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Factors for Occupational Exposure to Ultrafine Particles in Different Sectors of Activity
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30 January 2024
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Abstract
The primary sources of particulate matter are linked to human activity. Certain particulate emissions, particularly those of a finer nature, can significantly impact human health, making them one of the most concerning pollutants. Ultrafine particles (UFP), which have a diameter of less than 100 nm, are of particular concern due to their impact on human health and the difficulty in controlling them. The concentration of ultrafine particles (UFP) in the workplace is a growing concern and is classified as an emerging risk. Workers may be exposed to UFP through inhalation, skin absorption, ingestion, or a combination of these routes. This study aims to determine the levels of UFP exposure among workers in environments with varying direct particle emission patterns. Measurements were conducted to compare the results with the levels recommended by the WHO. The study monitored industrial workplaces with direct particulate matter emissions, such as a carpentry and a bakery, as well as social sector sites without or almost without direct particle emissions, such as a school and a health clinic. One conclusion drawn from this study is that all tasks and occupations are susceptible to high levels of UFP, exceeding WHO recommended values in virtually all monitored environments. Therefore, monitoring and controlling UFP is crucial. Further in-depth studies on this subject are also necessary..
Keywords:
Subject: Environmental and Earth Sciences - Environmental Science
1. Introduction
Over time, man has found polluted air to be harmful to health and well-being. Indoor air can be contaminated by several emissions of different contaminants, thus becoming an increasing environmental concern [1].
Today, we spend around 90% of our lives inside places such as offices, homes, schools, vehicles, aeroplanes, and other spaces. Consequently, the way these environments are designed and used has a profound impact on the health of their occupants [2].
Exposure to air pollutants is associated with several effects on human health. Studies indicate that such effects have been present since the beginning of the last century, with increases in morbidity and mortality rates being detected after short episodes with high levels of air pollutants [3,4,5].
Particulate matter or airborne aerosols are pollutants composed of a complex mixture of solid and liquid particles in a gas. Particulate Matter (PM) varies in size and composition depending on its source and formation [6].
PM particles are classified based on their size and formation mechanism as either primary or secondary. Primary particles originate from direct emission sources, both natural and anthropogenic. In contrast, secondary particles are formed in the atmosphere through chemical and photochemical reactions or physical processes involving primary particles. The chemical composition of the particles is determined by the emission process, which is caused by the different possibilities of chemical combinations [7]. These particles are PM10 (i.e. particles up to 10 μm in aerodynamic equivalent diameter), coarse particles or PM2.5-10 (particles between 2.5 and 10 μm in aerodynamic equivalent diameter), PM2.5 or fine particles (particles up to 2.5 μm in aerodynamic equivalent diameter) [8].
One of the main sources of Particulate Matter are anthropogenic, this sources which refer to the sources of pollutants that have the potential to release particulate matter into the air and which are related to characteristics or activities typically associated human activity [9]. These sources may vary depending on the context, but can be important sources of emissions, such as from fuel combustion and other anthropogenic activities that emit different forms of particulate matter. Many industrial activities, such as metallurgy, foundry, cementing and materials processing, can generate large amounts of particulate matter during their processes [10]. Construction and demolition activities also generate particulate matter in the air, especially when excavating soil, handling particulate materials, cutting and using heavy equipment [11].
Occupational exposure to Ultrafine Particles (UFP) is currently a new and increasing concern, which classifies it as an emerging risk.
Ultrafine particles are extremely small solid or liquid particles, typically less than 100 nanometres in diameter. These particles are so small that they can be compared to the size of individual molecules, making them significantly smaller than other forms of particulate matter. Because of this tiny size, they have a remarkably large surface area relative to their mass, resulting in extensive interactions with the surrounding environment, making them highly reactive. This increases their transport potential and toxicity. In addition, ultrafine particles tend to aggregate and form clusters due to the attractive forces between them. This agglomeration significantly affects their properties and behaviour in different environments, such as liquids or the atmosphere. Because of their small size and ability to remain suspended in the air for long periods, these ultrafine particles are more likely to be inhaled and transported within the human body. This raises health and toxicity concerns [5,10,15,16].
Ultrafine Particles is also a minor contributor to the total mass concentration of indoor and outdoor aerosols [5]. Due to the limited detectability and reliability issues of mass concentration, the focus on UFP is on particle number concentration, which refers to the number of particles present in a given volume of air.
Human exposure routes to UFP may include inhalation via the respiratory tract; absorption via the skin; ingestion via the mouth; or combinations of these routes [12].
In fact, the most important route of human exposure to UFP is inhalation. By this route, and due to their size and other characteristics, UFP may reach the alveolar region and behave similarly to fine particles, giving rise to inflammatory processes in the lungs and subsequent cardiovascular morbidity and mortality [13].
Several epidemiological studies have shown that dust in the workplace is a risk factor for workers exposed to it, and that it can cause pathologies and affect the quality of life of workers [4].
