[sustran] Canadian series on cars
Craig Townsend
townsend at central.murdoch.edu.au
Mon May 21 11:21:29 JST 2001
A 12-part series looking at issues surrounding Canadian society's reliance
on automobiles has just begun running in the Vancouver Sun newspaper. The
first piece discusses some general air pollution issues including the
unintended consequences of catalytic converters which seem relevant to
Sustran. Unless anyone objects, I will continue to post the reports as I
read them.
________________________________________________
From the Vancouver Sun, 19 May 2001
"Why this B.C. doctor says cars are killers: Dr. David Bates, a lung
disease expert, says society has no choice but to work towards
pollution-free cars.'That has to be our aim.'"
Paul McKay Vancouver Sun
When the world's worst single "killer smog" episode engulfed London,
England, in December 1952, Dr. David Bates was a young lung-disease
researcher working at an inner-city hospital there.
According to recently unclassified records, the smog would claim the lives
of 8,000 people. Thousands more had their lungs permanently damaged by the
sulphur-laden fog.
The tragedy shaped his social conscience and career. Bates emigrated to
Canada in 1956, becoming a specialist in air quality and lung disease at
McGill University. Later, he became dean of the University of British
Columbia, then retired as professor emeritus in epidemiology.
The 1952 tragedy also left a permanent mark on Dr. John Last, now professor
emeritus in epidemiology at the University of Ottawa.
"I happened to be in London that week," he recalls. "I remember walking
along Piccadilly and not being able to see my feet because the swirling fog
was so thick. It was eerie. You could hear people's footsteps on the
pavement, or buses go by, but you could never see them."
"People were dying. They were mostly those that already had a delicate
state of health. They were elderly, or they had chronic lung diseases, or
they were very young children."
After emigrating to Canada, the Australian-born doctor became a professor,
public-health advocate and noted author and editor of medical textbooks and
journals. Meanwhile, Bates pioneered the technique of comparing
computerized hospital admission data and air-quality levels, led the
campaign to remove lead from gasoline, advised the state of California on
its notorious smog problem, and published numerous medical papers.
Both are still defending lungs, and fighting air pollution.
"Lungs are the same everywhere," Bates said during an interview at his home
near UBC. "The current Canadian (smog damage) figures are horrendous. The
economic burden of these health costs is appalling."
The message is clear, he says. "We are paying a heavy price for the current
levels of urban air pollution. We have to confront the fact that the auto
used for commuting must be pollution-free. Period. That has to be our aim."
Last concurs. "It's pretty obvious that the sheer number of cars has led to
great increases in emissions and atmospheric pollution.
"Almost every urban area -- if you look down from an aircraft over Ottawa,
Toronto, Vancouver, Calgary -- there's a yellowish layer that you descend
through. That's the sulphur, emitted mostly from automobile exhaust."
In 1999, Bates helped design a landmark Ontario Medical Association study
on air pollution and health effects in the province. Last year, the OMA
reported the annual toll:
-1,900 premature deaths in Ontario;
- 9,800 hospital admissions;
-13,000 emergency room visits;
- 47 million fewer days of work productivity;
- an additional $500 million in direct hospital costs.
A study published in the Canadian Journal of Public Health in 1998,
concluded that polluted air caused 5,000 additional deaths per year in 11
Canadian cities during the 1980s.
Those deaths occurred even though the first wave of catalytic converters on
cars, which were ordered on vehicles in the 1970s, began to reduce
polluting emissions. But, since then, the number of vehicles has doubled
and emissions have re-accelerated in most Canadian cities. A revised
estimate puts the annual national toll at up to 16,000 deaths per year.
Another recent series of Canadian studies on the sulphur compounds emitted
by vehicles -- the leading pollutant implicated in the London smog tragedy
- concluded that reducing just sulphur in gasoline to current California
standards would save $5 billion in national health costs over the next two
decades.
While factories, electric power plants and fossil fuels used for home and
commercial heating release some of these pollutants, the emissions from 18
million passenger vehicles, buses and trucks are the single biggest source.
Tailpipe exhaust accounts for an estimated 41 per cent of nitrous oxides
found in air across Canada, 19 per cent of volatile organic compounds, 38
per cent of carbon monoxide, 53 per cent of benzene, 25 to 30 per cent of
microscopic soot particles, and up to 60 per cent of sulphur dioxide. These
are average figures: The concentrations in congested cities are far higher.
In Vancouver, vehicle emissions are already the largest source of air
pollution -- and growing fast.
"The health implications are considerable. In the next 25 years, the
population in Vancouver and its atmospheric basin will at least double,"
Last says. "There will be a higher proportion of both older people, and
infants and young children. They are the most vulnerable to the effects of
increased atmospheric pollution.
"We can expect sharp increases in the number of acute respiratory episodes,
and more chronic respiratory damage, and more deaths."
Bates and Last say auto pollutants are especially dangerous because they
are generated where 20 million Canadians live, and because up to half of
the microscopic tailpipe particles that are breathed into lungs are not
breathed out again.
"From vehicles you have particles directly emitted, about the size of a
micron, diesel particles the same size, that are directly respirable,"
Bates says.
