Engineering Pseudomonas putida for efficient aromatic conversion to bioproduct using high throughput screening in a bioreactor.

Pseudomonas putida KT2440 is an emerging biomanufacturing host amenable for use with renewable carbon streams including aromatics such as para-coumarate. We used a pooled transposon library disrupting nearly all (4,778) non-essential genes to characterize this microbe under common stirred-tank bioreactor parameters with quantitative fitness assays. Assessing differential fitness values by monitoring changes in mutant strain abundance identified 33 gene mutants with improved fitness across multiple stirred-tank bioreactor formats. Twenty-one deletion strains from this subset were reconstructed, including GacA, a regulator, TtgB, an ABC transporter, and PP_0063, a lipid A acyltransferase. Thirteen deletion strains with roles in varying cellular functions were evaluated for conversion of para-coumarate, to a heterologous bioproduct, indigoidine. Several mutants, such as the ΔgacA strain improved fitness in a bioreactor by 35 fold and showed an 8-fold improvement in indigoidine production (4.5 g/L, 0.29 g/g, 23% of maximum theoretical yield) from para-coumarate as the carbon source.

Restoration of biofuel production levels and increased tolerance under ionic liquid stress is enabled by a mutation in the essential Escherichia coli gene cydC.

BACKGROUND: Microbial production of chemicals from renewable carbon sources enables a sustainable route to many bioproducts. Sugar streams, such as those derived from biomass pretreated with ionic liquids (IL), provide efficiently derived and cost-competitive starting materials. A limitation to this approach is that residual ILs in the pretreated sugar source can be inhibitory to microbial growth and impair expression of the desired biosynthetic pathway. RESULTS: We utilized laboratory evolution to select Escherichia coli strains capable of robust growth in the presence of the IL, 1-ethyl-3-methyl-imidizolium acetate ([EMIM]OAc). Whole genome sequencing of the evolved strain identified a point mutation in an essential gene, cydC, which confers tolerance to two different classes of ILs at concentrations that are otherwise growth inhibitory. This mutation, cydC-D86G, fully restores the specific production of the bio-jet fuel candidate D-limonene, as well as the biogasoline and platform chemical isopentenol, in growth medium containing ILs. Similar amino acids at this position in cydC, such as cydC-D86V, also confer tolerance to [EMIM]OAc. We show that this [EMIM]OAc tolerance phenotype of cydC-D86G strains is independent of its wild-type function in activating the cytochrome bd-I respiratory complex. Using shotgun proteomics, we characterized the underlying differential cellular responses altered in this mutant. While wild-type E. coli cannot produce detectable amounts of either product in the presence of ILs at levels expected to be residual in sugars from pretreated biomass, the engineered cydC-D86G strains produce over 200 mg/L D-limonene and 350 mg/L isopentenol, which are among the highest reported titers in the presence of [EMIM]OAc. CONCLUSIONS: The optimized strains in this study produce high titers of two candidate biofuels and bioproducts under IL stress. Both sets of production strains surpass production titers from other IL tolerant mutants in the literature. Our application of laboratory evolution identified a gain of function mutation in an essential gene, which is unusual in comparison to other published IL tolerant mutants.

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.

Increased rates of asthma among World Trade Center disaster responders.

BACKGROUND: Studies have documented high rates of asthma symptoms among responders to the World Trade Center (WTC) disaster. However, whether there are increased rates of asthma among responders compared to the general population is unknown. METHODS: The study population consisted of a prospective cohort of 20,834 responders participating in the WTC Medical Monitoring and Treatment Program between July 2002 and December 2007. We calculated prevalence and standardized morbidity ratios (SMRs) of lifetime asthma and 12-month asthma (defined as ≥1 attacks in the prior 12 months) among WTC responders. The comparison population consisted of >200,000 adults who completed the National Health Interview Survey in 2000 (for pre-9/11 comparisons) and between 2002 and 2007 (for post-9/11 comparisons). RESULTS: WTC responders were on average 43 ± 9 years old, 86% male, 59% white, and 42% had an occupation in protective services. The lifetime prevalence of asthma in the general population was relatively constant at about 10% from 2000 to 2007. However, among WTC responders, lifetime prevalence increased from 3% in 2000, to 13% in 2002, and 19% in 2007. The age-adjusted overall SMR for lifetime asthma among WTC responders was 1.8 (95% CI: 1.8-1.9) for men and 2.0 (95% CI: 1.9-2.1) for women. Twelve-month asthma was also more frequent among WTC responders compared to the general population (SMR 2.4, 95% CI: 2.2-2.5) for men and 2.2 (95% CI: 2.0-2.5) for women. CONCLUSIONS: WTC responders are at an increased risk of asthma as measured by lifetime prevalence or active disease.