UFP have different toxicological properties compared to larger airborne particles such as PM2.5/PM10. These differences are mainly due to differences in inhalation deposition (local dose) and intrinsic toxicity related to their physicochemical properties. Remarkably, health effects associated with exposure to UFP have been observed independently of other air pollution measures such as PM2.5 and NOx. Interestingly, certain UFP, unlike larger PM particles, may move from the respiratory system to the cardiovascular system and other organs [14].
The main question we want to answer is what levels of UFP workers are exposed to in environments with different direct particle emission patterns
For that purpose, the main questions we want to answer are:
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- What are the levels of UFP in traditionally particulate polluted sites?
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- Are UFP also present at sites where PM emissions are low or non-existent?
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- What is the relationship between the presence of UFP and other pollutants such as PM10, PM2.5, carbon dioxide (CO2) and carbon monoxide (CO)?
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- What is the relationship between the levels of UFP and other parameters, such as temperature (T) and relative humidity (RH)?
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- How do the values measured indoors relate to the values observed outdoors?
In order of that, the study involved monitoring industrial workplaces with PM emissions, such as a carpentry and a bakery, as well as at social sector sites without or almost without direct PM emissions, such as a school and a health clinic.
2. Materials and Methods
The study was observational, descriptive, analytical, and cross-sectional.
Non-probabilistic sampling was used to monitor environmental parameters and pollutants at four sites: two industrial (a carpentry and a bakery) and two social sector (a school and a health clinic). The industrial sites were chosen for their high PM emissions, while the other two sites had low or no direct PM emissions.
The carpentry is an open space facility measuring approximately 500 m2, constructed with masonry and a ceiling height of 5 m. Natural ventilation is present, with local extraction available when using wood cutting and sanding machines. The only existing control is local extraction for wood powder. Monitoring was carried out at several points representative of the work areas: painting, sawing (including sanding), and assembly.
The bakery is an industrial facility that produces goods for sale in stores. It has a total area of 200 m2 and a ceiling height of 4 m. The space is divided into several rooms, each approximately 30 m2 in size. The rooms are constructed with metal sandwich panel walls to facilitate hygiene and cleaning. The only method of controlling pollutants and temperature is through forced ventilation. Various measurement points were defined to characterize the different areas, including manufacturing, production, dispatch, warehouse, and office.
This study focuses on verifying occupational conditions in the workplace, specifically work offices and workrooms where workers typically spend extended periods of time. The workrooms and offices measured approximately 40 m2 and 20 m2 respectively, with a ceiling height of 3.5 m. The construction is made of masonry and is covered with paint, with natural ventilation. No control system was applied during the measurements. The windows were kept closed throughout the duration of the study to ensure consistency.
The health clinic comprises three laboratories, each measuring approximately 10 m², and an administrative and waiting room of around 30 m². The laboratory walls are covered in ceramic and stainless steel, while the reception area is painted masonry. The laboratories are equipped with air conditioning featuring air recirculation and heap filters, while the reception area benefits from natural ventilation. During the measurements, the windows were kept closed to ensure accuracy.
The measurements were conducted between 2022 and early 2023, comprising multiple collection moments and a total of 1926 measurements at workplaces, including an outdoor control site. The assessments were conducted during normal facility operation and working hours to ensure the sample was representative of occupational exposure to pollutants. The equipment was aimed at a central area within the measurement areas. Fifteen-minute measurements were taken at various times throughout the day to characterise daily exposure. Average values were then calculated and adjusted to standard values to assess exposure levels.
According to WHO recommendations, for the measurements, the equipment was placed at a central point in the space, about 1.5m from the floor, at a height closest to the occupant’s airways, at least 1 metre from sources of particulate matter and at least 1 metre from walls. [17].
For the analytical collection of the parameters evaluated, specific portable equipment of real time reading was used (Table 1).
The data collected during the study were statistically treated using Statistical Package for Social Sciences (IBM SPSS) software version 28.0 for Windows. A 95% confidence level and a random error of less than or equal to 5% were taken into account for the estimation of statistical inference.
A normality test was conducted and the data was found to follow a normal distribution. This allowed for the use of a linear correlation test for data analysis.
Pearson's correlation, also known as linear correlation, was performed in the statistical tests. It is a statistical measure that quantifies the linear relationship between two continuous variables. This correlation is represented by the Pearson correlation coefficient (r), whose value ranges between -1 and 1.
The reference values used to discuss the results are based on the American Conference of Governmental Industrial Hygienists - Threshold Limit Values (ACGIH – TLV) for PM10, PM2.5, CO and CO2. These buildings are being assessed from an occupational health perspective.
The provision of occupational health and safety measures to protect health workers is also fundamental to well-functioning and resilient health systems, quality of care and the maintenance of a productive health workforce. WHO work to protect the health and safety of health workers includes developing norms and standards for the prevention of occupational hazards in the health sector [18]. In the case of UFP, given the absence of guidelines, the values suggested by the WHO for prioritising the control of UFP emitting sources were used as reference values (Table 2) [9,15].
3. Results and Discussion
Table 3 presents the number of evaluations conducted at various sampling points. A total of 1926 measurements were taken.
