The quality of the air we breathe; part 2.


Emily Sullivan, Air Quality Consultant

Moving beyond compliance.

Public awareness and attitudes to air pollution, be it indoor or outdoor pollution, are changing. It is increasingly recognised that there are no safe levels of exposure to air pollution – with the harm to health not stopping once you reach the limit values. Indeed, studies have found health benefits associated with relatively modest reductions in air pollution. For example, recent research completed by Asthma UK and the British Lung foundation reported a reduction in symptoms for one in six people during the first period of the Covid-19 lockdown.

In September 2021 the World Health Organisation (WHO) tightened its air quality guidelines in response to increased scientific evidence on health impacts at relatively low pollutant concentrations. The new guidelines represent up to a 75% reduction in concentrations when compared to the previously published guidelines in 2005.

The WHO guideline for particulate matter PM2.5 was incorporated into the London Plan 2021, with the Mayor of London stating his commitment to making air quality in the capital “the best of any major world city”, and there is now a growing call for the UK government to adopt the tougher 2021 WHO guidelines for all pollutants across in the UK.

Additionally, the benefits of moving to beyond compliance through voluntary accreditation schemes, such as the WELL Standards, is growing in recognition. Building owners and occupiers recognise that environments with high standards of indoor air quality can command higher rental incomes as well as boosting health, wellbeing and productivity for occupants.

There are, therefore, clear health benefits to improving air quality in general and striving for ‘beyond compliance’ levels of air pollution.

Air quality monitoring.

Air pollution in indoor environments consists of a mix of sources from those released within the building itself – such as emissions from paints/varnishes, soft furnishings and activities such as cooking and cleaning – and pollution sources released outdoors that make their way indoors – such as emissions from road traffic vehicles, industrial activities or farming.

As a result, a balance is often needed in order to provide adequate ventilation and dilution of any indoor emission sources but also to restrict emissions of outdoor pollutant sources from entering the building.

It is often difficult to perceive when air pollution levels are high or starting to increase because many pollutants are odourless and invisible. The use of indoor air pollution monitoring, through relatively low-cost sensors, is a useful tool to provide an alert if concentrations start to build up and allow the occupant or building manager to take action to adjust ventilation levels or prevent further pollutant emissions entering the building.

The cost of air quality sensors is reducing as more products come onto the market and it seems likely that the use of this type of technology will become more commonplace and an important area of development in the field of air quality, moving forward.

Indoor air quality – the inside story.

The health effects associated with air pollution are the same irrespective of where pollution is inhaled. There is well-established guidance and legislation for external air pollution but, at present, indoor environments are not subject to the same legally binding air quality objectives.

The situation is complicated by the many different types of indoor environments that any given individual may find themselves in, such as their home, place of work, a train station, bus, taxi, pub, restaurant, shop etc. As such, there is an inconsistency between the way air quality is assessed outdoors versus indoors and this is likely to be an important area of focus for the air quality industry as a whole, going forward.

The Institute of Air Quality Management (IAQM) has recently released a comprehensive guidance document to assist professionals in the assessment of indoor air quality. The guidance establishes a methodology for indoor assessment with a focus on the health of building occupants. It also aims to ensure all indoor environments are assessed in a consistent manner.

This guidance, and documents like it, are an important first step in improving indoor air quality and, looking to the future, the topic of indoor air quality should be an area of growth for the industry as a whole.

Re-evaluating an ever-changing issue.

The predictions and measurements made by professionals can be viewed as a ‘snapshot’ of air quality at the development site for a given moment in time, most usually the opening year. In reality, air quality is a dynamic and ever-changing issue that can be influenced by a range of factors – from occupants’ behaviours through to citywide, or even national, initiatives.

So, predictions or measurements made at the planning stage will not always necessarily be representative of the air quality situation as time passes. Regularly re-assessing external and indoor environments will ensure that any air quality mitigation measures recommended for a scheme, such as filtration, remain relevant and fit for purpose should improvements in air quality be realised in future years.

Multi-disciplinary design collaboration.

Although some of the concepts outlined will ultimately be driven by policy change at a national level, there are improvements in air quality that could be achieved by ensuring a collaborative, multidisciplinary approach in the design and operation of buildings on a project-by-project basis.

It is important that air quality is considered fully in a building’s design, both through understanding, monitoring and identifying sources of pollution, as well as maintaining regular upkeep of building services.

The involvement of air quality practitioners early in the design process is key – this will help to ensure that exposure to air pollutants from both indoor and outdoor sources are fully considered, and essentially minimised, in order to achieve the overall goal of improving air quality for everyone.