Hazy forecast for safety of road construction dust

Wilmette residents are not all breathing easy as work nears its fifth month on the $20 million Sheridan Road Reconstruction Project.

Dust stirred up by the roadwork not only coats windows and cars but clouds the air for residents and construction workers to inhale — which over an extended period of time could seriously impact respiratory health.

Limited exposure to construction-produced dust, such as driving through the project on a daily commute, will at most cause mild respiratory irritation, said Michael Mark, executive director of the American Lung Association of Greater Chicago. Long-term contact, however, can lead to greater health problems.

“The dust that’s generated will impact a certain percentage of the population,” said Mark, who has worked as a nurse and respiratory therapist. “People who need to be concerned are individuals with chronic lung disease like bronchitis, COPD [chronic obstructive pulmonary disease] or asthma.”

Most air pollution health concerns stem from particulates in two categories: particles smaller than 2.5 microns and those ranging between 2.5 and 10 microns, said Dr. Daya Upadhyay, a pulmonologist at Stanford Hospital and Clinic in Stanford, Calif.

Particles smaller than 2.5 microns, which include diesel and automobile fumes, can settle in the lungs and decrease lung function, she said. Larger particles, up to 10 microns in size, contribute to respiratory inflammation and irritation without penetrating deep into lungs.

A human hair is 30 times wider than the largest particle in this range, the U.S. Environmental Protection Agency explains on its Web site.

“It not only affects patients’ lungs,” Upadhyay said. “[The particles] can cause a system-wide effect.” She said the cardiovascular system is especially vulnerable to particulate air pollution.

While construction workers are at the greatest risk for dust-induced respiratory disorders, Mark said people who live and work in the direct vicinity of construction sites should also take precautions.

“Avoidance of this problem is not an easy thing to do,” he said. “The construction is not going to go away. The responsibility has to fall back on the consumer.”

Upadhyay said individuals with pre-existing lung conditions like cystic fibrosis or COPD should wear masks, or, if possible, re-locate.

“They need to avoid the dust as much as possible,” she said, regardless of what compounds are in the particles.

Mark said Sheridan Road residents should check their heating, ventilation and air conditioning system to make sure it is intact and that all filters are changed regularly. If the dust is especially bad, filters may need more frequent replacement.

Researchers have not established how much dust correlates with negative health effects, Upadhyay said, though it is clear there is a connection between dust and respiratory illness. A 2002 study in urban areas of France, Austria and Switzerland found 6 percent of deaths in those regions could be linked to exposure to particles 10 microns in size.

A big question about the dust from the Sheridan Road site, which spans the length of Wilmette, is whether it contains silica, a compound often found in the sand used to make concrete, Mark said.

“If you inhale that stuff, are there issues like silicosis? Yes,” he said. “A chronic exposure to silica inhalation ultimately causes problems when it lodges in the lungs, where it can create scar tissue.”

Silicosis impedes the lungs’ ability to extract oxygen from the air, the Occupational Safety and Health Administration Web site said. An estimated 2 million people are exposed to silica dust annually, OSHA reported. The disease makes people more vulnerable to infection, as well as tuberculosis and lung cancer.

Most cases of silicosis develop after 10 or more years of excessive exposure to silica, though in rare cases where a large amount is inhaled it can develop within a few weeks.

Brad Mitchell, regional director of public education [1] for the U.S. Department of Labor, said most silica exposure occurs through drilling, hauling or dumping contaminated concrete.

“If [construction workers] know they’re working in an enclosed or confined area, they need to test the air to make sure the silica levels are below the highest permissible level,” he said. “But if you stand in a dust cloud, it doesn’t matter if you’re inside or outside. The particles can be enough that they will damage lungs.”

While it’s impossible for OSHA inspectors to visit every construction site and test for excessive silica in the air, the agency does conduct routine inspections.

As of April 11, the Des Plaines branch of OSHA reported no inspectors had visited the Sheridan Road construction project, which started in December and will likely continue until July 2009.

Brigitte Mayerhofer, director of engineering for Wilmette, said there is no indication that the dust from the Sheridan Road site contains silica or other especially hazardous compounds.

“Testing for silica is not typical for construction projects, that I’m aware of,” she said.

But Upadhyay said road construction is often a source of silica and other damaging particles.

The Illinois [2] Department of Transportation publishes a book that defines the standard safety specifications for roadwork. The manual instructs workers to control dust by sprinkling sites with water, Mayerhofer said, particularly in summer months when there are several consecutive days without rain.

David Di Paolo, vice president of Di Paolo Company, the Glenview-based contractor working on the Sheridan Road project, said the firm takes an aggressive approach to dust management.

“Unfortunately, dust is a necessary evil,” he said. “We do what’s practical to avoid dust that naturally occurs from construction, demolition, road excavation, and dumping and loading of stone, but we can’t eliminate it 100 percent.”

Equipment used for activities that generate a lot of dust are outfitted with special watering systems that dampen the site as work takes place, keeping the dust from becoming airborne, he said.

Though company does not test for specific compounds in the air, Di Paolo said the EPA requires monitors on some equipment that make sure water is properly suppressing the dust.

“God did not create you to breathe dust,” Mark said. “He created you to breathe air. If you breathe in a foreign substance like concrete dust, your airway is going to react to that.”