The Health Hazards of
by Agnes Malouf and David
UPdate Summer 2001
cooking with gas? Think again.With natural gas rolling ashore in Nova Scotia,
it is tempting to believe industry and government promises that if only
we could plug into this rich new local resource we could see our fuel bills
drop and free up money in the budget for the nicer things in life.
we still feel the same way if we were to learn that, in trying to save
those hard-earned dollars, we were undermining our health by polluting
the air we breathe in our very homes? It may be discouraging to hear, but
now is the time to listen to what the experts have to say before we make
what may be the wrong decision for us and for our families.
natural gas can be a health hazard both for people who are healthy and
for those who are already ill. It is especially risky for people who have
weakened immune systems, including those who are asthmatic, allergic, or
chemically sensitive. Gas appliances create a constant low level
exposure to gas which can
cause or increase illnesses.
Natural gas is a sensitizer, which means that exposure can lead to intolerance
and adverse reactions both to
it and other substances in our environment.
medical journal, The Lancet, reported in1996 that the use of domestic gas
appliances, particularly gas stoves, was linked to increased asthma, respiratory
illness, and impaired lung function especially in young women. Women
using gas stoves had double the respiratory problems of women cooking on
electric stoves. The same study showed that using extractor fans which
vented the cooking fumes outside did not reduce adverse effects of gas.
Mortgage and Housing Corporation (CMHC) Clean Air Guide (1993) identified
gas water heaters, furnaces, unvented space heaters and cook stoves as
significant contributors to chemical contamination in the home. They recommended
that gas appliances be replaced with electrical ones to reduce indoor air
In a combined series of studies
of 47,000 patients, two doctors found that "the most important sources
of indoor pollution responsible for generating (environmental) illness
were the gas cook stoves, hot water heaters, and furnaces" writes Dr. Bill
Rea, of the Dallas Environmental Health Centre.
natural gas is a pollutant chemical that can worsen both classical allergy
and chemical sensitivity. This effect has been seen mostly in areas
where natural gas is in widespread use," wrote Dr. Gerald Ross, Past President
of the American Academy of Environmental Medicine in1997.
"For the chemically
susceptible individual this gas may be the worst form of fuel," writes
Dr. T. G. Randolph. But surprisingly, his studies found that when
gas stoves were removed from the home of a person with chemical sensitivities,
not only did their health improve, but so did the health of all family
Other studies have found that
children living in homes with gas stoves had more than double the risk
for respiratory symptoms, including asthma. Asthma patients who used a
gas stove seven or more times a week were found to have doubled their risk
of emergency room treatment. Infants who grow up in households with gas
are almost twice as likely to develop childhood asthma as those who live
with second-hand smoke. (Second hand smoke itself doubles a child's risk
of developing asthma.) These studies have all been published in respected
gas is burned, as in cooking and heating, the chemicals create nitrogen
dioxide, carbon monoxide, fine particulates, polycyclicaromatic hydrocarbons,
volatile organic compounds (including formaldehyde) as well as other chemicals.
Just imagine what you are breathing when you bend over a gas cook stove
to stir your food or when you open the oven door. This stuff sticks to
your food, so you eat it as well. It sticks to clothes in gas dryers so
you are covering your skin in it. It is lighter than air so it rises up
into your living and sleeping areas, concentrating higher up nearer your
head. This is one reason why gas is more of a health hazard than fuel oil
which is heavier than air and thus sinks.
It's been estimated that, when
a typical gas oven and three burners are turned on, they release the same
amount of combustion by-products as a typical gas water heater. Regulations
require that all gas water heaters (and gas furnaces) be connected to a
chimney or a side vented directly outdoors. Not so for stoves. Gas driers
are also not vented through chimneys, but through side vents. Side
vents are usually located low on buildings, and vented fumes can re-enter
the living areas through windows, doors and cracks.
At a conference
on air quality and children's health sponsored by the New Brunswick Lung
Association, much attention was given to the respiratory problems caused
by moulds. Natural gas turns out to be a contributor to mould growth.
One of the
principal products of gas combustion is water vapour. Cooking with gas
or burning gas in any way without perfect venting generates considerable
amounts of moisture. When this moisture remains inside a building it is
enough to be a significant contributor to moulds. This excess moisture
also provides better growing conditions for dust mites, viruses and bacteria.
brings harmful chemicals into homes through the methane it contains. Methane
(which gives the flame its blue colour as it does in propane) is
an asphyxiant. It typically contains impurities and additives including
radon and other radioactive materials, BTEX (benzene, toluene, ethylbenzene
and xylene), organometallic compounds such as methylmercury, organoarsenic
and organolead. Mercaptan odorants are also added to natural gas
so that it can be detected by scent before reaching explosive levels.
of the gas itself, as well as products of incomplete combustion including
nitrogen diozide, carbon monoxide and others, have health implications
individually and synergistically, as they combine with each other and with
other indoor pollutants.
is dangerous for several reasons," says health advocate Helen Lofgren .
"Even if you don't use the gas appliance, it is always there, leaking into
the environment. It is dangerous for everybody, even those who do not notice
its effects. If apartment buildings converted to gas stoves and water heaters,
the total effect could be quite serious," Lofgren adds. "Unplanned leaks
and the danger of explosion compound the risks of gas."
Is there a safe way to use natural
gas in the home? Yes and no. If you are going to use gas furnaces or water
heaters, the adverse effects can be lessened considerably by putting them
in a separate building downwind of the house with underground connections.
Failing this, putting a state-of-the-art, totally sealed furnace and water
heater in a separate sealed room with outside air intakes ducted directly
into their combustion chambers, and automatic fans forcing exhaust up a
chimney that extends above the roof line, will result in a substantial
lessening of harmful effects. No side venting should ever be allowed.
all these precautions, when combustion gases leaving a chimney cool they
become heavier than air. Depending on wind conditions, they can reenter
the living space. And there is really no way at present to reduce the risk
of gas appliances like stoves and clothes dryers. It is safest not to have
any combustion at all inside the house.
hearings in Nova Scotia have looked at whether there should be a gas pipeline
and who should own it. But there has been no government assessment
or public hearings into the health effects of home use of natural gas.
Natural gas isn't all bad news.
Using gas to fire up the generators that produce electricity to heat our
homes and run our appliances and in large industrial settings makes environmental
and economic sense. Natural gas is a relatively clean-burning fuel
and it is less polluting of our air than the coal and oil fuels we have
keep it far away from the air we breathe inside our houses, apartment buildings
and schools. If we consider health care costs and the impact of living
with illness, bringing natural gas into our homes is not a sensible choice.
For More Information:
Natural Gas websites: www.geocities.com/RainForest/6847
(note especially the Medical-Environmental Report) and www..gascape.org/
The Healthy Home Handbook: All You Need
to Know to Rid Your Home of Health & Safety Hazards by John Warde,
Random House Inc., 1997.
is a teacher and is a member of the Board of the Nova Scotia Allergy and
Environmental Health Association.
is an environmentalist who has been concerned about the health hazards
of natural gas for many years. He has made presentations on behalf of AEHA-NS
and other organizations at several natural gas public hearings since1996.
He can be reached by email at [email protected]
for additional information.