Examination of Witnesses (Questions 480-499)|
7 FEBRUARY 2007
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 studiesBristol,
Manchester, Aberdeen, Kent and Isle of Wighthave 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
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
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
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
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
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 electronicsheaters, TVs, microwaves, computer
screenshave 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
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'
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.