Effects of Chalk Use on Dust Exposure and Classroom Air Quality (original) (raw)
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Environmental monitoring and assessment, 2009
The study was undertaken to examine the nature of particulate chalk dust settled on classroom floor during traditional teaching with dusting and non-dusting chalks on two types of boards viz. rough and smooth. Settling chalk particles were collected for 30 min during teaching in glass Petri plates placed in classrooms within 3 m distance from the teaching boards. Particle size distribution, scanning electron microscopic images of chalk dusts and compressive strength of two types of chalks were tested and evaluated. Results showed that a larger proportion of dusts generated from anti-dusting chalks were of <4.5 and <2.5 μm size on both smooth and rough boards, as compared to dusting chalks. Non-dusting chalks, on an average, produced about 56% and 62% (by volume) of <4.5 μm (respirable) diameter, on rough and smooth boards, respectively, while the corresponding values for dusting chalks were 36% and 45%. Also, on an average, 83% and 94% (by volume) of the particles were <11 μm (thoracic) in case of non-dusting chalks against 61% and 72% for dusting chalks on rough and smooth boards, respectively. Interestingly, taking into account the mass of chalk dust produced per unit time, which was higher in dusting chalks than non dusting chalks, the former was actually producing higher amount of PM <4.5 and <11 particles from both types of boards. Scanning electron microscope images revealed that chalk particles had random shape, although in dusting chalks prevalence of elongated particles was observed, apparently due to the longitudinal breaking of the chalks during writing, which was confirmed during compressive strength testing. We could conclude that dusting chalks could be potentially more harmful than anti dusting chalks, as they produced higher amount of potentially dangerous PM 4.5 and PM 11.
A PRELIMINARY STUDY ON THE EFFECT OF CHALK DUST ON HUMAN HEALTH
International Journal of Zoology and Applied Biosciences, 2022
The chalk used in educational institutions is of two types, dusting chalk and non-dusting chalk. The regular dusting chalk produces a finer and lighter dust, which is more likely to linger in the air and be breathed in. Non-dusting chalks produce a heavier dust that is less likely to linger in the air. In most of the cases, a lot of the dust is heavier and do not tend fly at all. It is very similar to the regular dusting chalk and still creates dust. The ultimate difference lies in the fact how fine the dust is. Since the dusting chalk paves the way for many allergies this was becoming a problem. But on the other hand, the nondusting chalks have more chemical composition when compared to dusting chalk. As both the chalks have different compositions, they have their own effect on human health. The present study explores human exposure to the harmful dust when chalk is used for teaching. In this study, a preliminary attempt was made to observe the varied responses of people of various age groups to share their responses on the effects of chalk in their lives through a structured survey. Various health issues caused were reported based upon the dust they were exposed to and concluded accordingly.
Trace Elemental Characterization of Chalk Dust and Their Associated Health Risk Assessment
It is evident that chalk produces dust on use, i.e., particulate matter, which will alter the air quality of classrooms and can cause health hazards in teachers. The possible causes for health effects of chalk dust on teachers are still unclear. Hence, the aim of this study is to estimate the concentration of trace elements (Al, Cr, Mn, Fe, Co, Ni, Si, Pb) in chalk dust collected from classrooms by using ICP-MS. Both suspended and settled chalk dust was collected from selected classrooms. Suspended chalk dust was collected with PM2.5 filter paper using fine dust sampler, and settled chalk dust was collected by placing petriplates at a distance of 3 m from the board for a duration period of 30 min. Scanning electron microscopy images of chalk dust were taken up. Potential health risk analysis was also assessed. Results showed that Al, Fe, and Mn are in higher concentration (>1000 μg kg −1 ) in both settled and suspended chalk dust. Cr, Mn, Fe, Co, and Ni were beyond the minimal risk levels in both settled and suspended chalk dust. There are no minimal risk levels for the elements Al, Si, and Pb. The concentration of trace elements in suspended chalk dust was higher than that in settled chalk dust. The SEM images of PM2.5 filter papers (suspended chalk dust) showed that all pores of the sampled filter papers are clogged with chalk dust. The few SEM images of the settled chalk dust showed fibrous shape which is associated with good-quality chalk whereas others showed circular and more aggregated nature of chalk dust from low-quality chalk
Impact of Ventilation on the Indoor Particulate Matter Concentrations in a School
2017
Indoor air quality in schools is one of the main concerns for the health of children. Inside a classroom there are high levels of different pollutants concentrations along with high levels of particulate matter (PM). Many studies showed that PM can severely affect the health of children, especially those with asthma problems. In this article an experimental campaign was conducted in two identical classrooms as size, orientation and number of persons with the purpose to evaluate the PM concentration. The only difference is one classroom is ventilated with fresh air while the other one is not. With two GRIMM measurement equipment we have measured for two days the indoor levels. In fact, the ventilation system was found efficient especially for larger particles (PM10) of dust while for smaller ones (PM1) the results were similar. We have calculated a reduction of PM concentration of 10%,...,12% on the mean values. It is concluded that ventilation of schools has multiple benefits on the...
