A comparative study on air quality at St.Michael School

Abstract

The project aims to analyze the air at St.Michael School for around 400hrs (17 days) by measuring Nitrogen Oxide gas (NO ₂ ), VOC, Carbon Dioxide gas (CO ₂ ), PM1, PM2.5, PM4, and PM10. This study was carried out to sensitize the social community such as the St.Venera local council and the school community about the air breathed by a population of 400 persons for 35 hours and 36 weeks per year. This study was in collaboration with other schools in Malta and Gozo, so it will also be a comparative study based on geographic location. This study will also compare results from a previous study on air quality. The project aims to analyze the air quality at St. Michael School over approximately 400 hours (17 days) by measuring the levels of nitrogen dioxide (NO2), volatile organic compounds (VOCs), carbon dioxide (CO2), and particulate matter (PM1, PM2.5, PM4, and PM10). The study was conducted to raise awareness within the community, including the St. Venera local council and the school community, about the air inhaled by a population of 400 individuals for 35 hours per week over 36 weeks per year. This research was carried out in collaboration with other schools in Malta and Gozo, allowing for a comparative analysis based on geographic differences. Additionally, the study will compare its findings with those from a previous air quality study conducted in 2021. Results indicate that St. Michael School has some of the highest concentrations of NO2 and particulate matter levels. This study provides evidence supporting these findings and proposes actions to reduce NO2 levels at both the national and local levels, particularly around the school carried out on 2021. Results indicated that St Michael School has among the highest concentrations of NO ₂  levels and PM levels. This study provides evidence which supports the results obtained. It also proposes actions on how NO ₂  can be lower at both national and local levels, especially around the school.

Key words: Air quality, Nitrogen Dioxide, Emissions, Clouds, Temperature, Traffic, Atmosphere, Carbon Dioxide, PM1, PM2.5, PM4, PM10, VOC, Airborne Particular matter (PM).

Hypothesis: Our school is situated in a busy and urbanized area. Previous study of 4 years ago noted a high level of NO ₂ . Based on geographical location, the NO ₂  , TVOC and PM levels will be high.

Research Questions

What is the effect of air pollution from traffic around the school? A similar project was carried out 4 years ago. Comparing the results, was there any difference in Nitrogen levels? The PM levels are within limits? Is there any relation between NO ₂  levels and PM levels? Does temperature, Humidity, and Rain affect air quality? And what is the effect of pollution on such parameters?

Urbanization and high dependency on private cars are causing an increase in nitrogen levels. Supported with the knowledge obtained by the students during sharing of ideas during meetings with their collaborating partners together with the research conducted on air quality, it was concluded that nitrogen dioxide level and PM levels around the school are high. Introduction

The aim of this study was to find the level of NO ₂  gases and VOC, CO ₂  and PM levels present in the air around the school and how this has changed since its reading was last recorded (4 years ago). The observation and monitoring period was between November 2024 and December 2024 and readings were taken from 1 site in the school facing a busy main road. Nitrogen dioxide (NO ₂ ) gas is an increasing problem for air quality all over the world. Gas can cause serious problems such as lung damage, acid smog or rain. As little as 50 ppb can cause airway inflammation in lungs. NO ₂  primarily gets in the air from the burning of fuel. NO ₂  forms from emissions from cars, trucks and buses, power plants, and off-road equipment. Our school is situated in a busy and urbanized area. Previous studies noted a high level of NO ₂ . Volatile organic compound (VOC) are organic chemical compounds that under normal conditions are gaseous or can vaporise and enter the atmosphere. VOCs include such compounds as methane, benzene, xylene, propane and butane. Exposure to very high levels of VOCs may cause damage to the liver, kidney, or central nervous system (brain and spinal cord). High levels may also cause vision and memory problems. VOCs are a class of chemicals, not a single chemical. Some are known to be highly toxic while others have no known health effects. PM stands for particulate matter (also called particle pollution): the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Exposure to such particles can affect both your lungs and your heart. Numerous scientific studies have linked particle pollution exposure to a variety of problems, including premature death in people with heart or lung disease, nonfatal heart attacks, irregular heartbeat, aggravated, astma decreased lung function, increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. People with heart or lung diseases, children, older adults, minority populations, and low socioeconomic status populations are the most likely to be affected by particle pollution exposure, either because they are more sensitive or may have higher exposures. Indoor CO ₂  levels are generally higher than outdoor levels due to CO ₂  exhaled by occupants. It should be noted that there can be harmful impacts when concentrations are higher than about 1000 ppm such as health risks and reduced work efficiency. This study was done to increase awareness of the large number of harmful gases which are found near the school’s premises. It was also carried out to show that climate change is upon us, and action must be taken to reduce the presence of these gases. Additionally, readings for other factors, of which weather parameters, were also measured and reported. A barometer was used to measure the air pressure, a thermometer was used to measure the temperature, and a measuring cylinder was used to measure the amount of rainfall. The wind direction was also recorded as it could have had an impact on the results.

