Concentrations Of Inhalable Particles Research Articles

Real-time Monitoring of Aerosol Generating Dental Procedures

ObjectiveWe aimed to quantify aerosol concentrations produced during different dental procedures under different mitigation processes. MethodAerosol concentrations were measured by the Optical Particle Sensor (OPS) and Wideband Integrated Bioaerosol Sensor (WIBS) during routine, time-recorded dental procedures on a manikin head in a partitioned enclosure. Four different, standardised dental procedures were repeated in triplicate for three different mitigation measures. ResultBoth high-volume evacuation (HVE) and HVE plus local exhaust ventilation (LEV) eradicated all procedure-related aerosols, and the enclosure stopped procedure-related aerosols escaping. Aerosols recorded by the OPS and WIBS were 84 and 16-fold higher than background levels during tooth 16 FDI notation (UR6) drilling, and 11 and 24-fold higher during tooth 46 FDI notation (LR6) drilling, respectively. Ultrasonic scaling around the full lower arch (CL) or the full upper arch (CU) did not generate detectable aerosols with mitigation applied. Without mitigation the largest concentration of inhalable particles during procedures observed by the WIBS and OPS was during LR6 (139/cm3) and UR6 (28/cm3) drilling, respectively. Brief aerosol bursts were recorded during drilling procedures with HVE, these did not occur with LEV, suggesting LEV provides protection against operator errors. Variation was observed in necessary fallow times (49 – 280 minutes) without mitigation, while no particles remained airborne when mitigation was utilised. ConclusionThis data demonstrates that correctly positioned HVE or LEV is effective in preventing airborne spread and persistence of inhalable particles originating from dental AGPs. Additionally, a simple enclosure restricts the spread of aerosols outside of the operating area. Clinical significanceEmploying correctly positioned HVE and LEV in non-mechanically ventilated clinics can prevent the dispersal and persistence of inhalable airborne particles during dental AGPs. Moreover, using enclosures have the additive effect of restricting aerosol spread outside of an operating area.

Small-Angle Particle Counting Coupled Photometry for Real-Time Detection of Respirable Particle Size Segmentation Mass Concentration.

Respirable particulate matter air pollution is positively associated with SARS-CoV-2 mortality. Real-time and accurate monitoring of particle concentration changes is the first step to prevent and control air pollution from inhalable particles. In this research, a new light scattering instrument has been developed to detect the mass concentration of inhalable particles. This instrument couples the forward small-angle single particle counting method with the lateral group particle photometry method in a single device. The mass concentration of four sizes of inhalable particles in the environment can be detected simultaneously in a large area in real-time without using a particle impactor. Different from the traditional light scattering instrument, this new optical instrument can detect darker particles with strong light absorption, and the measurement results mainly depend on the particle size and ignore the properties of the particles. Comparative experiments have shown that the instrument can detect particles with different properties by simply calibrating the environmental density parameters, and the measurement results have good stability and accuracy.

Daily levels of coarse inhalable particles and sick leaves

BACKGROUND AND AIM: Road traffic is typically the main source of coarse inhalable particles (2.5 µmdiameter10 µm) in urban areas. Consequently, exposure is high e.g. during commuting to work, in northern conditions especially during the spring time. Our aim was to evaluate whether daily outdoor levels of coarse inhalable particles are associated with the daily number of new sick leaves in Helsinki, Finland. METHODS: Data on work absenteeism among the employees of the city of Helsinki (approx. 50 000) was obtained for the years 2001-2017. Concentration of coarse inhalable particles was calculated by subtracting daily fine particle concentration from the concentration of inhalable particles, both measured at an urban background monitoring site. Statistical analyses were conducted using generalized additive quasi-Poisson regression, separately for the whole year and the spring dust period (15.3.-15.5). RESULTS:There were almost 2 million sick leaves in the data. The same day coarse particle concentration was associated with an increased risk of sick leave: relative risk for a 10 µg/m increase in exposure was 1.018 (95% confidence intervals 1.005-1.030). Fine particles had similar effect but with one day lag. During the spring dust period, coarse particles were not associated with the outcome. CONCLUSIONS:Exposure to road dust seems to increase the risk of work absenteeism. However, during the spring dust period particle toxicity may be reduced e.g. because of aging of the material during winter. KEYWORDS: air pollution, coarse particles, work absenteeism, short-term