Priority effects in microbiome assembly.

Advances in next-generation sequencing have enabled the widespread measurement of microbiome composition across systems and over the course of microbiome assembly. Despite substantial progress in understanding the deterministic drivers of community composition, the role of historical contingency remains poorly understood. The establishment of new species in a community can depend on the order and/or timing of their arrival, a phenomenon known as a priority effect. Here, we review the mechanisms of priority effects and evidence for their importance in microbial communities inhabiting a range of environments, including the mammalian gut, the plant phyllosphere and rhizosphere, soil, freshwaters and oceans. We describe approaches for the direct testing and prediction of priority effects in complex microbial communities and illustrate these with re-analysis of publicly available plant and animal microbiome datasets. Finally, we discuss the shared principles that emerge across study systems, focusing on eco-evolutionary dynamics and the importance of scale. Overall, we argue that predicting when and how current community state impacts the success of newly arriving microbial taxa is crucial for the management of microbiomes to sustain ecological function and host health. We conclude by discussing outstanding conceptual and practical challenges that are faced when measuring priority effects in microbiomes.

Odor identification ability and self-reported upper respiratory symptoms in workers at the post-9/11 World Trade Center site.

UNLABELLED: Following the World Trade Center (WTC) collapse on September 11, 2001, more than 40,000 people were exposed to a complex mixture of inhalable nanoparticles and toxic chemicals. While many developed chronic respiratory symptoms, to what degree olfaction was compromised is unclear. A previous WTC Medical Monitoring and Treatment Program study found that olfactory and nasal trigeminal thresholds were altered by the toxic exposure, but not scores on a 20-odor smell identification test. OBJECTIVES: To employ a well-validated 40-item smell identification test to definitively establish whether the ability to identify odors is compromised in a cohort of WTC-exposed individuals and, if so, whether the degree of compromise is associated with self-reported severity of rhinitic symptoms. METHODS: The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 99 WTC-exposed persons and 99 matched normal controls. The Sino-Nasal Outcomes Test (SNOT-20) was administered to the 99 WTC-exposed persons and compared to the UPSIT scores. RESULTS: The mean (SD) UPSIT scores were lower in the WTC-exposed group than in age-, sex-, and smoking history-matched controls [respective scores: 30.05 (5.08) vs 35.94 (3.76); p = 0.003], an effect present in a subgroup of 19 subjects additionally matched on occupation (p < 0.001). Fifteen percent of the exposed subjects had severe microsmia, but only 3% anosmia. SNOT-20 scores were unrelated to UPSIT scores (r = 0.20; p = 0.11). CONCLUSION: Exposure to WTC air pollution was associated with a decrement in the ability to identify odors, implying that such exposure had a greater influence on smell function than previously realized.

World Trade Center disaster: assessment of responder occupations, work locations, and job tasks.

BACKGROUND: To date there have been no comprehensive reports of the work performedby 9/11 World Trade Center responders. METHODS: 18,969 responders enrolled in the WTC Medical Monitoring and Treatment Program were used to describe workers' pre-9/11 occupations, WTC work activities and locations from September 11, 2001 to June 2002. RESULTS: The most common pre-9/11 occupation was protective services (47%); other common occupations included construction, telecommunications, transportation, and support services workers. 14% served as volunteers. Almost one-half began work on 9/11 and >80% reported working on or adjacent to the ''pile'' at Ground Zero. Initially,the most common activity was search and rescue but subsequently, the activities of most responders related to their pre-9/11 occupations. Other major activities included security; personnel support; buildings and grounds cleaning; and telecommunications repair. CONCLUSIONS: The spatial, temporal, occupational, and task-related taxonomy reported here will aid the development of a job-exposure matrix, assist in assessment of disease risk, and improve planning and training for responders in future urban disasters.

