The disease dates to the ancient Greeks and Romans, and it continues to kill workers today. Oil and gas is the latest industry to face its threat.

Silicosis is an incurable but preventable disease caused by breathing in particles of sand, or respirable crystalline silica. Some particles are invisible to the eye, but the perfect size to slice into the lung’s tightest corners.

Sand is used in hydraulic fracturing, and breathing in too much of it can be deadly. It can also cause lung cancer.

A 2012 study by the National Institute for Occupational Safety and Health raised an alarm that workers at fracking sites in Colorado and four other states were exposed to silica dust at levels that exceeded occupational exposure limits.

That exposure hasn’t translated into patient diagnoses yet, according to interviews with four experts, but the disease can hide for a decade before causing symptoms.

Many companies in the industry have changed the way they handle fracking sand. Innovations suggest a technological fix can protect workers while increasing operational efficiency and better protecting workers.

Dangerous sand dust

At its worst, dust clouds full of silica can bloom in the air at an oil and gas well.

Sand arrives at a site in a truck, then travels through a sand mover, transfer belt and blender hopper before it plunges underground in hydraulic fracturing fluid. The fluid fissures rock underground, and the sand props open the fissures so oil and gas can flow out.

The problem is this: the more the sand moves around above ground, the finer it grinds and the more dust it releases into the air. Often, trucks offload sand using compressed air, blowing it aloft.

New businesses have formed to deliver sand without the dust. Instead of moving sand on its own, they keep it in a box resembling a metal freight container. When a crew is ready for the sand, they release it from the bottom of the box using gravity, not air pumps.

U.S. Well Services uses a system supplied by Houston-based SandBox Logistics on two of its nine frack fleets. The company already used a dust filtration system and wanted to save money on trucking, CEO Brian Stewart said.

Liberty Oilfield Services’ two Colorado-based frack crews also use SandBox, and the company has plans to extend the system to its four remaining crews, spokesperson Audrey Carlson said. A gravity-fed system is quieter than the traditional way of delivering sand with pneumatic pumps, so it cuts down on noise and community complaints, she said.

“I think this will become an industry standard,” Carlson said.

Montana-based Grit Energy Solutions and Georgia-based Portare are two other companies offering a similar gravity-fed system.

The nose on a dime

The U.S. government has warned about the dangers of breathing silica dust as far back as 1938. In 1971, the Occupational Safety and Health Administration set the current standard for workplace exposure.

It says that in the span of a workday, you can breath in about twice as much dust as can fit on President Franklin Roosevelt’s nose on the face of a dime. If you’re in construction, the standard is for five times FDR’s nose in silica.

It might seem small but it’s too much dust, according to doctors and OSHA itself. Breathing in silica can also lead to lung cancer, kidney disease, and an increased risk of tuberculosis.

“I think for the current OSHA standard, the allowable limit for respirable silica is high and does not protect many workers adequately,” said Dr. Cecile Rose, lung expert at National Jewish Health.

Since 1974, OSHA has unsuccessfully tried to update the standard.

The latest attempt was in 2013 when OSHA proposed new rules to halve the amount of silica workers can breath in. OSHA claims tightening restrictions will save 700 lives and prevent 1,600 people from contracting silicosis annually.

Many industry representatives oppose greater government restrictions on worker silica exposure.

The U.S. Chamber of Commerce commented to OSHA that “there is no need for, or benefit from, this OSHA rulemaking.”

“This proposed rule is not technologically feasible for the hydraulic fracturing industry,” according to The American Petroleum Institute’s comments to OSHA.

Not everyone in the oil and gas industry agrees.

Josh Oren, CEO of Sandbox Logistics, testified in April 2014 OSHA hearings in support of new rules, saying the technology exists (including Sandbox products) to implement the stricter standards.

In interviews, company executives also say the new rules are feasible.

“We already exceed those requirements, so it is possible,” U.S. Well Services’ Stewart said.

‘Dust is my enemy’

It’s already too late for workers in other industries diagnosed with silicosis.

Gilbert Banuelos, for example, gasps for air during the smallest chores. A few minutes of plucking weeds from the garden or sweeping the back patio knocks him into a chair. If he’s not careful, it can knock him unconscious.

His wife of nearly 35 years, Valerie Banuelos rolls over the green oxygen tank. Gilbert Banuelos inserts the tube into his nose and heaves in air.

“I have to be his mom sometimes because he won’t stop,” said Valerie Banuelos, wiping tears off her cheeks. Most of her husband’s former co-workers are dead, she said.

After high school, Gilbert Banuelos worked for 17 years at a diatomaceous earth factory, manufacturing gritty mineral material that’s used in everything from pool filters to makeup. Inside, dust piled up on the floor and glinted in the California sunshine that streamed through the skylights, Banuelos said.

Now in his 60s and living in Erie, Gilbert Banuelos’ lungs are riddled with scars from silicosis. The Banuelos are waiting to hear if he is a candidate for a lung transplant.

“Dust is my enemy,” Gilbert Banuelos said.

Every year it gets harder and harder to breath.

This report is part of a collaboration with the Center for Public Integrity on their Unequal Risk series examining toxic substances in the workplace. Read more at http://www.publicintegrity.org/