Healthy buildings or toxic buildings?

By Kate de Selincourt

The ASBP’s Healthy Buildings Conference and Expo 2018 in February was a fact-packed call to action to the whole construction industry – from component manufacture at one end right through to users and managers at the other – to stop buildings harming people, and fix them to actively promote health instead.

It was horrifying to learn how many gaps in both knowledge and practice there are. What was heartening was the determination of scientists and practitioners to pursue facts and evidence, and to get those facts out there to drive change.

Prof. Stephen Holgate

The day was kicked off by a powerful presentation by Professor Stephen Holgate CBE, Clinical Professor of Immunopharmacology at the University of Southampton and co-author of The Royal College of Physicians ‘Every breath we take‘ report, on the international and national burden of air pollution, both outdoor and in.

Of particular concern to Professor Holgate were airborne particulates (microscopic airborne particles). Globally they impose an equivalent health burden to smoking.

Particulates are often but not always the result of combustion, for example of vehicle fuels, biomass or rubbish. The reason they are so dangerous is because relative to their mass, they have a very large surface area to which all sorts of toxins – allergens, organic compounds, heavy metals and so on – adhere – on top of the many complex and potentially toxic organic compounds which they are made up of in the first place. As the particles are microscopically small, they are suspended in the air we breathe, and carried into our lungs, bringing their toxic burden with them.

As the lungs get the biggest hit, respiratory disease is the most obvious consequence. But lung tissue is designed to absorb as much as possible from the air into the body, so these toxins make their way into our bloodstream and beyond, where, Professor Holgate explained, they are implicated in all kinds of major diseases – diabetes, cancer, dementia.

“The smallest particles are effectively like a gas so come straight in to buildings”, Professor Holgate warned. Particulates are also produced indoors – from cooking, candle burning, fires and stoves. House dust too is “full of toxins” – and we breathe that in as well.

In the ‘Every breath we take’ report, Professor Holgate and his colleagues pulled together the available literature and found that in the UK air pollution causes around 40k deaths per year, with a cost to the nation estimated around £20bn.

The life-shortening effects of air pollution hit older people hardest. For example pollution appears to hasten the onset of dementia: “Someone genetically destined to develop the condition will begin to suffer 6 or 8 years sooner because of it”, Professor Holgate said.

But it is babies and young children who are most vulnerable, especially to becoming sick, and the impact of the damage can be lifelong.

Professor Holgate said he and his colleagues felt their first report could not do justice to indoor air quality issues:  “There is a real paucity of information on what elements of outdoor air get in. At the moment we don’t know what or how much people are exposed to indoors, we lack the recorded data.  We really tried to find out – it’s awful that we couldn’t.”

Such studies as there are almost always only look at one pollutant and one outcome, Professor Holgate explained – “We don’t actually know if the peak exposures have the greatest impact or if the damage is cumulative, or how pollutants interact.”

Outdoor air pollution is regulated in theory at least and regulation means that monitoring takes place and data is available. But indoor air quality is barely regulated at all, especially in the home. Yet indoors is where majority of us spend the most of our time.

Speakers at the event were all concerned about the rapid rise in new chemical entities in our day-to-day environments. Consultant Clinical Psychologist at UCL, Dr Sarah Mackenzie Ross told the meeting that “there are around 100,000 potentially neurotoxic substances in commercial use, with 2300 new ones every year. There is no way for research into their impacts to keep up; all they look for is the lethal dose.”

Human body exposure to toxic chemicals

What we do know, however, is concerning. Professor Holgate pointed out that many chemicals in the home are intended to be long lasting – plastics for example. “These substances are taken up and stored by the body, they accumulate.” Medical science is trying to understand how much we store, but we already know they get into all parts of our bodies, even our bones.

One worry was the poorly understood impact of some persistent organic compounds on fertility. “We might think our home is our castle but perhaps it’s not so safe as you think – unless you want to think of it as a contraceptive,” he said.

