World Trade Center (WTC) Health Studies and Information on Health Services
New York State Personnel Who Responded
The Department of Health in collaboration with the New York State Governor's Office of Employee Relations, the Division of Military and Naval Affairs, and the Department of Civil Service (Employee Health Services), offered New York State employees and National Guard personnel who were directed to respond to the WTC disaster a medical monitoring examination. Medical monitoring evaluations were conducted for 1,677 total personnel and consisted of completion of a health and exposure questionnaire, physical examination, laboratory tests, and pulmonary function tests. A related epidemiological study involved analysis of health outcome data collected during those evaluations. In addition, biological samples were collected and archived by the Wadsworth Center for approximately 1,300 responders. There are over 10,000 archived samples. A pilot study of potential markers of WTC exposures analyzed a subset of samples for analytes, such as metals, dibenzodioxins, dibenzofurans, perfluorinated compounds and others.
A separate cohort study is evaluating asthma and related symptoms among responders compared to a control group of similar, but unexposed state employees. This project involved data collection over a three-year period, from 2003 to 2006. An additional 2007 study evaluated clinical tests of respiratory status in a subgroup of the study population in comparison with a control group. These tests assessed airway inflammation and respiratory function.
Health Effects in New York State Personnel who Responded to the World Trade Center Disaster
(J Occup Environ Med. 2007 Nov;49(11):1197-205)Information Sheet
- Objective: To conduct an evaluation of health effects in New York State personnel who responded to the World Trade Center disaster.
- Methods: Data from a medical monitoring program, including questionnaire data, physical examination results, and clinical and laboratory test results were evaluated for 1423 participants. Descriptive statistics were reviewed and data were analyzed using logistic regression.
- Results: Lower and upper respiratory symptoms were reported by nearly half of the study participants. One third reported a psychological symptom. Some health effects, including respiratory symptoms and symptoms suggestive of posttraumatic stress disorder, were associated with having been caught in the cloud of dust on September 11, 2001.
- Conclusions: This cohort probably experienced less overall exposure than other World Trade Center responder cohorts did. Results suggest that being present when the buildings collapsed was associated with reported symptoms.
Development of an Exposure Assessment Method for Epidemiological Studies of New York State Personnel who Responded to the World Trade Center Disaster
(Ann Occup Hyg. 2008 Mar;52(2):83-93. Epub 2008 Feb 13)Information Sheet
- Objectives: An exposure assessment method was developed for use in assigning an exposure score to New York State personnel who responded to the World Trade Center disaster site after the 11 September 2001 terrorist attacks.
- Methods: The method consists of an algorithm with two instantiations. Each represents a major component of the overall exposures at the site: dust and smoke. The algorithm uses US Environmental Protection Agency air monitoring data collected between 23 September 2001 and 28 February 2002, as well as information on duration, location and time period of work assignment and type and frequency of personal protective respiratory equipment (PPE) use, collected by a self-administered mailed questionnaire. These data were used to calculate an overall exposure score for each participant. For each time period/location combination, individuals provided average number of hours and number of days worked. This was multiplied by a weighting factor derived from the median of the air monitoring data for the time period/location. Calcium was chosen as a surrogate for the dust exposure, so the weighting factors for the dust instantiation were calculated from calcium air monitoring data. Total hepta-chlorinated dibenzo-p-dioxin was chosen as a surrogate for the smoke exposure and was similarly used in the smoke instantiation.
- Results: More individuals in the highest exposure score category performed tasks such as search/rescue and hand digging than those in the lowest exposure category. Also, those in the highest exposure category had a higher mean number of hours at the site than other exposure groups.
- Conclusions: The exposure assessment method presented accounts for PPE use, amount of time at the site, proximity to the site and ambient air monitoring results taken in the immediate vicinity. The algorithm can be used to rank individuals in the same study with very different patterns of exposure, such as high-level, short-term exposures and low-level, long-term exposures. The concepts could be modified for use in other epidemiological studies where long-term chronic exposure is a concern.
