Effect of Smoke Evacuator on Reduction of Volatile Organic Compounds and Particles in Surgical Smoke: A Randomized Controlled Trial

BACKGROUND

Surgical smoke is an occupational health problem and is increasingly recognized as a potential source of virus transmission. Dedicated smoke evacuators are used to protect against surgical smoke exposure. We tested the hypothesis that using smoke evacuators would reduce volatile organic compounds and the number of particles in surgical smoke during the laparotomy procedure.

STUDY DESIGN

A randomized, double-blind clinical trial was conducted in patients undergoing laparotomy from June 11, 2021, to March 30, 2022, to compare the effectiveness of smoke evacuators with a control (registration, UMIN000044250). The primary outcome was a change in the acetaldehyde level. Secondary outcomes were changes in the formaldehyde level and particle count assessed by the particle size of 0.3, 0.5, 1.0, and 5.0 nm.

RESULTS

A total of 42 patients were randomized and assessed (smoke evacuator group, n = 22 vs control group, n = 20). The acetaldehyde level was significantly lower in the smoke evacuator group than in the control group: mean (95% CI), 10.6 (3.7 to 17.5) vs 47.2 (19.9 to 74.5) μg/m 3 , p < 0.001. Similarly, the formaldehyde level was 72.2% lower in the smoke evacuator group than in the control group. Particle counts by each particle size category were 80% to 95% lower in the smoke evacuator group than in the control group (all, p < 0.001).

CONCLUSIONS

Dedicated smoke evacuators reduced the level of acetaldehyde and formaldehyde, and the number of particles in surgical smoke, minimizing the potential exposure to volatile organic compounds and particle matters during surgery.

Surgical smoke and the orthopedic surgeon: a non-systematic review of the hazards and strategies for mitigating risk

INTRODUCTION

Surgical smoke generated through the use of electrical surgical devices poses a risk to the surgeon, medical personnel in the operating room, and the patient by exposing them to environmentally hazardous particulate matter. Previous investigation has shown that surgical smoke leads to an increased risk of pulmonary conditions, circulatory disorders, and irritation of the eyes, nose, and throat. Transmission of infectious disease can occur through inhalation of viral particles, and the presence of carcinogens are also of major concern. The deleterious effects of surgical smoke are well documented in several subspecialties, namely dermatology and general surgery, but there has been little discussion on the topic amongst orthopedic surgeons.

METHODS

A non-systematic review of the literature was completed with the aim of identifying the major categories of adverse health effects associated with surgical smoke inhalation and offering recommendations to reduce these hazards in the orthopedic surgical community.

RESULTS

Three primary categories of risk associated with surgical smoke inhalation were identified: inflammation, viral/bacterial transmission, and carcinogenicity. In addition, strategies for mitigating risk and best practice recommendations were explored.

CONCLUSION

Surgical smoke is an under-recognized occupational hazard within the orthopedic surgery literature. There are several strategies which can be employed to reduce risk. Further investigation is needed to understand the long-term impact of these risks, as well as what can be done to improve the practicality and compliance with protective measures.

HeLP: Development of occupational protection mask against surgical smoke

OBJECTIVES

to describe a technological innovation in the development of an individual, ergonomic, sustainable and effective occupational respiratory protection mask for workers exposed to surgical smoke.

METHODS

applied, exploratory, quantitative research, using design methods and tools: Sense Intent, Know Context, Know People, Frame Insights, Explore Concepts, Frame Solutions, Realize Offerings, in addition to the Product Development Process tools. It was developed from March 2019 to December 2021.

RESULTS

from the prototyping mold, it became possible to represent the abstract to the physical, where all the concepts created in the methodological steps were implemented and the necessary adjustments were made to create the model as a technological innovation, which will have the concept for product commercialization.

CONCLUSIONS

a mask for protection against surgical smoke (HeLP) was developed, from the design step to the prototype development, being a technological innovation.

Measurements, emission characteristics, and control methods of fire effluents generated from tunnel asphalt pavement during fire: a review

Tunnels are widely used in high-grade roads, particularly in mountainous areas; however, tunnel fires often result in severe economic losses and casualties. The fire effluents produced from asphalt pavement have attracted significant research attention. The main objective of this study is to assimilate information on various aspects of bituminous mixture emissions during fires. In this study, the fume emissions of bitumen and bituminous mixtures during combustion are comprehensively reviewed and summarized. First, the test methods for fire effluents produced by bitumen and bituminous mixtures after combustion are summarized. Second, the factors influencing the fume concentration and composition are determined. In addition, different methods to reduce the emission of fire effluents are compared, particularly for the suppression of toxic gas emissions. Then, reasonable suggestions are proposed to reduce the damage caused by hazardous gases to humans and the environment. This review is beneficial for comprehensively understanding the fume emission behaviour and future research on the smoke suppression of highway tunnel asphalt pavements during fires.

