Introduction
Close proximity to industrial plants is considered a factor in the development of asthma, mainly in children. Traffic-related air pollution (TRAP), exposure to polluted air and second-hand smoke (SHS) are important risk factors for the development of asthma, mainly in children. According to the definition proposed by the international team of experts GINA (Global Initiative for Asthma), bronchial asthma is a characteristic disease of the respiratory system, dominated by symptoms such as a feeling of constant pressure in the chest and a cough characterized by variability and severity over time, wheezing and shortness of breath. The etiology of asthma is multifactorial; its development is influenced by both environmental and individual factors (including genetics). Environmental factors that potentially influence the development of asthma include allergens and exposure to various types of infectious agents [1].
Asthma is considered the most common chronic disease of the lower respiratory tract in children (it occurs in 2–20% of the pediatric population). It is estimated that currently in Poland, 100,000–150,000 children in the 1–5 age group may have asthma [2–4].
Approximately 13% of the global incidence of childhood asthma is attributable to TRAP. Asthma as a chronic disease is also closely related to the inhalation of PM2.5 and PM10 suspended dust, which is found in polluted air. These are some of the most dangerous pollutants for human health and life. Exposure to suspended dust (PM2.5 and PM10) and NO2 is associated with a high risk of developing asthma until the age of 20. Currently, almost 4 million new cases of asthma are diagnosed in children each year as a result of NO2 air pollution. PM2.5 causes 16 million new cases of asthma in children each year. Dust particles penetrate the respiratory tract and then reach individual organs, causing severe asthma attacks [5–8]. They are also transported to the circulatory system through the pulmonary alveoli and absorb many toxic substances floating in the air on their surface, including heavy metals, polycyclic aromatic hydrocarbons (PAHs) and organic/inorganic ions [9].
Asthma is currently an incurable disease, and the increased content of dust suspended in the air and pollutants in the environment adversely affects its course [10–12].
Bronchial asthma as a chronic disease is perceived by parents and children as a traumatic phenomenon. In the school environment, these children are exposed to contact with sensitizing factors, which intensify its course. These include dust in classrooms and locker rooms, on maps and boards, and in mattresses used during physical education lessons. Allergens are also present in biological laboratories where animals and plants are present and in chemical laboratories. Chalk dust may also cause conjunctival irritation [13, 14].
The geographical location of the city of Bielsko-Biala favors the ventilation of the urban area, because the terrain slopes from south to north and from west to east. However, there are local depressions in the ground, so appropriate spatial development is important, especially in urbanized areas [15].
The most densely built-up, central part of the city of Bielsko-Biala lies in the meridional valley of the Biala River, which is sheltered from the east and west by mountains intersected by river valleys. In this area, within compact buildings, mainly municipal and post-industrial, there are the highest concentrations of air pollutants in the city and the most unfavorable ventilation conditions. Urbanization processes, which result in increasingly denser and taller buildings, additionally limit wind speed and the ability to remove pollutants outside the city. Due to the nature of the development, this area is practically devoid of effective ventilation channels and there is no real possibility of separating such channels without disturbing the existing urban fabric [15, 16].
On the local scale of the city of Bielsko-Biala, the second element, next to the topography, that modifies wind conditions is the compact development of the city center. Clusters of buildings with different heights, different compactness and different locations constitute a clear obstacle to the free flow of air masses, causing various types of turbulence. The increase in friction reduces the wind speed at the earth’s surface, while turbulent mixing and wind gustiness increase [17].
So, ultimately, the city area in terms of ventilation can be basically divided into two different types, i.e. “well-ventilated” areas, represented by the areas to which data from the meteorological station in Aleksandrowice refer (areas with e.g. hills) and areas less ventilated, which constitute valley areas where the percentage of calm and weak winds is much higher, thus reducing the possibility of air exchange and purification in the city. Most silences (over 20%) occur in the period from November to January, i.e. during the period of increased pollutant emissions associated with the heating season [18, 19].
Aim
The aim of this study was to analyze the incidence of bronchial asthma among children in selected primary schools in Bielsko-Biala, a city that is diverse in terms of geography and industrialization.
Material and methods
In February 2024, with the consent of the principals of primary schools (PS 22, PS 26, PS 28, PS 29, PS 32, PS 36) in Bielsko-Biala, data were obtained on the number of students of grades VI–VIII (without sensitive data) with bronchial asthma diagnosed by a doctor. Selected primary schools are located in different parts of Bielsko-Biala. The school hygienist collects medical information about the health of each student in the health card, which is obtained from parents. Based on the collected data (without sensitive data), a table was prepared illustrating the epidemiology of asthma among children. The study assumes that the students’ place of birth is the city of Bielsko-Biala and they attend schools with the corresponding districts in accordance with Resolution No. VIII/92/2014 of the City Council in Bielsko-Biala.
Primary schools in Bielsko-Biala were distinguished in terms of terrain (lack of air corridors, industrialization). The main criterion that determined the selection of individual primary schools was their diverse spatial (topographic) location within the city (districts). It is understood as the configuration of the relief/land surface, and in particular the presence and relative location of industrial facilities, municipal sources and schools (places of residence).
Primary School No. 22 in the General Education School Complex Stefana Zeromskiego is located in the Dolne Przedmiescie district in the city center, where there are no industrial plants. There are residential and service buildings (tenement houses), apartment blocks, commercial, cultural, scientific and office buildings. There are dense buildings, which hinders natural ventilation of the city. The elevation of the school is 313 m above sea level (Figure 1).
