Exposure Mitigation Research Articles

Identifying septic pollution exposure routes during a waterborne norovirus outbreak - A new application for human-associated microbial source tracking qPCR

In June 2017, the Pennsylvania Department of Health (PADOH) was notified of multiple norovirus outbreaks associated with 179 ill individuals who attended separate events held at an outdoor venue and campground over a month period. Epidemiologic investigations were unable to identify a single exposure route and therefore unable to determine whether there was a persistent contamination source to target for exposure mitigation. Norovirus was detected in a fresh recreational water designated swimming area and a drinking water well. A hydrogeological site evaluation suggested a nearby septic leach field as a potential contamination source via ground water infiltration. Geological characterization revealed a steep dip of the bedrock beneath the septic leach field toward the well, providing a viral transport pathway in a geologic medium not previously documented as high risk for viral ground water contamination. The human-associated microbial source tracking (MST) genetic marker, HF183, was used as a microbial tracer to demonstrate the hydrogeological connection between the malfunctioning septic system, drinking water well, and recreational water area. Based on environmental investigation findings, venue management and local public health officials implemented a series of outbreak prevention strategies including discontinuing the use of the contaminated well, issuing a permit for a new drinking water well, increasing portable toilet and handwashing station availability, and promoting proper hand hygiene. Despite the outbreaks at the venue and evidence of ground water contamination impacting nearby recreational water and the drinking water well, no new norovirus cases were reported during a large event one week after implementing prevention practices. This investigation highlights a new application for human-associated MST methods to trace hydrological connections between multiple fecal pollutant exposure routes in an outbreak scenario. In turn, pollutant source information can be used to develop effective intervention practices to mitigate exposure and prevent future outbreaks associated with human fecal contaminated waters.

Monitoring for clean air spaces during wildfire events

Background: Many communities are exposed to extended periods of smoke from wildland fires. A common recommendation to reduce exposure during smoke events is to go indoors. However, building characteristics that translate to clean air spaces during such events are poorly understood. The purpose of this study was to compare outdoor and indoor fine particulate (PM2.5) at commercial buildings during smoke events.Methods: Purple Air Sensors (PA-II-SD) were co-located with regulatory grade reference monitors to generate individual sensor correction equations. Outdoor and indoor sensors were co-located at 18 buildings in Missoula, MT from July to September 2019. Outdoor to indoor daily PM2.5 averages were compared for assessment of building air handling systems. Spikes in indoor PM2.5, identified as any hour where the standard deviation of the 2-minute data was over 10% of the hourly average, were flagged and removed from the comparisons.Results: Individual correction equations and strength of agreement were similar across the set of sensors (slope: 0.36 -0.47 and R2: 0.91 to 0.95). Censoring of data flagged as indoor generated PM2.5 accounted for <5% to 14% of observations across buildings. Fourteen buildings had MERV8 filter systems, two buildings had higher MERV rating filters, and two buildings had no air handling systems. All buildings with air handling systems had reductions in indoor PM2.5 compared to outdoor concentrations but building-to-building observations were highly variable (6% to 44% reduction for MERV8 buildings). Outdoor-to-indoor reductions were similar during smoke impacted periods compared to non-smoke periods.Conclusions: This study demonstrates the utility of low-cost PM2.5 sensors for identifying poor indoor air quality. The variable findings for buildings with similar air handling filter ratings indicate that other building features and operation behaviors are important factors and need to be understood to inform exposure mitigation strategies during smoke events.

Aerospace Environmental Health: Considerations and Countermeasures to Sustain Crew Health Through Vastly Reduced Transit Time to/From Mars.

