By Alex Roslin
Thursday, July 16, 2009
The Georgia Straight
[Read story at the Straight website]
Remember
when they called it “swine flu”? The first pandemic flu in 41 years was quickly
renamed “H1N1” in its early days after the pig industry, in damage-control
mode, proclaimed loudly that people couldn’t get sick from eating pork. And
they said that it looked like the flu was spreading worldwide from person to
person—not from pigs to people.
More
than two months after the initial outbreak, it’s still not clear how the flu
started. The most accepted explanation is that a farm worker at a massive swine
operation in Mexico got the virus from a pig and carried it into the wider
population, where it spread without any more involvement from pigs.
But
a closer look at the data on H1N1 cases in B.C. and the rest of Canada suggests
the pandemic has a much closer relationship with pig farming than suspected.
That relationship is especially striking in the most serious cases of the flu
that have caused hospitalization and death.
The
Fraser Health Authority, the district with the largest number of pigs in the
province—and one of the most intensively farmed areas in Canada—has a
39-percent-higher rate of confirmed H1N1 cases per capita (9.7 per 100,000
people) than the provincial average (7.0 per 100,000), according to data from
the B.C. Centre for Disease Control as of July 6. B.C.’s first confirmed death
from H1N1 flu occurred on July 13 in the region.
The
rate is even higher in the Northern Health Authority, which has the highest
ratio of pigs to people in the province. The northern region has a
48-percent-higher per capita H1N1 rate (10.3 per 100,000) than the B.C.
average.
The
data shows a near-perfect 93-percent correlation between the number of pigs in
a health region and the number of confirmed H1N1 cases there. (Correlation
measures the strength of the relationship between two groups of data. A
correlation of 70 percent or higher is generally considered to be strong.)
Density
of pigs also seems to have a relationship with H1N1 rates—especially when it
comes to the most recent flu cases. There is a 95-percent correlation between
new cases of H1N1 confirmed during the week of June 29 and the number of pigs
per farm in a particular region.
The
same high correlations exist Canada-wide, according to Statistics
Canada figures on pig
farms and an analysis of data on confirmed
H1N1 cases from the
Public Health Agency of Canada as of July 8. The data shows that the flu has
been more severe in areas with intensive, large-scale hog production.
The
total number of confirmed H1N1 cases in each province has a 99-percent
correlation with the number of pig farms in that province.
In
Quebec, the province with the highest number of pigs—4.3 million—residents were
twice as likely to be hospitalized when they acquired H1N1 as the Canadian
average. Quebec’s death rate from H1N1 per capita has been 60 percent higher
than the national average.
The
flu outbreak has been even more severe in Manitoba, which has 2.4 pigs per
person, more than any other province. There, the number of H1N1
hospitalizations per capita is triple the national average. The rate of H1N1
deaths per capita in Manitoba has been more than 3.7 times higher than the
Canadian average.
The
high correlations surprised even long-time critics of intensive, large-scale
farming. “Wow, that’s astounding,” said Peter Fricker, projects and communications
director for the Vancouver Humane Society.
“If
there is a possible link between pig farms and susceptibility to disease,
public-health authorities should definitely be investigating. If the
correlations are correct, the whole issue of factory farming has to be looked
at,” he said in a phone interview.
“Wow,
really. I don’t think anybody’s looked at this before,” said Bob Martin, who
headed the Pew Commission on Industrial Farm Animal Production, which released
a major
study last year that said
workers in large farms and their neighbours have high rates of asthma and other
respiratory illnesses due to manure runoff and emissions like ammonia and
fine-particle pollution.
Martin,
speaking from Washington, D.C., said some people living near pig farms could be
more susceptible to H1N1 and to more severe reactions because of such
respiratory ailments.
As
of mid-June, 40 percent of the people who had died of H1N1 in the U.S. had had
an additional medical condition like asthma, diabetes, a compromised immune
system, or heart disease, according to the U.S. Centers for Disease Control.
Dr.
David Patrick, director of epidemiology at the B.C. Centre for Disease Control,
said the data could mean people living in hog-producing regions have a higher
predisposition to catching H1N1. But he cautioned that there could be other,
unknown explanations for the high correlations, too.
