Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 480-499)



  Q480  Chairman: What about the Bristol study where they are monitoring children long term?

  Professor Custovic: The Bristol study is one of a whole range of prospective birth cohort studies. We are extremely fortuitous in the UK to have probably the best prospective birth cohort studies which are currently, for the first time, all acting together as a consortium trying to understand these very important questions. Five major British birth cohort studies—Bristol, Manchester, Aberdeen, Kent and Isle of Wight—have agree to work together in order to try to answer these very important questions. The real problem of course is the multitude of exposures, very few of them being independent of each other and trying to tease out what exactly is the role of one as opposed to another is sometimes not easy. It is very much like a diet: is it vitamin C or is it eating an apple that is good remains quite interesting as a concept.

  Q481  Baroness Platt of Writtle: Do current building regulations adequately take into account the needs of allergy sufferers in the home?

  Mr Ager: No, there is no policy that I am aware of in building regulations on the use of formaldehyde or chemicals used in insulation or gas cookers and there is no regulation which covers air quality within the home. Certainly in Scotland housing that social landlords build has to be barrier free to standard. Arguably you could include air quality within that but it is not in there at the moment, it is more for physical disability.

  Mr Bryson: The building regulations are a minimum building standard so they are the basic minimum. There are two things about that really, one is that they only apply to new dwellings or conversions; they do not extend to existing buildings so they cannot be applied to those as well. Bearing in mind the length of time that houses currently standing will have to remain occupied, the recurrent rate of replacement is about a thousand years.

  Q482  Baroness Platt of Writtle: Are there any ways in which you think these regulations could be improved to control exposure to allergens and other pollutants more stringently? Of course you have just mentioned older houses, particularly in that context.

  Dr Harrison: It is very difficult through building regulations alone and ventilation requirements alone to make a big impact because of the vast proportion of existing housing that cannot be easily remedied. I know there is a lot of science that goes into the establishment of the ventilation requirements and I would not criticise that. I just think there is a limit to what can be achieved through the building regulations.

  Mr Ager: In Norway there is an allergy specification included within building regulations and standards but again that applies to new build and not what is there at the moment.

  Dr Harrison: I think there is an option for looking at labelling and emission standards for building products and materials so that materials used in homes are not high emitters of potentially polluting substances like formaldehyde. There are standards in existence but I think more could be done to encourage the use of cleaner materials in that sense and lower emitting substances and lower emitting appliances used in the home.

  Mr Ager: We would support that but it is actually quite hard to source materials in the building centre at the moment to meet needs. For fourteen units we could not source the materials so the supply is not there at the moment. It can be there but it is very expensive.

  Q483  Baroness Perry of Southwark: Returning to the issue of existing housing stock, there is now a requirement when you are selling your house to have a survey done yourself and passed on and I know there has been some discussion that that might include, for example, tests for energy efficiency for your house so that the person purchasing it is warned they are buying a house which is not very energy efficient. Would you see a case in the future for including the allergy count of your house? Apparently houses on average change hands every seven years so you soon begin to tackle the existing housing stock.

  Mr Ager: Personally I am not sure of the value in that because unfortunately it does not drive people when they are buying a property. Energy efficiency will but unless you have someone within your family who has an allergy or asthma I do not think it is a selling point.

  Q484  Baroness Perry of Southwark: Forty per cent of the population does suffer from some kind of allergy and that is a lot of purchasers who do care about it.

  Mr Ager: That is true but there is this sort of dichotomy in the realms of affordable housing and I am not sure of the value personally.

  Mr Bryson: I think the introduction of the house condition report in the home information pack is voluntary at the moment and there seems to be some question as to whether it will be made compulsory. I think that is unfortunate personally. Averages, as ever, do not tell the true story; there are a lot of people who live in the same dwelling for many, many years so a house condition report would be of limited value to them. On the sale of houses, of course, people are more interested in the value and the cost than they are the condition.

  Q485  Baroness Perry of Southwark: Is there also a tension between the building itself and the contents which the people bring with them? From what you were saying most of the house dust mites would be residing in the furnishings rather than in the building so they would bring their own house dust mites with them in their beds and pillows.