The concept of implementation of environmental health protection and sustainment in aerospace environments by definition implies a One Health systems approach. One Health indicates an inherently complex, contextually interrelated system with consideration of human, animal, plant, systems engineering, and environmental health, their interrelationships, and networks. One Health implies seamless integration of subsystem co-dependencies to achieve an outcome of overall health protection for the individual. One of the most challenging aspects of space travel involves prevention, mitigation and protection from radiation injuries. While avoidance altogether is the best approach, these authors will focus on minimized exposure through limiting time in the space radiation environment in the transit to Mars and back. Implementation of the pillars of time, distance and shielding comprise ALARA, “As Low as Reasonably Achievable” (www.cdc.gov/nceh/radiation/alara.html) and is stressed in this strategy. This general overview will briefly describe the critical components of space environmental health in anticipation of increasing duration and interaction of human, animal, and plant habitation of aerospace and extreme environments into the future. Of the many considerations that could be addressed, precision medicine, and bioinformatics are the most rapidly evolving. Complex interdependencies will emerge from macro- and micro-environmental ecosystems data analysis, not yet fully comprehended or understood in the context of space health. We will conclude this contribution with suggested new countermeasure strategies gleaned through big data analytics that may protect space crew through mitigation of radiation exposure in flight.

Mitigation of indoor human exposure to airborne particles of outdoor origin in an urban environment during haze and non-haze periods

During the 2019 smoke haze episode in Singapore, elevated levels of fine particulate matter (PM2.5) were observed, deteriorating both ambient and indoor air quality (IAQ). We investigated the mitigation of indoor human exposure to PM2.5 of outdoor origin under diverse exposure scenarios with and without filtration of PM2.5 during both hazy and non-hazy days. The key objective of our study was to make a comparative evaluation of the effectiveness of portable air cleaners (PACs) and air conditioning (AC) systems equipped with particle filters in improving IAQ and to assess related long-term carcinogenic and non-carcinogenic health risks. We conducted real-time measurements of PM2.5, black carbon mass concentrations and particle number concentrations in both indoor and outdoor areas, quantified the relative concentrations of the water-soluble fraction of toxic trace elements in PM2.5 for health risk assessment, and estimated the levels of thermal comfort. In addition, we calculated the total estimated cost of indoor air pollution control. Our findings suggest that indoor air cleaners are more effective at mitigating human exposure to airborne particles and reducing health risk with less consumption of electricity and better cost-effectiveness compared to AC. This information would be beneficial for public health interventions during major air pollution events.

A Total Worker Health Approach to Skin Exposure Assessment: Experiences from the Firefighter Cancer Initiative.

Increasing scientific evidence suggests that addressing complex, wide-ranging concerns among worker populations should include the integration of traditional occupational safety and health with often siloed worksite wellness programs. The Total Worker Health (TWH) approach developed by the National Institute for Occupational Safety and Health can support skin cancer prevention efforts by integrating organizational-level policies, programs, and practices that strategically merge both skin protection from work-related safety and health hazards with promotion of skin illness prevention efforts. In the firefighter workforce, epidemiologic studies suggest an increased risk of skin cancer despite the use of personal protective equipment during fire incident response. Mechanisms for dermal absorption of carcinogenic compounds such as polycyclic aromatic hydrocarbons have given insight into how these hazardous chemicals can enter the skin and increase cancer risk. Mitigation of carcinogenic exposures requires a TWH approach that merges skin protection and promotion, routine surveillance, skin health assessment, worksite-based interventions, and regular evaluation of program activities. In this commentary, an example of a TWH approach is provided from the Firefighter Cancer Initiative (FCI), a transdisciplinary initiative focused at addressing excess burden of cancer in the firefighter workforce. The FCI builds on the TWH approach through the following components: (i) organizational leadership commitment; (ii) elimination of workplace hazards and promotion of worker well-being; (iii) engagement of workers in program design and delivery; (iv) ensuring confidentiality and privacy in program participation; and (v) integrating systems effectively. Occupational hygienists have strong potential to play a crucial role beyond traditional risk assessment, exposure assessment, and health protection that further includes skin health promotion and integration of related programs into a TWH framework.

Aflatoxin B1 exposure and liver cirrhosis in Guatemala: a case–control study

ObjectiveIn Guatemala, cirrhosis is among the 10 leading causes of death, and mortality rates have increased lately. The reasons for this heavy burden of disease are not clear as the...

