Informa Markets

Author Bio ▼

Safety and Health Practitioner (SHP) is first for independent health and safety news.
January 9, 2013

Get the SHP newsletter

Daily health and safety news, job alerts and resources

Services sector – internal work environment – Interior motives

As a consequence of the many sources of pollution in buildings, air quality indoors can often be worse than outdoors, says Simon Birkett, who considers the evidence, the impact of poor air quality on workers and visitors, and what can be done to address the problem.

When the Great Smog hit London in 1952 we knew little about the many health effects of air pollution. Over the last 60 years, however, and particularly during the past decade, our understanding of its impact on human health has improved considerably.

A report by the Government’s Committee on the Medical Effects of Air Pollution estimated that 29,000 deaths in the UK in 2008 could be attributed to long-term exposure to ‘invisible’ airborne particles.1 This compares with 4075 deaths due to short-term exposure to ‘visible’ air pollution in London, in December 1952. Around some of the UK’s busiest streets, levels of nitrogen dioxide (NO2) – the only substance regulated within the gas component of ambient (outside) air pollution – are more than twice the legal limits. Indeed, only eight of 43 zones in the UK met the EU’s 2010 deadline for compliance with limits for NO2, set back in 1999.2 Yet, only smoking causes more premature deaths than air pollution.

Ambient air quality (AAQ) assessment typically focuses on particle-mass concentrations and gases, although there is increasing concern among scientists about the health impact of higher particle-number concentrations and surface area of smaller particles. The most common forms of indoor air pollution include: fine combustion particles from traffic and power stations (PM2.5); volcanic dust; bio-aerosols and pathogens, such as pollen, bacteria, viruses and fungal spores; environmental tobacco smoke (ETS); asbestos; and silica dust. Molecular pollutants, such as gases and vapours, include: carbon monoxide; oxides of nitrogen (NOx) and sulphur; ozone; radon; and volatile organic compounds (VOCs). Consideration should also be given to carbon dioxide (CO2) levels, temperature, relative humidity and ventilation rates.

Effects

A significant proportion of air pollution found indoors originates from outside. IAQ can be further affected by: tobacco smoke from indoor smoking (nowadays, just in homes rather than workplaces, assuming employers comply with the smoking ban); combustion (such as gas cooking or candles); water systems, leaks and condensation; and substances emitted from some building materials, furnishings and cleaning agents. Indoor concentrations of some pollutants can also be much higher than those outdoors.

In addition, European citizens spend, on average, more than 90 per cent of their time indoors. So, in a large city, domestic gas combustion (for example, from cooking and heating) may, in turn, contribute more than 20 per cent to ambient air emissions of NOx.3

In February 2009, the EnVIE project published a major report entitled ‘Coordination action on indoor air quality and health effects’, followed, in 2011, by ‘Promoting actions for indoor air quality’.4,5 These reports identified the most widespread and significant causes of human-health impacts of IAQ and evaluated the existing operational building-related policies aimed at controlling them. EnVIE estimated the UK as having the worst health effects of the EU 27 countries for ‘non-ideal’ IAQ, for both asthma and chronic obstructive pulmonary disease (COPD), and among the worst countries for sick-building syndrome and infectious respiratory diseases.

The same reports estimated the UK as having the worst contribution to exposures for bio-aerosols and among the worst for VOCs and pathogens. They also ranked the UK worst for the following sources of indoor air pollution: water systems, dampness and mould; ventilation and conditioning systems; and building materials.

Actions

The good news is that the productivity benefits from improving indoor air quality (IAQ) can be up to 60 times greater than investments in addressing the issue, and these investments can usually be recovered within two years.6 Research by Pavel Wargocki found that the performance of office workers increased by 1 per cent for every 10-per-cent reduction in the proportion of office workers dissatisfied with indoor air quality (IAQ).7 Meanwhile, a study of short-term sick leave at consumer-electronics company, Polaroid, found a 35-per-cent reduction in sick-leave rates associated with increased ventilation.8 Several other studies have also found a connection between low student performance in classrooms and high concentrations of CO2 in the internal environment.