Occupational exposure to particles and air pollutants in a car paint workshop

Abstract Background In auto paint workshops there are several chemical, physical and biological agents that are harmful to health, making it essential to guarantee the well-being and safety of workers. In this sense, the assessment of the Indoor Air Quality (IAQ) of these places, in an associated context of occupational health, proves to be important. Methods The present study had as main objective to evaluate the occupational exposure of workers in an automobile painting workshop to particles and air pollutants. The data collection consisted of the evaluation of air quality, using for this purpose, the assessment of atmospheric pollutants carbon monoxide (CO), carbon dioxide (CO2), Volatile Organic Compounds (VOC), formaldehyde (CH2O), carbon dioxide sulfur (SO2), nitrogen dioxide (NO2), hydrogen sulfide (H2S) and particulate matter (PM2.5, PM10, breathable and inhalable particles) and the meteorological variables temperature and relative humidity. The collected data was processed using the statistical software IBM SPSS version 27.0. The interpretation of the statistical tests was performed with a 95% confidence level for a maximum random error up to 5%. Results We found that the concentrations of inhalable particles recorded in some workstations exceeded the legally established exposure limit value. Conclusions IAQ should be a priority concern for the government and for all professionals working in the area of Occupational Health and Safety having in mind the implementation of measures that promote the continuous improvement of the IAQ of the facilities, thus guaranteeing a good assessment and monitoring of workstations, preventing atmospheric pollutants from reaching concentrations that could put workers' health at risk.

Comparative Analysis of Indoor and Outdoor Particulate Matter Concentrations and Air Quality in Ogbomoso, Nigeria

Background.Airborne particulates are an issue in many urban regions around the world and their detrimental impact on human health has increasingly become a public health concern.Objectives.The aim of the present study was to examine particle pollution in an urban settlement in Nigeria. This study examines the extent, spatial variation, and sources of indoor and outdoor particulate matter (PM) concentrations in Ogbomoso, Nigeria.Methods.The survey research method was adopted. Sampling included 385 buildings across selected precincts and different residential zones in the town of Ogbomoso. Particulate matter analytes (PM1, PM2.5 and PM10) within/around each building were measured with a particle counter and details on domestic utilities/practices were obtained with a questionnaire. Analysis of variance was used to determine inter-zonal variations in PM levels and simple linear regression was used to analyze the relationship between indoor and outdoor air quality.Results.Indoor and outdoor respirable particle (PM2.5) concentrations were lower than the World Health Organization (WHO) Interim Target limit of 75 μg/m3, while concentrations of inhalable particles (PM10) were higher than the set limit of 150 μg/m3 for daily averages. Coarse particles dominated, with an accumulative PM2.5/PM10 ratio of 0.24. The inter-zonal analysis of PM concentrations revealed that indoor and outdoor PM levels varied significantly by residential zone (p = 0.0005; p = 0.01, respectively). Regression analysis showed a significant but weak relationship between indoor and outdoor PM levels (r = +0.221), while the coefficient of determination (R2 = 0.049) showed that only about 5% of the variation in indoor air quality was associated with outdoor air quality. Particle pollution inducers were identified in the residents' waste disposal methods and adopted fuels/energy sources, with firewood and charcoal linked with increased concentrations of particulate matter.Conclusions.Air quality was relatively poor in the study area given observed particulate matter concentrations. Cleaner fuels, effective waste management systems and improved roads are needed to foster better air quality in the study area.Competing Interests.The authors declare no competing financial interests

Design of Intelligent Window Closing System

In today’s society, windows are mainly used in people’s home life in manual switching mode, and with the improvement of the quality of life, the perspective of intelligent home is gradually being realized. It has become a topic that people often talk about. This design is based on the stc series single-chip microcomputer as the main control chip. The rain sensor is used to detect whether the rainwater enters the house. Whether the concentration of inhalable particles in the environment is too large and take corresponding measures, the wind speed sensor detects the strength of the wind, and finally the stepper motor is required to complete the function of the window’s active opening and closing itself, so that the window has intelligent functions. Circuit components are relatively practical and reliable, so they have the characteristics of simple circuits, economical and applicable, and easy maintenance.

