Respiratory Symptoms Were Associated With Lower Spirometry Results During the First Examination of WTC Responders

The implementation of medical monitoring programs following potentially hazardous exposures: a medico-legal perspective

CONTEXT

Clinical toxicologists may be called upon to determine the appropriateness of medical monitoring following documented or purported exposures to toxicants in the occupational, environmental, and medical settings.

METHODS

We searched the MEDLINE database using the Ovid^® search engine for the following terms cross-referenced to the MeSH database: ("occupational exposures" OR "environmental exposures") AND ("physiologic monitoring" OR "population surveillance"). The titles and abstracts of the resulted articles were reviewed for relevance. We expanded our search to include non-peer-reviewed publications and gray literature and resources using the same terms as utilized in the MEDLINE search. There were a total of 48 relevant peer-reviewed and non-peer-reviewed publications. Publications excluded contained no information relevant to medical monitoring following potentially harmful toxicologic exposures, discussed only worker screening/surveillance and/or population biomonitoring, contained redundant information, or were superseded by more recent information. Approaches to medical monitoring: A consensus exists in the peer-reviewed medical literature, legal literature, and government publications that for medical monitoring to be a beneficial public health activity, careful consideration must be given to potential benefits and harms of the program. Characteristics of the exposure, the adverse human health effect, the screening test, and the natural history of the disease are important in determining whether an exposed population will reap a net benefit or harm from a proposed monitoring program. Broader interpretations of medical monitoring: Some have argued that medical monitoring programs should not be limited to exposure-related outcomes but should duplicate general preventive medicine efforts to improve public health outcomes although an overall reduction of morbidity, mortality and disability by modifying correctable risk factors and disease conditions. This broader approach is inconsistent with the targeted approach advocated by the Agency for Toxic Substances and Disease Registry and the United States Preventive Services Task Force and the bulk of the peer-reviewed medical literature. Medical monitoring in legal contexts: Numerous medical monitoring actions have been litigated. Legal rationales for allowing medical monitoring claims often incorporate some of the scientific criteria for the appropriateness of monitoring programs. In the majority of cases in which plaintiffs were awarded medical monitoring relief, plaintiffs were required to demonstrate both that the condition for which medical monitoring was sought could be detected early, and that early detection and treatment will improve morbidity and mortality. However, the treatment of medical monitoring claims varies significantly depending upon jurisdiction. Examples of large-scale, comprehensive medical monitoring programs: Large-scale, comprehensive medical monitoring programs have been implemented, such as the Fernald Medical Monitoring Program and the World Trade Center Health Program, both of which exceeded the scope of medical monitoring typically recommended in the peer-reviewed medical literature and the courts. The Fernald program sought to prevent death and disability due to non-exposure-related conditions in a manner similar to general preventive medicine. The World Trade Center Health Program provides comprehensive medical care for World Trade Center responders and may be viewed as a large-scale, federally--funded research effort, which distinguishes it from medical monitoring in a medico-legal context. Synthesis of public health approaches to medical monitoring: Medical monitoring may be indicated following a hazardous exposure in limited circumstances. General causation for a specific adverse health effect must be either established by scientific consensus through a formal causal analysis using a framework such as the Bradford-Hill criteria. The exposure must be characterized and must be of sufficient severity that the exposed population has a significantly elevated risk of an adverse health effect. Monitoring must result in earlier detection of the condition than would otherwise occur and must confer a benefit in the form of primary, secondary or tertiary prevention. Outcome tables may be of use in describing the potential benefits and harms of a proposed monitoring program.

CONCLUSIONS

In the context of litigation, plaintiffs may seek medical monitoring programs after documented or putative exposures. The role of the clinical toxicologist, in this setting, is to evaluate the scientific justifications and medical risks and assist the courts in determining whether monitoring would be expected to result in a net public health benefit.

Health Risks to Ecological Workers on Contaminated Sites - the Department of Energy as a Case Study

BACKGROUND

At most contaminated sites the risk to workers focuses on those 'hazardous waste workers' directly exposed to chemicals or radionuclides, and to the elaborate approaches implemented to protecting their health and safety. Ecological workers generally are not considered.

OBJECTIVES

To explore the risks to the health and safety of ecological workers on sites with potential chemical and radiological exposures before, during or after remediation of contamination. To use the U.S. Department of Energy as a case study, and to develop concepts that apply generally to sites contaminated with hazardous or nuclear wastes.

METHODS

Develop categories of ecological workers, describe their usual jobs, and provide information on the kinds of risks they face. Ecological activities include continued surveillance and monitoring work on any sites with residual contamination, subject to institutional controls and engineered barriers following closure as well as the restoration.

RESULTS

The categories of ecological workers and their tasks include 1) Ecological characterization, mapping and monitoring, 2) biodiversity studies, 2) Contaminant fate and transport, 3) On-going industrial activities 4) Remediation activities (environmental management), 5) Environmental restoration, 6) Post-cleanup surveillance and monitoring, and 7) Post-closure future site activities. There are a set of functional activities that can occur with different frequencies and intensities, including visual inspection, collecting biological samples, collecting media physical samples, collecting biological debris, restoration planting, and maintaining ecosystems.

CONCLUSIONS

Ecological workers face different exposures and risks than other environmental cleanup workers. Many of their tasks mimic shift work with long hours leading to fatigue, and they are exposed to biological as well as chemical/radiological hazards. DOE and other entities need to examine the risks to ecological workers on site with an eye to risk reduction.