The number of collections was determined based on the evaluation area, as well as the number of tasks and workplaces to be assessed. This explains the difference in the number of assessments. Out of a total of 1926 measurements, 58.1% were taken in the bakery, 35.7% in the carpentry, and 3.3% each in the school and health clinic. The language used is clear, concise, and objective, with a formal register and precise word choice. The sentence structure is simple and the information flows logically, with causal connections between statements. The text is free from grammatical errors, spelling mistakes, and punctuation errors. No changes in content were made as per the instructions.
Table 4 presents the results of indoor and outdoor measurements. The concentrations observed indoors suggest the presence of significant indoor sources of the pollutants. The outdoor air does not appear to contribute to the degradation of indoor air, as the pollutant values are lower in the outside environment. Therefore, we can conclude that higher ventilation levels could lead to an important contribution of outdoor air to the improvement of indoor air quality. The values for CO and CO2 show significant differences. The indoor and outdoor CO values are similar, while the indoor/outdoor CO2 values have greater differences, likely due to contamination by occupants.
The next step was to check compliance with the PM10 and PM2.5 standard according to the ACGIH - TLV guidelines. The figures found are somewhat interesting, as they are almost all within the guidelines limits, probably due to the collective protection systems (in the carpentry extraction located at dust producing workstations and forced ventilation in the bakery). In fact, only 0.3% of the values in PM2.5 and 0.1% in PM10 are over the guidelines limits (Table 5).
Upon checking the UFP values against WHO recommendations for 24-hour mean PNC levels, it appears that the recorded values are not favourable for the workers. More than half of the UFP measurements (53.4%, 1,028 occurrences) are medium values, while the remaining 46.6% (898 measurements) exceed the WHO recommendations for PNC 24-hour mean. The results suggest that individuals exposed to ultrafine particles (UFP) in their occupational environment may experience higher exposure levels compared to the background concentration (refer to Table 6). This implies that certain occupational activities or environments may have higher exposure to UFP. [5,17,20,21].
We then looked at UFP levels by workplace in line with WHO recommendations. As expected, carpentry is the one with the highest frequency of high values with 65.4%, followed by bakery with 38.6%. In the school and in the health clinic, values are similar although the lowest values are, as expected, in the school where offices and workrooms were monitored (Table 7). In the following results, we will look at how the generation of UFP can be verified in the different locations.
These values are in line with the literature presented, as carpentry is a primary source of UFP due to the tasks developed [3,5,22]. As mentioned before, UFP can be emitted directly from anthropogenic sources or combustions, or even more frequently in chemical reactions and dynamic processes such as nucleation, condensation, and coagulation. These cases can be the origin of the UFP found in this assessment [6,22,23,24,25].
Now analysing the workplaces in more detail, Table 8 shows the results of the measurements taken in the various sectors of each workplace.
To verify the exposure levels, we calculated the adjusted mean values of the measurement points and identified the minimum and maximum values recorded for the UFP.It can be confirmed that the highest average and maximum values align with what is expected based on the literature for the sources that generate UFP. The carpentry industry typically produces particles during sawing and painting tasks. It is important to note that this information is based on objective data from primary sources. The values for particle generation are in line with WHO average values, with assembly tasks producing lower levels. [13,23,26]. In the bakery, the production area stands out (average 36 209; maximum 86 846) and even higher the manufacturing (average 48 580) agreeing with the literature that refers to industrial and combustion activities as generating UFP [13,27,28,29]. As expected, the school, lacking primary sources of UFP, has average exposure levels. It is predictable that the highest levels would occur in industries where UFP are more likely to be generated or released, such as manufacturing, construction or mining. Work processes that involve activities such as cutting, grinding, burning or the use of certain chemicals may generate ultrafine particles (UFP) as by-products. This can lead to higher exposure of workers in these environments. It is important to note that UFP can have negative health effects on workers, making it crucial to implement proper safety measures. [5,7,20]. Contrary to initial expectations, the laboratories of the health clinic have very high values.
Finally, to better understand what is influencing the UFP, we checked Pearson's correlation between the pollutants assessed, including UFP, per assessment site (Table 9).
In this analysis we were able to verify a number of correlations, some of which were expected, but others were completely unexpected. In carpentry, as expected, there is a strong positive correlation between CO and UFP, as well as between RH and UFP. These results can probably be explained by the presence of combustion sources and humidity in the air, which favour the secondary formation of UFP. On the other hand, and from a less expected perspective, there is a strong negative correlation between UFP and T. Here, some of the studies that talk about the formation of UFP associate T with the agglutination of particles that can make them no longer long in the spectrum of ultrafine particles [11,19,22,37]. Another strongly negative correlation is that between UFP and CO2. As expected, this can be strongly influenced by the ventilation that takes place after painting by aerating the room; this air renewal can favour the improvement of UFP and CO2 levels. Also in carpentry, sawing, which includes sanding, shows a strong positive correlation with PM10 and PM2.5, in line with the direct formation of UFP. In assembly, this correlation is exactly the opposite, strongly negative, probably due to the lack of direct formation of UFP. There is no wood decomposition in this zone [7,15,28,32].
