Art Cullen is editor of the Storm Lake Times in Northwest Iowa. He is author of the book “Storm Lake: Change, Resilience, and Hope in America’s Heartland.”

Ah, the sweet smell of money on a fine spring morning! That’s what we used to say here in Iowa, the pork capital of the United States, where manure covers the black loam like dew. This month, science confirmed what our noses have been telling us for some time: It’s killing us.

We long have known that chemical fertilizer (anhydrous ammonia) and livestock manure (from cattle, swine, poultry) have conspired to make Midwestern surface waters toxic with nitrate and phosphorous, which promote deadly blue-green algae from Toledo to Des Moines. It’s suffocating the Gulf of Mexico, too. All sorts of maladies result from drinking the water from Lake Erie in northwestern Ohio and the Raccoon River in Iowa.

Now comes a study led by researchers from the University of Minnesota, published in the proceedings of the National Academy of Sciences, reporting that 15,900 deaths per year from air pollution can be attributed to people living around livestock.

Northwest Iowa has the densest concentration of farm animals of any place in America. And the livestock industry keeps expanding.

We are flooded in manure. We wear suspenders with our belts — applying enough anhydrous to yield 200 bushels of corn per acre, then throwing some chicken litter on top for insurance. So the Floyd River has nitrate levels four timesgreater than considered safe by the University of Iowa College of Public Health.

Resentment over the pollution isn’t partisan. I have buddies who voted for Donald Trump who will not eat a walleye caught in the Little Sioux River. They know what’s in it. They bemoan the loss of habitat as every last acre of grass is plowed up for corn to feed our 24 million hogs, at least a third of which will be cut into pork for China. In fact, Smithfield Foods, a subsidiary of a giant Chinese conglomerate, is the leading pork processor in the world, and has a major presence in Iowa. We in Northwest Iowa are paying the price for all that ammonia floating into the air from the hogs, from the particulates of manure suspended beneath our noses, and from the tillage that makes the sun glow pink from the dust it kicks up.

Years ago, scientists demonstrated the threat of lung disease for pig-barn workers. Most rural Midwesterners are well aware of higher incidences of asthma among schoolchildren, including those who live among Iowa’s 56 million laying hens.

The Minnesota study puts a number on the death toll.

Of course, the livestock industry pooh-poohs it. Thirty years ago it claimed that the Raccoon River was so hot near Storm Lake because of the nine-hole golf course and lawns, until eye rolls retired that line.

People who put up with it know better. In Ohio, a poll commissioned by the Environmental Law and Policy Center in Chicago, conducted in April by Ann Selzer, reported that 93 percent of northwestern Ohioans (near Lake Erie) said that clean water is their top issue, ranking above jobs or health care; 81 percent want more regulations on confined feeding operations.

In other polls and surveys over the years, Selzer has found strong support in Iowa for clean water and remediation. In 2010, more than 60 percent of Iowa voters approved a constitutional amendment to devote a fraction-of-a-cent sales tax to natural resource preservation. The legislature has refused to enact it.

There is little in either state to hold back the expanding tide of air and water pollution from livestock owned by corporate feeders. Just enforcing the existing manure management plans or following Iowa State University fertilizer guidelines would be a good start. But nobody even knows where all those plans are anymore: Iowa’s coordinator for confined livestock operations was laid off a few years ago.

Fish kills are routine when manure pumplines burst into the Raccoon in Iowa or the Maumee River feeding Lake Erie. The operator gets a fine and lives to fill his manure trucks while they chew up our gravel roads. Iowa has 24 million hogs pooping the equivalent of 83 million people. The land is saturated. The slurry has no place to go but into the air and water. Yet more hoghouses are being built up the Missouri River in South Dakota, where the soil types can’t filter it.

Farmers are none the better for it. There are half as many in my county as there were before livestock moved indoors. But a lot more people are demanding protein in their diets. Since regulation is clearly off the table, we can hope that world population trends down, because the planet can’t stand the abuse from yet more corn feeding more hogs. Or that the production of meat grown in a fermentation lab ramps up — they say it tastes like chicken.

People think we’ve hit our limit. Not Big Pork. The National Pork Producers Council is urging U.S. Agriculture Secretary Tom Vilsack to speed up the slaughterhouse kill line; he refused, and appeals are likely. More hogs are on the way, and time is money. Smells like money, too, if it doesn’t kill you.

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