Site Monitoring and Test Results

We understand Chicagoans in every neighborhood are concerned about air quality, especially in communities with a history of industrial activity, like Little Village. The City of Chicago is committed to keeping residents safe and healthy and will hold anyone violating clean air laws accountable. That is why we worked in partnership with US Environmental Protection Agency and Illinois Environmental Protection Agency to monitor air quality and dust in the area of the Crawford Site, both after the implosion of the Crawford smokestack and until all demolition of the Crawford site was complete.

Testing of air, dust and soil was conducted by two governmental agencies following the demolition by implosion:

  • Chicago Department of Public Health (CDPH)
  • US Environmental Protection Agency (US EPA)

Dust Monitoring

Chicago Department of Public Health (CDPH) installed 7 dust monitors around the perimeter of the site and in the neighborhood. The monitors measured particulate matter, including PM10 and PM2.5, from 7 am to 7 pm every day for eight months. View monitor locations here and read daily reports here.

Because this was a public health concern, the particulate action levels were based on the NAAQS value of 150 µm/mg3 PM10. An exceedance of the 5-minute action level was used as an indicator that dust could be leaving the site and, therefore, prompted extra dust control measures, such as wetting the area. 

CDPH also installed Purple Air sensors at City properties in the neighborhood around Crawford between April 21 and April 24, 2020 to provide continuous, real-time measurements of particulate matter.  A map of the locations is available here and results for the WiFi connected sensors are available here

Past Testing and Monitoring


After the building implosion on April 11th, testing of air, dust and soil was conducted by 2 governmental agencies following the demolition by implosion:

  • Chicago Department of Public Health (CDPH)
  • US Environmental Protection Agency (USEPA)

Test results showed the following:

Air Quality – Particulate Matter

Testing done by CDPH and the US EPA.

US EPA dust sensors' readings in the days following the implosion did not show sustained exceedances of the Agency’s health-based national air quality standards.  More specifically, the Illinois ambient network (i.e., the air monitoring network maintained by the Illinois EPA) and the US EPA trackers indicate that there were no PM NAAQS (National Ambient Air Quality Standard) violations during or since the event.  US EPA measured for particulate matter (PM 2.5 and PM 10). Learn more about the NAAQS here. See daily reports from US EPA dust monitors here.

To learn more about the US EPA’s past and ongoing work in Chicago’s Little Village neighborhood, please visit the US EPA website.

SUMMA canisters installed by CDPH detected low levels of volatile organic compounds (VOC’s) and we are reviewing these results with experts to better understand potential sources and impacts and compare to background levels found in the air, both in Little Village and across the city.

Settled Dust Composition

Testing done by CDPH. Analysis and validation by a non-governmental third-party agency.

No asbestos was detected in dust samples taken in the vicinity of the dust cloud.

This is consistent with our expectations. The smokestack was sampled well before the implosion to confirm there was no asbestos present, and also after the implosion which further confirmed that there was no detection of asbestos. That information is also consistent with the results of the wipe samples that were taken, which likewise did not detect asbestos.

Small concentrations of metals (lead and barium) were found in dust samples taken in the vicinity of the dust cloud, at levels that pose little health risk to residents. (See “What The Test Results Are And What They Mean” section for more information about this)

Crawford Site Soil Composition

Testing done by CDPH. Analysis and validation by a non-governmental third-party agency.

Metals (lead, barium and arsenic) and Polychlorinated Biphenyls (PCBs) were found in soil samples taken from near the stack consistent with expectations for this kind of site.

CDPH will continue to monitor the site and perform sampling. The metals and PCBs are part of IEPA’s overall cleanup oversight through the IEPA’s Site Remediation Program.  This work started in 2018 and will continue until future buildings, roads and grassy areas are installed. The public can track the project on the IEPA Site Remediation Program here. Search for “Crawford Station” in the Site Name Filter Box.

(Please note that additional testing and analysis will be conducted by US EPA and Chicago Department of Public Health in the coming days and updates will be shared here when available. Air and dust monitoring will continue throughout the demolition phase.)

More Information

Click on the links below to learn more about what was tested, where samples were taken from, what results we found and what it means.

Dust samples collected from windshields were tested for asbestos and seven heavy metals (arsenic, barium, cadmium, chromium, lead, selenium and silver). Mercury was excluded because not enough sample was available to test.

Soil samples taken from around the site of the smokestack were tested for semi-volatile organic compounds, polychlorinated biphenyls (PCBs), pesticides, metals, mercury, cyanide and asbestos.

Air samples taken from the North side of the site were tested for particulate matter and volatile organic compounds.

Building Debris sample of galvanized siding that was removed by the developer from the exterior of  an adjacent building prior to the smokestack demolition was tested for asbestos and polychlorinated biphenyls (PCBs).

Water samples were taken from the site and tested for mercury, metals, PCBs, semi-volatile organic compounds and volatile organic compounds..

  • US Environmental Protection Agency Dust Trackers Measuring Particulate Matter PM 2.5 and PM 10 Map
  • Chicago Department of Public Health Settled Dust Samples Map
  • Chicago Department of Public Health SUMMA Canisters Map

We tested for substances most likely to be found at the site that pose the greatest health risks. The following are substances that were detected in some of our samples.