In the bakery, as expected, the greatest influence is from CO2, which in areas with a higher number of workers increases the UFP. These strongly positive correlations may be due to a greater formation of these particles as well as the tasks performed allow a greater permanence or elevation of these in the air. Interestingly, in manufacturing and production there is also a strong positive correlation with T. Is a local with relative high temperature, but with very large gradients, which may induce the presence of gaseous and other precursors for the formation of ultrafine particles by condensation of vapours or by favouring chemical reactions [3,6,25,27,33]. On the other hand, RH has a significant effect in the shipping area and less so in the production area. Again, this may be due to favouring condensation or secondary formation of UFP [34]. An unexpected influence was that of CO in the warehouse and office, which can only be justified by the contamination of the room, since it is closer to the oven area. This low occupancy is reflected in negative correlations with all other pollutants. In reality, this occupation is concentrated in the unloading of materials and the loading of raw materials into the production area, 3 to 4 times a day for short periods of time. The same reasoning applies to PM10, PM2.5 and CO2 in the office [8,20].
In the school the only correlation we found is of the remaining particulate matter PM10 and PM2.5 in the workrooms, this may be due to the movement of materials or people and the agitation in particulate matter that makes the occurrence of this in the air. As expected at the beginning of the study the UFP values are not very relevant in this activity [1,5].
In the health clinic, in the reception area, as in the school, the only positive correlation is with PM10 and PM2.5, most likely due to the movement of people. The strong positive correlation with CO2 was not expected in the laboratories. This must be due to the density of occupation of the space and the greater constraints on ventilation, avoiding contamination, for reasons of safety of samples and results. The less significant correlation with PM10 may be due to the presence and operation of equipment for the tasks.
4. Conclusions
The processed assessments enabled us to observe the relationship between UFP and commonly monitored parameters. A significant conclusion drawn from this study is that UFP levels are very high according to WHO values, while almost all other evaluated pollutants are within reference limits. The consulted studies confirm a positive correlation between the presence of UFP and secondary formation. This correlation is observed in cases where UFP is generated by dust or combustion of materials. Additionally, in some cases, RH can also favour the appearance of UFP.
The cross-sectional study comparing companies that generate UFP with those that do not has highlighted the need to control them in all locations.
UFP levels increase in carpentry and painting tasks due to dust production, combustion, and humidity leading to secondary formation of UFP. However, UFP levels decrease with temperature due to particle agglomeration.
The bakery achieved the expected manufacturing and production results, with primary and secondary particle generations corresponding to expectations. However, unexpected contamination was found in the office and warehouse. Dispatch operations can benefit from improved UFP levels through ventilation.
Surprisingly, workrooms in the school had high levels of UFP, which was unexpected.
The study's main finding was the high levels of UFP present in the health clinic, particularly in the laboratories. This is due to poor ventilation and occupation, which increases the risk of contamination.
The study also suggests that indoor sources are the primary cause of pollutants, as outdoor values are consistently lower.
It is important to note that while primary sources of UFP are related, they are not the only source of the problem. Many of our assessments emphasise the importance of controlling sources of PM that favour the formation of UFP.
Additionally, it is important to control other factors such as CO, CO2, temperature, and relative humidity as they are precursors to the formation of secondary UFP.
Key findings:
- Sources of UFP are indoor.
- All activities have high UFP levels.
- Activities without primary sources of UFP also have high levels compared to WHO guidelines.
- Occupancy rate, temperature and relative humidity are precursors of secondary UFP formation.
- Ventilation of rooms is of paramount importance to improve UFP parameters.
It is crucial to recognise the significance of controlling UFP for both human health and the environment. Due to their small size, with diameters of less than 0.1 micrometres, they can penetrate deep into the lungs and bloodstream, posing a serious health risk. Reducing UFP is challenging as they are not easily filtered out by conventional pollution control systems. There is an urgent need for standards and regulatory measures to control polluting sources or utilise more efficient emission control technologies. The importance of monitoring and controlling UFP should not be underestimated. Further and more in-depth studies on this subject are also necessary. In the future, the research team intends to continue evaluating UFP and carrying out further research into its health effects.
Author Contributions
F.M.M., A.F. and N.B. designed the study. F.M.M. Design the questionnaire, collected the data and performed the statistical analysis. F.M.M., A.F. and N.B. prepared the original draft of the manuscript. F.M.M., A.F. and N.B. critically interpreted the results, reviewed the draft version, and approved the final manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by the Coimbra Heath School of the Polytechnic Institute of Coimbra.
Institutional Review Board Statement
This study was authorised by the President of the Higher Education Institution (HEI) where the study was conducted, and the study protocol was approved by the HEI Data Protection Officer.
Informed Consent Statement
Informed consent was obtained from all the subjects involved in the study.
Data Availability Statement
The data presented in this study are available on request from the corresponding author.
