The role of the FASTS Occasional Paper series
is to bring significant issues to the attention of the community, the
government and the bureaucracy.
In the case of the
paper prepared by the Clean Air Society of Australia and New Zealand, the
science is well established. Measurements have been done, evidence collected,
and the implications emphasised. There is a clear and present danger. A
significant proportion of our community is at risk, and will remain at risk
until the governments of Australia tackle issues which affect the quality of
air within the buildings where we work, live and study.
The paper makes a
number of recommendations. These range from establishing a national body to
take responsibility for the issue of indoor air quality and the setting up of
programs offering practical solutions, to filling in gaps in the data. These
recommendations deserve close scrutiny from all levels of government, and a
coordinated response.
Often science-based
issues demand a whole-of-government response, because the issues cross the
administrative boundaries established by the allocation of portfolio
responsibilities. Australia has been slowly improving its capacity to respond
to matters that involve a number of ministers or require actions at all levels
of government.
It is our belief
that Australia requires a wider whole-of-government approach to coordinate the
national research effort because of the pervasiveness of science to almost all
policy areas, and because many issues involve federal, state and territory
governments. COAG-the Council of Australian Governments-has a role
here.
There have been promising signs in Australia in
recent years as both major political parties have increased their commitment to
science and technology. The commitment has been accompanied by some modest (but
welcome) increases in funding, but the missing ingredient has been the absence
of a long-term strategy that would allow science and technology to serve its
rightful place as a driver of the economy and solution to our environmental
problems.
The issues raised in this paper are an illustration
of the fact that Australia still lacks a national commitment to making the best
of its science.
President
Federation of Australian Scientific and Technological Societies
Indoor air quality is a most significant environmental issue
that has not been seriously addressed in this country. Unhealthy indoor air is
costing the Australian community an estimated $12 billion a year. Australia is failing its responsibilities of a 'duty
of care' to protect the community in the environment where we spend most of our
time.
Resolution of the issue requires
assessment of the problem, the setting of standards, formation of a central
responsibility for indoor air, and initiation of actions to improve air
quality.
Though further assessment will be
needed to better define the problem, the facts before us already
show:
·
we spend up to 90 percent of
our time indoors
·
while on the one hand,
national enforceable standards (NEPMs) are rarely exceeded outdoors, on many
days every year millions of people inhale air in excess of air quality
standards or goals while indoors
·
the indoor air pollutants
that often exceed acceptable levels include nitrogen dioxide, carbon monoxide,
particles, formaldehyde, environmental tobacco smoke, and house dust
mites
·
in 2000 there were five
fatalities from carbon monoxide poisoning in dwellings in Victoria alone, and
by calculation the health of millions of people is being impaired by indoor air
pollution.
Australia has national enforceable
standards for ambient air (NEPMs), where people spend only around 10 percent of
their time, but it has only non-enforceable interim guidelines for some indoor
air pollutants. There is a very much wider range of pollutants indoors that are
of concern when compared to outdoors. Ott and Roberts stated
in Scientific
American (February 1998) that 'Of the hundreds of air pollutants covered by US laws, only
ozone and sulfur dioxide remain more prevalent outdoors'. It is imperative that national standards are set for indoor
air quality in the very near future so the extent of indoor pollution can be
fully established.
A critical factor that has permitted the poor
condition of indoor
air to deteriorate to its present state is the lack of government ownership of
this environment. In the case of outdoor air, the state governments have passed
legislation that is enforced by regulation. Fines of up to $1 million can be
imposed for infringements that result in unhealthy air. The environment
ministers in the states and the Commonwealth have formed a partnership to
ensure everyone in the community has access to clean air in the ambient
environment. However, in the indoor environment there is only a fragmented
interest spread amongst departments of public health, environment, building,
work safety, and so on. This has resulted in sporadic involvement, usually by
issuing information brochures on isolated issues such as unflued gas heaters or
passive smoking. Environment Australia has funded some research studies on
indoor air. Although well over 15 years have passed since the first major study
revealed very serious air pollution levels in homes, hospitals, schools and
caravans, the community remains uneducated and the government largely
unmoved.
It seems astonishing that certain
environmental programs are being put in place without full consideration of the
total exposure of the population to air pollutants. This is exemplified in the
strong government program associated with the construction of new dwellings and
commercial buildings to conserve energy, and thereby reduce greenhouse gas
emissions. Unfortunately, without due consideration of the effects on the
indoor environment, this can result in modern building designs that are
reducing ventilation and thus potentially causing a very serious decline in the
quality of indoor air and the health of the occupants.
The immediate steps required to
address the issue of indoor air pollution are to:
·
establish a national body
(linked or similar to the National Environment Protection Council, or NEPC)
responsible for indoor air
·
establish indoor standards of
air quality for the most common and serious pollutants
·
collate existing measured
indoor air pollution levels into a national database
·
commence studies in areas
where insufficient data are available
·
establish programs that will
address the most serious problems
·
commence a wide-ranging and
comprehensive public education program.
The sooner these steps are taken
the sooner the health and economic benefits will
accrue.
Len Ferrari
President
Clean Air Society of Australia and New Zealand
It has long been known that substances in the air can damage
human health. Air pollution (of ambient air) came into focus with London's
'killer smogs' in the early 1950s-an estimated 4000 people lost their lives in
one incident alone. The smogs brought swift government action to improve the
situation. However, it was another two decades before a similar level of
concern was expressed about the quality of air within non-industrial buildings.
This slow rise of concern about indoor air quality was
addressed by a rapid rise in overseas interest and research into indoor air
quality. In Australia, the first major investigations occurred in the 1980s.