Implementing a Surgical Smoke Evacuation Policy and Procedure: A Quality Improvement Project

Energy-generating surgical devices (eg, electrosurgical units, lasers) produce surgical smoke that can cause negative health effects in exposed individuals. In 2019, a review of nursing documentation at an urban teaching hospital revealed that personnel were properly evacuating surgical smoke during less than 0.5% of applicable procedures. To address the noncompliance and reduce exposure to surgical smoke, an interdisciplinary team initiated a quality improvement project to implement a surgical smoke evacuation policy for all smoke-generating procedures. The project included creation and implementation of a smoke evacuation policy, staff member education on the hazards of surgical smoke and proper evacuation device use, and acquisition of the proper smoke evacuation equipment. After instituting the policy in June 2020, results of a three-month chart audit showed that there was nursing documentation confirming personnel used energy-generating devices and the corresponding surgical smoke evacuation devices during 664 of 2,224 procedures, for a compliance rate of 30%.

Urgent safety considerations for dermatologic surgeons in the COVID-19 pandemic

Dermatologic surgeons are at increased risk of contracting SARS-COV-2. At time of writing, there is no published standard for the role of pre-operative testing or the use of smoke evacuators, and personal protective equipment (PPE) in dermatologic surgery. Risks and safety measures in otolaryngology, plastic surgery, and ophthalmology are discussed. In Mohs surgery, cases involving nasal or oral mucosa are highest risk for SARS-COV-2 transmission; pre-operative testing and N95 masks should be urgently prioritized for these cases. Other key safety recommendations include strict control of patient droplets and expanded pre-clinic screening. Dermatologic surgeons are encouraged to advocate for appropriate pre-operative tests, smoke evacuators, and PPE. Future directions would include national consensus guidelines with continued refinement of safety protocols.

Easy-to-use electrocautery smoke evacuation device for open surgery under the risk of the COVID-19 pandemic

OBJECTIVE

This study was performed to introduce an easy method of surgical smoke evacuation for patients with confirmed or suspected COVID-19 undergoing emergency surgery.

METHODS

An easy, inexpensive, protective, and practical surgical smoke evacuation device/system was developed and is herein described.

RESULTS

The use of this surgical smoke evacuation device/system in open surgery is convenient and effective. It allows for easy, economic, useful, and protective surgical smoke evacuation.

CONCLUSIONS

COVID-19 infection causes direct mortality and morbidity, and its incidence has recently increased. Protection from electrosurgery-related smoke is recommended particularly during the current pandemic. This surgical smoke evacuation device/system is easy to use and provides a convenient and effective method of smoke evacuation during both open surgery and all cauterization interventions.

Wood stove interventions and child respiratory infections in rural communities: KidsAir rationale and methods

BACKGROUND

Acute lower respiratory tract infections (LRTIs) account for >27% of all hospitalizations among US children under five years of age. Residential burning of biomass for heat leads to elevated indoor levels of fine particulate matter (PM2.5) that often exceed current health based air quality standards. This is concerning as PM2.5 exposure is associated with many adverse health outcomes, including a greater than three-fold increased risk of LRTIs. Evidence-based efforts are warranted in rural and American Indian/Alaska Native (AI/AN) communities in the US that suffer from elevated rates of childhood LRTI and commonly use wood for residential heating.

DESIGN

In three rural and underserved settings, we conducted a three-arm randomized controlled, post-only intervention trial in wood stove homes with children less than five years old. Education and household training on best-burn practices were introduced as one intervention arm (Tx1). This intervention was evaluated against an indoor air filtration unit arm (Tx2), as well as a control arm (Tx3). The primary outcome was LRTI incidence among children under five years of age.

DISCUSSION

To date, exposure reduction strategies in wood stove homes have been either inconsistently effective or include factors that limit widespread dissemination and continued compliance in rural and economically disadvantaged populations. As part of the "KidsAIR" study described herein, the overall hypothesis was that a low-cost, educational intervention targeting indoor wood smoke PM2.5 exposures would be a sustainable approach for reducing children's risk of LRTI in rural and AI/AN communities.

Surgical Smoke-Hazard Perceptions and Protective Measures in German Operating Rooms

(1) Background: Hazardous substances in surgical smoke that is generated during laser or electrosurgery pose a potential health hazard. In Germany, the Technical Rules for Hazardous Substances (TRGS 525) have included recommendations for appropriate protective measures since 2014. Up to now, no empirical data has been available on the extent to which recommendations have been implemented in practice. (2) Methods: In 2018, 7089 surgeons in hospitals and outpatient practices were invited by email to participate in an online survey. In addition, 219 technical assistants were interviewed. The questionnaire dealt with knowledge of, and attitudes toward, the hazard potential of surgical smoke, as well as the availability and actual use of protective measures. Furthermore, manufacturers and distributors of smoke extraction devices were asked to give their assessment of the development of prevention in recent years. (3) Results: The survey response rate was 5% (surgeons) and 65% (technical assistant staff). Half of all surgeons assumed that there were high health hazards of surgical smoke without taking protective measures. Operating room nurses were more often concerned (88%). Only a few felt properly informed about the topic. The TRGS recommendations had been read by a minority of the respondents. In total, 52% of hospital respondents and 65% of the respondents in outpatient facilities reported any type of special suction system to capture surgical smoke. One-fifth of respondents from hospitals reported that technical measures had improved since the introduction of the TRGS 525. Fifty-one percent of the surgeons in hospitals and 70% of the surgeons in outpatient facilities "mostly" or "always" paid attention to avoiding surgical smoke. The most important reason for non-compliance with recommendations was a lack of problem awareness or thoughtlessness. Twelve industrial interviewees who assessed the situation and the development of prevention in practice largely confirmed the prevention gaps observed; only slight developments were observed in recent years. (4) Conclusions: The low response rate among surgeons and the survey results both indicate a major lack of interest and knowledge. Among other measures, team interventions with advanced training are needed in the future.