Professor Holgate and his colleagues are not resting on their laurels, and in order to tackle the lack of information and guidance on indoor air pollution, the Royal College of Physicians and the Royal College of Paediatrics and Child Health have set up  a working party to investigate. The focus is on children because they are the most vulnerable, and the damage from air pollution can potentially affect them for the rest of their lives.

“We want to  to establish a medical/ building science collaboration,” he said. Some charities have already supported us but it is difficult because there are huge vested interests. Professor Holgate said they needed around another £50,000 to ensure the research could proceed. Click here to find about more about the research project and to make a donation.

One of the aims of this investigation – subtitled ‘Help us improve the air they breathe’, was to make a big impact on the public at a key moment, where change could take place for the better – or for the worse, Professor Holgate said. “With Brexit, regulation will be up for grabs,” he pointed out.

CIBSE’s Head of Sustainability Development Julie Godefroy echoed Professor Holgate’s concern about Brexit, and in particular, the provisions of the EU withdrawal bill. She called on colleagues to make their voices heard – “The precautionary principle is at risk, as is ‘polluter pays’” she said.

The withdrawal bill gave ministers the power to amend or delete EU-derived environmental law without public consultation. “Civil society scrutiny has been much weakened. We need professionals and non-profit organisations to be vocal to ensure we keep those principles in place after Brexit.”

Stephen Holgate defined health as ‘more than the absence of illness’ – it was about living and engaging fully. Yet as Julie Godefroy pointed out, Part F of UK Building Regulations does not say anything about health, or define healthy indoor air.  “The regs are weak“ she said. “They only require ‘adequate’ ventilation rates; the only pollutant levels that are set relate to moisture. And Part F explicitly ignores outdoor pollution.” And as Professor Tim Sharpe, Glasgow School of Art, told the meeting, research by his team at MEARU in Glasgow has shown that even the regulations that we do have, frequently are not met.

Thus many people are living in situations that are far from healthy, as Tim Sharpe described. For example poor provision for ventilation may be exacerbated by people’s wish to avoid noise or outdoor air pollution, or because of concerns about security. In summer this can increase the risk of overheating, which as well as being unhealthy in itself, increases the rate of off-gassing of potentially irritant or toxic substances from materials in the home, as these become more volatile as temperatures rise.

Professor Sharpe’s research has shown that levels of ‘indicator’ pollutants such as CO2 are regularly a lot higher than recommended. But Sharpe and Godefroy agreed that we need to be more specific about which pollutants are of concern, and what levels constitute ‘healthy’ air. While it is easier to detect substances such as CO2 or total VOCs, they are not necessarily directly linked to specific health effects. To bring about improvement, we need “hard metrics”, Godefroy said. This was echoed by Tim Sharpe: “Improving the regulations is not yet a priority and it won’t be if we can’t produce figures. There needs to be an evidence base to force change.”

CIBSE is therefore updating Technical Memorandum TM40 on Health & Wellbeing, to define individual pollutant limits as far as possible and try to cut through the current confusing picture, where standards have been set by differing bodies often with widely differing requirements, and generally carrying no weight of enforcement.

Sarah Mackenzie Ross talked about one set of the chemicals in our environments – the ones that have potential to damage our nerves, and thus our brains. Neurotoxins can affect behaviour, cognition (for example concentration or memory), and emotion. “In buildings we are putting people and potentially toxic chemicals close together,” she said “There are so many new substances all the time – plastics, pesticides, flame retardants and many more – and we don’t know if they are playing a role in increases we have seen in developmental disorders or dementia.”

Organophosporus compounds are particularly concerning to her, as they are known neurotoxins but are commonly found in the home. They are present in pesticides (for example, flea treatments used on pets) and can also be present in flame retardants in foams such as furniture or insulation.