Acknowledgments
The authors would like to thank all the professionals who participated in this work, in particular those who answered the questionnaire of this study. Special thanks are due to the researcher Nelson Barros and the FP-I3ID of the University Fernando Pessoa for their support.
Conflicts of Interest
The authors declare no conflict of interest. References must be numbered in order of appearance in the text (including citations in tables and legends) and listed individually at the end of the manuscript. We recommend preparing the references with a bibliography software package, such as EndNote, Reference Manager or Zotero to avoid typing mistakes and duplicated references. Include the digital object identifier (DOI) for all references where available.
References
- Monteiro F, Ferreira A, Moreira F. Indoor air quality in gyms - a case study in the county of Coimbra. Millenium - J Educ Technol Heal [Internet]. 2018;2(02):111–20. Available from: https://doaj.org/article/a8288175b34648be974aab77cdf840eb.
- Kembel SW, Jones E, Kline J, Northcutt D, Stenson J, Womack AM, Bohannan BJM, Brown GZ, Green JL. Architectural design influences the diversity and structure of the built environment microbiome. ISME J. 2012;1469–79. [CrossRef]
- Viitanen AK, Uuksulainen S, Koivisto AJ, Hämeri K, Kauppinen T. Workplace measurements of ultrafine particles-A literature review. Ann Work Expo Heal. 2017;61(7):749–58. [CrossRef]
- Pasquiou A, Pelluard F, Manangama G, Brochard P, Audignon S, Sentilhes L, Delva F. Occupational exposure to ultrafine particles and placental histopathological lesions: A retrospective study about 130 cases. Int J Environ Res Public Health [Internet]. 2021;18(23). Available from: https://eds.s.ebscohost.com/eds/pdfviewer/pdfviewer?vid=0&sid=ef1c257c-a2ad-40da-a432-faed9fe2711a%40redis.
- Marval J, Tronville P. Ultrafine particles: A review about their health effects, presence, generation, and measurement in indoor environments. Build Environ [Internet]. 2022;216(March):108992. [CrossRef]
- Jones NC, Thornton CA, Mark D, Harrison RM. Indoor/outdoor relationships of particulate matter in domestic homes with roadside, urban and rural locations. Atmos Environ. 2000 Jan 1;34(16):2603–12. [CrossRef]
- Ferreira Martins V. Air quality in subway systems: particulate matter concentrations, chemical composition, sources and personal exposure. TDX (Tesis Dr en Xarxa) [Internet]. 2016 Apr 27 [cited 2019 Apr 23];Ferreira Martins, V. (2016). Air quality in subway. Available from: http://www.tesisenred.net/handle/10803/399787.
- Kirešová S, Guzan M, Sobota B. Using Low-Cost Sensors for Measuring and Monitoring Particulate Matter with a Focus on Fine and Ultrafine Particles. 2023;1–22. [CrossRef]
- Castro AH, Silva GM, Araújo RS. Qualidade Do Ar – Parâmetros De Controle E Efeitos Na Saúde Humana: Uma Breve Revisão. Holos [Internet]. 2014;5(5):107. Available from: http://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=92954858&site=eds-live.
- Sousa M, Arezes P, Silva F. Occupational exposure to ultrafine particles in metal additive manufacturing: A qualitative and quantitative risk assessment. Int J Environ Res Public Health. 2021;18(18). [CrossRef]
- Fireman E, Edelheit R, Stark M, Shai AB. Differential pattern of deposition of nanoparticles in the airways of exposed workers. J Nanoparticle Res. 2017;19(2). [CrossRef]
- Kranjec N, Galičič A, Eržen I, Kukec A. The impact of ultrafine particles on daily counts of deaths from respiratory diseases in the Municipality of Ljubljana: A temporal variability study - Sanitarno Inženirstvo. 2016;10(1):35–48. Available from: https://journal.institut-isi.si/impact-ultrafine-particles-daily-counts-deaths-respiratory-diseases-municipality-ljubljana-temporal-variability-study/.
- Audignon-Durand S, Gramond C, Ducamp S, Manangama G, Garrigou A, Delva F, Brochard P, Lacourt A. Development of a Job-Exposure Matrix for Ultrafine Particle Exposure: The MatPUF JEM. Ann Work Expo Heal. 2021;65(5):516–27. [CrossRef]
- Cassee FR, Morawska L, Peters A, (Eds). White Paper on Ambient ultrafine particles: evidence for policy makers. “Thinking Outs box” Team [Internet]. 2019;33. Available from: https://efca.net/files/WHITE PAPER-UFP evidence for policy makers (25 OCT).pdf.
- Boudjema J, Lima B, Grare C, Alleman LY, Rousset D, Perdrix E, Achour D, Anthérieu S, Platel A, Nesslany F, Leroyer A, Nisse C, Lo Guidice JM, Garçon G. Metal enriched quasi-ultrafine particles from stainless steel gas metal arc welding induced genetic and epigenetic alterations in BEAS-2B cells. NanoImpact. 2021;23(August). [CrossRef]
- Jordakieva G, Grabovac I, Valic E, Schmidt KE, Graff A, Schuster A, Hoffmann-Sommergruber K, Oberhuber C, Scheiner O, Goll A, Godnic-Cvar J. Occupational exposure to ultrafine particles in police officers: No evidence for adverse respiratory effects. J Occup Med Toxicol. 2018;13(1):1–10. [CrossRef]
- WHO. WHO global air quality guidelines. Coast Estuar Process. 2021;1–360.
