Since Spring of 1999, Indiana Department of Environmental Management has conducted air toxics monitoring in four at-risk counties in Indiana. Those counties are Elkhart, Lake, Marion, and Vanderburgh. Each city has one monitor for two years and three supporting monitors for six months. A monitor takes a sample every sixth day.

IDEM posts the results on its “ToxWatch” webpage. Check it out at www.state.in.us/idem/oam/toxwatch. It is a great place to get a handle on the issue of air toxics and air toxics monitoring.

At the site, you can get the results for each day tested for a long list of chemicals. Most importantly, IDEM has provided concentrations that have been published by other organizations as representing an acceptable lifetime exposure risk.

A few cautions as you check out the site:

• Use the benchmark concentrations with extreme caution. They give a relative sense of toxicity. Many of the numbers do not reflect the hazards posed to children or other sensitive populations.
• Read the guides. It may take time, but they can help you make sense of the data.
• Many of the chemicals reported are monitored only because they form ozone not because of their toxicity. IDEM provides the results anyway. It can be confusing, though.
• Watch out for the 0.00s. 0.00 means that the chemical was below the detection limit NOT that the chemical is not present. IDEM is working to fix this problem.