An agent-based modeling approach to estimate pathogen exposure risks from wheelchairs

Contributions of contaminated wheelchairs to nosocomial pathogen transmission are relatively unknown. Our aim was to develop a model predicting pathogen exposures for patients utilizing wheelchairs and estimate exposure reduction potential of wheelchair disinfection between rides. An agent-based model was informed by wheelchair location data from a connected 215-bed acute care and 250-bed long-term care facility. Simulated scenarios varied in frequencies of patient wheelchair contamination and wheelchair disinfection in between trips. Clostridioides difficile and methicillin-resistant Staphylococcus aureus concentrations on patient hands at the end of wheelchair trips were estimated. Exposure reductions due to disinfection, assuming low real-world efficacies (50%, 70%, and 90%), were compared. In the simulation, when few patients introduced contamination to wheelchairs, disinfection in between patients 50% of the time decreased baseline (no disinfection) estimated exposures for the 50th wheelchair rider by >99.999%. When patients had a 50% chance of being contaminated before the wheelchair ride, disinfection did not reduce exposures consistently. The efficacy of disinfection in between patient rides as an exposure mitigation strategy likely depends on the frequency of infected patient wheelchair use. During outbreak, high contamination conditions, disinfection, alone, is not enough to protect patients from wheelchair-mediated exposures.

Patient satisfaction with telemedicine encounters in an allergy and immunology practice during the coronavirus disease 2019 pandemic

The use of telemedicine dates as far back as 50 years ago, when the University of Nebraska used interactive telemedicine to transmit neurologic examinations.1 Since that time, despite advances in available technologies and proven utility of telemedicine in allergy and immunology (AI),2,3 the use of telemedicine by AI physicians remains low.4 With the global spread of the novel coronavirus disease 2019 (COVID-19), AI physicians were abruptly forced to change their mode of health care delivery. Given the need for social distancing and exposure mitigation, many practices quickly adapted to remote encounters from primarily in-person care.

Effectiveness of Small-scale Dust Collectors in the Mitigation of Dust Exposure

Effectiveness of Small-scale Dust Collectors in the Mitigation of Dust Exposure

The Importance of Universal Preprocedural Testing for the Novel Coronavirus 2019

The Importance of Universal Preprocedural Testing for the Novel Coronavirus 2019

Biomonitoring in firefighters for volatile organic compounds, semivolatile organic compounds, persistent organic pollutants, and metals: A systematic review

Firefighters are exposed to a wide range of toxic chemicals due to combustion, with numerous biomonitoring studies completed that have assessed exposure. Many of these studies focus on individual classes of chemicals, with a few considering a broad range of systemic exposures. As yet, no review process has been undertaken to comprehensively examine these studies. The aims of this review are to: (1) ascertain whether biomonitoring studies pertaining to firefighters demonstrate occupational exposure to volatile organic compounds, semivolatile organic compounds, and metals; (2) determine and present results of biomonitoring studies; (3) provide any recommendations presented from the literature that may support exposure mitigation; and (4) suggest future study parameters that may assist in providing a greater understanding surrounding the occupational exposure of firefighters. A systematic review was undertaken with regards to firefighters and biomonitoring studies utilising the matrices of blood, urine, semen and breast milk. This yielded 5690 results. Following duplicate removal, inclusion and exclusion criteria screening and full text screening, 34 studies remained for review. Results of over 80% of studies analysed determined firefighters to experience occupational exposure. Results also show firefighters to be exposed to a wide range of toxic chemicals due to fire smoke; potentially exceeding the range of exposure of other occupations. As firefighters may face increased risk of health effects due to the additive, synergistic, and/or antagonistic effects of chemical exposure, all care must be taken to reduce exposure. This may be achieved by considering tactical decisions, increased personal hygiene, and thorough decontamination procedures. Future biomonitoring studies recognising and assessing the range of chemical exposure firefighters face would be beneficial.

In hot water: effects of climate change on Vibrio-human interactions.