Back to Basics: Protection From Surgical Smoke: 1.2 www.aornjournal.org/content/cme

Surgical smoke is formed when energy-generating devices (ie, electrosurgery units, lasers, powered instruments) raise the intracellular temperature of tissue to at least 100º C (212º F), causing tissue vaporization in the form of surgical smoke. Surgical smoke contains components that are known health hazards, such as benzene, toluene, hydrogen cyanide, formaldehyde, volatile organic compounds, viruses, and bacteria. There have been case reports of human disease tied to the inhalation of surgical smoke; therefore, it is important for perioperative team members to minimize their exposure and patient exposure. In spite of the health risks, many perioperative departments do not consistently and effectively evacuate surgical smoke. This Back to Basics article provides basic steps that perioperative team members can take to protect themselves and their patients from the harm caused by surgical smoke exposure.

The impact of the 1952 London smog event and its relevance for current wood-smoke abatement strategies in Australia

There is a certain complacency about air pollution in rural towns in Australia. An image of crystal clear skies seems to dominate general perceptions, and few locations actually monitor air pollution levels. Nevertheless, where measurements have been made, particulates have been shown to be the major type of air pollution, and they do reach levels expected to impact on human health. In this article, the contemporary attitudes and behaviour of the government and the population in rural and regional Australia are shown to have a strong resemblance to those that were prevalent prior to the smog events in London in December 1952. Wood smoke poses similar significant health issues in many countries. Insights obtained from the London events, together with more recent research results, are applied to the Australian situation to suggest policy options that are likely to be successful in overcoming the health effects of particulate pollution. Implications: The contemporary attitudes and behaviour of the government and the population in rural and regional Australia are shown to have a strong resemblance to those that were prevalent prior to the smog events in London in December 1952. Insights obtained from the London event of 1952, together with more recent research results, are applied to the Australian situation to suggest policy options that are likely to be successful in overcoming the health effects of particulate pollution.

Determining the Enablers and Barriers for the Adoption of Clean Cookstoves in the Middle Belt of Ghana-A Qualitative Study

Despite its benefits and espousal in developed counties, the adoption of clean cookstoves is reportedly low in less developed countries, especially in Sub-Saharan Africa. This qualitative study aimed at exploring and documenting the enablers and barriers for adoption of clean cookstove in the middle belt of Ghana. The findings showed convenience of clean cookstove use, reduced firewood usage, less smoke emission and associated health problems resulting from indoor air pollution and time for firewood gathering and cooking, good smell and taste of food as enabling factors for clean cookstove adoption. Factors such as safety, financial constraint (cost), non-availability of spare parts on the open market to replace faulty stove accessories, stove size and household size were the potential barriers to clean cookstove adoption. These findings help us to understand the factors promoting and inhibiting the adoption of clean cook stoves, especially in rural settings.

Traditional cooking practices and preferences for stove features among women in rural Senegal: Informing improved cookstove design and interventions

Nearly half the world’s population burns solid fuel for cooking, heating, and lighting. The incomplete combustion of these fuels is associated with detrimental health and environmental effects. The design and distribution of improved cookstoves that increase combustion efficiency and reduce indoor air pollution are a global priority. However, promoting exclusive and sustainable use of the improved stoves has proved challenging. In 2012, we conducted a survey in a community in rural Senegal to describe stove ownership and preferences for different stove technologies. This report aims to describe local stove and fuel use, to identify household preferences related to stove features and function, and to elicit the community perceptions of cleaner-burning stove alternatives with a focus on liquid propane gas. Similar to many resource-limited settings, biomass fuel use was ubiquitous and multiple stoves were used, even when cleaner burning alternatives were available; less than 1% of households that owned a liquid propane stove used it as the primary cooking device. Despite nearly universal use of the traditional open fire (92% of households), women did not prefer this stove when presented with other options. Propane gas, solar, and improved cookstoves were all viewed as more desirable when compared to the traditional open fire, however first-hand experience and knowledge of these stoves was limited. The stove features of greatest value were, in order: large cooking capacity, minimal smoke production, and rapid heating. Despite the low desirability and smoke emisions from the traditional open fire, its pervasive use, even in the presence of alternative stove options, may be related to its ability to satisfy the practical needs of the surveyed cooks, namely large cooking capacity and rapid, intense heat generation. Our data suggest women in this community want alternative stove options that reduce smoke exposure, however currently available stoves, including liquid propane gas, do not address all of the cooks’ preferences.

Surgical Smoke: Putting the Pieces Together to Become Smoke-Free: 1.6 www.aornjournal.org/content/cme

Surgical smoke is generated when tissue vaporizes from the use of various energy-generating devices (eg, electrosurgery units, lasers). Surgical smoke contains toxic gases and vapors that can be hazardous to patients and perioperative staff members. In addition to ocular and upper respiratory tract irritation, surgical smoke can have mutagenic potential. Although many regulatory agencies agree that surgical smoke is dangerous, they have been slow to commit to a firm standard to address the inhalation hazards related to surgical smoke. With the clear evidence supporting the need to filter surgical smoke, perioperative nurses and surgical technologists at our facility implemented a plan to protect patients and staff members. The plan included identifying and evaluating in-house equipment and the perceived barriers to becoming smoke-free. Perioperative personnel tested multiple smoke-evacuating products to determine which best met the needs of our staff members and facility, and our ORs are now smoke-free.

