Indoor pollution: effects and solutions

Pollution in closed environments – or indoor pollution – is a hot topic.

When we speak of pollution, we almost always refer to the alteration of the biological properties of an outdoor environment. Actually, this latter type is referred to as “environmental or outdoor pollution”, as there is a second form of contamination that involves the air in indoor environments where human activities take place, and which we will analyse in this section. This category excludes industrial sites, the pollution of which depends on the type of work carried out within them and which is subject to specific laws and regulations on occupational/professional risks.

In the case of public or private buildings, therefore, we refer to indoor or closed-environment pollution, which is often underestimated regardless of the fact that it is no less harmful than outdoor or industrial pollution. Only the hospital sector seems to respond adequately to this problem, mainly because it is subject to more inspections to safeguard patients and staff. Therefore, in order to improve the quality of life of these indoor environments and tackle the problem of indoor pollution, we need to take these issues seriously, knowing that people spend roughly 90% of their time in indoor environments. How? The mechanical ventilation system with heat recovery (MVHR) allows for renewing the air and eliminating the problems and effects caused by indoor pollution.

Indoor pollution

The technical regulations and guidelines defined over the years emphasise how to raise environmental quality standards by implementing procedures and building and system technologies that allow for tangibly reducing indoor pollution. The Italian Ministry of the Environment defines indoor pollution as “the presence in the air of physical, chemical and biological contaminants not present naturally in the outdoor air of high-quality ecological systems”: this definition refers to the concentration of pollutants deriving from the outside environment, odours (due to cooking, perfumes, detergents), heating-cooling plants, construction materials, allergens, furniture and furnishings, poor ventilation and poor air renewal.

The sum of these factors means that man, who breathes 22,000 times a days, inhales unhealthy air (the air we breathe contains more than 900 chemical compounds, with a greater concentration compared to outdoor environments). This is why the quality of indoor air must be monitored for our health: the risk of indoor pollution is determined by assessing the concentration of polluting agents in relation to the time they remain in the environment, with multiple effects, as shown by sector studies.

Indoor pollution and lung diseases

Particulate, namely particles dispersed in the environment, is often caused by tobacco smoke concentrations (50%–90%). The acronym “PM10” (10 micrometres) often heard in the news corresponds to the classification of particulate based on its size: the pollution levels are measured by calculating the weight/volume of the emission to obtain the number of microgrammes of polluting substance per cubic metre (?g/m3). Dyspnea (shortness of breath), wheezing and asthma are only three minor health effects caused by particulates, as well as by the impact of nitrogen dioxide – two serious sources of pollution in indoor environments.

Another risk factor includes biomass fuels (fire and stoves) which produce high levels of particulates and carbon monoxide (CO) and are currently responsible for the highest number of deaths attributable to atmospheric pollution. The risks of contracting lung diseases such as chronic obstructive pulmonary disease (COPD), lung infections, lung cancer, asthma and tuberculosis (TBC) are particularly high, whenever biomass fuels are used in indoor environments. Volatile organic compounds, such as radon, are also very harmful and may cause reduced lung function. Clearly the impact of indoor pollution on our health cannot be neglected in any way.

Allergens, moulds and bacteria

Gli allergeni sono sostanze che possono provocare manifestazioni allergiche: si trovano nei tappeti, nelle piante, nella polvere e negli animali domestici, e l’esposizione può causare malattie come asma o allergie a causa dell’interazione con il sistema immunitario. Anche l’umidità e le muffe che si sviluppano sui mobili e sulle pareti sono altrettanto dannose, in quanto aumentano il rischio di infezioni polmonari, asma, bronchiti e dispnea.

All these harmful elements are so widespread in homes that roughly 50% of the world population is exposed daily to multiple risk factors related to indoor pollution.

Mechanical ventilation with heat recovery against indoor pollution

There is a solution for reducing indoor pollution and decreasing the possibility of developing diseases linked to the air quality in indoor environments: ventilation systems, which combine tangible benefits with a reduction of the symptoms and critical factors.

Mechanical ventilation systems with heat recovery (MVHR) allow for changing stale air with fresh air and recovering the heat (which is lost by aerating the room). Often the air in rooms cannot be changed regularly. In such case, mounting an MVHR system can improve the air quality, lower the level of internal humidity without wasting thermal energy and prevent pollution in indoor environments. The air is simply sucked through nozzles into ducts running inside the walls or on the ceiling, before being purified by filters and reintroduced into the room.

Mechanical ventilation with heat recovery (MVHR), combined with FITT Air ducts with SANITIZED antimicrobial treatment, allows for eliminating indoor pollution, thus considerably improving our health.