“The
fact that particulates can predispose people to asthma is clear. If
particulates are an issue, we have to gradually improve our environment,” he
said.
“If
we have issues of predisposition [to catching H1N1], that’s a question for
sober inquiry by people in environmental health.”
Until
now, he said, public-health officials have believed H1N1 spreads randomly
between people or may cluster in areas with dense human populations.
“Probably
the most important message is if people with flu symptoms have asthma or
chronic lung disease or anything that affects their immune system, see a doctor
right away because antivirals can help avoid hospitalization,” he said.
The
B.C. Pork Producers Association didn’t return a call for comment.
In
the province’s agricultural
heartland, the Fraser Valley, H1N1 seems to be going strong instead of dying
off after the end of the usual flu season, as initially predicted. So far, the
vast majority of incidents have been mild, but a flurry of 22 new H1N1 cases
there was confirmed during the week of June 29. That number was the highest in
any region of the province and almost twice as many per capita as the
provincial average.
The
high numbers coincide with a trend of relatively high incidence of recent H1N1
cases in some of the biggest hog-producing provinces. During the week after
July 3, Manitoba saw the highest rate of new confirmed H1N1 cases per capita in
Canada (8.4 per 100,000)—5.6 times more than the Canadian average (1.5 per
100,000).
The
location of new flu cases also seems to have a close relationship with
especially high concentrations of pig farming. There is an 80-percent correlation
between the number of new cases in the seven days after July 3 and a province’s
ratio of pigs to people. In other words, the more pigs there are per person,
the higher the rate of the flu.
And
no region of Canada has a higher density of farm animals by weight than the
Fraser Valley, according to Hans Schreier, a soil scientist and professor
emeritus at the University of British Columbia who has studied agricultural
pollution in the Valley.
“We’re
generating so much manure in these operations, it winds up in the soil and
water,” he said in a phone interview.
Thanks
in large part to massive amounts of farm waste pouring into the Fraser River
watershed, the Georgia Basin is “perhaps the most threatened area in the
country” for coastal eutrophication—a process that stimulates algae blooms and
chokes marine life—according to a study Schreier coauthored in 2006 in the
journal Biogeochemistry.
The study said farm-waste discharge is poorly regulated across Canada.
An
Agriculture Canada report in 2002 found factory pig farms were causing health
and pollution risks to farm workers and the local community. “In B.C.’s Fraser
Valley, this chemical soup [from farm emissions] is so thick it causes a
visible haze and can make up 70 per cent of the airborne particles in summer,”
said the report, which was quoted in a 2002 Ottawa Citizen story and was obtained under an
access-to-information request.
And
of all the farm animals in the region, pigs are by far the single biggest
source of smog-causing fine-particle pollution, contributing 64 percent of the
total fine-particulate matter from all farm-animal sources in the Fraser Valley
Regional District, according to a 2004 study done for the district and
Environment Canada.
That
study noted that while air-quality improvement in the region had focused on
reducing emissions from vehicles and industry, “emissions from agricultural
operations have been relatively untouched.”
Meanwhile,
levels of nitrogen—another big emission from farms—in ground water in the
Central Fraser have been above the allowable limit for drinking water since
1981, according to a 1997 UBC study published in the journal Environmental
Management.
George
Peary, the
mayor of Abbotsford, shares his community with the highest number of pigs of
any agricultural district in the province—75,570, according to the 2006 census.
He acknowledged that manure from pig farms has seeped into ground water in some
areas and made some well water undrinkable, but he defended farming practices.
“I wouldn’t tie it [H1N1] to agricultural operations,” he said in a phone
interview.
“If
there were an issue, the public-health people would keep me informed.…There
would be all sorts of bells and whistles going off.”
A
top health official also dismissed the higher H1N1 rates in his region and said
they’re not worthy of further investigation or action. “It just doesn’t matter.
It spreads from person to person.…We’re not looking at it from that perspective,”
said Dr. Roland Guasparini, chief medical health officer with the Fraser Health
Authority.
