TABLES


Table 1

General Information on the World Trade Center Towers

Height

Tower One:  1,368 feet

Tower Two:  1,362 feet

Weight

1.5 million tons

Statistics

110 floors

6 basements (with 2 subway stations and PATH train station)

1 underground mall

43,600 windows

97 passenger elevators and 6 freight elevators

300 computer mainframes

Air conditioning had 60,000 tons of cooling capacity

Rentable Space

43,200 square feet per floor

10,000,000 total square feet

Owners and Operators

Port Authority of New York and New Jersey

Groundbreaking

August 5, 1966

Opening Ceremony

April 4, 1973  (Parts were opened between 1970-1973)

Construction Materials

Steel: 200,000 tons

Concrete: 425,000 cubic yards

Glass: 600,000 square feet

Electric cables: 12,000 miles


Table 2 2000 Census Block Level Population

Distance From WTC

Total Population

Housing Units

One-Quarter Mile

6,965

4,617

One-Half Mile

17,596

10,768

Three-Quarter Mile

29,667

16,482

The 16-acre site of the World Trade Center was buffered, and an aerial proportion technique was used to estimate the number of persons living in the area.


Table 3

Number of Buildings and Areas Within Buildings Sampled for Settled Surface Dust: Analyzed for Asbestos by PLMa and TEMb, SVFc by PLM, and Minerals by XRDd

Due to available sample size and analytical objectives, some samples were not analyzed by each method.

 

Lower Manhattan


Above 59th Street

Buildings

29

4

Residential Units

57

5

Common Areas

26

3

Outdoors

14

0


Table 4

Number of Buildings and Areas Within Buildings Sampled for Fibers in Air: Analyzed for Total Fibers by PCMe, Asbestos by TEM, and SVF by SEMf

Lower Manhattan

Above 59th Street

Total Fibers (PCM)

Asbestos (TEM)

SVF (SEM)

Total Fibers (PCM)

Asbestos (TEM)

SVF (SEM)

Buildings

30

5

4

4

0

4

Residential Units

59

3

3

5

0

5

Common Areas

29

3

2

3

0

1

Outdoors

29

0

0

3

0

3

 

Table 5

Number of Locations Sampled for Minerals in Airborne Dust,
Analyzed by XRD for Minerals

Lower Manhattan

Above 59th Street

PM100

PM10

PM4

PM2.5

PM100

PM10

PM4

PM2.5

Buildings

26

28

30

10

3

4

4

3

Residential Units

47

52

57

18

3

5

5

2

Common Areas

26

27

29

8

2

2

3

2

Outdoors

26

26

29

8

2

3

3

2


Notes:

        a.      PLM = polarized light microscopy

        b.      TEM = transmission electron microscopy

        c.      SVF = synthetic vitreous fibers

        d.      XRD = x-ray diffraction

        e.      PCM = phase contrast microscopy

        f.       SEM = scanning electron microscopy

Settled surface dust and air samples could not always be obtained together from the same sampling location.


Table 6

Summary of Locations With Asbestos or Synthetic Vitreous Fibers (SVF) in Settled Surface Dust Sampling locations that had either asbestos in the dust by PLM or TEM analysis or SVF in the settled surface dust by PLM analysis. Ranges of asbestos and SVF values for each type of location are included.

Sampling Locations:

Lower Manhattan

Total Number of Locations Sampleda

Number of Locations with Asbestos in Settled Surface Dust

(% of locations detected)b

Range of

Asbestos Foundc

Number of Locations with SVF in Settled Surface Dust (% of locations detected)d

Range of

SVF Founde

Outdoor

Asbestos (PLM)  = 14

Asbestos (TEM)  = 12

SVF (PLM)= 14

6
(43%)

<1%-
3.4 %

11
(79%)

1%-
72%

Common

Asbestos (PLM)  = 26

Asbestos (TEM)  = 25

SVF (PLM) = 26

5
(19%)

<1%-1.5%

14
(54%)

5%-27%

Residential

Asbestos (PLM)  = 57

Asbestos (TEM)  = 52

SVF (PLM) 
= 57

10
(18%)

<1%-1.5%

26
(46%)

2%-35% f

Whole Building

Asbestos (PLM) 
= 29

Asbestos (TEM) 
= 29

SVF (PLM) 
= 29

12
(41%)

<1%-3.4%

21
(72%)

