The Lower Manhattan Construction Command Center (LMCCC) currently directs BEM Systems, Inc. (BEM) to operate and maintain an ambient air quality monitoring program (AQMP) in Lower Manhattan. The air quality monitoring program is one segment of the LMCCC's overall environmental program, which is designed to minimize the environmental impacts associated with the redevelopment and reconstruction of Lower Manhattan.

The AQMP consists of four air monitoring stations located throughout Lower Manahttan.  Each air monitoring station is comprised of two monitors, one for PM_2.5 and one for PM₁₀. A discussion of PM_2.5 and PM₁₀ can be found here. To briefly summarize, PM_2.5 and PM₁₀ symbolize the size of particles that are suspended in the air and can generally be referred to as particle pollution. PM_2.5 is by and large associated with the combustion of fossil fuels, such as diesel exhaust, while PM₁₀ can be associated with dust from roadways, construction sites, and other sources. These particles are of concern because of the apparent links between them and certain health problems. The image below illustrates the relative size of particle pollution.

Particle Pollution Relative to a Human Hair

The LMCCC monitors particle pollution to assess the impact construction activities may be having on Lower Manhattan air quality during the urban renewal program. The LMCCC AQMP began with the collection of background data from August 25, 2005, through November 30, 2005. December 1, 2005, was the start date for construction monitoring. Since the inception of construction monitoring, particle pollution data has been collected from three air monitoring stations: PS234 at 292 Greenwich Street, PS126 at 80 Catherine Street, and 1WFC at 1 World Financial Center. The fourth station, 1CMP at 1 Chase Manhattan Plaza, became operational in August 2006. In addition, the NYSDEC shares particle pollution data from its Park Row site at 1 Pace Plaza with LMCCC.

The figures and graphs below convey the results of the Lower Manhattan air monitoring.

As explained in the particle pollution overview page, fluctuations in particulate levels can vary based on a number of different factors. In the figure below, seasonal PM₁₀ and PM_2.5 averages are plotted for four stations, PS234, PS126, 1WFC, and Park Row. From this data, it is apparent that particulate levels will fluctuate with changes in the season. A more detailed discussion of the climate and weather related impacts on particle pollution can be found on the particle pollution page (see "Seasonal Trends").

Air Quality Index 

The highest particle pollution levels are observed in the summer months, while the winter months have the lowest levels. Naturally, one would want to know whether the particle pollution levels are considered harmful or not. The EPA has a procedure to convert the concentration of criteria pollutants, such as particulate matter, to Air Quality Index (AQI) values.designed to help people understand whether the particle pollution levels are considered harmful or not.  

The AQI helps people understand what local air quality means to their health. The AQI is divided into six categories as represented on the following chart:

Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are as follows:

• "Good" The AQI value for your community is between 0 and 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
• "Moderate" The AQI for your community is between 51 and 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
• "Unhealthy for Sensitive Groups" When AQI values are between 101 and 150, members of sensitive groups may experience health effects. This means they are likely to be affected at lower levels than the general public. For example, people with lung disease are at greater risk from exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. The general public is not likely to be affected when the AQI is in this range.
• "Unhealthy" Everyone may begin to experience health effects when AQI values are between 151 and 200. Members of sensitive groups may experience more serious health effects.
• "Very Unhealthy" AQI values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects.
• "Hazardous" AQI values over 300 trigger health warnings of emergency conditions. The entire population is more likely to be affected.

Air Quality Index Colors

The EPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on. This allows public news groups, such as local radio stations, to broadcast readily understood warnings.

Air Quality Index Numerical Values

Using these guidelines, the particle pollution data from the four air monitoring stations during the first full year of construction monitoring are provided below. These graphs plot the daily average concentration for PM_2.5 at each station from December 1, 2005, to November 30, 2006. As these figures indicate, in terms of particle pollution, Lower Manhattan air quality was in the "Good" health category about 70 percent of the time, in "Moderate" health category almost 30 percent of the time, and in the "Unhealthy for Sensitive Groups" health category 1 to 2 percent of the time. The data never approached or entered the "Unhealthy" or "Very Unhealthy" health categories.

The few days where the AQI level for particle pollution was in the "Unhealthy for Sensitive Groups" health category were exclusively in the summer months and largely attributed to the New York region air quality and weather effects. This data is consistent with the New York metropolitan area being in non-attainment status regarding particulate matter compliance with USEPA regulations. Moreover, the few values that did achieve the "Unhealthy for Sensitive Groups" category would, until recently, have fallen in the "Moderate" category. This is because in September 2006 the USEPA promulgated a lower 24-hour average NAAQS for PM_2.5, which fell from 65 to 35 μg/m³.

To provide a review of all collected air quality data to date, the two graphs below were created. These graphs plot the monthly averages of all of the LMCCC four air monitoring stations (The NYSDEC station, Park Row, is excluded) since their inception. These graphs provide the viewer with an account of how the particulate levels have fluctuated since the start of the AQMP and also show the current levels relative to the background data collect from August through November 2005. The data depicted is through the end of February 2007.

As apparent in the Monthly Average Comparisons, the current and historic data is consistent with that observed during the background period in 2005. The PM_2.5 plot shows a greater seasonal dependence on particulate levels with a peak occurring from June through August 2006. The PM₁₀ plot shows less of a dependence on seasonal variations and depicts particulate fluctuations based on more immediate and localized sources.

The LMCCC intends to update the data on this page periodically in an effort to provide the Lower Manhattan community with informative and high-quality data. If you have any question or concerns about the content of the website, please click here to contact us.