A framework for integrating information resources for chemical emergency management and response.

Effective emergency management and response require appropriate utilization of various resources as an incident evolves. This manuscript describes the information resources used in chemical emergency management and operations and how their utility evolves from the initial response phase to recovery to event close out. The authors address chemical hazard guidance in the context of four different phases of emergency response: preparedness, emergency response (both initial and ongoing), recovery, and mitigation. Immediately following a chemical incident, during the initial response, responders often use readily available, broad-spectrum guidance to make rapid decisions in the face of uncertainties regarding potential exposure to physical and health hazards. Physical hazards are described as the hazards caused by chemicals that can cause harm with or without direct contact. Examples of physical hazards include explosives, flammables, and gases under pressure. This first line of resources may not be chemical-specific in nature, but it can provide guidance related to isolation distances, protective actions, and the most important physical and health threats. During the ongoing response phase, an array of resources can provide detailed information on physical and health hazards related to specific chemicals of concern. Consequently, risk management and mitigation actions evolve as well. When the incident stabilizes to a recovery phase, the types of information resources that facilitate safe and effective incident management evolve. Health and physical concerns transition from acute toxicity and immediate hazards to both immediate and latent health effects. Finally, the information inputs utilized during the preparedness phase include response evaluations of past events, emergency preparedness planning, and chemical-specific guidance about chemicals present. This manuscript details a framework for identifying the effective use of information resources at each phase and provides case study examples from chemical hazard emergencies.

A framework for integrating information resources for chemical emergency management and response.

Effective emergency management and response require appropriate utilization of various resources as an incident evolves. This manuscript describes the information resources used in chemical emergency management and operations and how their utility evolves from the initial response phase to recovery to event close out. The authors address chemical hazard guidance in the context of four different phases of emergency response: preparedness, emergency response (both initial and ongoing), recovery, and mitigation. Immediately following a chemical incident, during the initial response, responders often use readily available, broad-spectrum guidance to make rapid decisions in the face of uncertainties regarding potential exposure to physical and health hazards. Physical hazards are described as the hazards caused by chemicals that can cause harm with or without direct contact. Examples of physical hazards include explosives, flammables, and gases under pressure. This first line of resources may not be chemical-specific in nature, but it can provide guidance related to isolation distances, protective actions, and the most important physical and health threats. During the ongoing response phase, an array of resources can provide detailed information on physical and health hazards related to specific chemicals of concern. Consequently, risk management and mitigation actions evolve as well. When the incident stabilizes to a recovery phase, the types of information resources that facilitate safe and effective incident management evolve. Health and physical concerns transition from acute toxicity and immediate hazards to both immediate and latent health effects. Finally, the information inputs utilized during the preparedness phase include response evaluations of past events, emergency preparedness planning, and chemical-specific guidance about chemicals present. This manuscript details a framework for identifying the effective use of information resources at each phase and provides case study examples from chemical hazard emergencies.

Cytogenetic analysis of an exposed-referent study: perchloroethylene-exposed dry cleaners compared to unexposed laundry workers.

BACKGROUND: Significant numbers of people are exposed to tetrachloroethylene (perchloroethylene, PCE) every year, including workers in the dry cleaning industry. Adverse health effects have been associated with PCE exposure. However, investigations of possible cumulative cytogenetic damage resulting from PCE exposure are lacking. METHODS: Eighteen dry cleaning workers and 18 laundry workers (unexposed controls) provided a peripheral blood sample for cytogenetic analysis by whole chromosome painting. Pre-shift exhaled air on these same participants was collected and analyzed for PCE levels. The laundry workers were matched to the dry cleaners on race, age, and smoking status. The relationships between levels of cytological damage and exposures (including PCE levels in the shop and in workers' blood, packyears, cumulative alcohol consumption, and age) were compared with correlation coefficients and t-tests. Multiple linear regressions considered blood PCE, packyears, alcohol, and age. RESULTS: There were no significant differences between the PCE-exposed dry cleaners and the laundry workers for chromosome translocation frequencies, but PCE levels were significantly correlated with percentage of cells with acentric fragments (R2 = 0.488, p < 0.026). CONCLUSIONS: There does not appear to be a strong effect in these dry cleaning workers of PCE exposure on persistent chromosome damage as measured by translocations. However, the correlation between frequencies of acentric fragments and PCE exposure level suggests that recent exposures to PCE may induce transient genetic damage. More heavily exposed participants and a larger sample size will be needed to determine whether PCE exposure induces significant levels of persistent chromosome damage.

Monitoring microbial populations on wide-body commercial passenger aircraft.

