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L Project dust report | April 27 - May 4, 2020

Updated May 8, 2020

The safety of our customers, employees and the general public is the MTA's top priority. We take seriously public concerns about air quality in the L tunnel and in the stations along the L during this period of construction and have adopted very conservative standards for exposure of the public to dust and silica, a part of the dust generated by the demolition of concrete. Additionally, we strictly adhere to all federal and state occupational safety regulations for our employees. 

Post Construction Baseline Dust Concentrations Recorded Levels: 27 April – 04 May 2020

Below are dust concentrations taken in the public space at the Bedford Av and 1 Av stations during the period from 12pm on Monday 27 April 2020 until 12 PM on Monday 04 May 2020. These readings were taken when no tunnel work was occurring as this phase of the project was completed on April 27, 2020.  The purpose of doing the additional readings was to collect a baseline level as was done when the project began.  The baseline dust levels were well below the conservative health-protective standard of 3000 µg/m3 of dust. This standard was established by the American Council of Government Industrial Hygienists to be health protective for people exposed to these levels for 8 hours a day over a 45-year working career. As there is no established standard exposure limit to dust for the short periods of time that a typical subway passenger will pass through the station, we are using this long-term chronic standard so as to measure against a very conservative health-protective benchmark. 

This is the final dust report from the L Project tunnel rehabilitation. This report shows data collected after the tunnel work was completed. The purpose of the report is to show baseline data to compare the project data to when no work is happening.