"Any combustion particle in that size range has an effect on people. They
get deposited in the lungs at a high deposition rate. Between 40 and 50 per
cent you don't breathe out again. They are retained in the lung. You have
36 divisions of tubes, and a half a million tiny tubes. The particles are
small enough to get down those tubes."
The microscopic tailpipe particles, which are normally invisible and
odourless, carry compounds of sulphur and nitrogen, heavy metals, unburned
carbons, and secondary pollutants that form ground-level ozone. Pollutants
like carbon monoxide bind to the hemoglobin in blood, robbing it of oxygen.
Unburned carbon particles are toxic, and are listed as a carcinogen in the
U.S. when emitted by diesel engines.
"The particles are solids, aerosols, or gases of microscopic size. If they
are below a certain critical size, 10 microns, they will get into the
smallest tubes in the lung," Last says.
"If they are less than 2.5 microns, (one 50th the size of a human hair)
they will get into the air spaces at the very ends of the bronchial tubes
where the oxygen-to-blood exchange takes place."
"If the particles are acidic, like sulphur dioxide, they are capable of
eating away the lining of the lungs. Over a period of repeated exposures,
it can cause chronic, degenerative changes in the lungs."
Because their lungs are smaller, infants and young children are most
vulnerable, Last says.
"In order to achieve the necessary air exchange -- oxygen in, carbon
dioxide out -- they have to breathe more rapidly. Plus their lung mechanics
mean the smallest particles can get in more deeply, and their lung cells
are still growing. They also play outside in the summer, when the air
pollutants are worst."
The body has defence mechanisms to gradually excrete the particles, Bates
says, but medical studies indicate that the effort puts extra stress on the
heart and lungs. For those already suffering from chronic lung and heart
problems, the pollutants can trigger erratic pulse and heart rates, severe
asthma attacks, pneumonia, a weakening of the body's immune system, or death.
While catalytic converters on cars have helped cut tailpipe emissions,
Bates says they have also had an unintended side-effect: Pollutants that
aren't destroyed are burned into smaller particles and new versions are
created in microscopic aerosol form. These tiny particles are deadly in a
different way.
"The smaller the particles, the more (lung) surface area is covered, and
the more toxic the particle. There's a whole wealth of that data."
The Canadian smog and health statistics dovetail with similar studies
elsewhere.
Bates cites a blizzard of recent smog studies and statistics: levels during
the Atlanta Olympics; hospital admissions in Brisbane, Australia; a report
on health costs due to smog in Europe; the number of diesel taxis in
London; the cost of pollution control equipment on a generating station
near Vancouver; diesel concentrations in Santiago, Chile; a recent U.S.
Supreme Court ruling on diesel emissions.
Both experts agree that a clear pattern emerges from these studies:
impressive gains from catalytic converters on cars are being wiped out by a
250-per-cent increase in car use since they were introduced. And chronic
exposure to auto pollutants can cause more long-term health damage than
summer "spikes."
"Spikes produce acute episodes like the London smog of 1952, and some
recently here in Canada," Last says. "The long-term effects of much lower
levels are chronic damage. Repeated insults can tip that over the edge into
lethal damage (caused by) acute smog episodes."
Bates says the impact of summer smog spikes can be readily seen in next-day
hospital admissions - particularly for infants and elderly people with lung
and heart problems.
"Every study shows the same thing. In the summer, there is a strong
association between ozone and sulphates together, and hospital admissions
for asthma and other lung diseases."
He says a study of smog levels during the Atlanta Olympics, conducted by
the Centres for Disease Control in Atlanta and published in the Journal of
the American Medical Association, confirms that equally dramatic benefits
can occur when smog levels drop sharply.
"The ozone peak fell because there was a 20-per-cent reduction in
automobile use for 17 days, due to an appeal to the public. That produced a
40-per-cent reduction for emergency hospital admissions for asthma."
Both doctors also warn that the carbon dioxide constantly emitted by
vehicles (2.3 kilograms per litre of gasoline) is helping to cause a
"greenhouse effect" that magnifies smog damage and may trigger violent
climate changes.
"An increase of temperature would increase the formation of smog from
nitrous oxides," Bates says. "Even if the amount of air pollutants remains
constant, if the temperature goes up the ozone (smog) peaks will go up. And
the health damage will be proportional, even in places like southern
Ontario and Quebec."
"When we're talking about the adverse damage on health by exhaust from
automobiles, the direct bill comes from damage to respiratory systems,"
Last says.
"But I'm even more concerned about auto emissions and the atmospheric
accumulation of greenhouse gases. The long-term consequences will be
devastating, possibly catastrophic effects on the health of huge numbers of
people."
That evidence is now rock solid, Last says.
"Only a lunatic fringe, or those associated with the industries who are
causing the problem, deny that. Every new report on this makes the case
more persuasive. I know many of the health professionals who are working on
this. I have studied it. It is good science."
________________________________________________
Craig Townsend
Institute for Sustainability & Technology Policy
Murdoch University
South Street, Murdoch
Perth, Western Australia 6150
tel: (61 8) 9360 6293
fax: (61 8) 9360 6421
email: townsend at central.murdoch.edu.au
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