When the readings for the NO ₂  gases were taken, these were sent to a lab in Switzerland. The results indicated that NO ₂  levels are like those of 2021 which means pollution is still quite worrying.

Study site:

Our school is physically built in an urban environment, near two separate industrial areas and a main traffic artery which is laden with heavy traffic during most of the day.

The students identified 4 study sites around the school (Figure 1). The school has been supplied with a diffusion tube from Passam Laboratories in Switzerland, and this has been put up in front of school gate (Roadside) (Red). The VOC, CO2 and PM were monitored by a monitor with different sensors in the computer lab near an open window facing the same street. (Purple)

Weather parameters, such as cloud cover and sky conditions, air temperature, wind, rainfall, and humidity, were measured from the school roof using GLOBE Protocols. (Yellow). The car count was taken in front of the gate every day. (Blue)

Apparatus used:

Data loggers to measure air temperature, humidity and air pressure.

Rain Gauge

GLOBE Observer App to record cloud type and cover

1 Diffusion tube

Air quality monitor

Stopwatch

Data sheets

Clipboard and pen

Methodology: Every day from 11 ^th  November 2024 till 6 ^th  December 2024, the students took rainfall readings together with the air temperature, humidity and air pressure. They also observed the cloud cover using the GLOBE Observer App and described the general outlook of the weather and surface conditions following the steps of the GLOBE Protocols (GLOBE, 2014). During the same observation period the student carried a traffic count in front of the school using a stopwatch for 5 minutes. Everyday students also noted the results from the air quality monitor. (Figure 3 and 4) The diffusion tube, which measures NO ₂  gas, was put up on Monday 11 ^th  November at 08:00, in front of the school gate facing the main road. (Figure 2) The site was the same as the one used in a similar analysis done 4 years ago. The tube was numbered and marked with a special code provided by the laboratory. This was sponsored by ERA (Environment and Resources Authority).

The project was carried out in collaboration with 9 other schools across Malta and Gozo, sister island to Malta. The readings of the car count were taken in the morning. On the 6th of December, the tube was sent to Passam Laboratory in Switzerland for analysis together with those of Gozo and other Maltese Schools. Readings of humidity, rain, pressure, and cloud observations were taken around noon during the midday break. Other air quality parameters were taken during the day using another monitor with different sensors. (Figure 5)

Data Analysis:

All data collected (Air Temperature, Barometric Pressure, Humidity, Rainfall, Wind, Visibility, Car count, VOC, CO ₂ , PM) was recorded on a template and uploaded on GLOBE database through the Data Entry tool on the GLOBE Observer App. The diffusion tube was sent abroad for analysis and received by email after three weeks. Data collected was compared with a previous study which was carried out 4 years ago at our school which again focused on air quality, mainly NO ₂  only. Results:

The screenshots below show data uploaded on GLOBE website during observation period between November 2024 and December 2024 (Figures 6, 7, 8, 9, 10, 11). Students collected daily readings of air temperature, barometric pressure, humidity, rainfall and cloud cover and type together with surface conditions following GLOBE Protocols guide. All readings are shown in Table 1, 2, 3, 4. Graphs from Air monitoring apparatus where plotted showing the observation period (Figure 12)

 Table 1: Data Sheet – Atmospheric conditions and Cloud Type

Table 2: Data Sheet – Air quality parameters

Table 3: Data Sheet – NO2 results from different schools

Table 4: Data Sheet – Car count

Figure 12 Screenshots showing Air Quality parameters throughout the study

Discussion

The results obtained were discussed between all schools involved via Skype. Unfortunately, our school re-recorded almost the highest level of Nitrogen Dioxide among all schools. Having the data in our hands we did a comparative study between this study on air quality and a similar study of 4 years ago. Results were similar. Starting with the car count. We can confirm that our school is situated on one of the busiest streets in Malta among two industrial estates. During the morning it is more busy than during mid-day. Then although not investigated, it again will be very busy during the late afternoon. In some intances, there was a complete standstill of traffic. With the help of the ongoing air quality monitor, we can confirm that in rush hours there was almost always an increase in VOC, CO2, and PMs. When compared with a weekend, these levels were different. It was noted that there is a relation to an increase in VOC, CO2, and PM’s at the same time and hence they are related (Figure 13). Also noted that on weekends there were different readings of VOC, CO2, and PMs compared with the high numbers or sudden changes during the weekdays.

Conclusion Based on last study findings, most reasons remained the same. The level of NO ₂  has remained almost like 4 years ago study. The air quality within the school during rush hours is above the WHO (World Health Organization), as the limit is 400 ppm. The same reference levels from the EU when compared to findings are quite worrying as we didn’t test for all compounds mainly derived from fuel. Our study was also limited to a short period.

The reasons for this increase in Air Quality are :

An increase in population – The Maltese population has escalated in the last 20 years. As a result, more people go to work with their own private car and so, pollution increases. Many cars pass in front of our school every day, on average, 110 cars per 5 minutes during the rush hours which are between 6:45am – 8:30am and between 3:30pm – 6:30pm. 

Cars and vans stopping in front of school – Students are taken to school either by van or by their parent’s car. When they arrive at school, the vans and cars leave their engines on while the students are getting off. Even though this only takes a couple of seconds, this factor may still affect in the long run. 

Fuel Station – The fact that there is a fuel station exactly in front of the school’s main entrance may increase the levels of NO ₂  and other chemicals associated with fuel.  

 Urban area – St. Michael School is found between two industrial estates which apart heavy machinery and traffic leading to them, some of them use fuel to operate which lead to more emissions. Another point to add is that there is a lack of trees in the surrounding areas.

Our NO ₂  level infront of the school drop off (side of the main road) is 34.8 µg/m ³  , which is similar when compared to the 37.6 µg/m ³ ,of last study 4 years ago. Altough within the limits of 40 µg/m ³  of the EU per year. Still we believe that in certain days and time when also there is alot of slow moving traffic, the levels are much higher. This will also effect the VOC, PM’s, CO ₂  which are also a health hazard.

Our suggestions for reducing the levels of NO ₂  and other Air quality parameters within the school area would can be:

·       Car-pooling between students or workmates turning off car engines when dropping off students to school

·       Better traffic managment

·       Planting more trees which improve air quality in the area.

Recommendations:

The next study will be linked with this study where we will analyse and investigate the soil around the school for chemicals derived from traffic.

References

GLOBE teacher guide  https://  www.globe.gov/  (Accessed October 2024)

GLOBE Observer  https://observer.globe.gov/  (Accessed March 2024)

 https://www.sciencedaily.com/releases/2020/06/200626114750.htm 

 https://www.epa.gov/no2-pollution/basic-information-about-no2