Shoes are fashion’s version of drugs.

More than any other article of clothing, shoes alter the way we move, walk and feel. Shoes spur cravings, compulsions and crimes as no other clothing does. Some people can’t have sex without seeing or touching shoes. (Know any hat or tube-sock fetishists?) The fashion industry knows this. It tells us that shoes can improve our health, skill, speed: that, in effect, shoes are medicine. The industry tells us shoes can render us irresistible. Thus it knows it can charge us anything.

It also knows we can’t go DIY with shoes, the way we can with drawstring totebags and elastic-waisted skirts. When we buy shoes, we’re paying for technology — and design, transit, marketing, and manufacturing that (just as with real drugs) occurs far away under conditions we’d rather not envision as we buckle strappy sandals as seen on TV.

In 2005, the National Labor Committee and China Labor Watch reported that Chinese factory workers making New Balance shoes earned 40 cents an hour, which dropped to 32 cents after mandatory room-and-board deductions.

“I was unprepared for the heat,” says Beth Rosenberg, a Tufts University assistant professor of public health and community medicine who toured Chinese shoe factories as part of a project funded by the International Labor Organization. “Air conditioning — are you kidding? They don’t even have fans.”

Not permitted to sit, assembly-line laborers stood all day breathing solvent fumes amidst unguarded cutting machines in the factories Rosenberg toured, which produced shoes for Nike, Timberland, Clark, and other brands. The air outside the factories was palpably polluted. When Rosenberg asked workers what they’d like to change about their jobs, “they were so terrified that they would not answer the f—— question. Ask Americans that question, and they’ve all got opinions.” Staring floorward, the Chinese workers wouldn’t speak.

“Those factories are hellholes. Even the ones with corporate-responsibility programs, where the managers are trained not to scream in workers’ faces or schedule seventeen-hour shifts, are hellholes.”

Rising costs — minimum wage in Beijing is soon set to reach $140 a month — is driving factory production from China to cheaper locales such as Vietnam.

In the Philippines, Thailand and Indonesia, millions of shoes destined to be sold overseas are produced in private homes, as piecework, by entire families. By using men, women and children to stitch, glue and polish shoes at home, companies needn’t invest in factories, machinery or managers.

As part of the hard-to-regulate “informal sector,” home-based shoe assemblers are “invisible,” says chemical engineer Pia Markkanen, a professor in the University of Massachusetts’ Department of Work Environment. While researching her book Shoes, Glues, and Homework (Baywood, 2009), Markkanen visited many home-based shops such as this one in Thailand:

At the front door, stacks of shoeboxes were ready to be transported. … Two women sitting cross-legged on the floor were cleaning and polishing dozens of pairs of shoes. On the second floor, workers toiled surrounded by raw materials, boxes, tools, cooking equipment, glue cans, sewing machines, finished and unfinished shoes, and electrical wiring. Some of them ate a meal, drank a cup of coffee, or smoked cigarettes. … Toxic fumes emanated from open glue bowls and cleaning and polishing chemicals.

Home-based shoe production is widespread and “extraordinarily dangerous,” she says.

“Chemical hazards make shoemaking particularly hazardous. Organic solvents — used in glues, primers, and cleaning and polishing products — are essentially petrochemicals. The storage of toxic and flammable chemicals constitutes not only a health hazard but a fire and explosion hazard.”

The primary solvents used in Asian shoe manufacture are toluene and hexane. Primers contain mostly methyl-ethyl-ketone (MEK). All three are known neurotoxins, linked to reproductive problems and liver damage.

“Toluene and hexane and MEK are already very bad news, but it gets even worse. Petrochemical-based glues are often mixtures of multiple organic solvents — e.g. toluene, acetone, MEK, ethyl acetate, xylene, hexane, dichloromethane, and so forth,” Markkanen says. “These dangerous chemicals do not belong in anyone’s home.”

Their dangers are largely kept secret from the workers who use them — and whose children not only use them but eat, sleep and play near them:

“When I first got involved in shoe research in 2001, I placed different glue containers next to one another to read their labels. All adhesive, primer, and other chemical containers, anywhere I went, lacked information about active ingredients.”

When Markkanen asked glue-factory bosses why their labels were so vague, “I got the following answer: ‘If we put skulls, crossbones, and [other danger signs] on our containers, no one would buy our products.'”