- Wolf J, Prüss-Ustün A, Ivanov I, Mudgal S, Corvalán C BR et al. Preventing Disease Through a Healthier and Safer Workplace [Internet]. World Health Organization. 2018. 1–86 p. Available from: https://apps.who.int/iris/bitstream/handle/10665/272980/9789241513777-eng.pdf.
- World Health Organization. Methods for sampling and analysis of chemical pollutants in indoor air [Internet]. 2020. 55 p. Available from: https://www.euro.who.int/en/health-topics/environment-and-health/air-quality/publications/2020/methods-for-sampling-and-analysis-of-chemical-pollutants-in-indoor-air-supplementary-publication-to-the-screening-tool-for-assessment-of-health-risks-from-combi.
- Eshleman EJ, LeBlanc M, Rokoff LB, Xu Y, Hu R, Lee K, Chuang GS, Adamkiewicz G, Hart JE. Occupational exposures and determinants of ultrafine particle concentrations during laser hair removal procedures. Environ Heal A Glob Access Sci Source. 2017;16(1):1–7. [CrossRef]
- Geiss O, Bianchi I, Barrero-Moreno J. Lung-deposited surface area concentration measurements in selected occupational and non-occupational environments. J Aerosol Sci [Internet]. 2016;96:24–37. [CrossRef]
- Zhao Y, Wang F, Zhao J. Size-Resolved Ultrafine Particle Deposition and Brownian Coagulation from Gasoline Vehicle Exhaust in an Environmental Test Chamber. Environ Sci Technol. 2015;49(20):12153–60. [CrossRef]
- Ragde SF, Jørgensen RB, Føreland S. Characterisation of Exposure to Ultrafine Particles from Surgical Smoke by Use of a Fast Mobility Particle Sizer. Ann Occup Hyg. 2016;60(7):860–74. [CrossRef]
- Marcias G, Casula MF, Uras M, Falqui A, Miozzi E, Sogne E, Pili S, Pilia I, Fabbri D, Meloni F, Pau M, Sanna AM, Fostinelli J, Massacci G, D’aloja E, Filon FL, Campagna M, Lecca LI. Occupational fine/ultrafine particles and noise exposure in aircraft personnel operating in airport taxiway. Environ - MDPI. 2019;6(3). [CrossRef]
- Manigrasso M, Protano C, Vitali M, Avino P. Where Do Ultrafine Particles and Nano-Sized Particles Come From? J Alzheimer’s Dis [Internet]. 2019;68(4):1371–90. Available from: https://search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=136018353&site=eds-live.
- Trechera P, Moreno T, Córdoba P, Moreno N, Zhuang X, Li B, Li J, Shangguan Y, Dominguez AO, Kelly F, Querol X. Comprehensive evaluation of potential coal mine dust emissions in an open-pit coal mine in Northwest China. Int J Coal Geol. 2021;235. [CrossRef]
- Marcias G, Fostinelli J, Catalani S, Uras M, Sanna AM, Avataneo G, De Palma G, Fabbri D, Paganelli M, Lecca LI, Buonanno G, Campagna M. Composition of metallic elements and size distribution of fine and ultrafine particles in a steelmaking factory. Int J Environ Res Public Health. 2018;15(6). [CrossRef]
- Eshleman EJ, LeBlanc M, Rokoff LB, Xu Y, Hu R, Lee K, Chuang GS, Adamkiewicz G, Hart JE. Occupational exposures and determinants of ultrafine particle concentrations during laser hair removal procedures. Environ Heal [Internet]. 2017 Dec 29;16(1):30. Available from: https://ehjournal.biomedcentral.com/articles/10.1186/s12940-017-0239-z.
- Wallace L, Howard-Reed C. Continuous Monitoring of Ultrafine, Fine, and Coarse Particles in a Residence for 18 Months. J Air Waste Manage Assoc [Internet]. 2002;52(7):828–44. Available from: https://www.tandfonline.com/action/journalInformation?journalCode=uawm20.
- European Parliament and Council. Proposal for a Directive of the European Parliament and of The Council on Ambient Air Quality and Cleaner Air for Europe. 2022;0347.
- Sanchez-Crespo A. Lung Scintigraphy in the Assessment of Aerosol Deposition and Clearance. Semin Nucl Med [Internet]. 2019;49(1):47–57. [CrossRef]
- Li Y, Li P, Yu H, Bian Y. Recent advances (2010-2015) in studies of cerium oxide nanoparticles’ health effects. Environ Toxicol Pharmacol [Internet]. 2016;44:25–9. [CrossRef]
- Hussein T, Glytsos T, Ondráček J, Dohányosová P, Ždímal V, Hämeri K, Lazaridis M, Smolík J, Kulmala M. Particle size characterization and emission rates during indoor activities in a house. Atmos Environ. 2006 Jul 1;40(23):4285–307. [CrossRef]
- Songmene V, Kouam J, Bahloul A. Effect of minimum quantity lubrication (MQL) on fine and ultrafine particle emission and distribution during polishing of granite. Meas J Int Meas Confed [Internet]. 2018;114(17):398–408. 20 June. [CrossRef]
Table 1.
