Deadly air pollution has a surprising culprit: Growing corn

A
new study
raises serious concerns about the human health
consequences of growing corn. Though air quality has improved in
the United States in recent decades, fine particulate matter still
kills
about 71,000 people each year
— and is one of the
leading causes of death
globally. About 4,300 of those deaths
are from the process of growing corn, mostly due to the application
of ammonia as a fertilizer. That’s more people than died
in Hurricane Maria
, every single year.

“The magnitude of the problem is surprising,” said
University of Minnesota’s Jason Hill, the study’s lead author.
“We tend to think of air pollution from smokestacks and
tailpipes, but agriculture is a major contributor to reduced air
quality also.” Hill and his colleagues found that ammonia from
corn fertilizer significantly increases atmospheric PM2.5
levels
, a particularly deadly form of air pollution.

In total, corn alone is responsible for about a quarter of
agricultural-related air pollution deaths, with most of the rest
due to animal agriculture. Since corn is a primary source of animal
feed, the new study likely underestimates its impact on air
quality.

The study attempted to estimate the cost of growing corn on
human health and climate change. The researchers used the EPA’s
values of $9 million for every avoided death due to air pollution
and $43 per ton of CO2 for
the social cost of carbon
. In terms of air pollution and carbon
emissions, that means the harm caused by growing corn is equal to
about 70 percent of the value of the corn that’s produced — a
shockingly high value.

But even that doesn’t include the emissions from animal
agriculture or corn ethanol. Most corn
grown in America goes to producing ethanol, for use in animal feed,
and other industrial uses. Only a small percentage is for human
consumption.

“The full impact of corn is going to be much larger,” Hill
said.

This huge impact is likely not evenly distributed. Hill’s
previous research showed that the cost of air pollution in general
is borne
disproportionately by communities of color
. He’s working to
see if the same is true for agricultural-based air pollution.

In
an interview
with Brownfield Ag News, Nathan Fields, the vice
president of production and sustainability for the National Corn
Growers Association, called the study “divisive.” “It’s no
secret that corn production is an intensive cropping system,”
Fields said, noting that the industry has been trying to “lower
that footprint as much as possible” for decades.

“The way that we react, I would say, is just to highlight all
the work that’s been done, all the research that’s going into
nutrient use efficiency that’s out there and hopefully not spend
more money and more resources on paper studies trying to link it to
horrible situations,” he added.

Hill told me that the importance of his research is magnified
because it was funded in part by the USDA, EPA, and the Department
of Energy. “As members of publicly funded universities, our
charge is to look for problems that affect the public and solutions
to them,” Hill said. “The paper went into detail about the ways
that this problem could be alleviated.”

Among the solutions Hill floated: precision agriculture, using
different fertilizer types, changing the location of where corn is
planted so it’s not upwind from major cities, crop switching, and
even dietary shifts away from foods that use corn-based
ingredients.

“We need to do a better job at controlling ammonia emissions
from corn itself; that will have immediate benefits to human
health,” Hill said.

This story was originally published by Grist with the headline
Deadly air pollution has a surprising culprit: Growing corn
on
Apr 4, 2019.

Source: FS – All – Science – News
Deadly air pollution has a surprising culprit: Growing corn