Surgical smoke control with local exhaust ventilation: Experimental study

This experimental study aimed to evaluate airborne particulates and volatile organic compounds (VOCs) from surgical smoke when a local exhaust ventilation (LEV) system is in place. Surgical smoke was generated from human tissue in an unoccupied operating room using an electrocautery surgical device for 15 min with 3 different test settings: (1) without LEV control; (2) control with a wall irrigation suction unit with an in-line ultra-low penetration air filter; and (3) control with a smoke evacuation system. Flow rate of LEVs was approximately 35 L/min and suction was maintained within 5 cm of electrocautery interaction site. A total of 6 experiments were conducted. Particle number and mass concentrations were measured using direct reading instruments including a condensation particle counter (CPC), a light-scattering laser photometer (DustTrak DRX), a scanning mobility particle sizer (SMPS), an aerodynamic particle sizer (APS), and a viable particle counter. Selected VOCs were collected using evacuated canisters using grab, personal and area sampling techniques. The largest average particle and VOCs concentrations were found in the absence of LEV control followed by LEV controls. Average ratios of LEV controls to without LEV control ranged 0.24-0.33 (CPC), 0.28-0.39 (SMPS), 0.14-0.31 (DustTrak DRX), and 0.26-0.55 (APS). Ethanol and isopropyl alcohol were dominant in the canister samples. Acetaldehyde, acetone, acetonitrile, benzene, hexane, styrene, and toluene were detected but at lower concentrations (<500 μg/m3) and concentrations of the VOCs were much less than the National Institute for Occupational Safety and Health recommended exposure limit values. Utilization of the LEVs for surgical smoke control can significantly reduce but not completely eliminate airborne particles and VOCs.

Experimental investigation of performance and emissions of a VCR diesel engine fuelled with n-butanol diesel blends under varying engine parameters

The continuous rise in the cost of fossil fuels as well as in environmental pollution has attracted research in the area of clean alternative fuels for improving the performance and emissions of internal combustion (IC) engines. In the present work, n-butanol is treated as a bio-fuel and investigations have been made to evaluate the feasibility of replacing diesel with a suitable n-butanol-diesel blend. In the current research, an experimental investigation was carried out on a variable compression ratio CI engine with n-butanol-diesel blends (10-25% by volume) to determine the optimum blending ratio and optimum operating parameters of the engine for reduced emissions. The best results of performance and emissions were observed for 20% n-butanol-diesel blend (B20) at a higher compression ratio as compared to diesel while keeping the other parameters unchanged. The observed deterioration in engine performance was within tolerable limits. The reductions in smoke, nitrogen oxides (NO _x ), and carbon monoxide (CO) were observed up to 56.52, 17.19, and 30.43%, respectively, for B20 in comparison to diesel at rated power. However, carbon dioxide (CO₂) and hydrocarbons (HC) were found to be higher by 17.58 and 15.78%, respectively, for B20. It is concluded that n-butanol-diesel blend would be a potential fuel to control emissions from diesel engines. Graphical abstract ᅟ.

Low-smoke chulha in Indian slums: study protocol for a randomised controlled trial

BACKGROUND

Biomass fuel is used as a primary cooking source by more than half of the world's population, contributing to a high burden of disease. Although cleaner fuels are available, some households continue using solid fuels because of financial constraints and absence of infrastructure, especially in non-notified slums. The present study documents a randomised controlled study investigating the efficacy of improved cookstove on the personal exposure to air pollution and the respiratory health of women and children in an Indian slum. The improved cookstove was based on co-creation of a low-smoke chulha with local communities in order to support adaption and sustained uptake.

METHODS

The study will be conducted in a non-notified slum called Ashrayanagar in Bangalore, India. The study design will be a 1:1 randomised controlled intervention trial, including 250 households. The intervention group will receive an improved cookstove (low-smoke chulha) and the control group will continue using either the traditional cookstove (chulha) or a combination of the traditional stove and the kerosene/diesel stove. Follow-up time is 1 year. Outcomes include change in lung function (FEV1/FVC), incidence of pneumonia, change in personal PM2.5 and CO exposure, incidence of respiratory symptoms (cough, phlegm, wheeze and shortness of breath), prevalence of other related symptoms (headache and burning eyes), change in behaviour and adoption of the stove. Ethical clearance was obtained from the Institutional Ethics Committee of the Indian Institute of Public Health Hyderabad- Bengaluru Campus.

DISCUSSION

The findings from this study aim to provide insight into the effects of improved cookstoves in urban slums. Results can give evidence for the decrease of indoor air pollution and the improvement of respiratory health for children and women.

TRIAL REGISTRATION

The trial was registered with clinicaltrials.gov on 21 June 2016 with the identifier NCT02821650 ; A Study to Test the Impact of an Improved Chulha on the Respiratory Health of Women and Children in Indian Slums.