Variation Characteristics of Mass Concentration of Inhalable Particles in Qingdao, China

The geographical condition of Qingdao, China is relatively special; the transport of various inland pollutants, the emissions of marine aerosol and local pollutants will have an impact on the changes of atmospheric aerosol concentration. By using the stability classification method, trajectory clustering analysis and the NOAA HYSPLIT model, the seasonal distribution characteristics of atmospheric inhalable particulate matter concentration in Qingdao, China and its relationship with meteorological conditions, mixed layer height, and the seasonal characteristics of Qingdao pollutant transport were analyzed. The results show that the variation trends of PM2.5 and PM10 were about the same, and there are obvious seasonal differences, which are high in winter and spring, and low in summer and autumn. The concentration of inhalable particulate matter has a negative correlation with temperature, wind speed and relative humidity. The concentration of inhalable particulate matter is distinct in different relative humidity ranges. When the wind speed is less than 3 - 4 m/s, there are more inhalable particles, while the mass concentration shows obvious reduction with the wind speed more than 4 m/s. There is a significant negative correlation between the mass concentration of pollutants and the daily maximum mixed layer height. The larger the concentration of pollutants, the smaller the thickness of the daily largest mixed layer. Conversely, the smaller the mass concentration of pollutants, the larger the thickness of the daily largest mixed layer. The pollutant transport in Qingdao has obvious seasonal characteristics. The air mass in spring, autumn and winter is mainly medium-long distance transport from Mongolia and southern Russia, and medium-short distance transport from Inner Mongolia and northeast of China. The source of air masses in summer is mainly transported from the eastern and sea areas.

Evaluation Methods of Water Environment Safety and Their Application to the Three Northeast Provinces of China

Focusing on the topic of water environment safety of China, this paper has selected the three northeast provinces of China as the research object due to their representativeness in economic development and resource security. By using the Entropy Weight Method, the Grey Correlation Analysis Method, and the Principal Component Analysis Method, this paper has first constructed a water environment safety evaluation system with 17 indicators from the economic, environmental, and ecological aspects. Furthermore, this paper has screened the initially selected indicators by the Principal Component Analysis Method and finally determined 11 indicators as the evaluation indicators. After indicator screening, this paper has adopted the improved Fuzzy Comprehensive Evaluation Method to evaluate the water environment safety of the three northeast provinces of China and obtained the change in water environment safety of different provinces from 2009 to 2017. The results show that the overall water environment safety of the region had improved first but worsened afterward, and that in terms of water safety level, Jilin Province ranked first, followed by Heilongjiang Province and Liaoning Province. The three factors that have the greatest impact on the water environment safety of the three provinces are: Liaoning—Chemical Oxygen Demand (score: 17.10), Per Capita Disposable Income (score: 13.50), and Secondary Industry Output (score: 11.50); Heilongjiang—Chemical Oxygen Demand (score: 18.64), Per Capita Water Resources (score: 12.75), and Concentration of Inhalable Particles (score: 10.89); Jilin—Per Capita Water Resources (score: 15.75), Chemical Oxygen Demand (score: 14.87), and Service Industry Output (score: 11.55). Based on analysis of the evaluation results, this paper has proposed corresponding policy recommendations to improve the water environment safety and promote sustainable development in the northeast provinces of China.