"Sarcoid like" granulomatous pulmonary disease in World Trade Center disaster responders.

BACKGROUND: More than 20,000 responders have been examined through the World Trade Center (WTC) Medical Monitoring and Treatment Program since September 11, 2001. Studies on WTC firefighters have shown elevated rates of sarcoidosis. The main objective of this study was to report the incidence of "sarcoid like" granulomatous pulmonary disease in other WTC responders. METHODS: Cases of sarcoid like granulomatous pulmonary disease were identified by: patient self-report, physician report and ICD-9 codes. Each case was evaluated by three pulmonologists using the ACCESS criteria and only "definite" cases are reported. RESULTS: Thirty-eight patients were classified as "definite" cases. Six-year incidence was 192/100,000. The peak annual incidence of 54 per 100,000 person-years occurred between 9/11/2003 and 9/11/2004. Incidence in black responders was nearly double that of white responders. Low FVC was the most common spirometric abnormality. CONCLUSIONS: Sarcoid like granulomatous pulmonary disease is present among the WTC responders. While the incidence is lower than that reported among firefighters, it is higher than expected.

Work-related injuries and illnesses reported by World Trade Center response workers and volunteers.

INTRODUCTION: In 2002, the Mount Sinai Center for Occupational and Environmental Medicine, with support from the National Institute for Occupational Safety and Health (NIOSH), began coordinating the World Trade Center (WTC) Worker and Volunteer Medical Screening Program (MSP) to monitor the health of qualified WTC responders. Enrolled participants were offered a clinical examination; interviewed to collect medical, mental health, and exposure information; and requested to complete a self-administered medical questionnaire. The objective of this study was to better understand work-related injuries and illnesses sustained on-site by WTC responders. METHODS: A descriptive analysis of select data from the MSP self-administered medical questionnaire was conducted. Data collected July 2002 through April 2004 from MSP participants enrolled at the Mount Sinai clinic were reviewed using univariate statistical techniques. RESULTS: Records from 7,810 participants were analyzed, with most participants associated with either the construction industry (n = 2,623, 34%) or law enforcement (n = 2,036, 26%). Approximately a third of the participants (n = 2,486, 32%) reported at least one injury or illness requiring medical treatment that was sustained during WTC work/volunteer activities. Of the total 4,768 injuries/illnesses reported by these participants, respiratory complaints were most common (n = 1,350, 28%), followed by traumatic injuries excluding eye injuries (n = 961, 20%), eye injuries/ailments (n = 709, 15%), chest pain (n = 375, 8%), headaches (n = 359, 8%), skin conditions (n = 178, 4%), and digestive system conditions (n = 163, 3%). Participants reported that 36% of injuries/illnesses were treated off-site and 29% were treated on-site, with the remaining not specifying treatment location. Off-site treatment was prevalent for respiratory complaints, psychological stress, and chest pain. On-site treatment was predominate for eye injuries/ailments and traumatic injuries excluding eye injuries. CONCLUSION: Study results underscore the need for rapid deployment of personal protective equipment for disaster responders and medical care stations mobilized near disaster worksites. Additionally, the results, many of which are comparable to findings from previous WTC studies where data were collected in real-time, indicate that a screening program such as the MSP may be effective in retrospectively providing general information on disaster responder demographics and work-related injuries and illnesses.

Genomics Characterization of an Engineered Corynebacterium glutamicum in Bioreactor Cultivation Under Ionic Liquid Stress.