Asthma and Lower Respiratory Symptoms in New York State Employees who Responded to the World Trade Center Disaster
(Int Arch Occup Environ Health. 2010 Jan;83(1):21-7. Epub 2009 Nov 5)Information Sheet
- Purpose: To investigate whether New York State employees who responded to the World Trade Center disaster were more likely to report asthma or lower respiratory symptoms (LRS; cough, wheeze, chest tightness, shortness of breath) than non-exposed employees, 2 years post-September 11.
- Methods: Participants (578 exposed, 702 non-exposed) completed mailed questionnaires in 2003. A unique exposure assessment method was used; exposure scores were divided at the mean (at/below, above). Poisson regression was used.
- Results: Exposure was associated with LRS, but not asthma. Participants with exposure scores at/below the mean had a twofold increased risk of most LRS. Those with scores above the mean had a three to fourfold increased risk. For scores above the mean, the magnitude of effect was consistently higher for smoke exposure.
- Conclusions: Moderately exposed responders may experience health impacts from exposures in later stages of a disaster. Exposure to smoke may have had a greater lower respiratory impact than resuspended dust.
Long-Term Respiratory Symptoms in World Trade Center Responders
(Occup Med (Lond). 2010 Mar;60(2):145-51. Epub 2009 Dec 24)Information Sheet
- Background: New York State (NYS) employees who responded to the World Trade Center (WTC) disaster on or after 11 September 2001 potentially experienced exposures that might have caused persistent respiratory effects. NYS responders represent a more moderately exposed population than typical first responders.
- Aims: To assess whether NYS employees who were WTC responders were more likely than controls to report lower respiratory symptoms (LRS) or a diagnosis of asthma 5 years post-9/11. Persistence and severity of symptoms were also evaluated.
- Methods: Participants were initially mailed self-administered questionnaires (initial, Year 1, Year 2) and then completed a telephone interview in Year 3. Data were analysed using Poisson's regression models.
- Results: WTC exposure was associated with LRS, including cough symptoms suggestive of chronic bronchitis, 5 years post-9/11. When exposure was characterized using an exposure assessment method, the magnitude of effect was greater in those with exposure scores above the mean. WTC exposure was associated with persistence of LRS over the 3 year study period. Results also suggest that participants with the highest exposures were more likely to experience increased severity of their asthma condition and/or LRS.
- Conclusions: Our findings suggest that even in a moderately exposed responder population, lower respiratory effects were a persistent problem 5 years post-9/11, indicating that some WTC responders require ongoing monitoring.
Impulse Oscillometry and Respiratory Symptoms in World Trade Center Responders, 6 years post-9/11
(Lung. 2010 Apr;188(2):107-13. Epub 2009 Dec 12)Information Sheet
- This study evaluated whether impulse oscillometry (IOS) testing revealed signs of respiratory disease in New York State (NYS) World Trade Center (WTC) responders in comparison with unexposed NYS employees. It also compared self-reported respiratory symptoms between the two groups, 6 years post-9/11. For this evaluation participants completed a self-administered questionnaire regarding respiratory symptoms. IOS testing included measures of resistance and reactance to assess for peripheral versus central airway effects. Two hundred forty-eight subjects (99 exposed and 149 unexposed) were included in the final analysis. Since September 11, 2001, NYS responders were more likely to report new or worsening cough in the absence of a respiratory infection, cough consistent with chronic bronchitis, current respiratory symptoms, or lower respiratory symptoms in the last 12 months. Significant associations were found between IOS indices and gender, smoking history, and obesity. When comparing exposed and unexposed participants, there were no significant differences in the geometric means of the IOS indices. Responders who used a respirator with canister demonstrated significantly lower respiratory resistance at 5 and 20 Hz (R5 and R20). While this study has provided no evidence of an association between WTC exposure and peripheral airways disease in this cohort of responders, results do suggest that use of a respirator with canister may be protective for central airways in responders exposed to dust and smoke. This emphasizes the importance of stressing proper respirator use in planning responses to future disasters. Our control data also provide useful reference values for future IOS research.
