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.

Application of the Draft NIOSH Occupational Exposure Banding Process to Bisphenol A: A case study.

Bisphenol A is a commercially important chemical used to make polycarbonate plastic, epoxy resins, and other specialty products. Despite an extensive body of in vitro, animal and human observational studies on the effects of exposure to bisphenol A, no authoritative bodies in the U.S. have adopted or recommended occupational exposure limits for bisphenol A. In 2017, the National Institute for Occupational Safety and Health published a Draft process for assigning health-protective occupational exposure bands, i.e., an airborne concentration range, to chemicals lacking an occupational exposure limit. Occupational exposure banding is a systematic process that uses both quantitative and qualitative toxicity information on selected health effect endpoints to assign an occupational exposure band for a chemical. The Draft process proposes three methodological tiers of increasing complexity for assigning an occupational exposure band. We applied Tier 1 (based on the Globally Harmonized System of Classification and Labelling) and Tier 2 (based on authoritative sources/reviews) to assign an occupational exposure band to bisphenol A. Under both Tier 1 and 2, the occupational exposure band for bisphenol A was "E" (<0.01 mg/m3), an assignment based on eye damage. "E" is the lowest exposure concentration range, reserved for chemicals with high potential toxicity. If eye damage was excluded in assigning an air concentration exposure range, then bisphenol A would band as "D" (>0.01 to 0.1 mg/m3) under Tier 1 (based on reproductive toxicity and respiratory/skin sensitization) and under Tier 2 (based on specific target organ toxicity-repeated exposure). In summary, Tiers 1 and 2 gave the same occupational exposure band for bisphenol A when eye damage was included ("E") or excluded ("D") as an endpoint.

Translation research in occupational safety and health: A proposed framework.

Translation research in occupational safety and health is the application of scientific investigative approaches to study how the outputs of basic and applied research can be effectively translated into practice and have an impact. This includes the study of the ways in which useful knowledge and interventions are disseminated, adopted, implemented, and institutionalized. In this paper, a 4-stage framework (Development, Testing, Institutionalization, and Evaluation) is presented. Translation research can be used to enhance the use and impact of occupational safety and health knowledge and interventions to protect workers. This type of research has not received much attention in the occupational safety and health field. However, in contemporary society, it is critical to know how to make an impact with the findings and outputs of basic and applied research. This paper provides a novel framework for consideration of how to advance and prioritize translation research for occupational safety and health.

Exposure Estimation and Interpretation of Occupational Risk: Enhanced Information for the Occupational Risk Manager.

The fundamental goal of this article is to describe, define, and analyze the components of the risk characterization process for occupational exposures. Current methods are described for the probabilistic characterization of exposure, including newer techniques that have increasing applications for assessing data from occupational exposure scenarios. In addition, since the probability of health effects reflects variability in the exposure estimate as well as the dose-response curve-the integrated considerations of variability surrounding both components of the risk characterization provide greater information to the occupational hygienist. Probabilistic tools provide a more informed view of exposure as compared to use of discrete point estimates for these inputs to the risk characterization process. Active use of such tools for exposure and risk assessment will lead to a scientifically supported worker health protection program. Understanding the bases for an occupational risk assessment, focusing on important sources of variability and uncertainty enables characterizing occupational risk in terms of a probability, rather than a binary decision of acceptable risk or unacceptable risk. A critical review of existing methods highlights several conclusions: (1) exposure estimates and the dose-response are impacted by both variability and uncertainty and a well-developed risk characterization reflects and communicates this consideration; (2) occupational risk is probabilistic in nature and most accurately considered as a distribution, not a point estimate; and (3) occupational hygienists have a variety of tools available to incorporate concepts of risk characterization into occupational health and practice.

Flavoring exposure in food manufacturing.

Flavorings are substances that alter or enhance the taste of food. Workers in the food-manufacturing industry, where flavorings are added to many products, may be exposed to any number of flavoring compounds. Although thousands of flavoring substances are in use, little is known about most of these in terms of worker health effects, and few have occupational exposure guidelines. Exposure assessment surveys were conducted at nine food production facilities and one flavor manufacturer where a total of 105 area and 74 personal samples were collected for 13 flavoring compounds including five ketones, five aldehydes, and three acids. The majority of the samples were below the limit of detection (LOD) for most compounds. Diacetyl had eight area and four personal samples above the LOD, whereas 2,3-pentanedione had three area samples above the LOD. The detectable values ranged from 25-3124 ppb and 15-172 ppb for diacetyl and 2,3-pentanedione respectively. These values exceed the proposed National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit for these compounds. The aldehydes had the most detectable samples, with each of them having >50% of the samples above the LOD. Acetaldehyde had all but two samples above the LOD, however, these samples were below the OSHA PEL. It appears that in the food-manufacturing facilities surveyed here, exposure to the ketones occurs infrequently, however levels above the proposed NIOSH REL were found. Conversely, aldehyde exposure appears to be ubiquitous.

Occupational safety and health, green chemistry, and sustainability: a review of areas of convergence.

With increasing numbers and quantities of chemicals in commerce and use, scientific attention continues to focus on the environmental and public health consequences of chemical production processes and exposures. Concerns about environmental stewardship have been gaining broader traction through emphases on sustainability and "green chemistry" principles. Occupational safety and health has not been fully promoted as a component of environmental sustainability. However, there is a natural convergence of green chemistry/sustainability and occupational safety and health efforts. Addressing both together can have a synergistic effect. Failure to promote this convergence could lead to increasing worker hazards and lack of support for sustainability efforts. The National Institute for Occupational Safety and Health has made a concerted effort involving multiple stakeholders to anticipate and identify potential hazards associated with sustainable practices and green jobs for workers. Examples of potential hazards are presented in case studies with suggested solutions such as implementing the hierarchy of controls and prevention through design principles in green chemistry and green building practices. Practical considerations and strategies for green chemistry, and environmental stewardship could benefit from the incorporation of occupational safety and health concepts which in turn protect affected workers.

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.

Biological exposure assessment to tetrachloroethylene for workers in the dry cleaning industry.

BACKGROUND: The purpose of this study was to assess the feasibility of conducting biological tetrachloroethylene (perchloroethylene, PCE) exposure assessments of dry cleaning employees in conjunction with evaluation of possible PCE health effects. METHODS: Eighteen women from four dry cleaning facilities in southwestern Ohio were monitored in a pilot study of workers with PCE exposure. Personal breathing zone samples were collected from each employee on two consecutive work days. Biological monitoring included a single measurement of PCE in blood and multiple measurements of pre- and post-shift PCE in exhaled breath and trichloroacetic acid (TCA) in urine. RESULTS: Post-shift PCE in exhaled breath gradually increased throughout the work week. Statistically significant correlations were observed among the exposure indices. Decreases in PCE in exhaled breath and TCA in urine were observed after two days without exposure to PCE. A mixed-effects model identified statistically significant associations between PCE in exhaled breath and airborne PCE time weighted average (TWA) after adjusting for a random participant effect and fixed effects of time and body mass index. CONCLUSION: Although comprehensive, our sampling strategy was challenging to implement due to fluctuating work schedules and the number (pre- and post-shift on three consecutive days) and multiplicity (air, blood, exhaled breath, and urine) of samples collected. PCE in blood is the preferred biological index to monitor exposures, but may make recruitment difficult. PCE TWA sampling is an appropriate surrogate, although more field intensive. Repeated measures of exposure and mixed-effects modeling may be required for future studies due to high within-subject variability. Workers should be monitored over a long enough period of time to allow the use of a lag term.

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.