Monitoring equipment.
| Equipment | Pollutant | Equipment Range |
|---|---|---|
| TSI Q-Track Plus | CO | 0 -500 ppm |
| CO2 | 0–5000 ppm | |
| T | 0–50 oC | |
| RH | 5–95 %RH | |
| P-Trak Ultrafine Particle Counter - 8525 | UFP | 0–5x105 PNC |
| Lighthouse, model 3016 IAQ | PM10 | 0–350 mg.cm-3 |
| PM2.5 | 0–350 mg.cm-3 |
Table 2.
Guidelines /recommended concentrations.
| Pollutant | Limit/Recommended Values | Standard /recommendation |
|---|---|---|
| CO (ppm/8h) | 30 | ACGIH – TLV |
| CO2 (ppm/8h) | 1000 | ACGIH – TLV |
| T (ºC) | 22 | ILO |
| RH (%) | 65 | ILO |
| UFP (PNC 24h mean) | < 1000 Low | WHO |
| 1001 – 9999 Medium | ||
| > 10000 High | ||
| PM10 (ug.m-3/8h) | 10 | ACGIH – TLV |
| PM2.5 (ug.m-3/8h) | 3 | ACGIH – TLV |
PNC - Particle number concentration - WHO 2021. ILO – International Labour Organization
Table 3.
Total of measures performed per workplace.
| Workplace | Number of evaluation points | Frequency (%) |
|---|---|---|
| Carpentry | 630 | 32.7 |
| Bakery | 1 170 | 60.8 |
| School | 63 | 3.3 |
| Health Clinic | 63 | 3.3 |
| Total | 1 926 | 100.0 |
Table 4.
Indoor to outdoor concentration levels comparison.
| Pollutants | Indoor/Outdoor | N | Mean | Std. Deviation |
|---|---|---|---|---|
| PM10 (ug.m-3) | Indoor | 1 926 | 0.0496 | 0.254 |
| Outdoor | 1 926 | 0.0153 | 0.004 | |
| PM2.5 (ug.m-3) | Indoor | 1 926 | 0.3760 | 1.003 |
| Outdoor | 1 926 | 0.0887 | 0.413 | |
| CO (ppm) | Indoor | 1 926 | 2.0 | 0.210 |
| Outdoor | 1 926 | 1.9 | 0.091 | |
| CO2 (ppm) | Indoor | 1 926 | 553 | 239.075 |
| Outdoor | 1 926 | 351 | 21.784 | |
| UFP (PNC) | Indoor | 1 926 | 24 487 | 27 216.882 |
| Outdoor | 1 926 | 2 513 | 2 709.181 |
PNC - particle number concentration - WHO 2021.
Table 5.
Comparison of observed PM values with guidelines values.
| Occurrence | Frequency (%) | ||
|---|---|---|---|
| PM2.5 | Above Limit | 6 | 0.3 |
| Below limit | 1 920 | 99.7 | |
| Total | 1 926 | 100.0 | |
| PM10 | Above Limit | 2 | 0.1 |
| Below limit | 1 924 | 99.9 | |
| Total | 1 926 | 100.0 |
Table 6.
Observed UFP levels and WHO recommendations.
| WHO PNC recommended value (24h mean) | Occurrence | Frequency (%) | |
|---|---|---|---|
| UFP (PNC) | 1001 - 9999 - Medium | 1 028 | 53.4 |
| >10000 - High | 898 | 46.6 | |
| Total | 1 926 | 100.0 |
Table 7.
Results in different sectors compared with WHO recommendations.
| WHO PNC recommended value (24h mean) | Occurrence | Frequency (%) | |
|---|---|---|---|
| Carpentry | 1 001 – 9 999 – Medium | 218 | 34.6 |
| >10 000 - High | 412 | 65.4 | |
| Total | 630 | 100.0 | |
| Bakery | 1 001 – 9 999 - Medium | 718 | 61.4 |
| >10 000 - High | 452 | 38.6 | |
| Total | 1 170 | 100.0 | |
| School | 1 001 – 9 999 - Medium | 52 | 82.5 |
| >10 000 - High | 11 | 17.5 | |
| Total | 63 | 100.0 | |
| Health Clinic | 1 001 – 9 999 - Medium | 40 | 63.5 |
| >10 000 - High | 23 | 36.5 | |
| Total | 63 | 100.0 |
Table 8.
Average all measures per assessment (24 hours), maximum and minimum PNC of UFP by workplace and activities.
Table 8.