Inhalable and Respirable Particulate and Endotoxin Exposures in Kentucky Equine Farms

ABSTRACTAdverse respiratory health effects in the agricultural industry have been linked to particulate endotoxin exposure. However, whether the endotoxin concentration is significantly correlated to the size of the particle remains an open question. To date, limited research has been conducted to assess particulate endotoxin exposures in the agricultural industry in general or the equine industry in particular. A task-based exposure assessment was conducted to characterize the endotoxin levels of inhalable and respirable particles on four Kentucky farms during the summer season. We conducted personal sampling of respirable and inhalable particles (n = 75) across all four farms and particulate endotoxin (n = 58) on two of them. Simultaneously, we collected real-time area samples across all four farms by task – horse care, filing hooves, cleaning stalls, cleaning barns, cleaning dry lots, and cleaning trucks. The endotoxin concentration of inhalable particles (geometric mean: 50.2–1,024 EU/m3) was ~50 times higher than that of respirable particles (geometric mean: 1.72–19.0 EU/m3). Horse care generated the lowest endotoxin concentrations for both particle sizes, while cleaning tasks tended to produce higher concentrations. There was no significant correlation between the endotoxin and particle concentrations for each size fraction based on tasks by farm (R2 = 0.069 for inhalable; 0.214 for respirable). The equine workers in this study were exposed to higher endotoxin concentrations than workers in other industries, such as the swine industry. Providing exposure control guidelines and recommendations to the equine industry is necessary to reduce long-term endotoxin exposure and to prevent adverse respiratory symptoms.

Further Study on Permeability of Outdoor Particles in Temperature Difference into Indoor Air

To deeply understand the permeability of inhalable particles through window gap of buildings, an improved experimental setup was designed and experiments were conducted again based on the environmental chamber in Xi’an Jiaotong University. The experimental results indicated that in winter, with increasing of temperature difference between the indoor and outdoor air, more easily inhalable particles penetrated into indoor air, which was the same as those obtained in previous studies. When the temperature difference is less than 12℃, the greater the temperature difference, the higher the final equilibrium concentration of inhalable particles in indoor air. When the temperature difference is greater than 12℃, the final equilibrium concentration of indoor inhalable particles is basically the same, and it is not affected by the temperature difference. The temperature difference has a greater effect on the I/O ratio of PM2.5. High temperature difference increases not only the energy consumption of heating system but also the energy consumption of ventilation system.

The analysis and application of a new hybrid pollutants forecasting model using modified Kolmogorov-Zurbenko filter.

Cities in China suffer from severe smog and haze, and a forecasting system with high accuracy is of great importance to foresee the concentrations of the airborne particles. Compared with chemical transport models, the growing artificial intelligence models can simulate nonlinearities and interactive relationships and getting more accurate results. In this paper, the Kolmogorov-Zurbenko (KZ) filter is modified and firstly applied to construct the model using an artificial intelligence method. The concentration of inhalable particles and fine particulate matter in Dalian are used to analyze the filtered components and test the forecasting accuracy. Besides, an extended experiment is made by implementing a comprehensive comparison and a stability test using data in three other cities in China. Results testify the excellent performance of the developed hybrid models, which can be utilized to better understand the temporal features of pollutants and to perform a better air pollution control and management.

Exposure to Particulate Matter in Different Regions along a Road Network, Jharia Coalfield, Dhanbad, Jharkhand, India

Occupational particulate matter (PM) concentrations were measured during November 2014 along a road network in the mining and non-mining areas at Jharia coalfield, Dhanbad, Jharkhand, India. The monitoring was conducted for a week in the peak time using a portable GRIMM (model 1.109) aerosol spectrometer. Measured PM was designated as inhalable, thoracic and alveolic particles for aerodynamic diameter 10- 34, 4-10 and less than 4 m respectively. The main sources of PM along the roadside in the study area were mining operations as well as heavy traffic and resuspension of road dust. Concentration of inhalable particles was maximum at Bankmore (BMO), whereas concentration of thoracic and alveolic particles was maximum at Katrasmore (KMO) in the mining area. Concentration of all three types of particles was minimum at the Indian School of Mines in the non-mining area. The distribution curves of inhalable particles were positively skewed and platykurtic in nature, whereas for thoracic and alveolic particles these curves were positively skewed at all locations, except BMO and also platykurtic in nature, except Godhar (GDR). Contribution of alveoli particle sizes for 0.375 and 2.750 μm was observed to be significant in the mining area, whereas thoracic particle size for 5.750 μm and inhalable particle size for 22.500 μm were also observed to be higher in the mining area, except Matkuria check post and Kustaur. The results reveal that residents and local passengers were exposed to a prodigious amount of inhalable, thoracic and alveolic concentrations in the mining area, mostly at BMO, GDR and KMO.

Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi

A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81±90.97μg/m3) while the commuter of bus exhibited higher exposure of thoracic particles (292.23±110.45μg/m3) and car commuters were exposed to maximum concentrations of alveolic particles (222.37±26.56μg/m3). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon.

Exercise-induced effects on a gym atmosphere.

We report results of analysis of a month-long measurement of indoor air and environment quality parameters in one gym during sporting activities such as football, basketball, volleyball, badminton, boxing, and fitness. We have determined an average single person's contribution to the increase of temperature, humidity, and dust concentration in the gym air volume of 12500m(3) : during 90-min exercise performed at an average heart rate of 143±10bpm, a single person evaporated 0.94kg of water into the air by sweating, contributed 0.03K to the air temperature rise and added 1.5μg/m(3) and 5ng/m(3) to the indoor concentration of inhalable particles (PM10 ) and Ca concentration, respectively. As the breathing at the observed exercise intensity was about three times faster with respect to the resting condition and as the exercise-induced PM10 concentration was about two times larger than outdoors, a sportsman in the gym would receive about a sixfold higher dose of PM10 inside than he/she would have received at rest outside.

Using Traffic Density as a Surrogate to Predict Aerosol Exposures to Toll Workers

Background: It has shown traffic density was a good surrogate measure of exposure, and might be further be used in epidemiologic studies to explore health effects of exposure to traffic exhausts in the future. However, there is no information whether traffic density is also a good surrogate of inhalable particles. In addition, the sources and loading of PM2.5 and its degree of association with larger inhalable particles are poorly known. The purpose of this study was to examine the relation between traffic density of different types of vehicles and inhalable particles and to explore the relation between PM2.5 and inhalable particle in traffic-related air pollution in tollbooths. Methods: Tollbooth indoor monitoring samples were collected for 10 days to assess the 8 hours integrated inhalable concentrations and traffic density. Results: The mean inhalable particle concentrations in the bus and truck lanes were [760.2 µg/m3 (SD 297.3 µg/m3)], substantially higher compared with the car lanes with cash payment [465.3 (291.3)] and the car lanes with ticket payment [460.5 (265.1)]. The mass fraction of PM2.5 in inhalable particles accounted for 46 % in bus and truck lanes, whereas the corresponding figure was 33-34 % for car lanes. In linear regression adjusting for meteorological variables, a change in log(inhalable particle) was statistically significantly related to a unit change in log(PM2.5) (ß= 0.46, 95% CI 0.33 to 0.59). The 8- hour mean inhalable particle concentrations were statistically significantly correlated with traffic density (per 100 vehicles/hour) in truck and bus lanes. Conclusions: Traffic density is a surrogate to predict inhalable aerosol exposures only in the bus and truck lanes. PM2.5 is an important component of inhalable particle. Workers in toll stations are exposed to high levels of both PM2.5 and inhalable particles.

Seasonal, Diurnal and Spatial Variations of Environmental Variables in Australian Livestock Buildings

To identify the most practical and representative sampling locations for air quality and environmental variables inside intensive piggery buildings, the variation in the spatial, diurnal and seasonal concentration of major airborne pollutants, and related environmental parameters, were analysed over a 2.5-day period at several locations within different piggery buildings. Major airborne pollutants including, ammonia, carbon dioxide, and airborne particles were monitored along with environmental parameters of airspeed, temperature and humidity. To determine the air quality within each building, cyclone attachments were installed to measure particles of less than 5 mm along with a seven hole sampler attachment to measure inhalable airborne particles. An Osiris optical particle counter also monitored the concentrations of airborne particles. Ammonia and carbon dioxide were monitored using a multi-gas monitoring machine and airspeed was measured using a hot-wired anemometer. Interesting patterns in the concentration of carbon dioxide, dust and ammonia were observed over time and space. Carbon dioxide, airspeed and dust concentration demonstrated an obvious circadian pattern. The difference in the concentrations of ammonia and carbon dioxide was not statistically significant at alternative sampling locations inside each building. However, the gravimetric measurements indicated that the concentrations of inhalable particles were not uniform throughout the buildings and proved to be higher above the walkways. Ammonia and respirable particle concentrations were significantly higher in summer when compared to winter conditions. These results combined, identified the most appropriate sampling times and sampling places for reliable evaluation of air quality in intensive livestock buildings.