2%-72%

Sampling Locations: Comparison Buildings

Total Number of Locations Sampleda

Number of Locations With Asbestos in Settled Surface Dust

(% of locations detected)b

Range of
Asbestos Foundc

Number of Locations With SVF in Settled Surface Dust (% of locations detected)d

Range of
SVF  Found e

Common

Asbestos (PLM) 
= 3

Asbestos (TEM) 
= 3

SVF (PLM) = 3

0
(0%)

None Detected by PLM or TEM

0
(0%)

None Detected by PLM

Residential

Asbestos (PLM) 
= 5

Asbestos (TEM) 
= 4

SVF (PLM) = 5

0
(0%)

None Detected by PLM or TEM

0
(0%)

None Detected by PLM

Notes:

a.      All dust samples were initially analyzed by polarized light microscopy (PLM). Transmission electron microscopy (TEM) analysis was performed to confirm the absence of asbestos if not detected by PLM analysis.

b.      The number of locations containing asbestos in dust reflects locations with asbestos detected by either PLM or TEM (reported as <1% or more). The percentage of locations with asbestos detected is calculated from the total number of dust samples.

c.      The range represents the highest value detected at a location (PLM or TEM).

d.      The percentage of locations with synthetic vitreous fibers (SVF) detected is calculated from the number of SVF PLM samples.

e.      Some locations had an additional co-located sample obtained, the range shown considers the highest measured value for each sampling location.
f.     
One residential unit had an extra settled surface dust sample (taken from a window sill), which contained 40% SVF by PLM.


Table 7

Summary of Mineral Components of Settled Surface Dust by Sampling Location

Outdoor Settled Surface Dust of Lower Manhattan

Outdoor samples were not taken from comparison areas above 59th Street because no settled surface dust was visible.

Number of Occurrences,

14 samples totala

Minimum Detected

(% by weight)

Maximum Detected

(% by weight)

Average of Detections

(% by weight)

Number Above Comparisonb

Quartz

14 (100%)

1 Jd

27 J

12 J

NAc

Calcite

13 (93%)

0.8 J

19 J

6 J

NA

Portlandite

12 (86%)

0.07 J

6 J

2 J

NA

Gypsum

11 (79%)

0.03 J

27 J

6 J

NA

Mica

9 (64%)

0.05 J

0.3 J

0.1 J

NA

Halite

7 (50%)

<0.03 J

0.1 J

0.05 J

NA

Common Area Settled Surface Dust of Lower Manhattan

Common Areas of Comparison Areas Above 59th Street

 

Number of Occurrences,

26 samples total a

Minimum Detected

(% by weight)

Maximum Detected

(% by weight)

Average of Detections

(% by weight)

Number Above Comparisonb

Number of Occurrences,

3 samples total a

Minimum Detected

(% by weight)

Maximum Detected

(% by weight)

Average of Detected Values

(% by weight)

Quartz

21 (81%)

0.03 J

25 J

5 J

6 (23%)

2 (67%)

1 J

1 J

NA

Calcite

15 (58%)

0.02 J

10 J

3 J

9 (35%)

2 (67%)

0.03 J

0.4 J

NA

Portlandite

13 (50%)

0.04 J

4 J

2 J

9 (35%)

1 (33%)

0.05 J

0.05 J

NA

Gypsum

23 (88%)

0.07 J

20 J

5 J

6 (23%)

2 (67%)

2 J

3 J

NA

Mica

5 (19%)

0.06 J

0.6 J

0.2 J

5 (19%)

0 (0%)

ND

ND

NA

Halite

4 (15%)

0.04 J

0.06 J

0.05 J

1 (4%)

1 (33%)

0.04 J

0.04 J

NA

 

Residential Units Settled Surface Dust of Lower Manhattan

Residential Units of Comparison Areas Above 59th Street

 

Number of Occurrences,

57 samples totala

Minimum Detected

(% by weight)

Maximum Detected

(% by weight)

Average of Detections

(% by weight)

Number Above Comparisonb

Number of Occurrences,

5 samples

total a

Minimum Detected

(% by weight)

Maximum Detected

(% by weight)

Average of Detected Values

(% by weight)

Quartz

30 (53%)

0.05 J

31 J

9 J

15 (26%)

2 (40%)

1 J

2 J

NA

Calcite

20 (35%)

0.02 J

21 J

8 J

13 (23%)

1 (20%)

0.9 J

0.9 J

NA

Portlandite

21 (37%)

0.05 J

8 J

2 J

17 (30%)

2 (40%)

0.08 J

0.08 J

NA

Gypsum

45 (79%)

