Metals in Air- Benchmarks, Standards and Guidelines Established to Protect Public Health

The following is a description of some the benchmarks, standards and guidelines EPA used to evaluate environmental conditions in the aftermath of the World Trade Center disaster.

There were many metals used in the World Trade Center. The WTC collapse, and later cleanup efforts, could have potentially released these metals into the air and caused health problems. Therefore, EPA closely monitored the air at the site itself and in the surrounding area.

EPA analyzed lead and chromium first because we thought they had the greatest potential to be present at levels of concern. EPA then analyzed 18 other metals. We do not believe any of them will cause long term public health concerns.

About a third of these metals (beryllium, cobalt, mercury, potassium, selenium, silver and thallium) were not detected in any air samples. EPA did detect thirteen metals: antimony, arsenic, cadmium, manganese, nickel, aluminum, barium, copper, iron, magnesium, sodium, vanadium, and zinc. The first five of these are Hazardous Air Pollutants (HAPs), also called toxic air pollutants, under the Clean Air Act. Although we detected these metals, their low concentrations mean they pose no potential for significant risk of long-term health problems from the WTC cleanup effort.

Other Metals Detected at Sites Around WTC

View Monitoring Data for Metals in Air