However, in contrast to the overseas experience, the response to research
findings in Australia has been less comprehensive. We have seen concerted
action to address only a few of the pollutants identified as causes for concern
in research findings.
This summary paper focuses on concrete and immediate steps
to improve indoor air quality in Australia, based on the current state of
knowledge. As a means to that end it also looks at the six most serious indoor
air pollutants in the Australian context and attempts, briefly:
·
to review what is known about them
·
to indicate their possible impact on health
·
to estimate the population that may be at risk
·
to outline any significant actions that have already
been taken to improve the situation
·
to recommend ways to remedy identified problems.
The full paper
discusses 21 pollutants. A summary of all the pollutants and recommended
actions is included on page 6.
The term 'indoor air' has a wide range of meanings. We use
the term in accordance with the NHMRC definition: a non-industrial indoor space
where a person spends a period of an hour or more in any day. Thus indoor air
includes the air inside homes, offices, commercial premises (such as shops,
restaurants), schools, and automobiles including cars and buses.
Effectively, 'indoor air pollution' becomes all those air
pollutants indoors that are not controlled by occupational or ambient
legislation in the environment in which they are encountered.
Unless otherwise indicated, the section on potential health
effects for each pollutant has been drawn from the references listed in the
full paper and the Final Impact Statement for the National Environment
Protection Measure for Ambient Air (1998).
These sections indicate some of the salient, known adverse effects rather than
provide an exhaustive treatment of what is known about the health effects of
the pollutants.
Mention is made throughout of the National Environment
Protection Council (NEPC) and National Environment Protection
Measures (NEPMs).
The NEPC was established to set national environmental goals
and standards for Australia, through NEPMs. It is a statutory body with
law-making powers established under the National Environment Protection
Council Act 1994 (Commonwealth), and
corresponding legislation in the other jurisdictions. The objectives of NEPC
are to ensure that:
·
the people of Australia enjoy the benefit of equivalent
protection from air, water or soil pollution and from noise, wherever they live
·
decisions of the business community are not distorted,
and markets not fragmented, by variations between member governments in
relation to the adoption or implementation of major environment protection
measures.
Members of Council are ministers
(not necessarily environment ministers) appointed by first ministers from the
participating jurisdictions-the Commonwealth, state and territory
governments.
The NEPC Committee is the principal advisory body to the
Council. It comprises the NEPC Executive Officer and one nominee of each
Council member. A non-voting observer has been appointed by the President of
the Australian Local Government Association.
NEPMs are 'framework' documents outlining agreed national
objectives for protecting or managing particular aspects of the environment.
They may consist of any combination of goals, standards, protocols, and
guidelines. NEPMs must be agreed by a two-thirds majority of ministers of the
NEPC. Once they have been tabled in the Commonwealth Parliament, they become
law in each participating jurisdiction. Progress is reported annually through
state/territory parliaments and through the NEPC to the Commonwealth
Parliament.
In the past four years, the NEPC has made six NEPMs, including one on ambient
air quality (July 1998).
Ambient air pollution in Australia is generally well
understood and under control, if not yet completely within acceptable limits.
The situation for indoor air pollution is not nearly as positive. The state of
knowledge is paradoxical. Compared to ambient air quality, relatively little is
known about indoor air quality, but what is known shows that the situation is
generally much worse than outdoors. Furthermore, with limited exceptions, the
quality of indoor air is not improving. The following features of indoor air
pollution should increase the levels of concern of both citizens and all levels
of government.
1.
A
much wider range of possible air pollutants can be found at elevated levels
indoors than occur at levels of concern outdoors. This is because many of the sources of indoor air pollution are only
found indoors. Pollutants such as some solvents, formaldehyde, environmental
tobacco smoke and house dust mite allergen are rarely, if ever, found outdoors
at levels of concern. Indoors, they may frequently be present at levels that
are damaging to health, particularly for susceptible groups such as children,
old people, and people with chronic illnesses.
2.
The
health effects from constant exposure to mixtures of indoor air pollutants are
poorly understood.
3.
Levels
of indoor air pollutants may be as varied as the situations in which
they occur. This makes it difficult to predict with
any certainty the levels of even common pollutants that will be found
indoors. Every home has a different mix of possible
sources-new furnishings, a cat, a flueless gas heater, particle board floors,
etc. Owners may like to keep windows open in winter or prefer to close up tight
and save on energy bills. The range of situations makes it difficult to predict
with any certainty the levels of even common pollutants that will be found
indoors. Further, there are none of the increasingly sophisticated computer
models that are used to predict, accurately, ambient levels of pollution with
almost street-by-street resolution. There have been insufficient studies to
statistically define levels of indoor air pollutants in Australia. Thus it is a
much greater challenge to monitor indoor air quality than it is to monitor the
ambient environment-there are many more pollutants indoors and millions of
environments (individual houses and other structures) about which we need
information. Such information cannot be gathered by fixed ambient monitoring
networks such as those operated by the various state and territory
environmental agencies.
4.
There
is no national framework, such as the ambient air quality NEPM, to ensure a
systematic examination of the situation. The
results of studies undertaken to date are not easily comparable; nor do they
necessarily complement one another. They are mainly research studies; they have
not been coordinated nationally with a view to developing a cogent overview of
the current situation. There are few protocols for monitoring indoor air or for
the methods used. Thus research indicates those situations in which there are
harmful indoor levels of pollutants and their distributions, but they have yet
to be adequately documented. The available evidence consistently points to much
higher indoor levels of a much wider range of pollutants that are potentially
affecting many more people than those outdoors. In addition, Australians spend
most (up to 96 per cent) of their time indoors. However, what is clear is
community exposure to unacceptable levels of air pollution occurs
overwhelmingly indoors.