  Mr Ager: Arguably that is true. As I said before, you can have the cleanest house and controlled environment but when you walk in you pollute it immediately. If you bring in furniture you pollute it immediately. That reinforces what I was saying earlier.

  Dr Harrison: The behaviour of the occupants has a large impact on the conditions inside a house.

  Q486  Earl of Selborne: Is there a role for the Government to issue guidelines to the public on either how to reduce the risk of developing allergic diseases or minimising their aggravation by substances in the home or changes in lifestyle? Would it be feasible for the Government to offer such advice?

  Dr Harrison: I think so. I once worked in what was then the Department of the Environment in the indoor air quality branch and I actually addressed the question of setting guidelines. That was some 13 years ago I think and last year or the year before the Committee on the Medical Effects of Air Pollutants did produce a document which is called Guidelines for Indoor Air Quality (or something to that effect). It deals with a number of chemical or gaseous pollutants in the home and it suggests guideline values which line up very much with the WHO standards. It also suggests behaviours that would help improve indoor air quality. Unfortunately that document has not been very widely circulated and accessed. It remains on the DH web site but I do not think enough people have seen it and I think it is a good starting point to Lord Selborne's question about really giving good guidance to individuals about what they can practically do to improve their own situation.

  Q487  Earl of Selborne: Dr Harrison and I have both at one time sat on the Chemical Stakeholder Forum which was to try to identify chemicals in general use or in the environment which might be toxic or bio-cumulative or persistent in one form or another. One of the issues which is mentioned in the Fairfield study is that the resin which is most benign for sticking lino down was available in Holland but not in this country. Is there not an issue here that we are not making available some of these benign materials for some reason?

  Mr Ager: I do not think the market is fully developed for them yet. In the UK there is not a market for them. The Fairfield project is now four years old; there has not been a project to replicate it repeated in the UK to my knowledge. Certainly some of the factors that were put within the project have been used but there is not a huge market for them. There is no incentive for private developers. They will produce energy efficient housing but there is no incentive for them to enhance air quality. The materials are not there at the moment. Perhaps the Government has a role in looking at that.

  Q488  Earl of Selborne: This seems to be a market failure. If this would be even a modest help should we not try to encourage the building industry and do-it-yourself stockists to take it more seriously.

  Mr Ager: Possibly, yes.

  Dr Harrison: There has been an advance in the production of low VOC emitting paints and companies like B&Q created a symbol which they put on their products to encourage the use of low VOC emitting products and I think more can be done in that way. The use of symbols and labels as well as possibly other regulations to encourage the manufacture and use of low emitting products may be of use.

  Professor Custovic: That is very, very similar to the way the food labelling is going towards identifying what may be the healthy option; I stress what may be the healthy option. We pretty much know what good indoor air quality is without going into details.

  Q489  Baroness Perry of Southwark: When we talk about affordable low allergy housing, what exactly are we describing? Can you give us some of the features that would be found and what special adaptations such houses would have?

  Mr Ager: A dwelling that was designed avoiding where possible known pollutants or irritants to allergies at that present time and obviously focussing on air quality. There were four relatively simple features in the house which you do not really see. The most crucial thing was moisture management creating an environment that dust mites could not breed in by use of various ventilation strategies, your normal trickle strategies and fans, mechanical heat recovery methods and we also did five with the breathing wall method and the breathing ceiling to create an environment where dust mites find it difficult to breed. We completely avoided gas heating and gas cooking (so no naked flame or appliance within the home). There were two reasons for that, electricity being more sustainable and the fact of the evidence of naked flames, central heating and gas cookers do have an impact on allergy sufferers. We worked to non-toxic specifications where possible and we tried to look at taking out formaldehyde, toxic materials and preservatives where possible. We avoided Upvc windows and went for wooden windows because they do not have as much chemical content in them. More importantly, within the buildings themselves, we sourced linoleum floor covering for tenants who wanted that and we spent a great deal of time with the people going into the houses as an education as to how to use the house properly. In terms of features, to walk in you would not think there were any different features from a normal home but they are there.