There is plenty that safety, health and facilities professionals can do to improve the conditions in non-residential buildings to protect workers and visitors. EnVIE recommends: general policies (for example, to build public understanding); building construction (e.g. integrating IAQ into policies on urban development and developing moisture-control guidelines for buildings); ventilation (e.g. regularly inspecting and maintaining all heating, ventilation and air-conditioning systems (HVAC) – including installing EN 13779 compliant filters in HVAC systems, banning all unflued combustion heaters and integrating checks with energy performance inspections); testing and labelling of products; and occupant behaviour, operation and maintenance (e.g. following best-practice manuals for major buildings). Further action is also needed separately to reduce exposure to environmental tobacco smoke, particularly among children.

Campaigners are also putting pressure on the European Commission, as part of its ‘Year of Air’ in 2013, to encourage greater awareness of action that can be taken, as well as the need to design integrated systems that help address the problem of IAQ. This will become increasingly important as buildings become virtually ‘airtight’ to increase energy efficiency.

Current standards

The relevant European Standard (also now a British Standard) for air filtration is BS:EN 13779:2007,9 which specifies different grades of particle and gas filters for non-residential buildings, depending on AAQ and desired IAQ. The standard helps building engineers specify the quality of filtration needed by:

  • describing three ‘input’ levels for outdoor air quality – rural areas (away from sources of air pollution), smaller towns and city centres;
  • setting four categories for the desired ‘output’ level of air quality within the building – low, moderate, medium and high; and
  • recommending the level of filtration required, based on the ‘input’ air and desired quality of ‘output’ air in the building.

It is important to remember a building may have air conditioning, mechanical ventilation and/or air filtration, or any combination of these (or none of them). Nonetheless, generally, buildings located in an unpolluted rural area should only require a single-stage particle filter to maintain medium or high air quality indoors. To achieve high IAQ in cities where ambient air exceeds EU limit values by 50 per cent requires a two-stage particle filter, with a gas filter.

IAQ standards are supported by BS:EN 779:2012,10 which sets out standards of efficiency for air-filtration systems, based on what percentage of particles are removed. Higher-quality, low-energy air filters, such as those made from glass fibre, can achieve and sustain higher particle efficiencies at lower total lifetime cost.

Ultraviolet light may eliminate some pathogens but does little or nothing to eliminate particles, or gases. Some synthetic filter materials may depend on electrostatic charge to comply with standards initially but they lose their charge over time. Thus, they need to be replaced more frequently, along with all the associated maintenance and disposal costs. The efficiency of certain carbon filters also depends on charcoal’s ability to retain gas molecules on its surface, which, in turn, depends on the quality and surface area of charcoal and the type of gas, contact time and gas concentration.

How good is current building management on air quality?

To assess current standards on managing internal air quality, the Clean Air in London (CAL) campaign submitted information requests to central, regional and local government bodies in London, under Environmental Information Regulations (similar to Freedom of Information requests), asking the following: which buildings owned, occupied, or managed by the local authority use regularly maintained air filters that comply fully with European guideline EN 13779 – e.g. offices and schools?

Responses were received from all those contacted; however, it is important to note the limitations of this research. The responses received varied significantly, from complete lists of buildings complying with EN 13779 to short notes stating that all relevant buildings complied. Only a small number of local authorities was able to provide information on schools, with the remainder suggesting CAL approach schools individually for this information. Finally, CAL doesn’t know how many public buildings do not have filtered air, making it tricky to assess how seriously public bodies are taking this issue.

What the survey does show is that building management varies significantly between public bodies. Central bodies were able to provide detailed information on compliance with EN 13779 across their property portfolios, while other bodies were either unwilling or unable to provide this information, presumably owing to a lack of centralised information on their properties.

This situation appears to be particularly acute with regard to schools. Most local authorities told CAL that their school buildings are independently managed – for example, by the schools themselves. While we understand the logic of devolving building management to schools there is uncertainty over whether individual schools are receiving appropriate advice on compliance with EN 13779 and the need for air filtration (especially if they are located in areas of poor air quality).

