Demographic and exposure characteristics of the WTC MSP study
Received 9 August 2006; accepted 5 September 2006.
Table 1. Demographic and exposure characteristics of the WTC MSP study
population (n = 9,442).
No. (%)
Sex
Male 8,186 (86.7)
Female 1,256 (13.3)
Race
White 6,203 (65.7)
Black 1,060 (11.2)
Asian 121 (1.3)
Other 253 (2.7)
Unknown 1,805 (19.1)
Hispanic ethnicity
Yes 2,249 (23.8)
Language of exam
English 8,114 (85.9)
Spanish 984 (10.4)
Polish 311 (3.3)
Other 33 (0.3)
Union member
Yes 8,075 (86.0)
Union/organization affiliation
Construction 3,209 (34.0)
Law enforcement 2,776 (29.4)
Public sector (blue collar) 739 (7.8)
Technical and utilities 683 (7.2)
Transportation 516 (5.5)
Cleaning/maintenance 258 (2.7)
Volunteers 245 (2.6)
Firefighters (a) 138 (1.5)
Health care 83 (0.9)
News agencies 81 (0.9)
Office/administration/professional 50 (0.5)
Other 664 (7.0)
Time first began WTC-related work
11 September 2001 3,812 (40.5)
In dust cloud 1,878 (20.0)
Not in dust cloud 1,934 (20.5)
12-13 September 2001 2,801 (29.8)
14-30 September 2001 2,133 (22.7)
On or after 1 October 2001 666 (7.1)
Location of majority of work
On the pile/in the pit 3,215 (34.8)
Adjacent to pile/pit 5,074 (54.8)
Landfill 313 (3.4)
Barges/loading pier 106 (1.1)
OCME 77 (0.8)
Elsewhere south of Canal St. 466 (5.0)
(a) Does not include active-duty New York City firefighters.
Table 2. Prevalence of lower and upper respiratory symptoms among the
WTC MSP study population (n = 9,442).
Did not report
symptoms in year
before September 11
Reported symptoms in New symptoms
year before September while working at
11 [no. (%)] WTC site [no. (%)]
Lower respiratory symptoms
Dry cough 362 (3.9) 2,541 (28.3)
Cough with phlegm 325 (3.5) 1,183 (13.1)
Shortness of breath 344 (3.7) 1,477 (16.5)
Wheeze 557 (6.0) 1,232 (14.1)
Chest tightness 464 (5.1) 1,258 (14.6)
Any lower respiratory 1,451 (15.4) 3,486 (43.8)
symptom
Upper respiratory symptoms
Sinus-related (a) 2,169 (23.1) 2,219 (30.7)
Nasal-related (b) 1,967 (20.9) 3,254 (43.8)
Throat-related (c) 887 (9.4) 3,579 (42.0)
Any upper respiratory 3,148 (33.5) 3,453 (55.2)
symptom
Any respiratory symptom 3,767 (40.0) 3,443 (61.0)
Did not report symptoms in year before
September 11
Symptoms still present in month before exam
[no. (%)]
Lower respiratory symptoms
Dry cough 1,534 (17.1)
Cough with phlegm 742 (8.2)
Shortness of breath 1,266 (14.1)
Wheeze 749 (8.6)
Chest tightness 933 (10.8)
Any lower respiratory 2,535 (31.9)
symptom
Upper respiratory symptoms
Sinus-related (a) 1,863 (25.8)
Nasal-related (b) 2,536 (34.1)
Throat-related (c) 2,450 (28.8)
Any upper respiratory 2,772 (44.3)
symptom
Any respiratory symptom 2,846 (50.4)
(a) Facial pain or pressure, head or sinus congestion, or postnasal
discharge. (b) Blowing your nose more than usual, stuffy nose, sneezing,
runny nose, or irritation in nose. (c) Throat irritation, hoarseness,
sore throat, or losing your voice (laryngitis).
Table 3. Prevalence of new or worsened respiratory symptoms among WTC
workers by date of arrival for work at WTC site and by exposure to the
dust cloud (n = 9,442).