Another common neurotoxin the home is carbon monoxide. Carbon monoxide binds strongly to haemoglobin in the blood, displacing the oxygen that should be being carried around the body continuously. “The brain in particular is highly dependent on oxygen and being without enough even for just a few minutes can cause damage, sometimes long term or possibly even permanent,” said Dr Mackenzie Ross. “This is effectively the same was what happens in a stroke.”

While the highest exposures are caused if someone is involved in a fire, even “day-to-day” domestic exposure such as from faulty boilers can lead to neurological symptoms such as seizures – as well as other medical issues such as respiratory difficulties, headache and flu-like symptoms bad enough to lead to hospitalisation.

Some people are exposed chronically to neurotoxins because of inadequate ventilation – particularly an issue in some workplaces. One of Dr Mackenzie Ross’s patients was unwell as a result of the high formaldehyde levels in the NHS pathology lab where they worked, because the ventilation was so inadequate. We saw above how poor ventilation is in homes, too. However ventilation on its own cannot fix a toxic environment  – source control is essential.

Most of us are exposed all the time to more or less of these toxins, but in the awful event that we are exposed to a fire, the load will for a short time be hugely more.

“The hippocampus, which is involved in memory, seems particularly vulnerable to oxygen deprivation. I see patients who have been in a fire, or have cleaned up after one, who are suffering neurological/ psychological problems such as chronic fatigue, headaches or memory problems, that have significant impact on them,” Dr Mackenzie Ross said.

“By the time they are referred to me it is hard to track down what they have been exposed to – immediate high levels of toxins may no longer be detectable.” For example, carbon monoxide, which is given off by all fires, is only detectable for a short time. “And it’s not just carbon monoxide – there are many other toxic substances present in and after a fire,” she added.

Prof. Anna Stec

Most fire deaths and most fire injuries result from inhalation of toxic gases, which have increased with the widespread use of plastic materials. Professor Anna Stec, fire toxicity expert from University of Central Lancashire, described evidence that demonstrated that for many common materials carbon monoxide is not the only significant toxic gas given off when they burn. Hydrogen cyanide from burning polyurethane or polyisocyanurate foam, and hydrogen chloride from burning PVC are both produced in quantities that would be more rapidly toxic than the carbon monoxide given off at the same time.

Her research has shown that once the fire starts to consume more oxygen than is available (which happens a few minutes after ignition, once the fire has grown) carbon monoxide and hydrogen cyanide concentrations increase by factors of 10-50, together with smoke and irritant organic compounds.

Prof. Stec echoed the concern of other speakers that plastic in homes has increased tremendously but regulation has not kept up and changed accordingly. “There are regulations covering general fire safety matters within and around buildings. However there are no regulations on fire toxicity”. New products released on the market can meet all present fire regulations, but may still release concentrations of toxic gases 100 times higher compared to the ones that are used at present. Government does not have mechanism to check or restrict it”  she said.

Regulations on flammability require furniture sold in the UK to be treated with flame retardants. But many flame retardants contain halogens such as chlorine or bromine, which give off persistent molecules such as dioxins. As concerning was the fact that while fire retardants may delay ignition or fire spread, they also appear to increase the rate of production of the most toxic gases – the ones that can kill you very quickly, by asphyxiation. Laboratory research by Prof. Stec and her colleagues demonstrated that flame retardants increase the amount of carbon monoxide and hydrogen cyanide released when furniture burns.

Hydrogen cyanide was a particular concern to Prof Stec. The team examined a set of post-mortem reports for people who had died in fires, and found that of people whose post-mortem results suggested death via asphyxiation, over 60% did not appear to have inhaled enough CO to render them unconscious, suggesting another gases were likely to have been the cause. Prof Stec and her team suspect the culprit may be hydrogen cyanide as majority people die in the room of fire origin containing upholstery furniture.

Prof. Stec is concerned that fire hazards to human are being overlooked: “We know a number of Grenfell survivors were treated for cyanide poisoning. However there is nothing on fire toxicity in the review of building regulations led by Dame Judith Hackitt and no fire toxicity experts involved in the Sir Martin Moore-Bick inquiry (leading the judicial enquiry into Grenfell).”

