The World Health Organisation (WHO) estimates there are 360,000 premature deaths in the EU as a result of worsening air pollution. In central London the concentration of diesel and nitrogen dioxide (NO2) is about three times the level recommended by the WHO and the Harvard Six Cities survey indicated that central London suffers a 20% increase in mortality rates mainly as a result of traffic particle air pollution.
This kind of contamination increases the severity of asthma attacks, instances of heart failure and certain cancers. It reduces lung capacity so upsets the balance of nutrients and oxygen in the blood. A report commissioned by Mayor Boris Johnson revealed that nearly 9,500 Londoners die prematurely each year from air pollution – the total for the UK is estimated at 60,000.
As a result, central and local government officials are considering imposing new limits on transport because traffic is responsible for 42% of carbon monoxide, 46% of nitrogen oxides and 26% of particulate matter pollution. However, this kind of measure will take years to have any real impact and, in the meantime, we are building up a damaging health legacy for future generations. So is there anything we can do that is quicker, more practical and less expensive?
A ‘Smogmobile’ was used to measure alarmingly high levels of nitrogen dioxide (NO2). It detected that levels of NO2 were actually higher inside the car than outside – leading experts to suggest cycling and walking is safer than sitting inside a vehicle in a heavily polluted street.
So, while most of the focus seems to be on problems with OUTSIDE air – there needs to be an urgent shift to INSIDE air quality (IAQ) – and not just for cars. Our job as building engineering services companies is to turn our buildings into safe havens. If the government has lost control of outdoor pollution; could we protect building occupants from the worst effects? After all, people spend 90% of their time indoors.
The Healthvent EU research project reported that almost two thirds of the burden of disease traced back to poor indoor air quality (IAQ) was from pollutants coming into the building. If you live on a busy arterial road in London you are continually exposed to two or three times more harmful inhalable particulates than the WHO warning level. So, even inside a building, you are under siege.
Currently, most service and maintenance programmes do not cover IAQ. They may include some provision for ventilation hygiene and that might even extend to checking and replacing air filters, but very few people are specifically measuring IAQ. Schools are starting to do more because a direct causal link between poor learning and high concentrations of CO2 has been made. There may be CO alarms in some buildings, but who measures VOCs or NOx or the wide range of particulate matter you can find inside most city buildings?
Most professional FMs will make an annual inspection of the air handling units and a visual check of ductwork cleanliness – it could be relatively easy to extend that to taking samples to measure microbiological cleanliness. However, the issue, as with most service and maintenance arguments, is cost and what the building owner needs to do to meet minimum statutory requirements. Asking them to extend that to something they have never had to do before and have never been instructed to do is asking a lot.
So, we have to take small steps and set minimum parameters that keep the process cost-effective. That means looking at relative humidity (RH); ventilation rates; possible mould build up; temperature; CO2; VOCs; supply side particulates; NO2 and NOx. The Indoor Air Quality group led by the Building Engineering Services Association (BESA) – of which Ruskin is a member – is wrestling with this issue.
We know there is a huge problem in buildings, but how do we prove it to the extent that would force owners and FMs to tackle it? The answer is to keep our targets relatively low; be pragmatic and focus on what building owners could be doing most cost-effectively.
We should use a building classification system so that impossibly high IA standards are not imposed on buildings that don’t need them. The High; Medium; and Low categories contained in the BS EN 15780 standard makes sense and is based on a building’s purpose. Low risk buildings, like storage facilities, would only need two-yearly checking; but there are also statutory requirements on some equipment like filters and fire dampers.
Hospitals are at the other end of the scale and have their own guidelines, which are, of course, more prescriptive. CIBSE also has valuable guidance within its TM26 document on prescribed levels of airborne and surface sampling. This looks at typical situations where occupants may be reporting high instances of colds and respiratory issues; and it signposts visual indicators like mould and condensation. The BESA’s own ‘Guide to Good Practice – Internal Cleanliness of Ventilation Systems’ (TR/19) is an excellent source of advice for building managers on tackling the threat posed by poorly maintained ventilation systems.
Many of the measures needed are very low cost, such as cleaning intake grilles; and building owners will also get a financial payback because the systems will immediately start to operate more effectively. This problem is not unsurmountable and building owners should be responsive now air pollution is hitting the national headlines – so long as we keep the costs realistic.
Air tight building envelopes can be a good way of keeping out external pollutants, but they can lead to occupants opening windows because of elevated temperatures and perceived stuffiness, but this is not such a good idea unless you know the level of pollutants you are letting in. Ensuring the ventilation system works well is a better solution. Effective mechanical ventilation will help protect building occupants from rising outdoor pollution. The key is getting the message across that servicing and maintaining these systems is not an expensive process, but it must be done and, if you can turn your building into a safe haven from pollution, you will add considerably to its value – in both commercial and health terms.
Excerpt from the latest Ruskin Journal - download a copy.