Asbestos is a mineral fiber used in manufactured goods including building materials like roofing, siding and insulation. When asbestos containing material is disturbed, the fibers can be released into the air. Exposure to asbestos over time can lead to lung disease and cancer. The main building of the site was known to have asbestos, which was abated prior to demolition.

Arsenic occurs naturally in soil, and inorganic arsenic compounds are used to pressure treat wood. Exposure to low levels can lead to skin irritation, sore throat, circulatory issues, dizziness and nausea.

Barium compounds are used to make paint, bricks, ceramics, glass, and rubber and can be released from the burning of coal and oil. Ingestion of barium above levels normally found in water and food can cause short term gastrointestinal issues and muscle weakness.

Lead can be found in soil, air and water. It is found in old lead-based paint and is a product of coal combustion. Exposure to lead in young children can result in behavioral and development problems.

Mercury is produced by the burning of oil and coal. People are most often exposed to mercury through consumption of contaminated fish and shellfish. Exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system.

Polychlorinated Biphenyls (PCBs) are manmade organic chemicals used in many consumer products such as plastics, caulking, adhesives, paint and motor oil until their use was banned in 1979. Improper disposal and handling of PCB containing waste can lead to exposure. PCBs are probable human carcinogens and can also affect the immune, reproductive, neurological and endocrine systems.

Particulate Matter is a mixture of solid particles and liquid droplets found in the air. They can come from construction sites, unpaved roads, fields, smokestacks, fires or power plants, industries and automobiles.  Particulate matter contains microscopic solids or liquid droplets that are so small that they can be inhaled and cause serious health problems. Some particles less than 2.5 micrometers in diameter, also known as fine particles or PM2.5, pose the greatest risk to health. The dust cloud produced by the demolition was particulate matter.

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of over 100 chemicals formed during the burning of coal, oil and gas, garbage, tobacco and other organic substances. People take in PAHs by breathing in vehicle exhaust and cigarette smoke or by eating charred meats. Occupational exposure to large amounts of certain PAHs can cause blood and liver abnormalities. Some PAHs are classified as carcinogens.

Volatile Organic Compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) are chemicals emitted as gases into the air from certain liquids and solids, such as industrial solvents and petroleum fuels. They are most often found in higher concentrations indoors. Exposure to VOCs can have short and long term health effects.


Half of the dust samples taken in the vicinity of the Crawford Site, and in the direct path of the dust cloud, contained small amounts of lead and all of the samples contained small amounts of barium. These amounts are very low and pose little health risk to residents. For reference, the US EPA standard for lead in bare soil in residential play areas is 400 ppm. There is no dust or soil standard for barium, but it is found in most soils in concentrations between 15 and 3,500 ppm. No other metals or asbestos were detected.

Substance Results Range in PPM # Samples Taken # Samples Substance Present
Barium 3.5  - 18 14 14
Lead 2.7 - 10 14 7
Arsenic Not Detected 14 0
Asbestos Not Detected 14 0
Cadmium Not Detected 14 0
Chromium Not Detected 14 0
Selenium Not Detected 14 0
Silver Not Detected 14 0



All soil samples contained arsenic, barium, lead and mercury. Some samples contained PCBs and PAHs. This is not unexpected, given the historical use of the site and is consistent with background levels found in soil across the City. The soil on the site does not currently pose an immediate health risk to residents. CDPH will conduct additional soil testing with the assistance of an environmental consultant.

 Substance  Results range in PPM  # Samples Taken  # Samples Substance Present  Citywide soil study* results Range in PPM  # Samples Taken # Samples Taken 
 Arsenic  3.6 - 170  10   10  < 10 - 220  57  47
 Barium  230 - 420   10   10  100 - 697  57  57
 Lead  90- 3500  10   10  13 - 1910  57  57
 Mercury  0.076 - 0.26  10   10  <0.02 - 13.1  57  56

PPM means parts per million

*Source: USGS Water Resources Investigations Report 03-4105


SUMMA canisters detected low levels of some VOCs, and we are reviewing these results with experts to better understand potential sources and impacts and compare to background levels found in the air, both in Little Village and across the city. Nearby air monitors did not detect particulates in the air.


While the main building was not involved in the implosion, we did test some additional building materials on-site.Asbestos and one type of PCB were present. The asbestos material is non-friable, meaning that it cannot be broken apart and the fibers are not at risk of becoming airborne. Because of this, there is very little to no health risk to residents. The developer will be required to properly abate, remove and dispose of the materials.


Following heavy rains, water samples were collected to assess potential issues with discharge from the site during demolition activities. Testing found levels of iron and total suspended solids exceed state regulatory standards. The developer has modified plans and put mitigation measures in place to ensure that water discharged to the Sanitary and Ship Canal meets standards.

The dust, or soil contaminated with this dust, may get into your home. Like any dust, it can settle on the floors, counters and other items, including children’s toys. Here are a number of ways everyone can reduce their exposure within their homes:

  • Regularly wet-mop floors and wipe down counters and window sills using a household cleaner. Do not use bleach.
  • Avoid dry sweeping – this will spread dust.
  • Wash children’s hands after they come in from playing outside and before eating.
  • Regularly clean your children’s toys – use warm soapy water, then rinse thoroughly.
  • Use a doormat and remove your shoes before entering your home.
  • Consider keeping your windows closed on very dry and windy days when dust is visible.

To learn more, see our Get the Facts:

Dust Mitigation Fact Sheet in English

Dust Mitigation Fact Sheet in Spanish