Corynebacterium glutamicum is an ideal microbial chassis for production of valuable bioproducts including amino acids and next generation biofuels. Here we resequence engineered isopentenol (IP) producing C. glutamicum BRC-JBEI 1.1.2 strain and assess differential transcriptional profiles using RNA sequencing under industrially relevant conditions including scale transition and compare the presence vs absence of an ionic liquid, cholinium lysinate ([Ch][Lys]). Analysis of the scale transition from shake flask to bioreactor with transcriptomics identified a distinct pattern of metabolic and regulatory responses needed for growth in this industrial format. These differential changes in gene expression corroborate altered accumulation of organic acids and bioproducts, including succinate, acetate, and acetoin that occur when cells are grown in the presence of 50 mM [Ch][Lys] in the stirred-tank reactor. This new genome assembly and differential expression analysis of cells grown in a stirred tank bioreactor clarify the cell response of an C. glutamicum strain engineered to produce IP.

Quality of spirometry performed by 13,599 participants in the World Trade Center Worker and Volunteer Medical Screening Program.

OBJECTIVE: To determine the ability of spirometry technicians in the World Trade Center Worker and Volunteer Medical Screening Program to meet American Thoracic Society spirometry quality goals. METHODS: Spirometry technicians were trained centrally and performed spirometry sessions at 6 sites in the greater New York City area. We reviewed and graded the spirometry results for quality every month. RESULTS: About 80% (range 70-88%) of the spirometry sessions met the American Thoracic Society spirometry goals. In general, the spirometry technicians with the most experience were more successful in meeting the quality goals. Participant characteristics explained very little of the quality variability. CONCLUSIONS: The overall spirometry quality in this multicenter program was very good. Efforts to improve spirometry quality should focus on the performance of individual spirometry technicians.

Production of tetra-methylpyrazine using engineered Corynebacterium glutamicum.

Corynebacterium glutamicum ATCC 13032 is an established and industrially-relevant microbial host that has been utilized for the expression of many desirable bioproducts. Tetra-methylpyrazine (TMP) is a naturally occurring alkylpyrazine with broad applications spanning fragrances to resins. We identified an engineered strain of C. glutamicum which produces 5 â€‹g/L TMP and separately, a strain which can co-produce both TMP and the biofuel compound isopentenol. Ionic liquids also stimulate TMP production in engineered strains. Using a fed batch-mode feeding strategy, ionic liquid stimulated strains produced 2.2 â€‹g/L of tetra-methylpyrazine. We show that feedback from a specific heterologous gene pathway on host physiology leads to acetoin accumulation and the production of TMP.

Iron Supplementation Eliminates Antagonistic Interactions Between Root-Associated Bacteria.

The rhizosphere microbiome (rhizobiome) plays a critical role in plant health and development. However, the processes by which the constituent microbes interact to form and maintain a community are not well understood. To investigate these molecular processes, we examined pairwise interactions between 11 different microbial isolates under select nutrient-rich and nutrient-limited conditions. We observed that when grown with media supplemented with 56 mM glucose, two microbial isolates were able to inhibit the growth of six other microbes. The interaction between microbes persisted even after the antagonistic microbe was removed, upon exposure to spent media. To probe the genetic basis for these antagonistic interactions, we used a barcoded transposon library in a proxy bacterium, Pseudomonas putida, to identify genes which showed enhanced sensitivity to the antagonistic factor(s) secreted by Acinetobacter sp. 02. Iron metabolism-related gene clusters in P. putida were implicated by this systems-level analysis. The supplementation of iron prevented the antagonistic interaction in the original microbial pair, supporting the hypothesis that iron limitation drives antagonistic microbial interactions between rhizobionts. We conclude that rhizobiome community composition is influenced by competition for limiting nutrients, with implications for growth and development of the plant.

Genome-scale metabolic rewiring improves titers rates and yields of the non-native product indigoidine at scale.

High titer, rate, yield (TRY), and scalability are challenging metrics to achieve due to trade-offs between carbon use for growth and production. To achieve these metrics, we take the minimal cut set (MCS) approach that predicts metabolic reactions for elimination to couple metabolite production strongly with growth. We compute MCS solution-sets for a non-native product indigoidine, a sustainable pigment, in Pseudomonas putida KT2440, an emerging industrial microbe. From the 63 solution-sets, our omics guided process identifies one experimentally feasible solution requiring 14 simultaneous reaction interventions. We implement a total of 14 genes knockdowns using multiplex-CRISPRi. MCS-based solution shifts production from stationary to exponential phase. We achieve 25.6 g/L, 0.22 g/l/h, and ~50% maximum theoretical yield (0.33 g indigoidine/g glucose). These phenotypes are maintained from batch to fed-batch mode, and across scales (100-ml shake flasks, 250-ml ambr®, and 2-L bioreactors).