Average all measures per assessment (24 hours), maximum and minimum PNC of UFP by workplace and activities.
| Average | Minimum | Maximum | ||
|---|---|---|---|---|
| Carpentry | Paint | 42 612 | 3 331 | 140 883 |
| Sawing | 45 711 | 8 115 | 153 566 | |
| Assembly | 8 313 | 1 799 | 48 426 | |
| Bakery | Manufacture | 48 580 | 22 308 | 139 233 |
| Production | 36 209 | 16 356 | 86 846 | |
| Dispatch | 5 578 | 2 882 | 9 964 | |
| Warehouse | 5 038 | 2 410 | 10 138 | |
| Office | 3 107 | 1 092 | 5 036 | |
| School | Offices | 2 970 | 1 574 | 70 730 |
| Workrooms | 5 298 | 1 467 | 87 653 | |
| Health Clinic | Reception | 4 776 | 2 397 | 12 384 |
| Laboratory | 22 698 | 1 315 | 114 248 |
Table 9.
Correlations between UFP and other pollutants.
| CO | CO2 | PM10 | PM2.5 | RH | T | |||
|---|---|---|---|---|---|---|---|---|
| Carpentry | Paint | r | 0.819** | -0.702** | -0.020 | 0.030 | 0.860** | -0.895** |
| Sig. (2-tailed) | 0.000 | 0.000 | 0.750 | 0.710 | 0.000 | 0.000 | ||
| N | 210 | 210 | 210 | 210 | 210 | 210 | ||
| Sawing | r | -0.050 | 0.010 | 0.524** | 0.718** | 0.026 | -0.004 | |
| Sig. (2-tailed) | 0.480 | 0.900 | 0.000 | 0.000 | 0.708 | 0.957 | ||
| N | 210 | 210 | 210 | 210 | 210 | 210 | ||
| Assembly | r | -0.090 | -0.060 | -0.292** | -0.530** | 0.049 | -0.029 | |
| Sig. (2-tailed) | 0.190 | 0.430 | 0.000 | 0.000 | 0.480 | 0.678 | ||
| N | 210 | 210 | 210 | 210 | 210 | 210 | ||
| Bakery | Manufacture | r | 0.100 | 0.788** | -0.140 | 0.050 | 0.192* | 0.491** |
| Sig. (2-tailed) | 0.230 | 0.000 | 0.100 | 0.520 | 0.019 | 0.00 | ||
| N | 150 | 150 | 150 | 150 | 150 | 150 | ||
| Production | r | 0.050 | 0.524** | 0.783** | 0.100 | -0.075 | 0.824** | |
| Sig. (2-tailed) | 0.410 | 0.000 | 0.000 | 0.080 | 0.198 | 0.00 | ||
| N | 300 | 300 | 300 | 300 | 300 | 300 | ||
| Dispatch | r | -0.210** | 0.321** | 0.010 | 0.386** | 0.413** | -0.084 | |
| Sig. (2-tailed) | 0.010 | 0.000 | 0.880 | 0.000 | 0.000 | 0.304 | ||
| N | 150 | 150 | 150 | 150 | 150 | 150 | ||
| Warehouse | r | 0.889** | -0.162** | -0.564** | -0.645** | -0.641** | -0.303** | |
| Sig. (2-tailed) | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.00 | ||
| N | 300 | 300 | 300 | 300 | 300 | 300 | ||
| Office | r | 0.533** | -0.251** | -0.731** | -0.722** | 0.049 | -0.005 | |
| Sig. (2-tailed) | 0.000 | 0.000 | 0.000 | 0.000 | 0.420 | 0.938 | ||
| N | 270 | 270 | 270 | 270 | 270 | 270 | ||
| School | Offices | r | 0.120 | 0.160 | -0.090 | -0.060 | 0.217 | 0.100 |
| Sig. (2-tailed) | 0.550 | 0.440 | 0.640 | 0.770 | 0.276 | 0.621 | ||
| N | 27 | 27 | 27 | 27 | 27 | 27 | ||
| Services | r | 0.020 | -0.290 | 0.586** | 0.781** | 0.109 | -0.226 | |
| Sig. (2-tailed) | 0.920 | 0.080 | 0.000 | 0.000 | 0.526 | 0.185 | ||
| N | 36 | 36 | 36 | 36 | 36 | 36 | ||
| Health Clinic | Reception | r | -0.130 | 0.320 | 0.618** | 0.739** | 0.073 | -0.037 |
| Sig. (2-tailed) | 0.430 | 0.050 | 0.000 | 0.000 | 0.672 | 0.832 | ||
| N | 36 | 36 | 36 | 36 | 36 | 36 | ||
| Laboratory | r | -0.030 | 0.750** | 0.445* | 0.26 | -0.004 | 0.016 | |
| Sig. (2-tailed) | 0.860 | 0.000 | 0.020 | 0.190 | 0.985 | 0.936 | ||
| N | 27 | 27 | 27 | 27 | 27 | 27 |
Test: Pearson Correlation. **. Correlation is significant at the 0.01 level (2-tailed). *. Correlation is significant at the 0.05 level (2-tailed).
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