Particulate matter mass concentration (PM10) under different ventilation methods in classrooms
Recently, studies have shown that the classroom environment is very important for students' health and performance. Thus, the evaluation of indoor air quality (IAQ) in a classroom is necessary to ensure students' well-being. In this paper the emphasis is on airborne concentration of particulate matter (PM) in adult education rooms. The mass concentration of PM 10 particulates was measured in two classrooms under different ventilation methods in the University of Reading, UK, during the winter period of 2008. In another study the measurement of the concentration of particles was accompanied with measurements of CO 2 concentration in these classrooms but this study is the subject of another publication. The ambient PM 10 , temperature, relative humidity, wind speed and direction, and rainfall events were monitored as well. In general, this study showed that outdoor particle concentrations and outdoor meteorological parameters were identified as significant factors influencing indoor particle concentration levels. Ventilation methods showed significant effects on air change rate and on indoor/outdoor (I/O) concentration ratios. Higher levels of indoor particulates were seen during occupancy periods. I/O ratios were significantly higher when classrooms were occupied than when they were unoccupied, indicating the effect of both people presence and outdoor particle concentration levels. The concentrations of PM 10 indoors and outdoors did not meet the requirements of WHO standards for PM 10 annual average.
Investigation of Particulate Matters of the University Classroom in Slovakia
Energy Procedia, 2016
University students spend most of their time in classrooms that do not always represent an ideal environment for education. This is mainly due to the fact that most university buildings in Slovakia are old. Classrooms can be contaminated by various indoor pollutants, such as allergens, particles, volatile organic compounds etc. Indoor air pollution can lead to long-term and short-term health problems for students and staff but also can lead to decreasing productivity. It is therefore essential to deal with the monitoring of indoor environmental quality in universities in Slovakia and propose realizable measures to improve this situation. The aim of this study is to investigate the particulate matters. The measurements were carried out in the university classroom during lessons. These measurements were repeated during to lessons carried out once a week for the duration of one month. Handheld 3016 IAQ-device was used for determination of particulate matter concentrations. Air temperature and relative humidity was set with multifunction device Testo 435-4. Questionnaire survey based on subjective perception of indoor environmental quality was also performed during this study. Students fill in these questionnaires at the beginning and at the end of lessons. Analysis was used for investigation of occurrence of PM concentrations and subjective evaluation of students.
Children exposure to atmospheric particles in indoor of Lisbon primary schools
Atmospheric Environment
Evidence continues to emerge showing that poor Indoor Air Quality (IAQ) can cause illness requiring absence from schools, and can cause acute health symptoms that decrease students’ performance. Since children spend on average 7–11 h per weekday at school, the IAQ in classrooms is expected to play a key role in the assessment of the effects of their personal exposure to air pollution. Within this context the present study was conducted in order to fulfill three primary objectives 1) to measure the levels and the element composition of PM2.5 and PM2.5–10, in three primary schools placed in Lisbon, in order to assess the children exposure to these pollutants; 2) to study the relationship between indoor and outdoor atmospheric particles concentrations and 3) to investigate the sources of high aerosols concentrations in classrooms. In the studied classrooms, the concentrations of coarse particles significantly exceeded the ambient levels. Element concentrations suggested that the physical activity of students highly contributed to the re-suspension of sedimented particles. The high levels of CO2 indicated that in these schools the ventilation was inadequate. This fact contributed to the establishment of poor IAQ.► In classrooms, PM2.5–10 concentrations significantly exceed the ambient concentrations. ► Physical activity of the children led to re-suspension and increased levels of particles. ► In classrooms, mineral dust, building materials and chalk are important sources of particles. ► High CO2 levels indicate that inadequate ventilation contributes for poor IAQ. ► Measurements of outdoor particles do not provide an accurate estimation of children’s exposure.
Indoor Air, 1998
Insufficient cleaning may be a cause of the Sick Building Syndrome. Various improvements in cleaning methods have been tested in order to clarify whether they reduced the concentration of airborne dust, and the concentration of dust on surfaces, or whether the concentration of different microbiological components in the dust was reduced. The interventions were performed in an administration building, a school and a kindergarten. Dust measurements were performed on one day every week for a period of 28 weeks, using different interventions. The airborne dust concentration was measured by sampling on filters during the day. The concentration of surface dust was measured by the BM-Dustdetector foil sampling method. Dust samples were collected from the floors, after which analyses for different microbiological components were performed. Sampling from surfaces and the floor were performed prior to cleaning in order to ascertain the levels to which the room occupants had been exposed. One of the findings was a reduction in the dust concentration on the so-called easily accessible surfaces. Correlations between surface dust and airborne dust were also found. Furthermore, correlations between the measurements and other factors, such as activity during the day, and the climate, were obtained. Important findings of the study were the observations made on the relations between cleaning and dust in the indoor environment and the measuring methods applied.