Sea level rise and the anthropogenic warming of the world's oceans is not only an environmental tragedy, but these changes also result in a significant threat to public health. Along with coastal flooding and the encroachment of saltwater farther inland comes an increased risk of human interaction with pathogenic Vibrio species, such as Vibrio cholerae, V. vulnificus and V. parahaemolyticus. This minireview examines the current literature for updates on the climatic changes and practices that impact the location and duration of the presence of Vibrio spp., as well as the infection routes, trends and virulence factors of these highly successful pathogens. Finally, an overview of current treatments and methods for the mitigation of both oral and cutaneous exposures are presented.

Interventions to Reduce Exposures in the Workplace: A Systematic Review of Intervention Studies Over Six Decades, 1960-2019.

Background: Reducing occupational ill-health from chemical and biological agents is realized primarily through the mitigation and elimination of hazardous exposures. Despite evidence of declining exposure in European and North-American workplaces, comprehensive studies of the effectiveness of workplace interventions for reducing hazardous exposure and associated work-related ill-health seem rare. We reviewed occupational intervention studies targeting exposure to chemical and biological agents, and determined trends in frequency and quality of such studies.Methods: We searched Embase, Medline, and Web of Science for peer-reviewed original articles on occupational intervention studies published 1960–2019, aimed at reducing workers' exposure to dusts, gases, fumes, or liquids of chemical, biological, or mineral nature, or workers' risks for associated health outcomes. The frequency of articles, intervention types, intervention endpoints, and study quality of published intervention studies between 1960 and 2019 and according to 10-year intervals were analyzed.Results: Of 3,663 retrieved articles, 146 intervention studies were identified and reviewed, of which 63 concerned control measures, 43 behavioral change, 28 use of personal protective equipment, and 12 workplace policies. Intervention endpoints were occupational exposures (73%), health outcomes (22%), and a combination of both (5%). Of reviewed studies, 38% involved a control group, 16% randomized the intervention, 86% were planned interventions, and 86% compared exposure or health outcomes pre and post intervention. Over time the number of intervention studies identified in this search increased from none during 1960–1969 to ~60 during 2000–2009 and 2010–2019, respectively. The study quality improved over time, with no studies during 1960–1989 that complied with the highest quality criteria. During 2000–2009 and 2010–2019 16 and 12% of studies, respectively, were judged to be of highest quality.Conclusion: Despite an improvement over the last six decades in the frequency and quality of intervention studies targeting exposure to chemicals and biological agents, the absolute number of intervention studies remains low, particularly when considering only high quality studies. Occupational exposure to chemical and biological agents is still causing excessive disease in workforces worldwide. To reduce occupational ill-health caused by these exposures, it is important to expand the evidence on (cost-)effectiveness and transferability of interventions to reduce exposure and health effects.

Evaluation of the effectiveness of a portable air cleaner in mitigating indoor human exposure to cooking-derived airborne particles

Gas cooking is an important source of airborne particulate matter (PM) indoors. Exposure to cooking-derived PM can lead to adverse human health impacts on non-smokers, especially in poorly-ventilated residential homes. Most of the previous studies on gas cooking emissions mainly focused on fine particles (PM2.5) with little information on their size-fractionation. Moreover, studies dealing with mitigation of indoor human exposure to cooking-derived PM are currently sparse. Therefore, a systematic study was conducted to investigate the characteristics of PM2.5 and size-fractionated PM derived from five commonly used cooking methods, namely, steaming, boiling, stir-frying, pan-frying and deep-frying in a poorly-ventilated domestic kitchen under controlled experimental conditions. Additionally, an indoor portable air cleaner was employed as a mitigation device to capture cooking-derived PM and improve indoor air quality (IAQ). Results revealed that the oil-based deep-frying cooking released the highest airborne particles which were about 170 folds higher compared to the baseline levels for PM2.5 mass concentrations. The use of the air cleaner showed a statistically significant (p < 0.05) reduction in the indoor PM2.5 levels. Moreover, PM<0.25 (particles with diameter ≤ 250 nm) showed a very high mass concentration (378.2 μg/m3) during deep-frying, raising human health concern. A substantial reduction (~60–85%) in PM<0.25 mass concentrations and their total respiratory deposition doses (RDD) in the human respiratory tract was observed while using the air cleaner during the five cooking methods. Furthermore, morphological characteristics and the relative abundance of trace elements in cooking-derived PM were also investigated. This study provides useful insights into the assessment and mitigation of indoor human exposure to cooking-derived PM.

