Indoor Air Pollutants Testing

Indoor air quality is becoming a growing concern since people are spending a greater proportion of their lives indoors. As we benefit from urbanization, the outgassing from indoor synthetic materials cannot be neglected. Indoor air pollution is ubiquitous, and takes many forms, ranging from smoke emitted from solid fuel combustion, especially in households in developing countries, to complex mixtures of volatile and semi-volatile organic compounds present in modern buildings. The role of air pollution in human lung cancer has been difficult to assess or quantitate due to many confounding exposures and factors that may influence cancer. This is especially true for cancers of the respiratory tract where the vast majority of cancers have been related to cigarette smoking. Much of our understanding of the potential risk from air pollution is derived from experimental cancer studies on both individual chemicals and mixtures of air pollutants.

Fig. 1 Indoor air pollutants, sources, and health effects (Wagdi, D et al. 2018)

Indoor Air Pollutants mainly includes:

• Volatile Organic Compounds

Among different types of indoor air pollutants, VOCs have received the great majority of research attention. Even at imperceptible levels (<200 ppb), mixtures of VOCs are thought to cause symptoms of 'sick-building-syndrome' or 'building-related-illness'.

• Radon

Radon is an invisible, radioactive atomic gas that results from the radioactive decay of radium, which may be found in rock formations beneath buildings or in certain building materials. Exposure to Radon causes lung cancer in non-smokers and smokers alike. Overall, radon is the second leading cause of lung cancer. Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked.

• Secondhand smoke

Secondhand smoke (SHS) is also called environmental tobacco smoke (ETS). It is the third leading cause of lung cancer and responsible for an estimated 3,000 lung cancer deaths every year. Smoking affects non-smokers by exposing them to secondhand smoke.

• Molds and other allergens

• Carbon Monoxide

• Other Pollutants

There is a range of other indoor air pollutants that can lead to health problems, notably NOx, SOx, ozone, radon and particulate matter including bioparticles such as mold spores, suspended bacteria and viruses and microbial cell components. Whilst the biotechnological mitigation of pollutants other than CO₂ and VOCs have received little research attention, indoor plants have been shown to have removal capacity for NO₂, ammonia, SO₂, ozone and particulate matter. Whilst industrial processes for the reduction of many other pollutants are well known, the potential for the abatement of these materials indoors is currently undeveloped, and will undoubtedly receive growing attention in the future. The generation of microbial air pollution is often claimed as a major drawback to the use of biological air quality mitigation systems.

Indoor air quality testing projects include formaldehyde, benzene, TVOC, radon, ammonia, toluene, xylene, nitrogen, styrene, respirable particulate matter. Indoor total volatile organic compounds (TVOC) include benzene, toluene, P-xylene, xylene, O-xylene, styrene, ethylbenzene, butyl acetate, undecane and so on.

Fig.2 Principle tasks for indoor air pollution management (Oanh N.T.K et al. 2005)

The pollutants in the air that adversely affect the air quality comprise sulfur, nitrogen, carbon and halogen compounds, radioactive substances, and particles. To maintain air quality of both in indoor and outdoor environments the quantitative information of pollutants is essential.

• The techniques for determination of SO₂ in air samples used previously were spectrophotometry, chemiluminescence, IC, spectrofluorometric, potentiometric, and amperometric methods.

• For quantitative NO₂ determination in air samples, different analytical techniques have been developed such as the use of a spectrophotometer coupled with azo dyes, chemiluminescence, laser-induced fluorescence, optical sensors, electrochemical sensors, and applying different sampling approaches like a passive sampling method, etc.

• The presence of different aromatic hydrocarbons is determined using a differential optical absorption spectrometer (DOAS) and an automatic gas chromatograph (VOC analyzer).

• Inductively coupled air plasma–atomic emission spectrometry (air-plasma ICP-AES) is used to determine the presence of radioactive substances in air samples.

• In some air sample, various metals such as Cd, Co, Cr, Hg, and Pb can be detected using analytical techniques like neutron activation analysis, X-Ray fluorescence, and ICP optical emission spectroscopy.

Alfa Chemistry is professional in air quality analysis and we can provide accurate and reliable tests results within the time constraint. We have conducted ambient air analysis, Benzene/Formaldehyde VOC Monitoring, vapor intrusion analysis and mold, asbestos, radon analysis. Please feel free to contact us if you have any concern or would like us to perform any air quality testing. Check our instruments list to see our capabilities.

References

• Wagdi, D., Tarabieh, K. & Zeid, M.N.A. Air Qual Atmos Health (2018). https://doi.org/10.1007/s11869-018-0551-y.

• Torpy F.R., Irga P.J., Burchett M.D. (2015) Reducing Indoor Air Pollutants Through Biotechnology. In: Pacheco Torgal F.,

• Labrincha J., Diamanti M., Yu CP., Lee H. (eds) Biotechnologies and Biomimetics for Civil Engineering. Springer, Cham.

• Oanh N.T.K., Hung YT. (2005) Indoor Air Pollution Control. In: Wang L.K., Pereira N.C., Hung YT. (eds) Advanced Air and Noise Pollution Control. Handbook of Environmental Engineering, vol 2. Humana Press.