“If I try to get people to take this issue on board. I just get told that fire toxicity is not an issue (even after the Grenfell fire this has not changed) . When I try to raise toxicity in fire safety forums I feel as I am literally the elephant in the room. And yet 71 people died in Grenfell Tower fire, most likely from inhalation of fire gases.”

Valentina Marincioni from the UK Centre for Moisture in Buildings was also concerned about indoor toxins, the ones caused by moisture-related problems – usually too much in the wrong place.

UKCMB Report

The UKCMB has reviewed the evidence linking moisture in buildings to health. Numerous studies suggest strong relationships between mould and a range of health problems – mainly but not exclusively respiratory. House dust mite, which is also more prevalent in damper (and warmer) conditions, is also known to cause and exacerbate asthma.

Marincioni warned that tackling moisture in buildings needed a good understanding of the way buildings worked, the way they were used and the constraints faced by occupants. For example, Tim Sharpe’s research has shown the huge moisture burden imposed by indoor laundry drying, which is very common especially in low income households.

Cold surfaces, ineffective or uncomfortable ventilation, faulty construction, poor repair, faulty retrofit that allows water to penetrate masonry or prevents building elements from drying out – all could give rise to moisture hazards for building occupants.

Internal wall insulation is a particularly risky measure because the masonry behind it becomes colder than before. The standard ‘steady state analysis’ does miss some of the risks, Marincioni explained, because it does not account for the effects of wetting from outside, or moisture building up or evaporating away over time.

Though dynamic simulations (such as WUFI) give a lot more information, they take a long time to do. The UKCMB was therefore developing a risk assessment to define the ‘grey area’ in which a dynamic assessment really ought to be done in order to guide a safe decision, she said. UKCMB were also planning to develop guidance on safe use of cavity insulation, in partnership with the BRE .

However, Marincioni warned that however much research we do, there could never be certainty with a system as complex as  a building. “We have to accept uncertainty. It’s all about balance – we can’t just focus down on one parameter at a time, we need to look holistically. It is important to know where the risks lie and act accordingly, but they can never be eliminated.”

Simon Sturgis of Sturgis Carbon Profiling reminded delegates of the importance of considering the impact of materials and components used in construction on the wider environment – and in particular, the contribution that making, installing, replacing and disposing of materials might be making to global warming.

With a modern commercial building that has a really short lifespan, embodied carbon impact may even outweigh the carbon emissions associated with the lifetime energy use. In the commercial sector a building life of 40 years or even less is common – and building fit-outs are particularly wasteful, with shops being completely remodelled after alarmingly short intervals.

A warehouse in Slough was successfully dismantled and rebuilt elsewhere

One way to mitigate this dreadful wastefulness is to re-use building components. Buildings could be designed for easy and practical dismantling. Even if they hadn’t been designed with a ‘circular life cycle’ in mind, a surprising amount could still be retained and re-used. Simon Sturgis told the meeting that his practice had persuaded a client not to demolish an unwanted building, but to dismantle it and rebuilt it on their new site (Cambridge Avenue case study) – and around 70% of the original – a lot of metal and glass – was successfully reused. Although it sounds fiddly, the re-use of materials meant that overall the client saw a cost saving.

Lifecycle analysis is increasingly being recognised in sustainability standards, for example, it is now recognised in BREEAM. But it shouldn’t be an add-on. Simon Sturgis wants to see the embodied impact of building taken on board much earlier in the process. A lot of changes could be cost neutral or even cost-saving – but it is important that embodied impact is part of the design team’s thinking from the earliest stages.


Please also see Hattie Hartman’s summary article of the conference which has a focus on the speakers from the architecture and construction sectors – asbp-news/highlights-from-the-asbps-healthy-buildings-conference-2018.

All of the speaker presentations can be viewed here.

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