Sensor-as-a-Service: Convergence of Sensor Analytic Point Solutions (SNAPS) and Pay-A-Penny-Per-Use (PAPPU) Paradigm as a Catalyst for Democratization of Healthcare in Underserved Communities.

In this manuscript, we discuss relevant socioeconomic factors for developing and implementing sensor analytic point solutions (SNAPS) as point-of-care tools to serve impoverished communities. The distinct economic, environmental, cultural, and ethical paradigms that affect economically disadvantaged users add complexity to the process of technology development and deployment beyond the science and engineering issues. We begin by contextualizing the environmental burden of disease in select low-income regions around the world, including environmental hazards at work, home, and the broader community environment, where SNAPS may be helpful in the prevention and mitigation of human exposure to harmful biological vectors and chemical agents. We offer examples of SNAPS designed for economically disadvantaged users, specifically for supporting decision-making in cases of tuberculosis (TB) infection and mercury exposure. We follow-up by discussing the economic challenges that are involved in the phased implementation of diagnostic tools in low-income markets and describe a micropayment-based systems-as-a-service approach (pay-a-penny-per-use—PAPPU), which may be catalytic for the adoption of low-end, low-margin, low-research, and the development SNAPS. Finally, we provide some insights into the social and ethical considerations for the assimilation of SNAPS to improve health outcomes in marginalized communities.

Lowering the level of occupational exposure to noise in areas neighbouring compressor halls

A general problem in the vicinity of industrial compressors is the noise generated in the working environment by their operation. A large number of workers suffer from hearing problems caused by exposure to high levels of noise in the workplace. Thus, legal provisions regulating occupational noise exposure aim to reduce the risk of hearing loss by reducing noise level, the most effective measures being those applied directly to the noise source combined with the use of hearing protection. Quantification of noise exposure level and mitigation of occupational hazards generated by it at each workplace is required in order to prevent accidents and occupational diseases. The current paper analyses how noise generated by industrial compressors influences worker’s activity. Prevention of noise exposure must be based on noise level measurements. In this sense, the purpose of the paper is to analyse noise measurements performed at a compressor hall and to compare the values obtained with limit values set by in force legislation, in order to apply the best technical organizational methods for lowering noise exposure and increasing acoustic comfort in order to improve working conditions of those working in the compressor hall.

ASSESSMENT OF NATURAL RADIOACTIVITY AND RADON EMANATION RATE AT JOS TIN MINE TAILING SITES, JOS, PLATEAU STATE, NIGERIA

The tin mining activities in Jos result in a byproduct conventionally known as tailing(s). The release of this Radon gas into the atmosphere and the naturally occurring Radionuclide Materials associated with these tailings have radiological implications. In this research, assessment of Naturally occurring Radionuclide Materials, radon emanation rate and relevant radiological hazard indices have been carried out in three tailing sites in Jos, Nigeria using Gamma ray spectroscopy and RAD7 detector. The activity concentration of K-40 exceeds that of Th-232 and Ra-226 in all the three tailing sites. The absorbed dose for Barakinladi and Jos North tailing site exceeds the acceptable limit of 80 nGyhr-1. The equivalent dose however does not exceed the acceptable limit in any of the sampling area. Both the internal and external hazard index suggests that the radiological risk associated with the tailing site for Jos North and Barikinladi is too close to the acceptable limit of 1 mGyyr-1. This implies that the radiological hazard potential in the areas is quite significant and thus radiation exposure mitigation steps need to be taken accordingly. Jos South tailing site is generally safe from radiation hazard point of view since there is no significant value recorded in all the radiological hazard indices.