0.05 J

30 J

4 J

9 (16%)

4 (80%)

2 J

4 J

3 J

Mica

5 (9%)

0.03 J

0.3 J

0.1 J

1 (2%)

1 (20%)

0.08 J

0.08 J

NA

Halite

6 (11%)

0.03 J

0.1 J

0.06 J

0 (0%)

1 (20%)

0.4 J

0.4 J

NA

a.      Shows the number of samples where the mineral was detected and the percentage based on the number of samples obtained from this area.

b.      Shows the number of results, and the percentage of samples obtained from this area, that had estimated values greater than the maximum levels found at locations above 59th Street.

c.      NA = not applicable.

d.     J = estimated.


Table 8

Summary of Results for Locations With Airborne Fiber Levels
Higher Than Levels in Comparison Areas Above 59th Street.

Air samples were collected and analyzed by phase contrast microscopy for total fibers

(NIOSH 7400). All samples with fiber counts higher than the comparison areas above 59th Street were

re-analyzed to determine if those fibers were asbestos, synthetic vitreous fibers (SVF), or other material.

Building

(Area)

Aggressive

Samplinga

Fibers in Air by PCM

(f/cc)b

Asbestos in Dust by PLM or TEMc

Asbestos in Air by TEM

(f/cc)b

SVF in Dust by PLM

SVF in Air by SEM

(f/cc)b

1

(Residence)

No

0.006

NDg

<0.001d

20%

0.000162

2

(Common)

No

0.005

NDg

<0.001d

27%

0.000255

19

(Common)

No

Overloadede

NDg

<0.006f

ND

Not analyzed

24

(Residence)

No

0.005

NDg

<0.001d

10%

0.000037

26

(Common)

No

0.004

NDg

<0.001d

5%

<0.00004

26

(Residence)

No

0.012

NDg

<0.001d

ND

<0.00004

a.      Aggressive sampling refers to a technique used in some residential units where the vacuum exhaust (used for settled dust sample collection) was used to stir up the settled surface dust before the air sampling began.

b.      f/cc = fibers in each cubic centimeter (cc) of air as determined using phase contrast microscopy (PCM), transmission electron microscopy (TEM), or scanning electron microscopy (SEM) methods. This is calculated from the number of fibers seen on the air filter and the volume of air pulled through the filter measured in cubic centimeters of air.

c.      Value shown represents the highest of polarized light microscopy (PLM) or TEM results for this area.

d.      The TEM method employed here, National Institute of Occupational Safety and Health (NIOSH) 7402, counts fibers of the same size as those detected by PCM analysis. Fibers reported here are greater than or equal to 5 microns in length and 0.25 microns in width.

e.      A building renovation project was occurring near the area of this sampling equipment. Construction dust and building insulation material may have influenced this sample.

f.      Sample processing of the overloaded filter involved transferring the material to a new filter; this process provides less analytical sensitivity, resulting in a higher detection limit.

g.     ND = not detected.


Table 9

Summary of Airborne Fibers at Locations Where Asbestos Was Detected in Settled Surface Dust

Outdoor Areas in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

1

Outdoor

<1%

22%

No

0.001 f/cc

2e

Outdoor

1.3%

28%

No

0.003 f/cc

5

Outdoor

3.4%

25%

No

0.002 f/cc

7

Outdoor

1.7%

35%

No

<0.001 f/cc

15

Outdoor

1.9%

72%

No

<0.001 f/cc

27

Outdoor

<1%

15%

No

<0.001 f/cc

Common Areas in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

4

Common

<1%

15%

No

0.001 f/cc

6

Common

<1%

10%

No

<0.001 f/cc

10

Common

1.5%

20%

No

0.002 f/cc

24

Common

<1%

5%

No

0.001 f/cc

27

Common

<1%

10%

No

<0.001 f/cc

Residential Units in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

4

Residence 1

<1%

2%

Yes

<0.001 f/cc

4

Residence 2

<1%

5%

Yes

0.001 f/cc

5

Residence 1

<1%

10%

Yes

0.002 f/cc

5

Residence 2

<1%

20%

Yes

<0.001 f/cc

9

Residence 1

<1%

2%

Yes

0.001 f/cc

9

Residence 2

<1%

5%

Yes

0.003 f/cc

11

Residence 1

<1%

ND

Yes

<0.001 f/cc

11

Residence 2

1.5%

ND

Yes

<0.001 f/cc

15

Residence 1

<1%

ND

Yes

<0.001 f/cc

27

Residence 1

<1%

10%

No

<0.001 f/cc

a.      Value shown is highest of the reported polarized light microscopy (PLM) and transmission electron microscopy (TEM) results for this area.

