Clearing the Air: Unravelling the Impact of PAHs and VOCs on Our Environment and Health

The European Environmental Agency classified indoor air pollutants into four categories: biological pollutants, combustion products, legacy pollutants, and volatile organic compounds (VOCs). While some indoor air pollutants originate from the outside, the majority are released inside the building. Sources of indoor air pollutants vary, including tobacco smoke, cooking, household heating, and burning of candles. 

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds containing two or more aromatic rings and are found in both indoor and ambient air. In indoor environments, they may emerge from activities such as smoking, burning fuel for cooking, using candles, heating, or operating gas-fired appliances. In ambient air, they can be formed during incomplete combustion, household heating, or vehicular emission. The insufficient ventilation in many households means that indoor pollution often builds up, posing significant health risk.

The international Agency for Research on Cancer, has recognized PAHs as carcinogenic and mutagenic. Benzo[a]pyrene (BaP) is classified in group 1, indicating it is carcinogenic to humans. Dibenzo[a,h]anthracene (DahA) is in group 2A, likely carcinogenic, while compounds such as chrysene (Chry), benzo[a]anthracene (BaA), benzo[j]fluoranthene (BjF), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), and indeno(1,2,3-c,d)pyrene (IP) are categorised in group 2B, possibly carcinogenic. Some PAHs have not yet been classified, such as benzo[ghi]perylene (BghiP), fluoranthene (Flu), and pyrene (Pyr) warranting further research to determine any potential harmful effects. 

Volatile Organic Compound (VOCs), on the other hand, encompass various chemical substances like alcohols, ketones, aldehydes, esters, halogens, and amines, which are released into the atmosphere from both natural and anthropogenic sources. These compounds are often found in household items, as well as decomposing materials, and can come from smoking, furniture, domestic products, cleaning products, and may be released during cooking or renovation activities. 

Some VOCs can react with ozone to produce secondary pollutants which may adversely affect our health. VOCs such as benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) are of particular concern in assessing indoor air quality. For example, the World Health Organisation (WHO)  has classified Benzene as a carcinogenic compound due to its high toxicity.

 The full extent of indoor air pollution, whether in homes or public buildings, remains under-researched. Future studies should examine the potential impact of indoor air pollutants, particularly how they interact with biological macromolecules and their relationship to health outcomes, including cancer. The EDIAQI team members from the Institute for Medical Research and Occupational Health in Zagreb, Croatia, equipped with state-of-the-art facilities, will continue to study the presence, behaviour, and impacts of these pollutants on both the environment and human health. 

Note: This article has been published on behalf of Ivana Jakovljević & Goran Gajski, Institute for Medical Research and Occupational Health (IMROH), Zagreb, Croatia.

References:

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