In
recent years, the B.C. government has encouraged hog producers to spread far
north to the fertile Peace River region, where there’s more available farmland.
The policy has helped turn Peace River into the fastest-growing hog-producing
region in the entire country, with a threefold expansion in pig numbers between
2001 and 2006. The region is now home to 24,000 pigs, more than double the
human population of Dawson Creek, the region’s administrative centre.
And
it just so happens that the Northern Health Authority, which includes the Peace
River area, has the highest ratio of pigs to people in the province—and the
highest rate of confirmed H1N1 flu cases per capita.
Just
across the nearby Alberta border, Denis Sauvageau has all kinds of experience
with pig farms moving in next door. He is a fourth-generation farmer in a tiny
community called Falher.
On
April 28, Canada’s first death related to H1N1 occurred at the High Prairie
Health Complex, a 50-minute drive east from Sauvageau’s house. The woman had
had asthma-related difficulties, though there’s no evidence they were related
to farming emissions.
Sauvageau
still recalls vividly how hog producers first came to town in the late 1990s
with a slick promotion campaign promising a miracle of rural revitalization.
“They would create jobs, keep schools open, keep our children here,” he said.
Today,
the smell from a complex of large pig farms five kilometres away is often so
strong, Sauvageau can’t stay outside. “The stench is gut-wrenching. It makes
you want to puke. You’re done for the night.”
Sauvageau
and his neighbours started a protest group, the Peace River Environmental
Society, six years ago to demand improvements in farm waste management
practices. They held demonstrations. The group estimated that the 50,000 swine
in nearby farms produce 20 million gallons of manure per year.
Especially
worrisome, he said, are the health problems in nearby areas—high rates of
asthma and other respiratory illnesses.
The
group finally convinced a reluctant province to study air quality in the area.
“Odours do extend into surrounding areas at levels that may disrupt quality of
life,” a draft
version of the province’s report said
in 2007. “The subgroup agreed by consensus that odour from CFOs [confined
feeding operations] can have health effects.”
(The
report was never published because the committee writing it, dominated by
government and industry officials, couldn’t reach agreement on the document;
Sauvageau’s group posted the draft on its Web site.)
The
report cited other studies that had found ammonia from farms can reach levels
in the surrounding area that can cause eye and throat irritation, respiratory
problems, haze, and fine-particle pollution. Farm emissions of hydrogen
sulphide, an eye and respiratory-tract irritant and neurotoxin at high doses,
can “cause significant quality-of-human-life concern at the local scale”,
according to a 2003 U.S. National Research Council study cited in the report.
The
Alberta report also cited international research that found pig-farm workers
have rates of chronic bronchitis that are 2.5 to 5 times higher than those in
the wider population and 50- to 100-percent higher than those in dairy and
poultry workers.
The
possible connection between intensive hog operations and H1N1 means governments
should tighten rules on farm waste, according to the humane society’s Peter
Fricker. “They’re like small cities, except with no sewer system. You could
understand why there would be a risk to human health.”
The
Pew Commission’s Bob Martin agreed: “We have reached the point that we have to
decentralize this production. It’s really a critical kind of issue.”
With
22 new flu cases confirmed just on July 13 and 14—two-thirds in the
Fraser—maybe we’ll be calling it “swine flu” again soon.
H1N1 Flu Not
Linked to Cattle Farms
Canada-wide,
the death rate in confirmed H1N1 cases per capita in each province has an
88-percent correlation with the number of pigs per farm in that province (the
bigger the pig farms, the higher the death rate) and an 89-percent correlation
with the ratio of pigs to people in the province.
Also
worrisome are trends among new cases. The number of new confirmed cases since
July 3 in each province has a 97-percent correlation with the number of pigs in
the province.
H1N1
rates have a much weaker relationship with poultry and cattle farming. Although
a small correlation exists with H1N1 in some cases, especially with poultry
operations, it is, on balance, more than twice as high for pig farms. In B.C.,
H1N1 rates actually tend to have a negative correlation with cattle farming
(meaning the more cattle or dairy farms, the fewer flu cases there generally
are in a region).