5.
Even
on the limited available data, the adverse health implications of indoor air
quality have very significant economic effects. A CSIRO estimate is that poor
indoor air quality costs Australia $12 billion per annum. Furthermore, people whose health is the most
vulnerable spend almost all of their time indoors, possibly greatly increasing
their exposure to a wide range of harmful pollutants. They include children,
the elderly and the infirm. These are often the people least able to find out
about the impact of their indoor environments or, even if they did, to improve
the situation. There is an issue of 'duty of care' regarding the quality of
indoor air, particularly for government.
6.
There
is serious cause for concern-the appropriate response is immediate action to
improve the situation. The pollution
levels found, the extent of the potentially exposed population and the presence
of vulnerable groups all demonstrate that there is serious cause for concern
about the quality of our indoor air.
7.
Overwhelmingly,
any changes regarding indoor air quality have been incremental and
uncoordinated. Unlike ambient air, which has the NEPC and NEPMs, indoor air quality has no coordinated
system of control or even a single area of government (local, state or federal)
taking responsibility for it.
Responsibility can be split across government departments and agencies at state
and local government levels. Circumstances can easily arise for which no organ
of government is prepared to take responsibility or there is more than one
responsible area in government. The same air may need to meet different
standards or goals measured under different criteria. This is in stark contrast
to the situation in the ambient environment, where concerted action over
several decades has brought substantial and sustained improvements.
8.
Citizens
have little idea about the effect indoor air quality may be having on their
health, or its potential impact on their economic wellbeing. Lack of
information
and poor access to available material means people cannot make informed choices
or decide how to improve the situation. In these circumstances, people are inadvertently
harming themselves and those around them, including dependant children, through
their ill-informed actions, such as using particular appliances or products. On
the positive side, measures to reduce exposure to environmental tobacco smoke
in public areas demonstrate how substantial change is possible when citizens
become aware of possible dangers.
In all, we need to be much more
concerned about indoor air quality in Australia.
The following discussion of indoor air pollution provides
information on the pollutants found indoors, their source, possible health
effects and the size of the exposed population. In the discussion of exposures,
an estimate has been made of the number of times in a year that the level of a
pollutant indoors will exceed the relevant standard. An estimate has also been
made of the number of people exposed to these high levels.
An occasion when the level of the pollutant indoors exceeds
the relevant standard is referred to as an event. An occasion when a person is
exposed to an event is called a person-event. For example, if three people are
exposed to an event, there are three person-events; if three people are exposed
to two events, there are six person events.
Sources
Carbon monoxide is formed by the combustion
of carbon-containing substances (often in the form of fossil fuels). Important
potential indoor sources include:
·
flueless or poorly flued gas heaters or cooking
appliances, poorly flued wood heaters, kerosene heaters
·
motor vehicle exhaust in underground or enclosed car
parks, or where fumes from the car park may enter the rest of the building,
possibly through the ventilation system
·
motor vehicle exhaust in domestic situations where the
garage and the dwelling are connected by an internal door
·
environmental tobacco smoke.
Possible
health effects
Carbon monoxide binds with haemoglobin to
reduce the blood's oxygen-carrying capacity. This can be fatal at high
concentrations; at lower concentrations symptoms include headache or loss of
concentration. There is consistent evidence that people with heart disease are
a susceptible sub-population and are at risk at relatively low levels. The NEPM
ambient standard is 9 parts per million averaged over 8 hours, the same as the
NHMRC interim indoor goal. The WHO has also established goals for other
averaging times, including a one-hour goal of 25 parts per
million.
What
is known about it and its levels in Australia?
Some studies have determined carbon monoxide
levels where there are combustion sources indoors. While none of the published
results has provided sufficient detail to precisely estimate the percentage of
situations in which standards or goals are not met, we can estimate the size of
the potential exposed population. A 1993 study reported carbon monoxide levels
from flueless gas heaters that exceeded the WHO one-hour ambient goal in both
NSW and South Australia (but not Western Australia where there are mandatory
ventilation requirements). A 1990 study reported similar exceedences for gas
cooking appliances in South Australia. Situations where the goal is exceeded
are not isolated to one state, nor are they so infrequent that they were not
detected by the relatively small surveys reported.
In Victoria in 2000, there were five
deaths caused by carbon monoxide poisoning associated with gas heaters. Three
people died in a caravan where a flueless gas heater was in use and two people
died in a room where a leaking flued gas heater was
operating.
Ambient air quality measurements suggest that
the NEPM carbon monoxide standard is rarely exceeded except in situations
directly adjacent to heavily trafficked roads. Certainly, the WHO one-hour goal
would not be approached at any of the Australian ambient NEPM monitoring
stations. Clearly, indoor exposures can be significantly higher. There appear
to be few data available about levels of carbon monoxide in enclosed car parks
or in buildings attached to them.
Potential
exposed population
Based on ABS estimates, some 2 million people
live in a flueless gas-heated home, while some 7 million have a gas cooking
appliance. Estimates based on published data are that 2-4 per cent of flueless
gas heaters produce levels exceeding the WHO one-hour goal, as do perhaps as
many as 5 per cent of gas cooking appliances. This means that some 80,000
people may experience regular, unacceptable levels of carbon monoxide due to
gas heating. The equivalent number for gas cooking appliances may be as many as
350,000 people.
These exposures are likely to occur
regularly-often whenever the appliance is used or is used for more than a
certain period of time. Thus, in the case of flueless gas heaters, if
unacceptable levels were to occur for 3 hours a day for 50 days a year, this
represents 150 events per year with 160,000 people exposed to each event: a
total of 24 million person-events. Similarly, the level for gas cooking
appliances may be exceeded on, say, 100 days a year, representing some 35
million person-events.