b.      SVF = synthetic vitreous fibers. Measured by PLM analysis.

c.      Aggressive sampling refers to a technique used in some residential units where the vacuum exhaust (used for settled dust sample collection) was used to stir up the settled surface dust before the air sampling began.

d.      f/cc = the fibers in each cubic centimeter (cc) of air. This is calculated from the number of fibers seen on the air filter and the volume of air pulled through the filter measured in cubic centimeters.

e.      Building 2 also had a co-located dust sample; values represent the highest measured result.


Table 10

Summary of Airborne Fibers at Locations Where Only Synthetic Vitreous Fibers (SVF) Were Detected in Settled Surface Dust

Outdoor Areas in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

18

Outdoor

NDf

30%

No

<0.001 f/cc

24

Outdoor

NDf

55%

No

0.002 f/cc

28

Outdoor

NDf

15%

No

<0.001 f/cc

Common Areas in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

2

Common

NDf

27%

No

0.005 f/cce

7

Common

NDf

5%

No

0.001 f/cc

14

Common

NDf

5%

No

0.003 f/cc

25

Common

NDf

5%

No

<0.001 f/cc

26

Common

NDf

5%

No

0.004 f/cce

28

Common

NDf

10%

No

0.001 f/cc

Residential Units in Lower Manhattan

Building

Area

Asbestos in Dust

(PLM or TEM)a

SVF in Dust (PLM)b

Aggressive Samplingc

Fibers in Air (PCM)d

1

Residence 1

NDf

20%

No

0.006 f/cce

1

Residence 2

NDf

20%

Yes

<0.001 f/cc

2

Residence 1

NDf

25%

No

<0.001 f/cc

2

Residence 2

NDf

20%

Yes

0.002 f/cc

6

Residence 1

NDf

15%

Yes

<0.001 f/cc

6

Residence 2

NDf

15%

Yes

<0.001 f/cc

7

Residence 2

NDf

5%

No

<0.001 f/cc

10

Residence 1

NDf

15%

Yes

0.001 f/cc

10

Residence 2

NDf

10%

Yes

0.001 f/cc

12

Residence 1

NDf

5%

No

0.001 f/cc

12

Residence 2

NDf

5%

Yes

<0.001 f/cc

13

Residence 1

NDf

10%

Yes

0.003 f/cc

15

Residence 2

NDf

5%

Yes

<0.001 f/cc

18

Residence 1

NDf

30%

No

0.002 f/cc

18

Residence 2

NDf

35%

No

0.002 f/cc

24

Residence 2

NDf

10%

No

0.005 f/cce

25

Residence 1

NDf

5%

No

<0.001 f/cc

27

Residence 2

NDf

10%

No

<0.001 f/cc

a.      Value shown is highest of the reported polarized light microscopy (PLM) and transmission electron microscopy (TEM) results for this area.

b.      SVF = synthetic vitreous fibers. Measured by PLM analysis.

c.      Aggressive sampling refers to a technique used in some residential units where the vacuum exhaust (used for settled dust sample collection) was used to stir up the settled surface dust before the air sampling began.

d.      f/cc = the fibers in each cubic centimeter (cc) of air. This is calculated from the number of fibers seen on the air filter and the volume of air pulled through the filter measured in cubic centimeters.

e.      Scanning electron microscopy (SEM) and TEM results for these air samples are available and shown on Table 8.

f.       ND = not detected.


Table 11

Summary of Minerals in Indoor and Outdoor Air From Lower Manhattan and Comparison Buildings Above 59th Street a, b, c

 


Air Samples from Lower Manhattan


Air Samples From Comparison Buildings

 

Number of Samples

Quartz

Calcite

Portlandite

Gypsum

Mica

Halite

Number of Samples

Quartz

Calcite

Portlandite

Gypsum

Mica

Halite

PM 100

Number (Frequency detected %)

Air Concentration (mg/m3)

101

14 (14%)d

3-13 Je

9 (9%)

3-14 J

8 (8%)

16-95 J

24 (24%)

3-14 J

2 (2%)

9-13 J

4 (4%)

4-14 J

7

NDf

ND

ND

1 (14%)

3 J

ND

ND

PM 10

Number (Frequency detected %)

Air Concentration (mg/m3)

105

11 (10%)

