One of the longest-running air pollution monitoring programs in the nation was awarded a $5.9 million grant to continue the long-term monitoring of airborne pollutants in the Great Lakes for the next five years.

Indiana University was awarded the U.S. Environmental Protection Agency grant to continue managing the Integrated Atmospheric Deposition Network, a network of stations that monitor concentrations of toxic chemicals in air and precipitation in each of the five Great Lakes.

The IADN has been managed at Indiana University for the past 25 years under the leadership of Distinguished Professor Ron Hites and has collected more than a million toxic chemical measurements.

“The idea came after the Clean Air Act amendment in 1990, when it was recognized that atmospheric deposition was having a significant impact on the Great Lakes health and systems,” said Marta Venier, associate scientist at the O’Neill School of Public and Environmental Affairs and principal investigator on the award. “Initially, the program started monitoring polychlorinated biphenyls, or PCBs and organochlorine pesticides like DDT, which were the chemicals of concern at the time. And then slowly, more and more chemicals were added with time.”

The network now monitors PCBs, pesticides, polycyclic aromatic hydrocarbons (PAH), flame retardants and other toxic chemicals.

Venier, who’s overseeing the project with another O’Neill School of Public and Environmental Affairs scientist, Amina Salamova, said the IADN monitors chemicals at urban and rural sites across the Great Lakes Basin. Site operators collect samples from six sites every 12 days.

The samples help assess trends of toxic chemicals in Great Lakes air and help estimate the amount of chemicals deposited in the lakes through the air.

Venier said the amount of pollution that enters the lakes through the air is much more than people think.

“I think people tend to think that point source pollution, like if you see a channel discharging chemicals, is what contributes the most to the pollution of the lakes, but, in fact, atmospheric deposition is still one of the major drivers for impacting the water and fish that people then drink or eat,” said Venier.

In the decades since the project’s inception, Venier said the network has found evidence that environmental regulation has had an impact on the type and number of chemicals seen in the Great Lakes. She said the levels of many of the chemicals in the lakes have declined.

PCBs, a group of manmade chemicals used for hundreds of industrial and commercial applications, were banned in 1979 after the chemical was found to be probable carcinogens and led to many other adverse health conditions.

Decades after being banned, PCBs are still present in trace amounts in the Great Lakes atmosphere.

According to IADN’s website, atmospheric PCB concentrations have decreased in all sites since 1991 and are still falling. The researchers found that PCB concentrations are about 10 times greater in urban areas than in rural areas.

Organochlorine pesticides like DDT, chlordane and dieldrin were used for agriculture and mosquito control between the 1940s and 1960s. The pesticides were found to be carcinogenic and caused liver, kidney, thyroid, bladder and central nervous system damage through long-term exposure.

The pesticides were made famous in Rachel Carson’s Silent Spring, a book that helped inspire an environmental movement that led to the creation of the EPA.

“It’s interesting how you don’t think about it, but when you look, for example, at fish consumption advisories, the chemicals that are driving those advisories are mercury and PCBs. And that’s astonishing if you think about it, because PCBs were banned in the ’70s,” said Venier.

The IADN also tracks polycyclic aromatic hydrocarbon, or PAH, a group of over 100 different chemicals formed during the incomplete burning of coal, oil and gas, or other organic substances like tobacco or charbroiled meat. PAHs are usually found as soot, in a mixture containing two or more of the compounds.

PAHs have been confirmed by the EPA to cause cancer. High levels of PAHs are still detected at the Chicago and Cleveland collection sites, but concentration levels are on the decline at all sites.

Vernier says she and the EPA are most concerned about the prevalence of a common group of chemicals whose toxicity has only recently been acknowledged and will now be part of the IADN collection program.

“I think PFAS is the biggest emergency right now,” said Venier. “PFAS have been called forever chemicals, because once they are out there it’s basically impossible to degrade them.”

PFAS is the name of a group of 5,000 manmade chemicals used since the 1940s in stain- and water-repellant fabrics, nonstick pots, pans and other products, firefighting foams and many other products.

PFAS chemicals have been linked to cancer, reproductive and developmental problems in newborns, and liver and kidney damage.

PFAS is very prevalent in the Midwest. The chemicals have been found in the drinking water of two military installations in Indiana. More than 60 sites have been detected in Michigan.

Every person in the U.S. could be exposed to the chemicals, although in small levels.

“Studies have measured the blood concentration of a wide range of the population, and I think we all have significant levels of these chemicals in our blood. And it’s because it’s everywhere. Think about Gore-Tex, Teflon, anti-stick pans, and all the treatment for carpets,” said Venier.

Venier said the project has already purchased equipment needed to measure PFAS in the Great Lakes. IADN project members are currently working on the methodology they will use with that equipment.

She said the Indiana University team has been awarded the IADN grant multiple times in a row because the university has the right mix of people and knowledge to accomplish the difficult task.

“We have created, through time, the expertise and the environment to be able to conduct this work. But I wouldn’t be able to say any of this if it weren’t for the people that work for the project,” Venier said.

The grant will be disbursed in $1.2 million increments over five years.

You can check out the IADN’s data here.