Efficacy of interventions targeting household air pollution from residential wood stoves

Wood is commonly used for residential heating, but there are limited evidence-based interventions for reducing wood smoke exposures in the indoor environment. The Asthma Randomized Trial of Indoor Wood Smoke (ARTIS) study was designed to assess the efficacy of residential interventions to reduce indoor PM exposure from wood stoves. As part of a three-arm randomized placebo-controlled trial, two household-level interventions were evaluated: wood stove changeouts and air filtration units. Exposure outcomes included indoor measures such as continuous PM_2.5, particle counts, and carbon monoxide. Median indoor PM_2.5 concentration was 17.5 μg/m³ in wood-burning homes prior to interventions. No significant reductions in PM_2.5 concentrations were observed in the 40 homes receiving the placebo filter intervention. Sixteen homes received the wood stove changeout and showed no significant changes in PM_2.5 or particle counts. PM_2.5 concentrations were reduced by 68% in the filter intervention homes. Relative to placebo, air filtration unit homes had an overall PM_2.5 reduction of 63% (95% CI: 47-75%). Relative to the wood stove changeout, the filtration unit intervention was more efficacious and less expensive, yet compliance issues indicated a need for the evaluation of additional strategies for improving indoor air quality in homes using wood stoves.

Electrocautery Devices With Feedback Mode and Teflon-Coated Blades Create Less Surgical Smoke for a Quality Improvement in the Operating Theater

Monopolar electrocautery is a fast and elegant cutting option. However, as it creates surgical smoke containing polycyclic aromatic hydrocarbons (PAHs), it may be hazardous to the health of the surgical team. Although new technologies, such as feedback mode (FM) and Teflon-coated blades (TBs), reduce tissue damage, their impact on surgical smoke creation has not yet been elucidated. Therefore, we analyzed the plume at its source.The aim of this study was to evaluate if electrocautery FM and TBs create less surgical smoke.Porcine tissue containing skin was cut in a standardized manner using sharp-edged Teflon-coated blades (SETBs), normal-shaped TBs, or stainless steel blades (SSBs). Experiments were performed using FM and pure-cut mode. Surgical smoke was sucked through filters or adsorption tubes. Subsequently, filters were scanned and analyzed using a spectrophotometer. A high-performance liquid chromatography (HPLC-UV) was performed to detect benzo[a]pyrene (BaP) and phenanthrene as 2 of the most critical PAHs. Temperature changes at the cutting site were measured by an infrared thermometer.In FM, more surgical smoke was created using SSB compared with TBs (P < 0.001). Furthermore, differences between FM and pure-cut mode were found for SSB and TB (P < 0.001), but not for SETB (P = 0.911). Photometric analysis revealed differences in the peak heights of the PAH spectrum. In HLPC-UV, the amount of BaP and phenanthrene detected was lower for TB compared with SSB. Tissue temperature variations increased when SSB was used in FM and pure-cut mode. Furthermore, different modes revealed higher temperature variations with the use of SETB (P = 0.004) and TB (P = 0.005) during cutting, but not SSB (P = 0.789).We found that the use of both TBs and FM was associated with reduced amounts of surgical smoke created during cutting. Thus, the surgical team may benefit from the adoption of such new technologies, which could contribute to the primary prevention of smoke-related diseases.

Smoke suppression properties of ferrite yellow on flame retardant thermoplastic polyurethane based on ammonium polyphosphate

This article mainly studies smoke suppression properties and synergistic flame retardant effect of ferrite yellow (FeOOH) on flame retardant thermoplastic polyurethane (TPU) composites using ammonium polyphosphate (APP) as a flame retardant agent. Smoke suppression properties and synergistic flame retardant effect of FeOOH on flame retardant TPU composites were intensively investigated by smoke density test (SDT), cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermal-gravimetric analysis (TGA). Remarkably, the SDT results show that FeOOH can effectively decrease the amount of smoke production with or without flame. On the other hand, the CCT data reveal that the addition of FeOOH can apparently reduce heat release rate (HRR), total heat release (THR), and total smoke release (TSR), etc. Here, FeOOH is considered to be an effective smoke suppression agent and a good synergism with APP in flame retardant TPU composites, which can greatly improve the structure of char residue realized by TGA and SEM results.

Combustion By-Products and their Health Effects--combustion engineering and global health in the 21st century: issues and challenges

The 13th International Congress on Combustion By-Products and their Health Effects was held in New Orleans, Louisiana from May 15 to 18, 2013. The congress, sponsored by the Superfund Research Program, National Institute of Environmental Health Sciences, and National Science Foundation, brought together international academic and government researchers, engineers, scientists, and policymakers. With industrial growth, increased power needs and generation and coal consumption and their concomitant emissions, pernicious health effects associated with exposures to these emissions are on the rise. This congress provides a unique platform for interdisciplinary exchange and discussion of these topics. The formation, conversion, control, and health effects of combustion by-products, including particulate matter and associated heavy metals, persistent organic pollutants, and environmentally persistent free radicals, were discussed during the congress. This review will summarize and discuss the implications of the data presented.

Evaluation of a wildfire smoke forecasting system as a tool for public health protection

BACKGROUND

Exposure to wildfire smoke has been associated with cardiopulmonary health impacts. Climate change will increase the severity and frequency of smoke events, suggesting a need for enhanced public health protection. Forecasts of smoke exposure can facilitate public health responses.

