United States Environmental Protection Agency (EPA) secures the adherence to environmental standards and publishes reports on the environment, e.g. when catastrophes occur.
The EPA has collated their reports regarding the World Trade Center here.
Residential Dust Cleanup Program
In April 2002, the mayor of New York City asked the EPA to study the potential environmental consequences of the dust from Ground Zero spreading over downtown Manhattan, and to secure that the population was protected from possible health dangers. The initiated program meant that citizens living in the lower part of Manhattan could have
World Trade Center Residential Dust Cleanup Program,
Lower Manhattan Test and Clean Program
This voluntary program was offered the citizens and owners of property, if they feared potential contamination from the buildings impacted by the collapse of the Twin Towers.
Lower Manhattan Test And Clean Program,
World Trade Center Indoor Environment Assessment
Additionally, studies were done of the impact on the indoor environment.
World Trade Center Indoor Environment Assessment: Selecting Contaminants of Potential Concern and Setting Health-Based Benchmarks,
130 Liberty Street
Also known as the Deutsche Bank Building. This building was severely damaged when the World Trade Center 2 collapsed. The decision to demolish the building resulted in a number of reports.