Health effects of World Trade Center (WTC) Dust: An unprecedented disaster's inadequate risk management

The World Trade Center (WTC) twin towers in New York City collapsed on 9/11/2001, converting much of the buildings' huge masses into dense dust clouds of particles that settled on the streets and within buildings throughout Lower Manhattan. About 80-90% of the settled WTC Dust, ranging in particle size from ∼2.5 μm upward, was a highly alkaline mixture of crushed concrete, gypsum, and synthetic vitreous fibers (SVFs) that was readily resuspendable by physical disturbance and low-velocity air currents. High concentrations of coarse and supercoarse WTC Dust were inhaled and deposited in the conductive airways in the head and lungs, and subsequently swallowed, causing both physical and chemical irritation to the respiratory and gastroesophageal epithelia. There were both acute and chronic adverse health effects in rescue/recovery workers; cleanup workers; residents; and office workers, especially in those lacking effective personal respiratory protective equipment. The numerous health effects in these people were not those associated with the monitored PM2.5 toxicants, which were present at low concentrations, that is, asbestos fibers, transition and heavy metals, polyaromatic hydrocarbons or PAHs, and dioxins. Attention was never directed at the very high concentrations of the larger-sized and highly alkaline WTC Dust particles that, in retrospect, contained the more likely causal toxicants. Unfortunately, the initial focus of the air quality monitoring and guidance on exposure prevention programs on low-concentration components was never revised. Public agencies need to be better prepared to provide reliable guidance to the public on more appropriate means of exposure assessment, risk assessment, and preventive measures.

Pulmonary function predicting confirmed recovery from lower-respiratory symptoms in World Trade Center-exposed firefighters, 2001 to 2010

BACKGROUND

We examined the relationship between pulmonary function (FEV 1 ) and confirmed recovery from three lower-respiratory symptoms (LRSs) (cough, dyspnea, and wheeze) up to 9 years after symptom onset.

METHODS

The study included white and black male World Trade Center (WTC)-exposed firefighters who reported at least one LRS on a medical monitoring examination during the fi rst year after September 11, 2001. Confirmed recovery was defined as reporting no LRSs on two consecutive and all subsequent examinations. FEV 1 was assessed at the fi rst post-September 11, 2001, examination and at each examination where symptom information was ascertained. We used stratified Cox regression models to analyze FEV 1 , WTC exposure, and other variables in relation to confirmed symptom recovery.

RESULTS

A total of 4,368 fi refighters met inclusion criteria and were symptomatic at year 1, of whom1,592 (36.4%) experienced confirmed recovery. In univariable models, fi rst post-September 11,2001, concurrent, and difference between fi rst post-September 11, 2001, and concurrent FEV 1 values were all significantly associated with confirmed recovery. In adjusted analyses, both fi rst post-September 11, 2001, FEV 1 (hazard ratio [HR], 1.07 per 355-mL difference; 95% CI, 1.04-1.10) and FEV 1 % predicted (HR, 1.08 per 10% predicted difference; 95% CI, 1.04-1.12) predicted confirmed recovery. WTC exposure had an inverse association with confirmed recovery in the model with FEV 1 , with the earliest arrival group less likely to recover than the latest arrival group (HR, 0.73;95% CI, 0.58-0.92).

CONCLUSIONS

Higher FEV 1 and improvement in FEV 1 after September 11, 2001, predicted confirmed LRS recovery, supporting a physiologic basis for recovery and highlighting consideration of spirometry as part of any postexposure respiratory health assessment.

Persistence of multiple illnesses in World Trade Center rescue and recovery workers: a cohort study

BACKGROUND

More than 50,000 people participated in the rescue and recovery work that followed the Sept 11, 2001 (9/11) attacks on the World Trade Center (WTC). Multiple health problems in these workers were reported in the early years after the disaster. We report incidence and prevalence rates of physical and mental health disorders during the 9 years since the attacks, examine their associations with occupational exposures, and quantify physical and mental health comorbidities.

METHODS

In this longitudinal study of a large cohort of WTC rescue and recovery workers, we gathered data from 27,449 participants in the WTC Screening, Monitoring, and Treatment Program. The study population included police officers, firefighters, construction workers, and municipal workers. We used the Kaplan-Meier procedure to estimate cumulative and annual incidence of physical disorders (asthma, sinusitis, and gastro-oesophageal reflux disease), mental health disorders (depression, post-traumatic stress disorder [PTSD], and panic disorder), and spirometric abnormalities. Incidence rates were assessed also by level of exposure (days worked at the WTC site and exposure to the dust cloud).

FINDINGS

9-year cumulative incidence of asthma was 27·6% (number at risk: 7027), sinusitis 42·3% (5870), and gastro-oesophageal reflux disease 39·3% (5650). In police officers, cumulative incidence of depression was 7·0% (number at risk: 3648), PTSD 9·3% (3761), and panic disorder 8·4% (3780). In other rescue and recovery workers, cumulative incidence of depression was 27·5% (number at risk: 4200), PTSD 31·9% (4342), and panic disorder 21·2% (4953). 9-year cumulative incidence for spirometric abnormalities was 41·8% (number at risk: 5769); three-quarters of these abnormalities were low forced vital capacity. Incidence of most disorders was highest in workers with greatest WTC exposure. Extensive comorbidity was reported within and between physical and mental health disorders.

INTERPRETATION

9 years after the 9/11 WTC attacks, rescue and recovery workers continue to have a substantial burden of physical and mental health problems. These findings emphasise the need for continued monitoring and treatment of the WTC rescue and recovery population.

FUNDING

Centers for Disease Control and Prevention and National Institute for Occupational Safety and Health.