OBJECTIVES

We evaluated the utility of a wildfire smoke forecasting system (BlueSky) for public health protection by comparing its forecasts with observations and assessing their associations with population-level indicators of respiratory health in British Columbia, Canada.

METHODS

We compared BlueSky PM2.5 forecasts with PM2.5 measurements from air quality monitors, and BlueSky smoke plume forecasts with plume tracings from National Oceanic and Atmospheric Administration Hazard Mapping System remote sensing data. Daily counts of the asthma drug salbutamol sulfate dispensations and asthma-related physician visits were aggregated for each geographic local health area (LHA). Daily continuous measures of PM2.5 and binary measures of smoke plume presence, either forecasted or observed, were assigned to each LHA. Poisson regression was used to estimate the association between exposure measures and health indicators.

RESULTS

We found modest agreement between forecasts and observations, which was improved during intense fire periods. A 30-μg/m3 increase in BlueSky PM2.5 was associated with an 8% increase in salbutamol dispensations and a 5% increase in asthma-related physician visits. BlueSky plume coverage was associated with 5% and 6% increases in the two health indicators, respectively. The effects were similar for observed smoke, and generally stronger in very smoky areas.

CONCLUSIONS

BlueSky forecasts showed modest agreement with retrospective measures of smoke and were predictive of respiratory health indicators, suggesting they can provide useful information for public health protection.

Evaluation of interventions to reduce air pollution from biomass smoke on mortality in Launceston, Australia: retrospective analysis of daily mortality, 1994-2007

OBJECTIVE

To assess the effect of reductions in air pollution from biomass smoke on daily mortality.

DESIGN

Age stratified time series analysis of daily mortality with Poisson regression models adjusted for the effects of temperature, humidity, day of week, respiratory epidemics, and secular mortality trends, applied to an intervention and control community.

SETTING

Central Launceston, Australia, a town in which coordinated strategies were implemented to reduce pollution from wood smoke and central Hobart, a comparable city in which there were no specific air quality interventions.

PARTICIPANTS

67,000 residents of central Launceston and 148,000 residents of central Hobart (at 2001 census).

INTERVENTIONS

Community education campaigns, enforcement of environmental regulations, and a wood heater replacement programme to reduce ambient pollution from residential wood stoves started in the winter of 2001.

MAIN OUTCOME MEASURES

Changes in daily all cause, cardiovascular, and respiratory mortality during the 6.5 year periods before and after June 2001 in Launceston and Hobart.

RESULTS

Mean daily wintertime concentration of PM(10) (particulate matter with particle size <10 µm diameter) fell from 44 µg/m(3) during 1994-2000 to 27 µg/m(3) during 2001-07 in Launceston. The period of improved air quality was associated with small non-significant reductions in annual mortality. In males the observed reductions in annual mortality were larger and significant for all cause (-11.4%, 95% confidence interval -19.2% to -2.9%; P=0.01), cardiovascular (-17.9%, -30.6% to -2.8%; P=0.02), and respiratory (-22.8%, -40.6% to 0.3%; P=0.05) mortality. In wintertime reductions in cardiovascular (-19.6%, -36.3% to 1.5%; P=0.06) and respiratory (-27.9%, -49.5% to 3.1%; P=0.07) mortality were of borderline significance (males and females combined). There were no significant changes in mortality in the control city of Hobart.

CONCLUSIONS

Decreased air pollution from ambient biomass smoke was associated with reduced annual mortality in males and with reduced cardiovascular and respiratory mortality during winter months.

Smoking cessation and environmental hygiene

Although there are nonmodifiable genetic risk factors for COPD, most known risk factors for development and progression of COPD can be corrected. Continued efforts to encourage smoking cessation and measures to reduce exposure to SHS, outdoor air pollution, biomass smoke, and occupational and related amateur exposures will have a significant impact on worldwide health.

Intervention to lower household wood smoke exposure in Guatemala reduces ST-segment depression on electrocardiograms

BACKGROUND

A large body of evidence suggests that fine particulate matter (PM) air pollution is a cause of cardiovascular disease, but little is known in particular about the cardiovascular effects of indoor air pollution from household use of solid fuels in developing countries. RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects) was a randomized trial of a chimney woodstove that reduces wood smoke exposure.

OBJECTIVES

We tested the hypotheses that the stove intervention, compared with open fire use, would reduce ST-segment depression and increase heart rate variability (HRV).

METHODS

We used two complementary study designs: a) between-groups comparisons based on randomized stove assignment, and b) before-and-after comparisons within control subjects who used open fires during the trial and received chimney stoves after the trial. Electrocardiogram sessions that lasted 20 hr were repeated up to three times among 49 intervention and 70 control women 38-84 years of age, and 55 control subjects were also assessed after receiving stoves. HRV and ST-segment values were assessed for each 30-min period. ST-segment depression was defined as an average value below -1.00 mm. Personal fine PM [aerodynamic diameter ≤ 2.5 μm (PM₂.₅] exposures were measured for 24 hr before each electrocardiogram.

RESULTS

PM₂.₅ exposure means were 266 and 102 μg/m³ during the trial period in the control and intervention groups, respectively. During the trial, the stove intervention was associated with an odds ratio of 0.26 (95% confidence interval, 0.08-0.90) for ST-segment depression. We found similar associations with the before-and-after comparison. The intervention was not significantly associated with HRV.