Stories behind the symptoms: a qualitative analysis of the narratives of 9/11 rescue and recovery workers.

A qualitative study of the experiences of rescue and recovery workers/volunteers at Ground Zero following the terrorist attacks of 9/11/01 is reported. Information was extracted from a semi-structured clinical evaluation of 416 responders who were the initial participants in a large scale medical and mental health screening and treatment program for 9/11 responders. Qualitative analysis revealed themes that spanned four categories- occupational roles, exposures, attitudes/experiences, and outcomes related to the experience of Ground Zero. Themes included details regarding Ground Zero roles, grotesque experiences such as smells, the sense of the surreal nature of responding, and a turning to rituals to cope after leaving Ground Zero. These findings personalize the symptom reports and diagnoses that have resulted from the 9/11 responders' exposure to Ground Zero, yielding richer information than would otherwise be available for addressing the psychological dimensions of disasters. This work shows that large scale qualitative surveillance of trauma-exposed populations is both relevant and feasible.

Engineering Corynebacterium glutamicum to produce the biogasoline isopentenol from plant biomass hydrolysates.

BACKGROUND: Many microbes used for the rapid discovery and development of metabolic pathways have sensitivities to final products and process reagents. Isopentenol (3-methyl-3-buten-1-ol), a biogasoline candidate, has an established heterologous gene pathway but is toxic to several microbial hosts. Reagents used in the pretreatment of plant biomass, such as ionic liquids, also inhibit growth of many host strains. We explored the use of Corynebacterium glutamicum as an alternative host to address these constraints. RESULTS: We found C. glutamicum ATCC 13032 to be tolerant to both the final product, isopentenol, as well to three classes of ionic liquids. A heterologous mevalonate-based isopentenol pathway was engineered in C. glutamicum. Targeted proteomics for the heterologous pathway proteins indicated that the 3-hydroxy-3-methylglutaryl-coenzyme A reductase protein, HmgR, is a potential rate-limiting enzyme in this synthetic pathway. Isopentenol titers were improved from undetectable to 1.25 g/L by combining three approaches: media optimization; substitution of an NADH-dependent HmgR homolog from Silicibacter pomeroyi; and development of a C. glutamicum ∆poxB ∆ldhA host chassis. CONCLUSIONS: We describe the successful expression of a heterologous mevalonate-based pathway in the Gram-positive industrial microorganism, C. glutamicum, for the production of the biogasoline candidate, isopentenol. We identified critical genetic factors to harness the isopentenol pathway in C. glutamicum. Further media and cultivation optimization enabled isopentenol production from sorghum biomass hydrolysates.

Rhizobacteria Mediate the Phytotoxicity of a Range of Biorefinery-Relevant Compounds.

Advances in engineering biology have expanded the list of renewable compounds that can be produced at scale via biological routes from plant biomass. In most cases, these chemical products have not been evaluated for effects on biological systems, defined in the present study as bioactivity, that may be relevant to their manufacture. For sustainable chemical and fuel production, the industry needs to transition from fossil to renewable carbon sources, resulting in unprecedented expansion in the production and environmental distribution of chemicals used in biomanufacturing. Further, although some chemicals have been assessed for mammalian toxicity, environmental and agricultural hazards are largely unknown. We assessed 6 compounds that are representative of the emerging biofuel and bioproduct manufacturing process for their effect on model plants (Arabidopsis thaliana, Sorghum bicolor) and show that several alter plant seedling physiology at submillimolar concentrations. However, these responses change in the presence of individual bacterial species from the A. thaliana root microbiome. We identified 2 individual microbes that change the effect of chemical treatment on root architecture and a pooled microbial community with different effects relative to its constituents individually. The present study indicates that screening industrial chemicals for bioactivity on model organisms in the presence of their microbiomes is important for biologically and ecologically relevant risk analyses. Environ Toxicol Chem 2019;38:1911-1922. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Complete Genome Sequence of Agrobacterium sp. Strain 33MFTa1.1, Isolated from Thlaspi arvense Roots.