For local authorities that provided information on schools compliant with EN 13779 it is possible to calculate the proportion of their schools that comply. However, these figures may tell us more about the age of school buildings than whether the local authority is addressing poor indoor air quality, as new school buildings are far more likely to be mechanically ventilated (hopefully with air filtration) than older buildings.

All public buildings in areas of poor air quality should have adequate air filtration, in order to provide a healthy environment for their occupants. But priority should be given to buildings in which occupants are especially vulnerable to the impact of air pollution, such as schools and hospitals. It is evident from our inquiries that most local authorities do not know if their schools have adequate air filtration, and more research is needed to ascertain which schools are located in areas of poor air quality, in addition to giving school management guidance on providing clean, healthy air in their buildings.

Some organisations are already taking action. For example, the City of London Corporation has been working with City businesses to develop a list of simple, effective actions that can be taken by companies to improve air quality, in a programme called CityAir. Its guide for building engineers and facilities managers highlights the need to ensure that air filters in buildings with mechanical ventilation are regularly maintained and comply fully with EN 13779. It also notes the legal requirement to inspect all air-conditioning systems with a rated output of 12 kilowatts, or more at least every five years.11

Summary

Safety, health and facilities professionals should be encouraged to improve indoor air quality where they can, with a particular focus on health and energy savings. Attention should focus initially on buildings with existing mechanical ventilation and others for which standalone, or ducted air filtration may be needed. Through the actions identified above, there is a huge opportunity to provide better protection to safeguard the health of workers and the public, as well as save energy and money along the way.    

References
1     Committee on the Medical Effects of Air Pollution – www.comeap.org.uk
2     DEFRA (2012) – http://uk-air.defra.gov.uk/library/annualreport/
air_pollution_UK_2011_Compliance_Assessment_Summary.pdf
3     http://europa.eu/rapid/press-release_IP-03-1278_en.htm
4     EnVIE (2009): Coordination action on Indoor Air Quality and Health Effects – www.envie-iaq.eu
5     EnVIE (2011): Promoting actions for indoor air quality – ec.europa.eu/health/healthy_environments/docs/env_iaiaq.pdf
6    Wargocki, P (2003): ‘Estimate of an economic benefit from investment in improved indoor air quality in an office building’, in Proceedings of Healthy Buildings 2003 Conference, Singapore, December 2003
7     Wargocki, P (2008): ‘Improving indoor air quality improves the performance of office work and schoolwork, International Network for Information on Ventilation and Energy Performance’ – www.inive.org
8     Milton, DK, Glencross, M and Walters, MD (2000): ‘Risk of Sick Leave Associated with Outdoor Air Supply. Rate, Humidification, and Occupant Complaints’, in Indoor Air (2000), 10: 212-221
9     BS EN 13779:2007 Ventilation for non-residential buildings. Performance requirements for ventilation and room-conditioning systems – http://shop.bsigroup.com
10 BS EN 779:2012 Particulate air filters for general ventilation. Determination of the filtration performance – http://shop.bsigroup.com
11 City of London Corporation, CityAir campaign – www.cityoflondon.gov.uk/business/environmental-health/ environmental-protection/air-quality/cityair/Pages/default.aspx
 
Simon Birkett is founder and director of Clean Air in London (CAL).n

Approaches to managing the risks associated Musculoskeletal disorders

In this episode of the Safety & Health Podcast, we hear from Matt Birtles, Principal Ergonomics Consultant at HSE’s Science and Research Centre, about the different approaches to managing the risks associated with Musculoskeletal disorders.

Matt, an ergonomics and human factors expert, shares his thoughts on why MSDs are important, the various prevalent rates across the UK, what you can do within your own organisation and the Risk Management process surrounding MSD’s.

Related Topics

Subscribe
Notify of
guest

0 Comments
Inline Feedbacks
View all comments