Exposure to dust from the collapse of the World Trade Center has been associated with a multitude of respiratory outcomes. For the first time, researchers looked at how dwellings in Lower Manhattan were damaged, how they were repaired, how people cleaned up afterwards, and how these differences affected the likelihood of respiratory symptoms and diseases.
Lower Manhattan residents who sustained damage to their dwellings as a result of the collapse of the World Trade Center (WTC) were likely to report respiratory symptoms and diseases, and the methods they used to clean their homes or apartments following the attack had an impact on respiratory outcomes, according to a new study in the International Journal of Environmental Research and Public Health.
Data were evaluated from the World Trade Center Health Report (WTCHR) Wave 1 (W1), and Wave 2 (W2) surveys, which detailed the health of individuals directly exposed to the terrorist attack over time. W1 was conducted from September 2003 to November 2004 while W2 was recorded between November 2006 to December 2007. W1 and W2 information covering 6447 residents who were at least 18 years of age and lived south of Canal Street were included in the study. The mean age of affected individuals was 45.1 years, 42% were male, 45% had previously smoked cigarettes, and 44% recalled some dust cloud exposure.
Outcomes observed in the study were self-reported respiratory symptoms and physician-diagnosed diseases, which first occurred or worsened following the terrorist attack, had been recorded in W1, and were still present in W2. A total of 68% of lower Manhattan residents that reported any respiratory outcome were located within a half mile of the WTC site. Results varied and, upon analysis, were found to be linked to sustained damage to dwellings and cleaning practices.
The WTCHR included questions about conditions inside dwellings after the attack, including damage sustained to home or apartments, cleaning methods used, and whether certain household items were replaced.
Specific questions asked whether respondents experienced any broken windows, whether there was any damage to their dwellings or furnishings, and if they encountered any debris from the disaster. They were also asked if they replaced carpets, rugs, furniture, drapes, blinds, curtains, or air conditioners.
Questions about cleaning practices were also asked, as most residential exposures were caused by re-suspension of settled indoor dust during cleaning efforts or which remained in poorly cleaned environments. Respondents were asked about the presence of fine or heavy coatings of dust on surfaces and answered whether or not they had personally cleaned ventilation ducts, if they cleaned with water using sponges, mops, or cloths, whether they used a vacuum with or without a high-efficiency particulate air filter, and if they dusted or swept without water. Methods of cleaning after the collapse of the WTC varied substantially among respondents.
Researchers found that cleaning with water was associated with having a fine coating of dust and no broken windows. Those who used a vacuum or cleaned ventilation ducts were less likely to report a presence of dust but were more likely to report damage to their dwellings or furnishings. Links between cleaning practices were also found. Most respondents who cleaned with water also used a vacuum.
Regarding respiratory outcomes, those who encountered a heavy coating of dust had a 65% chance of reporting shortness of breath, a 43% chance of reporting wheezing, and a 59% chance of reporting chronic cough. Those who acknowledged damage to their dwellings or furnishings had a 33% higher chance of reporting shortness of breath and 36% greater odds of reporting upper respiratory symptoms. The reported presence of debris was associated with chronic cough and upper respiratory symptoms. Those who replaced air conditioners had a greater chance of having upper respiratory symptoms. Higher rates of COPD were reported by those who replaced carpets. Individuals who replaced drapes or curtains reported greater occurrence of shortness of breath. Dusting or sweeping without water was link to the greatest number of respiratory outcomes including shortness of breath, wheezing, and upper respiratory symptoms. Cleaning with water was associated with upper respiratory symptoms. Those who cleaned ventilation ducts reported greater occurrences of wheezing and coughing.
Demographic characteristics, household exposures resulting from damage to dwellings, and cleaning practices were analyzed using descriptive statistics that calculated means, standard deviations and proportions. Researchers calculated the self-reported prevalence of respiratory symptoms and diseases. The correlation between cleaning practices and conditions inside dwellings after the WTC attack was evaluated using multivariate logistic regression analysis adjusted for age, race, education, income, and gender. Cleaning practices were also modelled using logistic regression.
Geospatial analysis was conducted and controlled for 3 distinct groups. Different “priority” groups were established based off individuals’ vicinity to the WTC site. Priority group 1 was composed of individuals living south of Canal Street. Group 2 included individuals located north of Chamber Street but south of Canal Street. Group 0 included respondents living on or north of Canal Street in zip codes overlapping the Canal boundary or in other city boroughs.
Analyses were also controlled for environmental exposure to dust from the WTC. Respondents in W1 reported their location after they first encountered the enormous dust cloud. Data from W2 categorized dust exposure as “intense, some, and none.” Individuals that fit the “intense” category were those in the dust cloud who were unable to see more than a few feet, had difficulty walking or gaining a sense of direction, were completely covered with dust, and who couldn’t hear. Those in the “some” category were exposed to dust but not as severely. To fit into the “none” category, individuals had to not be exposed to the dust cloud at all.
Over 100,000 µm per cubic meter of particles were predicted to be present in the air for the first few minutes after the collapse of each building. Dust from the WTC was analyzed and found to be a mixture of dioxins, polychlorinated furans, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, cement dust, glass fibers, asbestos, and lead. Indoor dust was mostly composed of inhalable particles less than 53 µm. Comparatively, the majority of outdoor dust was primarily comprised of larger particles.
Health outcomes reported in the study persisted for a minimum of 5 to 6 years after the WTC attack which may have resulted in lower quality of life for many lower Manhattan residents.
ReferenceAntao VC, Pallos LL, Graham SL, et al. 9/11 Residential Exposures: The Impact of World Trade Center Dust on Respiratory Outcomes of Lower Manhattan Residents. Int. J. Environ. Res. Public Health. 2019;16(5). doi: 10.3390/ijerph16050798.