinghua University, China, is a low-cost, passive air sampler that can be used to monitor levels of the volatile organic compounds (VOC), benzene, toluene and xylene (BTX). ‘Rapid urbanisation in China has resulted in serious indoor BTX pollution in the past few decades. However, there is little quantitative information on indoor BTX exposure and corresponding health risks in China, primarily because there has been a lack of cheap and accurate passive samplers,’ says Zhang.
Passive sampling techniques are preferred over active ones, as they are low-cost, do not require a power supply and can be left for long-term, large-scale sampling. Zhang used hydrophobic silica zeolites as adsorbents in the samplers as they have a large capacity for adsorbing BTX and are compatible with thermal desorption, the method used to transfer the samples from the sampler to the gas chromatography-mass spectrometry machine.
There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.
Determination of IAQ involves the collection of air samples, monitoring human exposure to pollutants, collection of samples on building surfaces and computer modelling of air flow inside buildings.
Lowering indoor pollutants with Plants
Houseplants together with the medium in which they are grown can reduce components of indoor air pollution, particularly volatile organic compounds (VOC) such as benzene, toluene, and xylene. Plants can also remove CO2, which is correlated with lower work performance, from indoor areas. The effect was investigated in one study by NASA for use in space colonies. Plants also appear to reduce airborne microbes, molds, and increase humidity. However, the increased humidity can itself lead to increased levels of mold and even VOCs.