  Q490  Baroness Perry of Southwark: Was it expensive to produce that?

  Mr Ager: Arguably at the time it was but the cost today probably not. When you do a pilot the building industry is slightly nervous of what you are trying to do but the more you do it the easier it becomes. I do not think it was hugely expensive to do that.

  Q491  Baroness Perry of Southwark: Are there several projects of this kind or is it fairly rare still?

  Mr Ager: We were the first in the UK; I believe there is one other one in London but I am not sure where. We have not tried to replicate a new build of what was done there completely. We have used the mechanical ventilation strategies and again the paints. Going back to refurbishment of existing property, we have refurbished a small number of flats taking into account the principles we used, using a non-toxic specification.

  Q492  Lord Rea: What is the evidence that living in a low allergy house has an effect on either the allergic sensitisation or aggravation of existing allergies?

  Mr Ager: The research was, like a lot of things, inconclusive. It showed that the quality of the air within the home was increased quite substantially between the three different types. It was something like five to six per cent better in the houses with the ventilation strategies rather than the conventional house type. We did have the feel good factor with people within those houses; certainly people with asthma felt better and their reliance on inhalers and other medication decreased. However, I do not think the sample was big enough to give a conclusive answer. There was a slight improvement but you would need to do it over a much larger scale to look at it properly.

  Q493  Lord Rea: The change is sufficient to warrant at least the builders and the occupants thinking that it was worthwhile.

  Mr Ager: Yes, definitely. Going back to what one of my colleagues said about the age of people and allergies, the people in here generally are older and the disease is well developed and, as I said, they showed significant improvement because of the air quality within the home.

  Dr Harrison: I would say that this is a very good idea but it should not be seen as a panacea. I do not think it should be expected, almost miraculously, by living in a house like this that all your problems will disappear. It is certainly the case with allergic sensitisation that very often people who do not get allergic to house dust mite will get allergic to something else, if they are susceptible to that. I think in terms of well-being it is a very good idea to have these houses built with low emitting substances, certainly good ventilation, heat recovery et cetera, but all the studies that have been done that I know about have struggled to show a statistical improvement over a prolonged period of time and where, in the extreme case in Scandinavia, homes have been built with no man-made materials at all in the hope that people who suffer from chemical sensitivity will have a better life, this has often failed because wood emits turpines and other volatile materials which are similar to the chemicals that are present in man-made substances. Just because something is natural does not mean to say it is not potentially toxic. We have to be careful in making assumptions about the benefit of such housing, although it is clearly not a bad thing.

  Q494  Lord Rea: From the comments you have just given I can probably guess what your answer will be to my next question which is whether you think that low allergy specification should be incorporated into the design of all new housing and, to add to that, major refurbishment of older property requiring planning permission.

  Mr Ager: I do agree with Paul that it is not the magic answer but certain factors should be considered. The mechanical heat ventilation recovery systems are an excellent way forward. However, there is the big question, how do you track back and tackle existing housing stock and existing problems that are already there? Again, arguably, most people within social housing just want to be able to heat their home efficiently without anything else on top of that, so there is a big challenge there to be tackled as well.

  Dr Harrison: Yes, I would agree. I think that heating and ventilation is important. Also I think to not use substances which emit formaldehyde would be a good idea and to educate people in the way to manage their home so it does not build up high levels of house dust mites and mould would be a good thing.

  Professor Custovic: We have to stress that probably the emphasis on the term low allergen housing is wrong because what we are talking about is healthy indoor environment. Pretty much like healthy eating options you have healthy indoor environment. I think that by and large allergens are probably the least important part of the overall concept of healthy indoor environment.

  Q495  Lord Rea: What needs to be done to the current building regulations to ensure that houses that are built in the future conform to these specifications?

  Dr Harrison: There are ideas put forward by the Building Research Establishment (BRE) about healthy housing schemes. I do not know the details of those but I would suggest they were well thought out and worthy of consideration as to optimal design for new houses. Whether some or all of that should or could be built in with the building regulations I do not know.

  Mr Ager: Certainly air quality management could be built in but, as John said, building regulations are very basic at the moment and that is quite an advanced step forward.