Factories might have effective ventilation; tiny urban apartments don’t. She advocated the use of safer, water-based adhesives, but “the fact is that the petrochemical industry has been the major chemical supplier for footwear adhesive and primer manufacturers” for so long that many shoe-industry subcontractors refused to even consider switching.

Although toluene, hexane, and the other chemicals aren’t illegal in the United States, the manner in which they are handled and stored in foreign home workshops “definitely is. It is difficult to find an apartment unit or a neighborhood family house in the United States producing shoes with a mixture of hazardous chemicals,” Markkanen says. “But unfortunately, it is not difficult to find these in developing countries where people’s homes have become factories.”

And for what? To feed a largely gender-specific habit based on “the idea that you can change the shape of your body through the shape of your footwear,” says fashion historian Giorgio Riello, coeditor of Shoes: A History from Sandals to Sneakers (Berg, 2006).

“People might not remember what they ate yesterday, yet they know exactly which shoes they wore and which shoes they have in their wardrobes. They know the brands; they know which shoes they owned before and which shoes they wore on which occasions.”

This “strange but quite present idea of memory through footwear” springs from shoe-fixated pop-culture phenomena such as Lady Gaga and “Sex in the City” –of which “there was hardly an episode without a reference to shoes.”

The first shoes were probably leaves wrapped around prehistoric feet, “and although in principle there’s nothing more banal than a pair of shoes, people now notice shoes a great deal more than they did a generation ago,” Riello muses. “Shoes are becoming more important than clothes.”

Accounting for nearly 90 percent of footwear sold in the United States, Chinese-factory-made shoes cost around $13 each to produce: That’s $10 in materials and $3 in labor for “a pretty high-quality leather shoe in a large production run,” says Jeff Mandel, who crafts custom shoes by hand at ExIT, his one-man shop in Portland, Oregon.

To calculate standard shoe markups, “take the retail cost and work backwards through the supply chain. If the shoe retails for $100, it cost the retailer 50 percent or less than that to buy it from the distributor. That same shoe cost the distributor 50 percent or less of that price” to acquire from the manufacturer. Generally, it cost the manufacturer 50 percent less than that to produce — in other words, $12.50.

“More markup is built into different items. This has nothing to do with the cost of production. You can sell an expensive shoe made cheaply and easily because of the power of the brand. … Compare this with other areas, like technology –computers, disk drives, displays, memory, central processing units –where the margins are much smaller, and you can see there’s some decent profit to be made in footwear” … usually on the backs of neurotoxin-inhaling laborers.

“Making custom shoes is not a smaller version of big factory production,” says Mandel, who trained with European masters. “It’s really the inverse of this model. I can’t take advantage of the economy of scale that comes with large production. … There is hardly any supply chain of materials in the U.S. for shoemaking, so the cost of materials is extravagant by Chinese production standards. … There’s no cheap labor or cheap materials here.”

Doing all the tasks himself that would in a corporation be parceled out among design, marketing, labor, research-and-development, and retail divisions, he has to charge $1,200 a pair.

“That’s almost $300 of material cost and $1,000 of labor. To be honest, that $1,000 has to cover more than just my labor. It has to cover all the other costs of doing business too.”

Thus we’re pretty much stuck. However you choose to define “ethical shoes,” they’ll almost surely be spendy. You can congratulate yourself for shunning leather, but where were the shoes in question made and by whom? Even cheap cloth or rubber shoes made in Western countries with good working conditions bear prices reflecting those workers’ higher wages.

“Although a shoe seems to be a simple everyday product, it’s not as harmless as we would like to believe it is,” Pia Markkanen warns. “When I buy shoes, I try to look for information on the use of water-based adhesives. I have to admit that I’m not able to find this very often.”

Swedish researchers recently found high concentrations of harmful chemicals, especially phthalates, in plastic-based flip-flops, sandals, Crocs, and other shoes –particularly children’s shoes, she says.

“The environmental life-cycle of our everyday shoe is notorious — from the raw material acquisition through the production and finally to the waste disposal. The first stages of the shoe’s life-cycle go back to extremely polluting and treacherous industries like slaughterhouses, tanning and chemical production. … And finally, when a shoe has served its purpose, it is not a benign product to be disposed of.”

Rather, it spreads its toxic trail into the Earth or, incinerated, the air — thus right back into us.