Controls
or other responses by government, etc.
There have been few initiatives aimed
directly at reducing exposure to carbon monoxide indoors. Victoria has
published education brochures on flueless gas heaters. Modern gas heaters must
be fitted with an oxygen-deficit sensor, which should shut off before oxygen
levels fall below a certain level. In Victoria, education brochures have been
published on flueless gas heaters. Carbon monoxide detectors are used to detect
raised CO levels in several countries overseas.
Summary
·
Is it of concern?
Given that there have been recent deaths from
exposure to carbon monoxide indoors, and the very significant number of people
potentially exposed to it, carbon monoxide is a pollutant of
concern.
·
Possible actions
Few people appear to be are aware of the
risks posed by carbon monoxide emitted from poorly maintained or poorly
operating flueless combustion appliances such as gas heaters and gas
stoves.
A first step would be a national education campaign focusing on the need for
regular maintenance and describing early symptoms of an incorrectly operating
appliance. This
could be conducted as part of wider education campaign on indoor air
pollution.
A program to replace older flueless gas heaters with flued gas heaters or
reverse-cycle air conditioning would reduce exposures to unacceptable levels of
carbon monoxide. A building code that mechanically or electronically
linked gas stove use to exhaust fan operation would reduce
exposure.
Nitrogen dioxide is a by-product of combustion.
Important potential indoor sources include flueless gas heating and cooking
appliances, kerosene heaters, and environmental tobacco smoke.
Nitrogen dioxide irritates the lungs. Very high levels can
cause fatal swelling of the lungs. At lower levels, it can exacerbate asthma
and cause more frequent and more severe respiratory illness. There is a
significant link between exposure to nitrogen dioxide and poor health,
including increased hospital admissions for people with childhood asthma and
heart disease. There is also evidence that it suppresses the body's immune
system.
The standard for outdoor (ambient) air set by the National
Environmental Protection Councilis
0.12 parts per million (one-hour average). Studies of nitrogen dioxide levels
in indoor environments in Australia, including homes and schools, have
consistently found high levels where there are indoor sources, frequently at
levels well over the ambient standards. In contrast, ambient levels of nitrogen
dioxide now rarely, if ever, exceed the standard anywhere in Australia.
Some 2 million people live in a
flueless gas-heated home. Some 7 million have a gas cooking appliance.
Published research suggests that some 400,000 people in NSW alone could be
regularly exposed to levels of nitrogen dioxide from flueless gas heaters that
exceed the NEPM (ambient) level. They may be exposed repeatedly throughout the
heating season. In comparison, each year in NSW there may be one occasion at
most in which levels of nitrogen dioxide exceed the NEPM standard for ambient
air, affecting an area where up to 250,000 people live; an upper limit of
250,000 person events. On this basis the indoor exposure (person events) in NSW
from flueless gas heaters is estimated to be over 200 times greater than the
ambient exposure. Exposures in schools, hospitals, etc. would be additional. As
well, exposure in dwellings to nitrogen dioxide from gas stoves would be
expected to be of a similar magnitude to that from gas heaters. The above
estimates are based on NSW alone. The exposure of the whole Australian
population would be significantly greater, possibly reaching well over 100
million person-events/year.
In 1991, the Australian Gas Association (AGA) responded to
the unacceptable levels of nitrogen dioxide found in studies by introducing
appliance emission limits for nitrogen dioxide from new flueless gas space
heaters. The aim was to meet the then NHMRC level of concern of 0.30 parts per
million. A limit three times higher was set for new (flueless) cooking
appliances.
In 1989, monitoring in NSW government schools, where
flueless gas heaters are common, found levels of up to 2.9 parts per million;
with 7 per cent of heaters exceeding the then NHMRC level of concern. In 1990,
the NSW Department of Education responded to the test results with an extensive
heater testing and rectification program. A second component of the program was
intended to replace existing heaters with new heaters designed to meet the 1991
AGA requirements, over a time frame of about ten years. Over ten years later,
it is understood that this program is only now reaching the Sydney region
(where the majority of heaters are). In addition to the replacement program, a
directive was issued to schools requiring open window and door ventilation when
the heaters were used in classrooms.
In NSW, the state with the greatest number of flueless gas
heaters, AGL undertook a heater testing and rectification scheme in private
homes in the early 1990s.
·
Is it of
concern?
Yes. Many thousands of tests have shown a widespread
problem. When many of the studies were undertaken, the NHMRC goal for nitrogen
dioxide in ambient air was 0.16 parts per million, with a 'level of concern'
for indoor air of 0.30 parts per million. Since then, the NEPM process has
established a national ambient standard of 0.12 parts per million, reflecting
increased concerns about the potential harm caused by nitrogen dioxide. This
concern must transfer to the indoor environment, particularly in view of the
large number of people exposed to levels near or above the standard.
·
Possible
actions
Decisive action to reduce exposure to nitrogen dioxide
indoors is hampered by the lack of benchmarks for evaluating
measurements. The
NEPM standard for ambient air must be adopted immediately as an interim
benchmark for indoor air unless overwhelming evidence can be produced that the
effects of this pollutant indoors are different to those outdoors.
The emissions performance of flueless gas heaters
deteriorates with time. The current AGA regulation on the rate of
emission of nitrogen dioxide needs to be amended to require that any heater
will demonstrate continued compliance with a much lower emission limit over the
life of the appliance.