Professional Drivers Exposure to Black Carbon in London; the Diesel Exposure Mitigation Study

Background: Despite the health risks of diesel engine exhaust, minimal research has been undertaken to quantify the exposures of professional drivers. To address this, we examined personal black carbon (BC) exposures of professional drivers in London under a range of occupational settings, vehicle types and driving conditions. Method: GPS-linked BC sensors were provided to 130 drivers (taxi drivers, couriers, heavy freight, waste removal and emergency services) for 96 hours, with measurements every minute. Drivers also completed a questionnaire, detailing their ventilation preferences, vehicle type and their number of working hours per day. Preliminary Results: Average driver exposure to BC was 3x higher at work (3.5 ± 2.9 µg/m3) compared to periods at home (1.1 ± 0.7 µg/m3). During work, drivers experienced high spikes in exposure, often exceeding 100 µg/m3. The highest exposed drivers were taxi drivers (6.0 ± 4.6 µg/m3), while the lowest were those in emergency services (2.0 ± 0.7 µg/m3). Window position influenced BC exposures, with concentrations being 2.5x higher for drivers with windows open versus closed. Across the same monitoring period ambient BC concentrations were 2.5 ± 1.8 µg/m3 at a London roadside and 0.8 ± 0.7 µg/m3 at the London background. Conclusion: We have performed the largest study of driver exposures to a proxy of diesel exposure (BC) in an urban environment. These data confirm the very high exposures experience by professional drivers in their working lives, but also indicate that simple measures, such as closing vehicle windows can significantly reduce exposures. Measurements made at fixed monitoring sites were not representative of driver exposure to BC.

Occupational Exposures Among Hair and Nail Salon Workers: a Scoping Review.

To review the literature published from 2014 to 2019 on hair and nail salon workers concerning exposure assessment, reproductive and respiratory endpoints, and endocrine disruption, in relation to workplace exposures. We identified 29 relevant peer-reviewed publications. Overall, there were insufficient studies to determine whether working in these settings is associated with reproductive health endpoints, although prior studies suggest that reproductive effects are of concern. There is consistent evidence that working in hair and nail salons may increase the risk of respiratory effects. Also, despite the fact that many hair and nail care products contain endocrine disrupting compounds, no recent studies have evaluated endocrine-related endpoints. Moreover, few studies have evaluated chemical exposures in these settings and biomonitoring studies are sparse. Improved exposure assessment of chemical hazards in hair and nail salons is necessary to properly characterize occupational exposures and assess their potential health risks. Further studies on endpoints related to endocrine disruption and reproductive health outcomes among hair and nail salon workers are needed. Improved exposure and epidemiologic studies will help inform chemical exposure mitigation efforts in a vulnerable occupational population, as well as policies related to workplace and consumer product safety.

Effectiveness of nanoparticle exposure mitigation measures in industrial settings.

Inhalation of airborne nanoparticles is a well-known source of potentially health-hazardous occupational exposures. Effective mitigation measures are necessary to reduce exposure, but also challenging to implement due to the different characteristics of each individual emission source and industrial scenario. The present paper describes four different exposure case studies in the ceramic industry and quantifies the effectiveness of mitigation strategies implemented during: ceramic tile processing by thermal spraying, laser ablation, the use of diesel engines, and tile firing. The mitigation measures for exposure reduction were tailored to each industrial scenario. The NP removal efficiency of source enclosure (partial/full) combined with local exhaust ventilation (LEV) were quantified to range between 65 and 85% when the enclosure was partial. The efficiency reached 99% with full enclosure and vigorous ventilation (Air Change per Hour; ACH = 132 h-1). The elimination of the source was the optimal strategy to minimize exposure in the case of diesel forklifts use. The conventional ceramic kilns used intensively (>10 years) generated high NP exposure concentrations (>106/cm3). Appropriate maintenance and enhanced sealing enabled the reduction of exposure down to 52% of the initial value. It must be added that technologically advanced kilns, enabled even greater NP reductions (down to 84%), compared to the conventional ones. This proves technological improvements can lead to significant reduction of work exposures. This work evidences the need for tailored mitigation measures due to the broad variety of potential sources and activities in industrial scenarios. The quantitative efficiency rates reported here may be valuable for the adequate parametrization of exposure prediction and risk assessment models.