On Saturday, April 11, 2020, the former Crawford Power Plant smokestack located in Chicago’s South Lawndale neighborhood was demolished sending a cloud of dust off-site that blanketed the Little Village area of the neighborhood. On Monday, April 13, 2020, the City of Chicago Department of Public Health (CDPH) requested U.S. EPA assistance with monitoring the ambient air for particulates (such as dust, dirt, soot or smoke).
On May 6, 2020, CDPH assumed the particulate monitoring and sampling efforts from EPA. EPA will continue to provide technical support as necessary and will report analytical data from sampling conducted thru May 5, 2020 as they are received.
Chicago has set up a webpage for more information on their response.
From April 14 thru May 5, U.S. EPA and its START contractors placed air monitors at 7 locations selected by CDPH and began collecting data daily from 7 am to 7 pm. Daily summary tables of the data can be found in the Documents section of this website. (Note: No monitoring or sampling was performed on April 17, 2020 due to heavy accumulating snow.)
The monitors measured the amount of particulate matter in the air. The size of the particles is directly linked to their health effects. Small particles less than 10 micrometers in diameter (PM10) pose the greatest health problems because they can get deep into your lungs, and some may even get into your bloodstream. For comparison, the average human hair is 70 micrometers in diameter. From April 14 thru May 5, no site-related sustained readings exceeded U.S. EPA’s national air quality standard for PM10.
What Are National Ambient Air Quality Standards (NAAQS)?
Particulate Matter (PM) Basics
What are the harmful effects of PM?
The standard set for PM10 is 150 µm/mg3 (0.150 mg/m3). This means that during real-time monitoring, levels of dust above 150 µg/m3 (sustained for 5 minutes) serve as the indicator of excessive pollution leaving the site.
U.S. EPA used the TSI DustTrak DRX particulate monitor (DustTrak) at each location – around the site’s perimeter and nearby neighborhoods – to assess suspended particles in real time. DustTrak monitors check for particulate matter of various sizes, including those with a diameter of less than 10 microns (PM10) and 2.5 microns (PM2.5).
The monitors are factory-calibrated and therefore do not require adjustments in the field. However, they do require daily “zeroing” to ambient conditions before use, i.e., adjustment to a zero-point set to the typical environmental conditions in the area. Real-time readings were recorded on the devices, uploaded to a computer at the end of the day, and summarized in the available tables. Data irregularities and problems are identified and investigated. All data was reviewed for accuracy at the end of each workday.
From April 19 thru May 5, U.S. EPA also collected daily air samples set in the same place as the four fence-line monitors. Samples were collected using standard methods and sent to a laboratory to determine if they contain asbestos, metals and polychlorinated biphenyls (PCB). All samples were sent to a laboratory for analysis. Air sampling data and preliminary results will be published after completing analysis.
For many contaminants, EPA sets regional screening levels (RSL) that are considered by the agency to be protective of humans (including sensitive groups) over a lifetime. Preliminary results between April 19 and May 5, 2020 did not detect any concentration of metals or PCBs that exceeded an RSL.
Similarly, the U.S. Occupational Safety and Health Administration (OSHA) sets a Permissible Exposure Limits (PEL) for asbestos. Preliminary results from sampling between April 19 and May 5, 2020 show no asbestos in air above the OSHA PEL.