Concerted government action is needed to encourage users to shift to
flued heating or other forms of heating with less impact on indoor air quality,
including:
·
an immediate program to alert users of older
heaters (a substantial
proportion of the flueless gas heaters now in service were purchased before the
1991 AGA emission limit was implemented) of the potential risk. Such a program
may also reduce exposure to unacceptable levels of carbon
monoxide
·
funding a heater replacement program similar to
that currently operated in some parts of NSW and Tasmania for solid fuel
heaters.
Studies
consistently show that levels of nitrogen dioxide from gas cooking appliances
are as great a concern as levels from the use of flueless gas space heaters,
despite differences in the duration of use. The emission requirements for
flueless gas space heaters need to be extended to all flueless
appliances, taking into account the volume of
the room in which they are used. Indeed, the AGA limit for all such
appliances needs to be substantially reduced to reflect reduced ventilation rates in Australia's
housing stock and in addition with a requirement to meet the NEPM ambient
standard for nitrogen dioxide. Additionally, stricter controls
would be needed to ensure the emissions standards were met for the life of the
appliance. A building code that
mechanically or
electronically linked gas stove use to exhaust fan operation would reduce
exposure.
ETS is the complex mixture of chemicals and particles
(particulate matter) released into the air whenever someone smokes a cigarette,
cigar or pipe. It is a combination of sidestream smoke (smoke from the burning
tobacco product emitted directly into the air) and exhaled mainstream smoke
(the smoke inhaled by the smoker and subsequently exhaled).
ETS poses the same types of threats to the health of
involuntary smokers as active smoking does to smokers. These include acute and
chronic respiratory diseases, lung cancer, and increased incidence of heart and
coronary disease. The NHMRC says that children exposed to ETS are at increased
risk of developing asthma and other respiratory diseases.
Much of the work to determine levels
of ETS in indoor public places in Australia occurred before the relatively
recent practice of banning smoking from many of these areas. In many cases,
smoking bans have followed successful litigation by people harmed by ETS,
rather than extensive scientific research into actual levels. A recent report
on ETS levels in hospitality industry premises in Sydney show that all but one
venue where smoking was permitted had levels of particulate matter that
exceeded the ambient air quality standard. It concluded that these levels were
'likely to be associated with significantly increased risk for respiratory and
cardiovascular disease, particularly in employees'.
A recent study on PM10
levels in more than 130 homes in NSW used a device that accurately size selects
for PM10. The results show levels are significantly correlated with
the presence of smokers. While averaging times were longer than for the NEPM
standard, the majority of the homes with smokers could be inferred to
have PM10
levels that would exceed the ambient standard.
While the past decade has seen marked gains in reducing the
exposure of people to ETS in public places across Australia, there have been
few coordinated efforts to change the situation in homes. The ABS estimated in
1990 that 43 per cent of children aged less than 5 years live with one or more
smokers-some 1.6 million children. While there has since been a slight
reduction in levels of active smoking, the expected reduction in exposure of
children may be less in view of evidence that the rate of decline in smoking
has slowed for younger women, that is, women of prime child-bearing age. In the
recent study mentioned above, the majority of these 1.6 million children may be
exposed to PM10 levels above the NEPM standard.
Most state and territory governments have introduced
legislation that restricts or bans smoking in a variety of public places.
Additionally, owners/operators of other public places such as shopping centres
have taken voluntary action to either discourage or ban smoking, largely to
protect themselves from potential litigation. Little has been done to reduce
exposure to ETS in private dwellings other than by reducing the incidence of
active smoking. As this paper goes to print, NSW has launched an education
program aimed at reducing smoking in houses and cars.
·
Is it of concern?
Australia has one of the highest rates of asthma in the
world. An estimated 1.6 million children are exposed to ETS during the time of
their lives when they potentially develop asthma. This is a grave public health
concern.
·
Possible actions
There is growing evidence that traditional mechanisms to cut
the rate of smoking are becoming less effective as the number of smokers is
reduced to a 'hard core'. Neither education campaigns nor economic mechanisms
such as increasing excise are likely to have a real impact on this group. This
is confirmed by the number of pregnant women who decline to stop smoking even
after they have been warned of the adverse effects on the foetus.
There is urgent need for
action to reduce children's exposure to ETS. Whereas adults can remove themselves from
environments polluted by ETS, children, particularly young children, may not be
able to. While an adult is free to decide to smoke, that choice needs to be
controlled when it impinges on the wellbeing of others, just as drink-driving
laws curtail decisions to drink alcohol. Only government action
can bring about the necessary changes through new, more direct
mechanisms.
Formaldehyde is emitted from a wide range of building and
furnishing materials as a result of its use in their construction or
post-manufacture treatment. In Australia, the most common sources are
compressed wood products such as particle board, where formaldehyde often
occurs in the binding agent. Overseas, it is also associated with a type of
home insulation that is rarely used in Australia.
It can also be emitted from flueless gas appliances. A
recent preliminary study indicated excessive levels of formaldehyde can be
emitted from a 'low NOx' flueless gas heater under some conditions.
Formaldehyde is an irritant gas that potentially affects the
skin, eyes and lungs. Some people become hypersensitive to it, resulting in
symptoms at exposure to very low concentrations. There is evidence that
formaldehyde is a nasal carcinogen.
The NHMRC indoor goal is 100 parts per billion.
A number of studies across Australia have focused on
formaldehyde in situations in which compressed wood products are used
extensively, with the following findings:
·
levels in conventional homes have been found to meet
the NHMRC goal soon after renovation or extensive building works
·
it is unlikely that exposures in conventional housing
stock will exceed the NHMRC goal
·
levels in some conventional offices exceeded
the goal
·
levels of up to 8 and 12 times the goal have been
reported in new caravans and mobile homes and have exceeded the goal, often by
considerable margins, for many years after manufacture.