Arrived on 11
September
All responders In dust cloud
(n = 9,442) (n = 1,878)
[no. (%)] [no. (%)]
Lower respiratory symptoms
Dry cough 2,688 (28.7) 640 (34.2)
Cough with phlegm 1,320 (14.1) 328 (17.6)
Shortness of breath 1,613 (17.3) 390 (20.9)
Wheeze 1,408 (15.1) 339 (18.3)
Chest tightness 1,393 (15.4) 334 (18.5)
Any lower respiratory 4,371 (46.5) 1,017 (54.2)
symptom
Upper respiratory symptoms
Sinus-related (b) 510 (37.3) 785 (41.9)
Nasal-related (c) 4,552 (48.4) 982 (52.4)
Throat-related (d) 4,128 (43.9) 885 (47.2)
Any upper respiratory 5,883 (62.5) 1,233 (65.8)
symptom
Any respiratory symptom 6,479 (68.8) 1,376 (73.4)
Arrived on 11
September Arrived
Not in dust cloud 12-13 September
(n = 1,934) (n = 2,801)
[no. (%)] [no. (%)]
Lower respiratory symptoms
Dry cough 587 (30.6) 777 (28.0)
Cough with phlegm 256 (13.4) 373 (13.5)
Shortness of breath 298 (15.6) 471 (17.1)
Wheeze 296 (15.5) 403 (14.6)
Chest tightness 268 (14.4) 384 (14.3)
Any lower respiratory 912 (47.2) 1,232 (44.2)
Symptom
Upper respiratory symptoms
Sinus-related (b) 712 (36.9) 1,020 (36.6)
Nasal-related (c) 939 (48.6) 1,334 (47.9)
Throat-related (d) 847 (43.9) 1,199 (43.1)
Any upper respiratory 1,205 (62.4) 1,719 (61.7)
symptom
Any respiratory symptom 1,345 (69.7) 1,878 (67.3)
Arrived
Arrived on or after
14-30 September 1 October
(n = 2,133) (n = 666) Trend test
[no. (%)] [no. (%)] p-value (a)
Lower respiratory symptoms
Dry cough 538 (25.5) 140 (21.3) < 0.001
Cough with phlegm 275 (13.0) 84 (12.7) < 0.001
Shortness of breath 339 (16.1) 109 (16.6) 0.001
Wheeze 281 (13.4) 85 (13.0) < 0.001
Chest tightness 311 (15.2) 91 (14.1) 0.003
Any lower respiratory 930 (43.8) 271 (40.8) < 0.001
symptom
Upper respiratory symptoms
Sinus-related (b) 783 (37.0) 200 (30.1) < 0.001
Nasal-related (c) 981 (46.3) 300 (45.1) < 0.001
Throat-related (d) 923 (43.6) 264 (39.7) 0.001
Any upper respiratory 1,316 (62.1) 394 (59.2) 0.001
symptom
Any respiratory symptom 1,435 (67.7) 429 (64.5) < 0.001
(a) One-sided p-values using the Cochran-Armitage trend test. (b) Facial
pain or pressure, head or sinus congestion, or postnasal discharge.
(c) Blowing your nose more than usual, stuffy nose, sneezing, runny
nose, or irritation in nose. (d) Throat irritation, hoarseness, sore
throat, or losing your voice (laryngitis).
Table 4. Spirometry results (prebronchodilator) among the WTC MSP study
population (n = 8,384). (a)
WTC MSP population
National population (b) Never smoker
Never smoker (%) [no. (%)]
Normal 87.1 3,396 (73.2)
Obstruction (c) 8.0 237 (5.1)
Low FVC (d) 4.4 940 (20.3)
Obstruction and low FVC (e) 0.6 68 (1.5)
Total NA 4,641 (55.4)
WTC MSP population
Current
Former smoker smoker All
[no. (%)] [no. (%)] [no. (%)]
Normal 1,541 (72.8) 1,047 (67.1) 6,031 (71.9)
Obstruction (c) 97 (4.6) 114 (7.3) 451 (5.4)
Low FVC (d) 431 (20.3) 336 (21.5) 1,721 (20.5)
Obstruction and low FVC (e) 49 (2.3) 63 (4.0) 181 (2.2)
Total 2,118 (25.3) 1,560 (18.6) 8,384 (100.0)
NA, not applicable.
(a) Only acceptable quality spirometric examinations are included, as
described by Miller et al. (2005). (b) General U.S. population sample of
employed, adult, white males 17-69 years of age who never smoked
(Mannino et al. 2003; NHANES III). (c) FE[V.sub.1]/FVC ratio less than
5th percentile of predicted value and normal FVC. (d) FVC less than 5th
percentile of predicted value and a normal FE[V.sub.1]/FVC ratio.
(e) FE[V.sub.1]/FVC ratio less than 5th percentile of predicted value
and FVC less than 5th percentile of predicted value.
Table 5. Spirometry results (prebronchodilator) by date of arrival for
work at WTC site and exposure to the dust cloud among the WTC MSP study
population (n = 8,384). (a)
Arrived on 11 September
In dust cloud Not in dust cloud
[no. (%)] [no. (%)]
Normal 1,160 (68.5) 1,222 (69.9)
Obstructive (c) 81 (4.8) 96 (5.5)
Low FVC (d) 408 (24.1) 400 (22.9)
Obstruction and low FVC (e) 44 (2.6) 29 (1.7)
Arrived Arrived
12-13 September 14-30 September
[no. (%)] [no. (%)]
Normal 1,781 (71.6) 1,397 (75.3)
Obstructive (c) 140 (5.6) 104 (5.6)
Low FVC (d) 506 (20.3) 318 (17.1)
Obstruction and low FVC (e) 61 (2.5) 36 (1.9)
Arrived on or
after 1 October Trend test
[no. (%)] p-value (b)
Normal 453 (78.6) --
Obstructive (c) 28 (4.9) 0.418
Low FVC (d) 84 (14.6) < 0.001
Obstruction and low FVC (e) 11 (1.9) 0.095
(a) Only acceptable quality spirometric examinations are included, as
described by Miller et al. (2005). (b) One-sided p-values using the
Cochran-Armitage trend test. (c) FE[V.sub.1]/FVC ratio less than 5th
percentile of predicted value and normal FVC. (d) FVC less than 5th
percentile of predicted value and a normal FE[V.sub.1]/FVC ratio.
(e) FE[V.sub.1]/FVC ratio less than 5th percentile of predicted value
and FVC less than 5th percentile of predicted value.