BLOOMINGTON, Ind. -- Data on atmospheric levels of toxic pollutants in samples collected near the Great Lakes are now readily available through Indiana University to scientists, researchers and the public. The data come from the Integrated Atmospheric Deposition Network.
IU has launched the website IADN Data Viz to provide easy access to IADN measurements of persistent, toxic chemicals in Great Lakes air and precipitation. The website will be regularly updated as new data become available.
The data are collected every 12 days and come from seven sites: two near Lake Michigan, two near Lake Erie, one near Lake Ontario and two near Lake Superior. Most of these sites are in remote areas, except for those in Chicago and Cleveland.
IADN has been taking these measurements since 1990.
"We recognize the importance of sharing the data in a variety of different ways to suit the needs of a wide audience, from regulators to high school students. This new tool will allow users to visualize the million data points collected so far in a simple and intuitive manner," said scientist Marta Venier of IU's School of Public and Environmental Affairs.
"IADN is one of the longest and most comprehensive environmental measurement programs in the world, and having IADN's data easily available is important both nationally and internationally," said SPEA scientist Amina Salamova.
Venier and Salamova are two of the lead scientists managing IADN operations. The website was developed by Venier and Clayton A. Davis of IU's School of Informatics and Computing.
In addition to data on polychlorinated biphenyls, or PCBs, the website has measurements on chlorinated pesticides and polycyclic aromatic hydrocarbons (some of which are known carcinogens). Data on brominated flame retardants will be released soon. Users can manipulate the data to see how levels have changed over time and to identify the differences of concentrations across sampling locations.
Despite the complexity of the subject, the website is relatively simple to use. "We're bringing science to the people, and that's as it should be," Davis said. "Everyone concerned about the health of the Great Lakes now has access to this new tool, even if it's a high school student working on a class project."
Scientists discovered the Great Lakes were contaminated with many toxic organic chemicals that entered the lakes by way of the atmosphere. IADN measures and evaluates more than 150 pollutant concentrations in the atmosphere, including airborne vapor and particles and precipitation.
"In general, levels of pollutants in the atmosphere of the Great Lakes have steadily decreased since this project began," said Ronald A. Hites, a SPEA Distinguished Professor and one of the nation's foremost experts on the environment of the lakes. "The website will allow future generations of scientists and policymakers to take informed steps necessary to continue the encouraging trend."
IADN at IU is directed by Hites.
Based on the data, IADN at IU has already led to these conclusions:
- Most pollutants studied tend to peak in concentration during warm months.
- Concentrations of PCBs, in particular, are declining more slowly than other pollutants.
- Atmospheric concentrations of these pollutants are highly correlated with population density.
The Great Lakes are the largest surface freshwater system on Earth, containing about 84 percent of North America's surface fresh water and about 21 percent of the world's supply. Roughly 10 percent of the U.S. population and more than 30 percent of Canada's population lives in the Great Lakes basin.