Formaldehyde is not found in the ambient environment at
other than background levels, except in very limited areas around certain wood
product manufacturing plants. (Increased use of ethanol as a motor vehicle fuel
may increase levels of formaldehyde in ambient air.) Thus indoor exposures are
many times more significant in health terms.
It has been estimated that in 1996, more than 160,000
Australians were living in caravans or mobile homes either permanently (68,000
people) or while on holiday. More than 250,000 caravans were registered in
Australian in 1999. Added to this are workers and children in new, relocatable
offices and classrooms who would also be exposed to elevated levels of
formaldehyde.
Following early findings of unacceptable levels of
formaldehyde from emissions from compressed wood products, especially in
caravans, and relocatable offices and classrooms, industry undertook a
voluntary program to reduce emissions rates to meet the European standard.
Recent work shows considerable improvements in emission rates from these
products. The NHMRC indoor air standard would still be exceeded for some months
after manufacture, but this is a significant improvement on earlier findings.
Australian compressed wood products do not yet meet the (lower) European
standard.
·
Is it of concern?
Many Australians live permanently in mobile homes and
caravans. Of these, many are retirees whose age may make them more susceptible
to the effects of formaldehyde. Thus, this pollutant must remain of concern, in
spite of the improved emissions performance of modern Australian compressed
wood products. Imported products may well have higher emission rates.
·
Possible actions
The procedure used to assess compliance with emissions
standards can have a significant effect on the results obtained. It is
imperative that an Australian standard for testing the emission of formaldehyde
be established without delay. This would add focus and assurance to the voluntary
industry process. Furthermore, it is imperative that any testing
regime is extended to mandatory testing of imported compressed wood
products. Otherwise the situation could
arise where the testing and improvement initiatives for Australian manufactured
materials are undermined by imported product. This situation would be even
worse if the cost of producing low-emission product put Australian
manufacturers at a cost disadvantage to imports.
Further studies on formaldehyde emissions from 'low
NOx' flueless gas heaters are needed to provide a sound basis for
assessment.
House dust mites are ubiquitous in all dwellings, no matter
how clean. They live mainly on discarded skin cells. The allergen is present in
the faeces and parts of the dead mite.
For many asthma sufferers, the HDM allergen is a potent
asthma trigger. It has been estimated that some 85 per cent of young Australian
adult asthmatics are sensitive to the allergen. Furthermore, more than 30 per
cent of all children in a 1997 study showed allergic symptoms to HDM.
Temperatures between 17 and 25° C
and relative humidity greater than 60 per cent provide the optimal breeding
environment for HDM. Unfortunately, this describes the majority of Australian
indoor environments, especially on the coast, for most of the year, so it is
not surprising that levels of HDM allergen have been classified as high in
Australian coastal environments. HDM have been reported as most prevalent in
the home, where levels are between 20 and 40 times higher than in public
buildings.
In 1995, an estimated 11 per cent of Australians, or more
than 2 million people, had asthma. The percentage for children under 15 years
was around 15 per cent.
Although there have not been extensive surveys of HDM
levels, there have been a number of statistically based surveys on which to
base an estimate of potential exposures. Given the high levels of asthma in the
community, the large proportion of asthma sufferers who are sensitive to HDM
allergen, and the high levels of HDM in almost all houses in the temperate
zones, there is a very large population susceptible to exposure to this
pollutant.
While governments have provided
some educational material, direct control actions have not been taken.
·
Is it of concern?
The population at risk and the social and economic costs of
asthma in Australia indicate that HDM allergen is a very serious indoor air
pollutant.
·
Possible actions
It is not clear how many asthmatics
are aware of the potential role of HDM allergen in their illness, or what to do
to reduce exposure to it. A wider education program is needed to reduce the
incidence of HDM and to alert those who are sensitive.
Moulds and fungi can grow anywhere there is sufficient
moisture, using a range of materials such as wood, paint and insulation, as
sources of carbon. They release spores and/or particles into the air either as
part of their reproductive process or on death. These contain toxins that are
believed to cause ill health when inhaled. Species found indoors reflect those
in the ambient environment, although relative abundances may change where the
indoor environment favours a particular species. Air conditioning can be an
important means for increasing indoor levels of moulds and fungi by helping to
disperse spores and by providing areas such as moist ventilating ducts where
the fungi can grow. Where evaporative water coolers are used to reduce
temperatures, cooling increases relative humidity, which can provide a climate
for increased growth of moulds and fungi.
Use of flueless gas heaters, especially when operating on
natural gas, can significantly increase humidity levels in dwellings with
limited ventilation.
Strong associations have been made between mould and various
adverse effects on human health. Many are known to cause allergies such as
hayfever; some are known to be important triggers of asthma, particularly in
drier, inland Australia.
Tests conducted on building occupants suffering allergic
symptoms reported responses to fungi found in air conditioning ducts. A 1994
study found that repeated exposure to spores or other parts of fungi commonly
found in indoor air could result in allergies such as asthma and rhinitis;
extrinsic allergic alveolitis (a group of lung diseases) or hypersensitivity
pneumonitis, which has flu-like symptoms; 'sick building syndrome' including
symptoms such as headache, fatigue and mucosal complaints; or organic dust
toxic syndrome recognised by tightness of the chest, bronchitis and asthma.
Those with impaired immune systems are most at risk.
There have been only limited published studies of fungal
levels in Australian indoor environments. However, the levels found have often
substantially exceeded guidelines proposed by the WHO- including levels up to
36 times greater than the upper limit of the guidelines. In 80 Latrobe Valley
homes examined, one in every eight (12.5 per cent) had total spore counts that
were more than twenty times over the upper limit of the WHO guidelines, and 95
per cent had visible mould growth.