3-12 Je

10 (10%)

3-5 J

10(10%)

14-25 J

33 (31%)

3-14 J

1 (1%)

8 J

5 (5%)

4-5 J

10

ND

ND

ND

3 (30%)

3 J

ND

ND

PM 4

Number (Frequency detected %)

Air Concentration (mg/m3)

114

13 (11%)

4-19 J

13 (11%)

4-10 J

12 (11%)

21-84 J

40 (35%)

4-15 J

4 (4%)

14-43 J

3 (3%)

7-19 J

11

ND

ND

ND

3 (27%)

5 J

ND

ND

PM 2.5

Number (Frequency detected %)

Air Concentration (mg/m3)

34

1 (3%)

3 J

ND

ND

1 (3%)

3 J

ND

ND

6

ND

ND

ND

1 (17%)

3 J

ND

ND

Range of Detection Limits (mg/m3)

PM 100

PM 10

PM 4

PM 2.5

2-5 J

2-5 J

4-6 J

2-4 J

2-5 J

2-5 J

4-6 J

2-4 J

12-26 J

12-26 J

20-30 J

13-20 J

2-5 J

2-5 J

4-6 J

2-4 J

7-15 J

7-15 J

11-17 J

7-11 J

4-8 J

4-8 J

6-9 J

4-6 J

2-5 J

2-5 J

4-6 J

2-4 J

2-5 J

2-5 J

4-6 J

2-4 J

12-26 J

12-26 J

20-30 J

13-20 J

2-5 J

2-5 J

4-6 J

2-4 J

7-15 J

7-15 J

11-17 J

7-11 J

4-8 J

4-8 J

6-9 J

4-6 J

a.      Where two samples were co-located-the greatest value of the two was included in this summary. Each location is only represented once in this table.

b.      Concentrations shown are estimated values, indicated by "J."

c.      Air samples from all locations, indoor and outdoor, are pooled in this table due to uncertainties in the data.

d.      Cristobalite, a different crystalline form of silica, was found in one Lower Manhattan air sample at 15 micrograms per cubic meter of air (mg/m3) J in the PM 100 fraction.

e.      J = estimated.

f.       ND = not detected.


Table 12

Highest Amount of Materials Measured in the Indoor Settled Dust of Each Building

Building Number

Quartz
(%) a, d, e

Gypsum
(%)a, d, e

Asbestos
(%)b, f

SVF
(%)c, f

Comparison Locations 31-34

2 J

4 J

Non-Detect

Non-Detect

1

31 J

30 J

Non-Detect

20

2

23 J

14 J

Non-Detect

27

3

Not Sampled

Not Sampled

Not Sampled

Not Sampled

4

14 J

9 J

<1

15

5

11 J

9 J

<1

20

6

27 J

20 J

<1

15

7

21 J

15 J

Non-Detect

5

8

28 J

17 J

Non-Detect

Non-Detect

9

25 J

16 J

<1

7

10

3 J

0.8J

1.5

20

11

2 J

2 J

1.5

Non-Detect

12

4 J

1 J

Non-Detect

5

13

0.05 J

1 J

Non-Detect

10

14

0.03 J

2 J

Non-Detect

5

15

0.4 J

1 J

<1

5

16

Non-Detect

0.9 J

Non-Detect

Non-Detect

17

2 J

2 J

Non-Detect

2

18

0.9 J

1 J

Non-Detect

35

19

1 J

2 J

Non-Detect

Non-Detect

20

0.9 J

1 J

Non-Detect

Non-Detect

21

0.9 J

2 J

Non-Detect

Non-Detect

22

14 J

2 J

Non-Detect

3

23

2 J

1 J

Non-Detect

Non-Detect

24

0.03 J

Non-Detect

<1

10

25

Non-Detect

2 J

Non-Detect

5

26

0.7 J

2 J

Non-Detect

5

27

0.04 J

1 J

<1

10

28

Non-Detect

1 J

Non-Detect

10

29

1 J

2 J

Non-Detect

Non-Detect

30

1 J

4 J

Non-Detect

Non-Detect

a.      Minerals were measured by XRD. Quartz  is considered representative of the relative presence of portlandite and calcite (all are associated with concrete).

b.      Asbestos value represents the highest of the PLM and TEM result for each location.

c.      SVF is synthetic vitreous fiber and was measured by PLM.

d.      Results shown are estimated values, indicated by "J."

e.      % = weight of mineral per weight of dust.

f.       % = roughly area of fibers per area of dust.