Polychlorinated dibenzo-p-dioxins, Dibenzofurans, Biphenyls and Naphthalenes in Plasma of Workers Deployed at the World Trade Center after the Collapse
(Environ Sci Technol. 2010 Jul 1;44(13):5188-5194)Information Sheet
- Blood plasma samples (n = 43) collected retrospectively from New York State employees and National Guard personnel who had been assigned to work in the vicinity of the World Trade Center (WTC) during the week after the collapse of the buildings were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). On the basis of algorithms developed to rank individual exposures to dust and debris and to smoke, we categorized the samples as: more smoke exposure (MSE), more dust exposure (MDE), less smoke exposure (LSE), and less dust exposure (LDE). Mean concentrations of PCDDs were 1070, 223, 3690, and 732 pg/g lipid wt, and mean concentrations of PCDFs were 910, 1520, 230, and 117 pg/g lipid wt, for the MSE, MDE, LSE, and LDE groups, respectively. The concentrations of PCDFs were higher in the two "more exposure" groups than in the two "less exposure" groups. Calculated TEQ concentrations of coplanar PCBs and PCDD/Fs in plasma samples were, on average, 1.12 and 41.2 pg WHO-TEQ/g lipid wt, respectively. TEQ concentrations of PCDFs were higher than those of PCDDs in both "more exposure" groups but lower than those of PCDDs in "less exposure" groups. This result is suggestive of exposure of the WTC responders to PCDFs after the WTC collapse. PCDFs contributed the majority of TEQs and are therefore the critical dioxin-like compounds in MSE/MDE groups, whereas PCDDs are the critical compounds in the LSE/LDE groups.
Biomonitoring of Perfluorochemicals in Plasma of New York State Personnel Responding to the World Trade Center Disaster
(Environ Sci Technol. 2008 May 1;42(9):3472-3478)Information Sheet
- The collapse of the World Trade Center (WTC) on September 11, 2001 resulted in the release of several airborne pollutants in and around the site. Perfluorochemicals including perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), which are used in soil- and stain-resistant coatings on upholstery, carpets, leather, floor waxes, polishes, and in fire-fighting foams were potentially released during the collapse of the WTC. In this pilot study, we analyzed 458 plasma samples of New York State (NYS) employees and National Guard personnel assigned to work in the vicinity of the WTC between September 11 and December 23, 2001, to assess exposure to perfluorochemicals released in dust and smoke. The plasma samples collected from NYS WTC responders were grouped based on estimated levels of exposure to dust and smoke, as follows: more dust exposure (MDE), less dust exposure (LDE), more smoke exposure (MSE), and less smoke exposure (LSE). Furthermore, samples were grouped, based on self-reported symptoms at the time of sampling, as symptomatic and asymptomatic. Eight perfluorochemicals were measured in 458 plasma samples. PFOS, PFOA, perfluorohexanesulfonate (PFHxS), and perfluorononanoic acid (PFNA), were consistently detected in almost all samples. PFOA and PFHxS concentrations were approximately 2-fold higher in WTC responders than the concentrations reported for the U.S. general population. No significant difference was observed in the concentrations of perfluorochemicals between symptomatic and asymptomatic groups. Concentrations of PFHxS were significantly (p = 0.05) higher in the MDE group than in the LDE group. Concentrations of PFNA were significantly higher in the MSE group than in the LSE group. Significantly higher concentrations of PFOA and PFHxS were found in individuals exposed to smoke than in individuals exposed to dust. A significant negative correlation existed between plasma lipid content and concentrations of certain perfluorochemicals. Our initial findings suggest that WTC responders were exposed to perfluorochemicals, especially PFOA, PFNA, and PFHxS, through inhalation of dust and smoke released during and after the collapse of the WTC. The potential health implications of these results are unknown at this time. Expansion of testing to include all archived samples will be critical to help confirm these findings. In doing so, it may be possible to identify biological markers of WTC exposure and to improve our understanding of the health impacts of these compounds.
Questions on these studies or the original New York State WTC Medical Monitoring program may be directed to firstname.lastname@example.org or 518-402-7900.