With the limited data available it is difficult to assess
the likely population exposed to levels above the WHO guidelines. However, it
appears that many houses and air-conditioned buildings would have elevated
levels possibly affecting many people. Of greatest concern is the potential
that hospitals may have high levels of fungi in their air conditioning ducts,
when the health of the exposed population is already compromised.
New building codes directed towards improving energy
efficiency have unintentionally resulted in a worsening situation: ventilation
is sometimes reduced to a level where increased humidity favours the
development
of moulds and fungi.
·
Is it of concern?
The results of work conducted in Australian homes, hospitals
and other air-conditioned buildings indicate fungi are an indoor pollutant of
significant concern. Furthermore, it appears there is widespread lack of
knowledge in the general community about their possible adverse
health effects.
·
Possible actions
Urgent action is needed to determine whether
Australian hospitals have unacceptable levels of fungi so that immediate
remedial action can be carried out in any that do. Unfortunately, the proposed 1990 WHO
guidelines have been withdrawn and international airborne concentration goals
do not exist at present. In the absence of agreement about better measurement
techniques (such as direct microscopic examination) and new guidelines, it
would seem justified, in specific cases, to use the previous WHO values as one
means of informing the need for action. Furthermore, the community needs
to be made aware that moulds and fungi may have an important role in causing
ill health and what they can do to improve air quality.
In the past 20 years in Australia, studies of a wide range
of pollutants in indoor air have demonstrated that many represent serious risks
to health at the levels found. Yet there has not been a corresponding level of
action to address the situation for reasons indicated below.
1. Ventilation versus energy
efficiency
The simplest way to reduce levels of indoor air pollution in
domestic situations is to increase ventilation. This dilutes emissions from
sources and products in the home with (the generally much cleaner) ambient air.
However, the trend since the 1970s has been to reduce ventilation, thereby
improving the energy efficiency of houses and reducing the use of fossil fuels
for heating. Many building codes reflect this trend, and no longer require
fixed ventilation. 'Energy-smart' housing emphasises better sealing of
flooring, windows and doors, and in colder areas, double glazing. These are
excellent initiatives for reducing Australia's very large per capita energy
consumption, but they are not good for indoor air quality.
A study of ventilation rates for rooms being heated in
Sydney homes in the late 1980s showed the impact of changes to
building practice.
The average ventilation rate of these rooms was measured at around one air
change per hour. In homes less than five years old, it was only 0.37 air
changes per hour.
Actions to improve energy efficiency must be coupled with
actions to protect indoor air quality and to ensure that indoor sources of
pollution are reduced or eliminated.
2. Global concerns versus indoor air
quality
Concerns over the role of fossil fuel consumption in the
enhanced greenhouse effect have led consumers to seek fuels more likely to
lower global warming. Energy suppliers have tapped this trend as a way to
increase their market share. Thus, natural gas advertises itself as a cleaner
fuel than electricity (generated by coal combustion). While this is true at the
global level, the impact on indoor air quality has often been the opposite.
Electricity used for home space heating does not produce any indoor air
pollutants directly, whereas changing to natural gas heating by flueless gas
heater (the cheapest option) will significantly increase indoor levels of
nitrogen dioxide and other combustion gases.
3. Civil liberties versus protecting the
innocent
The quality of indoor air is often a result of choices made
by the owners or occupiers of that indoor environment. In some cases, the
person responsible for indoor air pollution is also the one to suffer any ill
effects. However, there are two circumstances regarding indoor air pollution
that transfer it from one of personal choice to one of the common good. First,
in almost all indoor environments, there are people-frequently children-subject
to the air quality who are not responsible for the sources that created it.
Second, 'freedom of choice' is almost always exercised in situations in which
the choice-makers have little information about the effects of their decisions
on indoor air quality. Informed choices can only be made when they are based on
adequate knowledge about the implications of the options. Currently, there is no adequate government approach
to providing education and guidance on such important issues.
4. Lack of
standards
It is much more difficult to provide choice-makers with
adequate information when there are no clear Australian standards, goals or
guidelines for the pollutants that may be emitted by a product. While some
people are willing to purchase a product with a lower emission rate on a
'safety first' basis, others are not persuaded unless the choice is between a
product that meets a standard and one that does not. Further, it is much more
difficult to convince manufacturers to improve product performance unless they
need to meet a standard of some type.
Rational debate in a
democracy requires that adequate information is available to all. At present,
there is little community understanding about the health risks posed by a range
of indoor pollutants, including many of those considered in this paper. Quick,
decisive action to improve indoor air quality sometimes requires action by
individuals. That is, there are areas where traditional regulation is not
feasible; rather, the only way forward is by influencing behaviour and choices.
This means that a substantial educational effort is required in much the same
way that education has been used to reduce active smoking and drink driving in
the community.
6. Lack of clear
ownership
Since no one sphere of government or government department
has obvious responsibility for ensuring acceptable indoor air quality, it is
too easy for areas requiring attention to 'slip through the cracks'. It is even
more difficult when the skills and resources needed to make an impact are not
available within a single area of government. To date, no one area of
government has sought to assume a leading or driving role. It has been left for
individual areas to make what progress they can, often without the benefit of a
'whole-of-government' approach. It is urgent that one area of government takes
a coordinating role to ensure that education, evaluation and/or regulation
occur as necessary.
A number of indoor air pollutants
pose a serious risk to public health in Australia. While the extent of this
risk has been understood for some time, little progress has been made in
improving the overall situation.