Although exposure to bacteria has been assessed in cabin air previously, minimal numbers of samples have been collected in-flight. The purpose of this research was to comprehensively characterize bacterial concentrations in the aircraft cabin. Twelve randomly selected flights were sampled on Boeing-767 aircraft, each with a flight duration between 4.5 and 6.5 h. N-6 impactors were used to collect sequential, triplicate air samples in the front and rear of coach class during six sampling intervals throughout each flight: boarding, mid-climb, early cruise, mid-cruise, late cruise and deplaning. Comparison air samples were also collected inside and outside the airport terminals at the origin and destination cities. The MIXED procedure in SAS was used to model the mean and the covariance matrix of the natural log-transformed bacterial concentrations. A total of 513 airborne culturable bacterial samples were collected. During flight (mid-climb and cruise intervals), a model-adjusted geometric mean (GM) of 136 total colony-forming units per cubic meter of air sampled (CFU x m(-3)) and geometric standard deviation of 2.1 were observed. Bacterial concentrations were highest during the boarding (GM 290 CFU x m(-3)) and deplaning (GM 549 CFU x m(-3)) processes. Total bacterial concentrations observed during flight were significantly lower than GMs for boarding and deplaning (P values <0.0001-0.021) in the modeled results. Our findings highlight the fact that aerobiological concentrations can be dynamic and underscore the importance of appropriate sample size and design. The genera analysis indicates that passenger activity and high occupant density contribute to airborne bacterial generation. Overall, our research demonstrates that the bacteria recovered on observed flights were either common skin-surface organisms (primarily gram-positive cocci) or organisms common in dust and outdoor air.

Assessing total fungal concentrations on commercial passenger aircraft using mixed-effects modeling.

The primary objective of this study was to compare airborne fungal concentrations onboard commercial passenger aircraft at various in-flight times with concentrations measured inside and outside airport terminals. A secondary objective was to investigate the use of mixed-effects modeling of repeat measures from multiple sampling intervals and locations. Sequential triplicate culturable and total spore samples were collected on wide-body commercial passenger aircraft (n = 12) in the front and rear of coach class during six sampling intervals: boarding, midclimb, early cruise, midcruise, late cruise, and deplaning. Comparison samples were collected inside and outside airport terminals at the origin and destination cities. The MIXED procedure in SAS was used to model the mean and the covariance matrix of the natural log transformed fungal concentrations. Five covariance structures were tested to determine the appropriate models for analysis. Fixed effects considered included the sampling interval and, for samples obtained onboard the aircraft, location (front/rear of coach section), occupancy rate, and carbon dioxide concentrations. Overall, both total culturable and total spore fungal concentrations were low while the aircraft were in flight. No statistical difference was observed between measurements made in the front and rear sections of the coach cabin for either culturable or total spore concentrations. Both culturable and total spore concentrations were significantly higher outside the airport terminal compared with inside the airport terminal (p-value < 0.0001) and inside the aircraft (p-value < 0.0001). On the aircraft, the majority of total fungal exposure occurred during the boarding and deplaning processes, when the aircraft utilized ancillary ventilation and passenger activity was at its peak.

Evaluating fungal populations by genera/species on wide body commercial passenger aircraft and in airport terminals.

Given the potential health effects of fungi and the amount of time aircrew and passengers spend inside aircraft, it is important to study fungal populations in the aircraft environment. Research objectives included documenting the genera/species of airborne culturable fungal concentrations and total spore concentrations on a twin-aisle wide body commercial passenger aircraft. Twelve flights between 4.5 and 6.5 h in duration on Boeing 767 (B-767) aircraft were evaluated. Two air cooling packs and 50% recirculation rate (i.e. 50:50 mix of outside air and filtered inside air) were utilized during flight operations. Passenger occupancy rates varied from 67 to 100%. N-6 impactors and total spore traps were used to collect sequential, triplicate air samples in the front and rear of coach class during six sampling intervals throughout each flight: boarding, mid-climb, early cruise, mid-cruise, late cruise and deplaning. Comparison air samples were also collected inside and outside the airport terminals at the origin and destination cities resulting in a total of 522 culturable and 517 total spore samples. A total of 45 surface wipe samples were collected using swabs onboard the aircraft and inside the airport terminals. A variety of taxa were observed in the culturable and total spore samples. A frequency analysis of the fungal data indicated that Cladosporium, Aspergillus and Penicillium were predominant genera in the culturable samples whereas Cladosporium, Basidiospores and Penicillium/Aspergillus were predominant in the total spore samples. Fungal populations observed inside the aircraft were comprised of similar genera, detected significantly less frequently and with lower mean concentrations than those observed in typical office buildings. Although sources internal to the aircraft could not be ruled out, our data demonstrate the importance of passenger activity as the source of the fungi observed on aircraft. Isolated fungal peak events occurred occasionally when concentrations of a particular genus or species rose sharply inside the cabin for a limited period. Overall, our research demonstrates that on the sampled flights the B-767 filtration system operated efficiently to remove fungal spores when two air cooling packs and 50% recirculation rate were utilized during flight operations.