(Repeats earlier item. John Kemp is a Reuters market analyst.
The views expressed are his own)
By John Kemp
LONDON, June 20 New air pollution standards on
emissions of mercury and other heavy metals from coal-fired
power plants will avert up to 11,000 premature deaths every year
in the United States.
The U.S. Environmental Protection Agency says the standards
will generate benefits worth between $37 billion and $90 billion
a year - with fewer heart attacks, asthma attacks and sick days
- at a cost to coal- and oil-fired power producers of less than
$10 billion ("Regulatory impact analysis for the final air
toxics standards", December 2011).
While the advantages of cleaning up U.S. power plants are
significant, they pale beside the health benefits and reduced
pollution that could be achieved from introducing even more
basic technology in China.
Smog cuts life expectancy in northern Chinese cities by an
average of 5.5 years per person compared with the country's
less-polluted southern regions.
The 500 million residents of northern China lost more than
2.5 billion life-years in the 1990s, according to researchers,
and the premature death toll continues to kill millions early
even today ("Evidence on the impact of sustained exposure to air
pollution on life expectancy", May 2013).
Air pollution is far worse in China, so the benefits from
reducing smog could therefore run into hundreds of billions of
dollars per year.
MERCURY AND HEAVY METALS
In the United States, the Environmental Protection Agency's
new rules target power plant emissions of mercury and other
heavy metals such as arsenic, cadmium, chromium and lead.
Mercury is a toxic metal emitted from most fossil-fuelled
power plants which is converted by microbes into methyl-mercury
and accumulates in fish, where it enters the human food chain.
Exposure to methyl-mercury has been linked to a variety of
neurological problems including reductions in intelligence,
impaired motor skills and attention/behavioural problems.
"The population at highest risk is the children of women who
consumed large amounts of fish and seafood during pregnancy,"
according to the U.S. National Academy of Science. "The risk ...
is likely to be sufficient to result in an increase in the
number of children who have to struggle to keep up in school."
U.S. power plants belched 53 tons of mercury into the
atmosphere in 2005, as well as 350,000 tons of hydrogen
chloride, a corrosive substance blamed for respiratory problems,
according to the federal government.
Emissions in China are far higher. The country's coal-fired
power plants are quite literally poisoning much of the
While mercury and other heavy metals have received most of
the attention, the biggest estimated benefits from the new
pollution standards come from reduced emissions of tiny
particles just a few micrometres in diameter.
Particles measuring just 10 micrometers or 2.5 micrometers
across can become suspended in the air from where they penetrate
deep into the lungs and enter the bloodstream, causing cancer.
Suspended particulates, which may be visible as smog or
haze, kill thousands prematurely in North America and Europe
Cutting emissions of particulates, known as PM10s or PM2.5s,
accounts for most of the measured benefits from the new U.S.
power plant rules, including most of the avoided premature
deaths, hospital admissions and days off work.
While particulate emissions have been gradually reduced in
the United States and other developed economies, they have
continued to grow in China.
The concentration of particulates suspended in the air in
China's northern cities in the 1980s and early 1990s was already
five times higher than it had been in the United States prior to
the enactment of the Clean Air Act in 1970.
EXISTING EMISSION FILTERS
The technology to cut particulate emissions has been
available for decades and is not complicated or expensive.
Emissions control technologies include electrostatic
precipitators, flue-gas desulphurisation units (FGDs), activated
carbon injection, dry sorbent injection, and fabric filters,
also known as baghouses.
These technologies can be used individually or preferably in
combination to eliminate more than 99 percent of the emissions
of particulates, mercury and other heavy metals, as well as
acid-rain-causing sulphur and nitrogen oxides (SOx and NOx).
All these technologies are already in widespread use in the
United States and Europe. In 2012, U.S. power producers captured
52 million tonnes of fly ash, according to the American Coal Ash
"Fly ash is a powdery material that is captured by emissions
control equipment before it can 'fly' up the stack," the
Almost 45 percent of this fly ash was recycled into concrete
(12 million tons), construction fills (3 million tons), blended
cement (2 million tons), and a host of other applications. The
rest is sent to landfill ("Beneficial use of coal combustion
products: an American recycling success story", 2013).
In addition, FGD units, known as scrubbers, use lime or
limestone to absorb sulphur and other elements from flu gases to
produce synthetic gypsum and other saleable compounds. In 2012,
power plants produced almost 24 million tons of FGD gypsum, of
which 12 million was recycled into commercial products.
Historically, all these coal combustion products would have
been sent up the stack and discharged into the atmosphere. In
China, many of them are still being emitted this way.
But U.S. and European power plants have been using
electrostatic precipitators, scrubbers, fabric filters and other
emissions controls for years.
The American Coal Ash Association - which aims to find
environmentally acceptable and commercially beneficial ways to
manage coal combustion products such as fly ash - was founded as
long ago as 1968.
CUTTING CHINA'S SMOG
Smog in China's cities is often presented as if it were the
same problem as greenhouse emissions and climate change.
In fact the two issues are separable, and cutting smog is
the easier of the two to solve.
China could significantly reduce its air pollution by
enforcing the same emission control techniques that have been
used in the United States and Europe for the last 30 years.
Central and provincial governments have already made a start
in compelling power producers to fit FGD units, electrostatic
precipitators and fabric filters ("Emissions of air pollutants
from power plants in China", 2012).
There are some questions about whether those tools are
always switched on, however, as power producers try to save
money ("China's war on pollution needs more than words", March
And the coal-fired boilers that supply northern China's
district heating systems continue to belch pollution with few
China could cut air pollution by retiring these small, old
coal-fired boilers and replacing them with larger, modern power
plants fitted with proper control technology.
China's health crisis is an immediate problem that requires
an urgent response. The technology already exists for China to
clean up its pollution in the short term, even while the country
figures out how to cut greenhouse emissions in the longer term.
(Editing by Dale Hudson)