CONCLUSIONS

The stove intervention was associated with reduced occurrence of nonspecific ST-segment depression, suggesting that household wood smoke exposures affect ventricular repolarization and potentially cardiovascular health.

Electrosurgery in perioperative practice

‘The yron is most excellent but that it is offensive to the eye and bringeth the patient to great sorrowe and dread of the burning and the smart’”. Inscription on a 15th century cautery instrument, The Guild of Barber Surgeons, St Audoens Church, Dublin.

Fine particulate matter source apportionment following a large woodstove changeout program in Libby, Montana

Before a community-wide woodstove changeout program, a chemical mass balance (CMB) source apportionment study was conducted in Libby, MT, during the winter of 2003-2004 to identify the sources of fine particulate matter (PM2.5) within the valley. Results from this study showed that residential woodstoves were the major source, contributing approximately 80% of the ambient PM2.5 throughout the winter months. In an effort to lower the ambient PM2.5, a large woodstove changeout program was conducted in Libby from 2005 to 2007 in which nearly 1200 old woodstoves were changed out with cleaner burning models. During the winter of 2007-2008, a follow-up CMB source apportionment study was conducted to evaluate the effectiveness of the changeout. Results from this study showed that average winter PM2.5 mass was reduced by 20%, and woodsmoke-related PM2.5 (as identified by the CMB model) was reduced by 28% when compared with the pre-changeout winter of 2003-2004. These results suggest that a woodstove changeout can be an effective tool in reducing ambient levels of PM2.5 in woodstove-impacted communities.

Experimental investigation on influence of smoke venting velocity and vent height on mechanical smoke exhaust efficiency

A set of burning experiments were conducted to investigate the influence of smoke vent height and exhausting velocity on mechanical smoke exhausting efficiency. Results have shown that the smoke exhausting process becomes more efficient due to the increased smoke vent height and the decreased exhausting velocity, which eliminate the plug-holing issue with fewer disturbances on the smoke layer interface. For each certain exhausting velocity, there is a critical value of distance between the vent and the bottom of the smoke layer. When the distance is less than the critical value, the smoke exhausting is inefficient, and the efficiency decreases sharply as the distance decreases. Contrarily, when the distance is greater than the critical value, a good efficiency can be acquired and the exhausted smoke increased relatively slowly as the distance increases. A critical Froude number, proposed by Hinkley to predict the onset of plug-holing effect in gravity venting systems, was validated in the experiments. However, the experimental results indicate that in the tests without the plug-holing, the fresh air entrained due to smoke exhausting is up to 48% of the mechanical exhausting rate.

[Surgical smoke: risks and preventive measures]

The application of the advanced technologies in medicine has led to the appearance of new risk factors for health personnel. One of these could be the surgical smoke produced by electrosurgical instruments, ultrasounds or laser. However, there is still insufficient evidence in the published population studies on the detrimental effects of chronic exposure to surgical smoke. The main concern on the possible damage to the health of operating room staff is mainly based on the components currently detected until the date and laboratory experiments. Caution must also be used when extrapolating the results of in vitro studies to daily clinical practice. The organisations responsible for protecting the health of the workers in different countries have still not issued guidelines for the treatment and removal of the surgical smoke generated in both open and laparoscopic procedures. In this article we try to present a view of the consequences that surgical smoke has on health and the preventive measures that can be adopted.

Results of a residential indoor PM2.5 sampling program before and after a woodstove changeout

During 2005-2007, a woodstove changeout program was conducted in a Rocky Mountain valley community in an effort to reduce ambient levels of PM(2.5). In addition to changes in ambient PM(2.5), an opportunity was provided to evaluate the changes in indoor air quality when old stoves were replaced with US Environmental Protection Agency (EPA)-certified woodstoves. PM(2.5) samples were measured in 16 homes prior to and following the changeout. For each sampling event, PM(2.5) mass was continuously measured throughout the 24-h sampling periods, and organic/elemental carbon (OC/EC) and associated chemical markers of woodsmoke were measured from quartz filters. Results showed that average PM(2.5) concentrations and maximum PM(2.5) concentrations were reduced by 71% and 76%, respectively (as measured by TSI DustTraks). Levoglucosan was reduced by 45% following the introduction of the new woodstove. However, the concentrations of resin acids, natural chemicals found in the bark of wood, were increased following the introduction of the new woodstove. There were no discernible trends in methoxphenol levels, likely due to the semi-volatile nature of the species that were measured. Although there is some uncertainty in this study regarding the amount of ambient PM infiltration to the indoor environment, these findings demonstrated a large impact on indoor air quality following this intervention.

PRACTICAL IMPLICATIONS

Emissions from residential woodstoves are an important air quality issue (both indoors and ambient) in many regions throughout the US and the world. More specifically, woodstoves have been identified as a major source of PM(2.5) in valley locations throughout the Northern Rocky Mountains, where biomass combustion is the predominant source of home heating. In this study, we present results that demonstrate the dramatic reduction in PM(2.5) concentrations (as measured by TSI, Inc. DustTrak PM(2.5) air samplers) inside homes following the replacement of old, polluting woodstove with new EPA-certified woodstoves.