  Mr Bryson: The building regulations react to development in construction in actual fact rather than lead the way.

  Q496  Lord Colwyn: You have ruled out the use of gas. Assuming you agree it is not a brilliant idea to live underneath power cables, can you say whether you believe that modern electronics—heaters, TVs, microwaves, computer screens—have any effect on the immune system and then possibly the introduction of allergic disease? Do we still hear about sick building syndrome? Is there such a thing as that?

  Professor Custovic: Oh yes.

  Dr Harrison: Certainly there is. Although nobody can say what causes it there have been various ideas. There was an interesting study done on microwaves which nobody could quite understand. It might not have been to do with the microwave but to do with the diet that the people were eating, using the microwave to cook their food. Again it is very difficult to tease out causative factors.

  Professor Custovic: I will step away from what I believe (because I kind of struggle with the concept of belief being part of an inquiry into what the evidence is); I do not think there is any evidence for the time being.

  Q497  Chairman: Mr Bryson, you very helpfully gave us some additional information which we have tabled today for the Committee and in it you point out that the Chartered Institute of Environmental Health has formed a commission on housing renewal and public health and that the commission recommends that the guidance on neighbourhood renewal assessment is revised to include a health impact assessment on the different options for action. I wondered how you envisaged this actually happening.

  Mr Bryson: What the commission found was that a lot of the emphasis in actual fact was partly on housing condition but predominantly it was about economic factors and social factors and in their submissions to the commission hardly any of them was a health assessment part of it. There was no particular assessment of that. The final report has not been produced but in the interim report the recommendation is that that could be part. There is what is described as a Neighbourhood Renewal Assessment Manual which is provided by the Department of Communities. It would not be difficult to introduce a health impact assessment into that. In our submission to the sub-committee, I think we also point to the work that has been done on Sheffield Homes to show the beneficial effects that can be produced by linking housing and health. At the moment our view is that there is an inadequate link between the two.

  Q498  Chairman: Given that we understand that the development of allergic diseases is determined by the interaction of genetic and environmental factors, I wondered what each of you feel is the main future thrust for research into environmental factors associated with allergic disease and where the research energy should go.

  Professor Custovic: I firmly believe that the day and age of simple public health advice where something is good for everybody is over. We are different individuals. What is very good for me may not necessarily work for you or may indeed really be bad for somebody else. We need to move away from the concept of one size fits all and that is in terms of intervention, in terms of drugs, to very targeted interventions aiming to make a difference in susceptible individuals. In order to develop that we have to ultimately understand how environmental factors interact with genetic predisposition in giving us the disease. The real tricky concept of all of that is that in the long term it may well be that in order to prevent allergy we will have to remove house dust mites or to add house dust mites or to remove microbes or to add a little bit of microbes. Each intervention is going to be specific for specific individuals at risk. I think that is the way to go. The way is to go in a much cleverer, holistic medicine way. We will appreciate and understand the individual susceptibilities of our patients and not look at them as mean patients derived from clinical studies.

  Q499  Chairman: From the non-clinicians' view point?

  Dr Harrison: I think that unfortunately interventions which seemed a very good idea at the time sometimes just do not work and then people rub their chins and wonder what went wrong. It is because we do not understand everything that is happening in the cause-effect chain. To answer your question, it seems to me that there are interesting impacts of exposure at different stages in life and it would be very useful to understand a bit better the important windows of exposure through one's lifespan which are important for different aspects of the environment we are exposed to. That I think would be a good focus for research.

  Mr Bryson: Obviously I am not qualified on the medical side. All I would say is that while any further research is taking place what is important from our point of view is that indoor air quality is improved and housing conditions are improved because quite clearly it is not improving people's health living in damp conditions and conditions where allergens can thrive.

  Mr Ager: I would not disagree with that. As a total non-clinician, I think we can get carried away with some of these allergy projects. It does add value but I think what is important is to research how we can improve existing homes to improve air quality. The knowledge is there for new build homes but it is looking back which is the predominant stock in this country, and how people modernise and improve. I think research should be focussed there.

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