Following is a list of essential steps for implementing a
process of general improvement, plus a concrete proposal for each step. While
the detail of each step is open to discussion and modification, as a whole they
are necessary conditions for providing acceptable indoor air quality for the
majority of Australians. In fact, they parallel decades of work on the ambient
environment that has resulted in a national approach under the ambient air
NEPMs. A similar national approach is needed for indoor air.
A national working fund would need to be put in place to
establish and initiate an indoor air quality strategy. This would soon be
self-funded by the return on investment generated by reduced heath costs.
The bottom line is that such action will substantially
reduce the $12 billion annual cost of unhealthy indoor air pollution.
1. Establish indoor standards of air quality for the
most common and serious pollutants
This is a trigger step. Until we have adequate Australian
benchmarks we cannot establish the degree of concern about levels of many of
the pollutants mentioned in this paper, and action for improving the situation
in Australia will always be slow.
The process of setting
benchmarks can start without delay by adopting all Australian ambient standards
and goals as interim standards for indoor air. The benchmarks would then be
expanded to other pollutants by adopting international levels as working
guidelines. In some cases it may be decided to await clarifying research. This,
however, would be the outcome of a process that is far more transparent than is
currently the case.
2. Collate
existing information into a national database, establish knowledge gaps and
fund research to fill them
Uncertainties as to the degree of concern about levels of
some individual pollutants need to be reduced as soon as possible by:
·
collating existing measured
indoor air pollution levels into a national database
·
commencing studies in areas
where insufficient data are available
The Commonwealth is funding an attempt to bring together in
a single, easily accessible source as many as possible of the measurements on
indoor air quality that have been undertaken in Australia. This is the first
component of work that needs to be undertaken to document study data, establish
knowledge gaps, assign priorities on the basis of existing knowledge, then fund
work to fill them.
Research on indoor air pollution requires a guiding body to
provide the necessary focus. This would overcome the current situation where
research is frequently fragmented and lacking a mechanism to ensure that the
various components create a cogent whole that could lead to action where
necessary. For example, there is little point in collecting more data on levels
if there is no complementary medical research to quantify the risks
to human health
posed by those levels.
3. Establish
a national body responsible for indoor air
There is no mechanism for
coordinating policy to improve indoor air quality within or between any spheres
of government. By its nature, indoor air quality will cross boundaries of
government responsibility. Compartmentalisation can be a significant hindrance
to action. It can be overcome by establishing, under the auspices of the
federal government, a high-level indoor air quality council to give direction
to all aspects of indoor air quality.
Such a council would be linked to or similar to the National Environment Protection Council, a
statutory body with law making powers established under the
Commonwealth National
Environment Protection Council Act 1994
(see page 4).
The role of the Indoor Air
Quality Council would be to address issues brought before it by its technical
committee or independently by its members. Actions agreed to by Council would
be binding on jurisdictions, as is the case with NEPC, and undertaken in each
jurisdiction under the leadership/direction of the relevant Council
member.
From time to time the
Council would need to establish expert working parties to provide advice about
specific issues. The working parties would assess current evidence and where
necessary, make immediate recommendations to the Council. Actions could include
education, appliance or product control, or direct regulatory control.
The Clean Air Society of
Australia and New Zealand, with its wide range of experts and
independent nature,
should be represented at an appropriate level in this national body.
4. Establish
an evaluation/monitoring mechanism
To close the loop, a mechanism is
needed to assess the effectiveness of measures to reduce exposures to a
particular pollutant indoors to acceptable levels and to determine whether
further actions were necessary. The detail of the mechanism could be determined
on a pollutant-by-pollutant basis at the time the course of action was being
considered. It is likely that these mechanisms would require continuing
monitoring in somewhat the same way that ambient air is subject to a monitoring
regime under the Air NEPM.
5. Create
programs to address the most serious
problems
Action can be taken before a substantial structure is
established and wide-ranging research commissioned. This paper describes
pollutants that are present at unacceptable levels in a substantial proportion
of indoor environments or in a well-defined subgroup of indoor environments.
Large numbers of citizen are potentially affected. Immediate action is needed.
Pollutants in this category include nitrogen dioxide, carbon monoxide,
environmental tobacco smoke, formaldehyde, house dust mites, and moulds and
fungi.
6. Commence a wide-ranging and
comprehensive public education program
In many cases, the poor state of
indoor air quality has been known for decades without effective action being
taken to address the problems. This situation cannot continue. It risks higher
health and other economic costs, and results in social dislocation caused by
preventable morbidity and mortality.
Part of the solution is to institute a coordinated eduction
program that will equip people with the knowledge they need to make informed
decisions about actions that could affect the quality of indoor air. This is
particularly important in those instances where traditional regulation is not
feasible and the only way forward is by influencing behaviour and
decisions.
One immediate action to raise the
community's awareness of indoor air quality would be to institute an annual
National Indoor Air Quality Day. This would highlight the issue and provide a
forum for announcing actions. The day would be an important anchor for
education programs to lift community awareness about indoor pollution.
ABS
Australian
Bureau of Statistics
AGA
Australian
Gas Association
AGL
Australian
Gas Light Company
CASANZ Clean Air Society of
Australia and New Zealand
CSIRO
Commonwealth
Scientific and Industrial Research Organisation
ETS
environmental
tobacco smoke
FASTS
Federation
of Australian Scientific and Technological Societies
HDM
house
dust mite
NEPC
National
Environment Protection Council
NEPM
National
Environment Protection Measure
NHMRC National
Health and Medical Research Council
NOx
total
oxides of nitrogen (a 'low-NOx' gas heater is designed to emit reduced
quantities of NOx)
PM10
particulate
matter with an aerodynamic diameter less than 10 micrometres
WHO
World
Health Organization