Agrobacterium sp. strain 33MFTa1.1 was isolated for functional host-microbe interaction studies from the Thlaspi arvense root-associated microbiome. The complete genome is comprised of a circular chromosome of 2,771,937 bp, a linear chromosome of 2,068,443 bp, and a plasmid of 496,948 bp, with G+C contents of 59%, 59%, and 58%, respectively.

Enduring mental health morbidity and social function impairment in world trade center rescue, recovery, and cleanup workers: the psychological dimension of an environmental health disaster.

BACKGROUND: The World Trade Center (WTC) attacks exposed thousands of workers to hazardous environmental conditions and psychological trauma. In 2002, to assess the health of these workers, Congress directed the National Institute for Occupational Safety and Health to establish the WTC Medical Monitoring and Treatment Program. This program has established a large cohort of WTC rescue, recovery, and cleanup workers. We previously documented extensive pulmonary dysfunction in this cohort related to toxic environmental exposures. OBJECTIVES: Our objective in this study was to describe mental health outcomes, social function impairment, and psychiatric comorbidity in the WTC worker cohort, as well as perceived symptomatology in workers' children. METHODS: Ten to 61 months after the WTC attack, 10,132 WTC workers completed a self-administered mental health questionnaire. RESULTS: Of the workers who completd the questionnaire, 11.1% met criteria for probable post-traumatic stress disorder (PTSD), 8.8% met criteria for probable depression, 5.0% met criteria for probable panic disorder, and 62% met criteria for substantial stress reaction. PTSD prevalence was comparable to that seen in returning Afghanistan war veterans and was much higher than in the U.S. general population. Point prevalence declined from 13.5% to 9.7% over the 5 years of observation. Comorbidity was extensive and included extremely high risks for impairment of social function. PTSD was significantly associated with loss of family members and friends, disruption of family, work, and social life, and higher rates of behavioral symptoms in children of workers. CONCLUSIONS: Working in 9/11 recovery operations is associated with chronic impairment of mental health and social functioning. Psychological distress and psychopathology in WTC workers greatly exceed population norms. Surveillance and treatment programs continue to be needed.

Standardization of spirometry in assessment of responders following man-made disasters: World Trade Center worker and volunteer medical screening program.

BACKGROUND: Spirometry is the most commonly used pulmonary function test to screen individuals for suspected lung disease. It is also used for screening workers with exposures to agents associated with pulmonary diseases. Although the American Thoracic Society (ATS) provides guidelines for spirometers and spirometry techniques, many factors are not standardized, so that results from individual pulmonary function laboratories vary substantially. These differences can create substantial difficulties in using data pooled from multiple sites to understand health consequences of disasters that involve exposures to pulmonary toxins. This article describes the approach used to minimize these differences for a consortium of institutions who are providing medical monitoring examinations to World Trade Center (WTC) responders. The protocol improved upon the minimal ATS guidelines. METHODS: Spirometric measurements were obtained before and after use of a bronchodilator. A fourth-generation spirometer was chosen that exceeded ATS spirometer accuracy standards. The accuracy was verified at the beginning of each day of testing. Technologists who performed the spirometry tests were centrally trained and certified and received regular reports on their performance. Reference values and normal ranges were obtained from the National Health and Nutrition Examination Survey (NHANES III) data set. A standardized interpretation flowchart was followed to reduce misclassification rates for airway obstruction and restriction. Patients with spirometric abnormalities were referred for more extensive diagnostic testing. RESULTS: More than 12,000 spirometry tests were performed during the first examination. The 20 spirometers used at the 6 participating institutions maintained accuracy within 3% for more than 4 years. Overall, more than 80% of the test sessions met ATS quality goals. Spirometry abnormality rates exceeded those obtained for adults who participated in the NHANES III survey. CONCLUSIONS: The program allowed standardization of the performance and interpretation of spirometry results across multiple institutions. This facilitated reliable and rapid diagnosis of lung disease in the large number of WTC responders screened. We recommend this approach for postdisaster pulmonary evaluations in other settings.