Sulfuric acid at workplaces—applicability of the new Indicative Occupational Exposure Limit Value (IOELV) to thoracic particles

Until 2009, the limit values for airborne sulfuric acid in Europe were based on the inhalable particle fraction (e.g. MAK (Maximum allowed concentration at workplace) value 0.1 mg m(-3) as the inhalable fraction). With the publication of the Commission Directive 2009/161/EU, an Indicative Occupational Exposure Limit Value (IOELV) of 0.05 mg m(-3) for sulfuric acid aerosols was based for the first time on the thoracic particle fraction. To permit a comparison of the measured values for the inhalable fraction with those of the thoracic fraction and to quantify the thoracic fraction, a cyclone was fabricated out of sulfuric-acid-resistant stainless steel that achieves suitable collection characteristics (PM(10)) at a flow rate of 5.34 L min(-1). 49 measurements were carried out in parallel in 21 companies. At concentrations well below the IOELV, there is little difference between the thoracic and inhalable particle concentrations. At higher concentrations (>0.1 mg m(-3) inhalable aerosol), larger droplets have a marked effect on the measured values and the thoracic fraction accounts for only 32.1 ± 12.5% of the inhalable fraction. The EU's IOELV and the proposal of the MAK Commission therefore provide a comparable level of protection. In the transposition of the IOELV into national law, an air limit of 0.1 mg m(-3) could therefore be implemented for the inhalable fraction.

Treatment of Airborne Pollutants in Livestock Buildings with Ozone as Potential Abatement Option

Previous research has demonstrated the negative effects of sub-optimal air quality on profitability, production efficiency, occupational health and safety, environmental sustainability and animal welfare. Ozone application has been used in North America to reduce internal air pollutant concentrations in livestock buildings and as a result potentially reduce airborne pollution emission. The main objective of this research was to evaluate the potential of using low concentration ozone (0.03 ppm) in Australian piggery buildings to reduce airborne pollution levels within piggery buildings and thus reduce pollution emission potentially. The data collected during the experiments demonstrated that ozone could be used effectively to reduce airborne bacteria (on average by 30% within this study) and reduce the concentration of inhalable particles (by 21% on average within this study). However, it appeared that ozone treatment did increase the concentration of respirable particles in the airspace of piggery buildings (within this study by approximately 26% on average).

Improving estimation of real-time concentration for inhalable particles < 10 μ m from a light scattering monitor

This study evaluated the relationship between the real-time concentration measurements of inhalable particles whose diameters were less than 10 μ m, from a light scattering monitor and a beta gauge monitor, at various instantaneous relative humidities. This work demonstrated that the mean inhalable particle concentrations as measured by the light scattering monitor were higher than those of the manual sampler, such that a factor of 0.74 was employed to adjust the light scattering monitor for inhalable particle concentration measurements. The mean inhalable particle concentrations determined by the beta gauge monitor at a low relative humidity setpoint correlated well with those obtained by the manual sampler. The real-time inhalable particle concentration of the adjusted light scattering monitor was further compared to those of the beta gauge monitor to investigate the effect of instantaneous relative humidity on the mass readings of the automatic monitors. The results demonstrated that the estimated concentration measurements by the adjusted light scattering monitor should be re-calibrated in real-time to improve the accuracy of the inhalable particle concentrations at various instantaneous relative humidities.

Environment and Health in China: Challenges and Opportunities

Environment and Health in China: Challenges and Opportunities