This allergy season has been terrible. It seems like everyone I know has been running around with leaky eyes, even those of us who aren't typically pollen-sensitive. Granted, there was an unusual amount of tree sperm in the air this year, but it seemed strange that everybody -- really, everybody! -- was afflicted. But a new study by Finnish researchers explains everything: The reason we’re all so sick is that we live in the city.

According to this study, published in Proceedings of the National Academy of Sciences and based on research done in Finland, people who live in cities are more prone to developing allergies and asthma because their environments lack biodiversity. That’s not biodiversity as in “not enough kinds of cuddly wildlife” (although that too!) -- it's about the diversity of bacteria that live on your skin. If you live in the city, these freeloaders are less varied, and that spells trouble.

Photo by Paul O'Donnell.

One man's trash is another man's airplane fuel.

Adventure-seeker Andy Pag aims to obtain funding and become the first person to fly a trash-fueled plane from one end of the U.K. to the other. His aircraft, a microlight plane, will be powered by gasoline made from un-recyclable plastics like bags and packaging.

The fuel is made by a British company using Fischer–Tropsch synthesis--a process of making synthetic fuel that dates back to before WWII. Pag says the fuel is worth highlighting because it produces limited CO2, and reduces the volume of plastics that otherwise would go to landfills.

What are you supporting when you leave your money in the oily hands of Bank of America? Among other evils, investment in coal-fired power plants and the bankrolling of climate change. Normally you don't think about that. You just get your money and scoot away. But Power Shift activists forced ATM users to think twice about what they were really doing by mindlessly punching buttons when they turned a bunch of Bank of America ATMs into "automated truth machines."

There’s good news and bad news about U.S. air pollution. We’ll hit you with the good news first.

The American Lung Association released its State of the Air 2012 report today, and the study shows some improvement in the nation’s air quality (huzzah!).

The volunteer health organization examined 2008-2010 ozone levels, the main ingredient of smog air pollution, and air-particle pollution at official measuring sites across the U.S.

Out of the 25 cities with the most ozone pollution, 22 saw improvements in air quality over last year's report. Similar advancements were seen among cities with the most year-round particle pollution.

And now for the bad news: Despite the progress, the country’s air is still woefully polluted. About 127 million Americans -- a whopping 41 percent of us -- still endure pollution levels that make it dangerous to breathe. Check out the top 10 regions with the dubious distinction of having the most year-round particle pollution. (Spoiler alert: If you’re from several parts of California, you may want to consider relocating).

Photo by Fried Dough.

Big Tobacco agreed way back in 1998 to stop marketing [PDF] cigarettes to kids. Turns out cigarette companies are still up to their old tricks -- they’re just being slightly more stealth about it.

Researchers from California’s Tobacco-Related Disease Research Program recently examined the advertising of menthol and Newport-brand cigarettes in the state. They found a much greater prevalence of cigarette advertising in areas near high schools with significant populations of African American students.

“There is a systematic targeting (of disadvantaged communities) by the tobacco industry, which is an extraordinary public health problem,” said Lisa Henriksen of the Stanford Prevention Research Center, who presented the research at a legislative briefing in Sacramento last week. “The addition of menthol to cigarettes makes it easier to smoke and more difficult to quit.”

Tara Hui points out an "illegal" Asian pear she's grafted onto an ornamental pear tree.

Ornamental fruit trees are the worst idea ever. And I'd argue they say a lot about our culture. As we’ve built and expanded cities, and planted public trees, we've decided that local fruit -- fruit you could pick right on the street -- was too messy. We wanted our fruit imported, wrapped in plastic, and safely compartmentalized in the produce aisle. So we bred trees accordingly. Pear trees with no pears. Cherry trees with no cherries.

Now this San Francisco-based group called the Guerrilla Grafters is challenging the very notion of the ornamental fruit tree. And they're working outside the law (city officials don't like rotten fruit on the sidewalk, nor the liability it suggests). They’re covertly grafting -- a practice of connecting two branches in a way that will allow their vascular tissues to join together -- fruit tree limbs onto the trunks of ornamental cherry, plum, and pear trees. (We’ve highlighted them before on Grist, but since NPR covered their illegal work again this weekend, I thought it was worth another mention.)

Planting trees in West Philly. (Photo by Danielle Clarke.)

One Saturday in November, a few hundred volunteers descended upon parks and creek banks in and around Philadelphia to plant more than 2,000 trees. That day’s plantings were just a piece of a broader initiative to plant 300,000 trees in the City of Brotherly Love by 2015. And that initiative is but one part of a much larger program spearheaded by the Pennsylvania Horticultural Society that aims to plug 1 million trees into the ground across 13 counties in southeastern Pennsylvania, New Jersey, and Delaware. The mid-Atlantic is seriously putting the moves on Mother Nature.

As cities around the country jockey to be the King of Green, mayors and community organizations have been eager to claim their place as the next urban Johnny Appleseed. (Upon becoming mayor in 2008, Philadelphia Mayor Michael Nutter declared the city would become the greenest in America, and established an office of sustainability to show everyone he meant business.) But despite all the work days and feel-good volunteerism, urban forests are losing ground, in part because many, if not most, trees planted in cities die early deaths.

The EPA is issuing new regulations for emissions from power plants, and the American Lung Association knows why. This map shows U.S. deaths caused by toxic power plant emissions. If you live in a state with a big red circle, you should be very very glad about the new rule -- Texas in particular should be jumping for joy, if they can manage to stop coughing for five minutes.

The Sierra Club and the Natural Resources Defense Council (NRDC) did a really good job at tugging every heartstring available in this new ad:

Seriously, how much do you want to cry now? Maybe they really should send asthmatic kids into Congress as lobbyists.

NRDC and Sierra Club are doing the closest thing possible without running afoul of child labor laws -- they’re running the ad in Virginia, Ohio, Pennsylvania, and D.C. So when a legislator comes home from a hard day on the Hill and settles in to watch Two and Half Men -- bam! -- now he's crying because he didn't go into politics to give kids asthma.

Regulations kill jobs? Yeah, we've heard that one before.

Cross-posted from the Center for Progressive Reform.

The Economist’s Feb. 18 edition offers a cover package of five articles on “Over-regulated America” (1, 2, 3, 4, 5). Our British friends want you to know there’s a problem here in the States that needs fixing:

A study for the Small Business Administration [SBA], a government body, found that regulations in general add $10,585 in costs per employee. It’s a wonder the jobless rate isn’t even higher than it is.

You can almost feel The Economist’s pain: The jobless rate should be a lot higher than it is, if the premise about the costs of regulations is correct. Surely if the regulatory burden were actually 12 percent of GDP -- that’s what the SBA numbers say, if you draw them out -- things would be far worse than they are. Ideologically unable to consider the obvious alternative -- that regulations don’t add $10,585 in costs per employee -- The Economist just, well, “wonders” aloud.