Reduction in personal exposures to particulate matter and carbon monoxide as a result of the installation of a Patsari improved cook stove in Michoacan Mexico

The impact of an improved wood burning stove (Patsari) in reducing personal exposures and indoor concentrations of particulate matter (PM(2.5)) and carbon monoxide (CO) was evaluated in 60 homes in a rural community of Michoacan, Mexico. Average PM(2.5) 24-h personal exposure was 0.29 mg/m(3) and mean 48-h kitchen concentration was 1.269 mg/m(3) for participating women using the traditional open fire (fogon). If these concentrations are typical of rural conditions in Mexico, a large fraction of the population is chronically exposed to levels of pollution far higher than ambient concentrations found by the Mexican government to be harmful to human health. Installation of an improved Patsari stove in these homes resulted in 74% reduction in median 48-h PM(2.5) concentrations in kitchens and 35% reduction in median 24-h PM(2.5) personal exposures. Corresponding reductions in CO were 77% and 78% for median 48-h kitchen concentrations and median 24-h personal exposures, respectively. The relationship between reductions in median kitchen concentrations and reductions in median personal exposures not only changed for different pollutants, but also differed between traditional and improved stove type, and by stove adoption category. If these reductions are typical, significant bias in the relationship between reductions in particle concentrations and reductions in health impacts may result, if reductions in kitchen concentrations are used as a proxy for personal exposure reductions when evaluating stove interventions. In addition, personal exposure reductions for CO may not reflect similar reductions for PM(2.5). This implies that PM(2.5) personal exposure measurements should be collected or indoor measurements should be combined with better time-activity estimates, which would more accurately reflect the contributions of indoor concentrations to personal exposures.

PRACTICAL IMPLICATIONS

Installation of improved cookstoves may result in significant reductions in indoor concentrations of carbon monoxide and fine particulate matter (PM(2.5)), with concurrent but lower reductions in personal exposures. Significant errors may result if reductions in kitchen concentrations are used as a proxy for personal exposure reductions when evaluating stove interventions in epidemiological investigations. Similarly, time microenvironment activity models in these rural homes do not provide robust estimates of individual exposures due to the large spatial heterogeneity in pollutant concentrations and the lack of resolution of time activity diaries to capture movement through these microenvironments.

Reduction in the incidence of acute myocardial infarction associated with a citywide smoking ordinance

BACKGROUND

Secondhand smoke exposure increases the risk of acute myocardial infarction (AMI). One study (Helena, Mont) examined the issue and found a decrease in AMI associated with a smoke-free ordinance. We sought to determine the impact of a smoke-free ordinance on AMI admission rates in another geographically isolated community (Pueblo, Colo).

METHODS AND RESULTS

We assessed AMI hospitalizations in Pueblo during a 3-year period, 1.5 years before and 1.5 years after implementation of a smoke-free ordinance. We compared the AMI hospitalization rates among individuals residing within city limits, the area where the ordinance applied, versus those outside city limits. We also compared AMI rates during this time period with another geographically isolated but proximal community, El Paso County, Colo, that did not have an ordinance. A total of 855 patients were hospitalized with a diagnosis of primary AMI in Pueblo between January 1, 2002, and December 31, 2004. A reduction in AMI hospitalizations was observed in the period after the ordinance among Pueblo city limit residents (relative risk [RR]=0.73, 95% confidence interval [CI] 0.63 to 0.85). No significant changes in AMI rates were observed among residents outside city limits (RR=0.85, 95% CI 0.63 to 1.16) or in El Paso County during the same period (RR=0.97, 95% CI 0.89 to 1.06). The reduction in AMI rate within Pueblo differed significantly from changes in the external control group (El Paso County) even after adjustment for seasonal trends (P<0.001).

CONCLUSIONS

A public ordinance reducing exposure to secondhand smoke was associated with a decrease in AMI hospitalizations in Pueblo, Colo, which supports previous data from a smaller study.

The use of pine bark and natural zeolite as biofilter media to remove animal rendering process odours

Studies of odour-control pilot-scale biofilters at a rendering plant were conducted for five years. The biofilters contained different sizes of crushed pine bark or a mixture of zeolite and crushed bark, and treated the exhaust gases from direct-fired meal dryers. The exhaust gases were odorous and contained significant smoke. The odour concentration of the rendering process air ranged between 50,000 and 307,200 OU m(-3). Odour-removal performance measurements of the biofilters were undertaken on five occasions using forced-choice dynamic-dilution olfactometry. Biofilter odour-removal efficiencies of between 80% and 99% were measured at various influent odour concentrations and air loading rates. There was no obvious deterioration in performance of these biofilters between various sampling times in the five year study period. The biofilters also reduced the "offensiveness" of the odour. The fine crushed bark biofilter generally reduced odour concentration more efficiently than the coarse bark biofilter. The additions of zeolite to the bark medium in the biofilter had little effect on the odour-removal performance. An increase in air loading rate produced only a very small decrease in odour-removal performance. The pilot-scale biofilters had smoke removal efficiencies between 71% and 100%. Finely crushed bark removed smoke more effectively than coarsely crushed bark. Drainage from the biofilters contained significant concentrations of pollutants, suggesting that controlled leaching has potential to remove accumulated substances in biofilter media from rendering gas emissions and increase the longevity of a biofilter system.