Apples lie in a box after harvest from a Polish orchard. Russia is restricting most fruit and vegetable imports from Poland. (Darek Delmanowicz/European Pressphoto Agency)

As the United States and Europe step up economic sanctions against Russia, Moscow’s food-safety epidemiologists have been working overtime.

In the past few weeks, Russian agricultural and consumer watchdog agencies have announced the discovery of harmful levels of antibiotics in U.S. poultry, contaminants in Ukrainian dairy, pests in European produce and bacteria in U.S. fast food. They have either imposed or threatened blanket bans on the products in question in response to the reported “violations.”

Is it a coincidence that the products are from countries that have imposed sanctions on Russia for its support of a separatist uprising in eastern Ukraine or have otherwise angered the Kremlin?

That’s what the Russian agencies maintain. But experts say the bans are highly politicized gestures in classic Russian diplomatic style. And because it may be too domestically costly for Russia to respond to measures restricting guns, oil exploration and banks in kind, they have settled for sticking it to fruit, cheese and fast food.

“There is always a regulatory agency, environmental agency, or something ready to act,” said Konstantin Sonin, a professor at Moscow’s Higher School of Economics, explaining that the tactics are common in Russia.

Service staff work at a McDonald’s in Moscow. Russian officials are considering banning some items from U.S. fast-food chains. (Denis Sinyakov/Reuters)

As evidence of the link to sanctions, Sonin pointed to the ink and airtime that have been devoted to publicizing the recent food bans in state-run media.

“You can tell by the way it was reported,” he said. “It would not be such a very big thing if this was a local issue.”

Indeed, Russian media has been almost as committed to reporting the unfolding serial drama of food regulations as it has to documenting the tit-for-tat accusations of cross-border shelling between Russia and Ukraine.

The first significant restrictions were directed at dairy products from Ukraine. Many of those products have been blocked from Russian markets since Ukrainians in Kiev’s Independence Square ousted pro-Russian President Viktor Yanukovych in February; the rest were formally curtailed in late July. Fruits and vegetables from Moldova, which, like Ukraine, agreed this summer to formally affiliate itself with the European Union, were the next to hit the chopping block, achieving

produce-non-grata status around the same time.

In the past few days, the scope of the limitations has expanded rapidly: As of Friday, Russian officials have banned most grain imports from Ukraine, stopped bringing in produce from Poland and are murmuring about potentially expanding the food blacklist to include European fruits and vegetables, U.S. chickens, and flagship items from U.S. fast-food restaurant chains such as McDonald’s, Burger King and KFC, according to reports. Separately this week, Wendy’s announced it would be closing its locations in Russia.

That the Russian government has not formally slapped the United States or the E.U. with blanket food bans hasn’t kept state news outlets from speculating that Russia could get along just fine without importing the food products in question. Russia gets about a quarter of its produce from the E.U., but these products could be replaced, a Russia 24 news channel report claimed, with imports from places such as Turkey, Israel, China, Iran and Argentina.

The situation has befuddled agricultural exporters, leaving them wondering how their products could have run afoul of Russian regulations overnight — and how they became apparent pawns in a diplomatic game.

James Sumner, president of the USA Poultry & Egg Export Council, has been involved in poultry exports to Russia for almost a ­quarter-century, since the days when the country bought about 40 percent of all the chickens that left the United States. Today, only about 7 percent of U.S. poultry exports end up in Russia. But because of that historically oversized dependency, he said, Russia has more say in how the chickens destined for its markets are processed than any other country that imports them from the United States.

“Over the last six months or so, there seemed to be no change in the way that this testing and results were being conducted,” Sumner said. “It’s somewhat surprising that at this point we would come under increased scrutiny, after a pretty long track record of working pretty seamlessly with Russian officials.”

U.S. chicken has been targeted before — most recently in 2010. And anti-McDonald’s crusades have been a favorite of Russian health advocates.

Indeed, food products have been in Russia’s regulatory crosshairs in the past, when the political relationship between importer and exporter changed. Such was the fate of Ukrainian chocolate last year, which Russia banned when negotiations between Ukraine and the E.U. surrounding a trade agreement intensified. And Russia reinstated Georgian wine imports just last year after a seven-year ban, supposedly instituted for health concerns in the mid-2000s, when Georgia made a concerted turn toward Europe.

Yet the stakes could always be higher. Over the past few months, as the United States and the E.U. have mulled sanctions, analysts have warned that Russia could retaliate by breaking arms control treaties or working to upset delicate diplomatic processes aimed at keeping Iran’s nuclear capacity and Syria’s civil war in relative check.

By comparison, chickens and produce may be safer and more symbolic targets. So for now, food exporters have no choice but to wait for Russia to decide if it will expand the bans.

“Nothing has changed in the way we produce chicken in the U.S.,” Sumner said. “We’re producing it the same way we always have. We’re just hoping that science prevails and there is no disruption.”