Figure 1
Location of the discussed primary schools in Bielsko-Biala. Source: own study based on data from the City Hall in Bielsko-Biała, Department of IT
Primary School No. 26 Zygmunta Lubertowicza is located in the Straconki district (south-eastern part of the city). It is dominated by single-family buildings. There are catering facilities and there are no industrial centers. Straconka covers an area of 596.55 ha and is also the starting point of numerous mountain hiking trails, including the Little Beskid Trail. The elevation of the school is 420 m above sea level, and for this reason, the quality of atmospheric air – compared to other surveyed schools – is better. There is no compact development (Figure 1).
Primary School No. 28 named after Gen. Jozefa Kustron is located in the most north-eastern part of the city (Hałcnow district). These are typical single-family buildings supplemented with a few commercial and catering buildings. Hałcnow has an area of 1,350.91 ha. The elevation of the school is 337 m above sea level (Figure 1).
Primary School No. 29 Janusz Korczak is located in the Komorowice district (the northernmost part of the city). These are typical industrial and service buildings. There are single-family residential buildings and numerous apartment blocks. This is a part of the city where there are numerous industrial plants. These include TI Poland, Strabag, Polmotors, Nemak Poland, Fiat Auto Poland, Celma Indukta, Marbet, Marpol, Power Train Technologies, Grammer Automotive Poland and Electropoli-Galwanotechnika. Important communication routes also run through the northern district of Bielsko-Biala: expressway S1 (E75) E462 to Cieszyn, national road No. 1 (E75) E462 to Tychy, national road No. 52 to Głogoczow near Krakow and provincial road No. 942 to Wisla. The elevation of the school is 287 m above sea level. Due to the low elevation of the terrain, conditions here are favorable for the accumulation of air pollutants, including those that have moved from higher areas of the city, where they arise from industrial and municipal sources (Figure 1).
Primary School No. 32 named after Ludwika Warynskiego is also located in the industrial zone of the city (Wapienica, the western part of the city). There are industrial plants in this district of the city, including mainly Dimico, Klingspor, Proseat, Eko-Export, Hutchinson Poland and Eaton Automotive Poland. The Wapienica estate has an area of 25,880 km2. It is the largest settlement in Bielsko in terms of area and the third largest in terms of population. The elevation of the school is 360 m above sea level (Figure 1).
Primary School No. 36 with Integration Departments in the General Education School Complex Armii Krajowej is located in the southern part of the city. It is a typical development of blocks of flats (Beskidzkie estate). It has an area of 0.4 km2 and is located in close proximity to the Aleksandrowice district, which is “well aerated”. The elevation of the school is 370 m above sea level (Figure 1).
Results
The analyzed primary schools in Bielsko-Biala have 927 students in grades VI–VIII. Based on the data obtained, it was calculated that out of this number, 157 students suffer from asthma. There are 122 students with asthma in Primary School 29 and Primary School 32, which are located in typical industrial zones (Komorowice and Wapienica). The number of students in grades VI–VIII in these schools is 455. In Primary School No. 29, 214 children attend grades VI–VIII and 59 students (27.6%) are sick, while in Primary School No. 32, 63 students in grades VI–VIII have been diagnosed with asthma, which is 26.14% (Figure 2). Primary schools 29 and 32 have the largest number of students in grades VI–VIII, as well as children with asthma. What is important is the fact that other educational institutions have fewer students (the number of classes is between 3 and 4), which was confirmed by the principals of the surveyed schools on the basis of statistical school documentation, unlike Primary School 29 and Primary School 32, where the number of classes is higher and is 6–8.
Discussion
Currently, there is a noticeable dynamic increase in the incidence of bronchial asthma in industrial areas. It should take into account cause and effect relationships, which include the influence of climatic zones, the level of civilization development, differences in diet, lifestyle, and the degree of pollution of the natural environment, including dust pollution from industrial plants [18].
It is also important to determine the factors that contribute to the deterioration of health and quality of life of patients. Not all individual and environmental factors have the same importance, so it is necessary to determine which have a stronger impact in order to better control and treat the disease in question. The increased content of suspended dust and other pollutants in the air originating from industrial plants and pollutants has an adverse effect on the respiratory system (mainly asthma), which is confirmed by numerous studies conducted in children [20–24]. In many countries, significant relationships have been found between the emission of atmospheric pollutants and the severity of asthma symptoms [25, 26].
In Poland, studies have been conducted on the impact of air pollution on human health, but most of them were carried out on children and related to general health or the incidence of diseases of a specific system [1, 27]. One of them analyzed the health effects of exposure to air pollution, confirming the relationship between the concentrations of suspended dust and SO2 in the air and the incidence of respiratory diseases. The lung ventilation efficiency, the frequency of symptoms and the incidence of asthma were assessed. The authors of the study estimated that the likelihood of developing bronchial asthma was 50% higher on days with “high” air pollution levels than on days with “low” air pollution. Researchers have detected a strong positive effect of the concentration of air pollutants, mainly SO2, on the incidence of bronchial asthma symptoms. The authors concluded that such results indicate the need to reduce the emission of certain pollutants, especially SO2, in order to alleviate the course of asthma, and in the case of nitrogen oxides and carbon monoxide, they postulated the need to conduct further research after adopting different assumptions [28].
The influence of the place of residence and school attendance of children in relation to the occurrence of asthma (and other chronic diseases) was also described by Palocci et al. (2022). They noted that in a group of over 2000 children aged 10–16 years living in Italy near industrial plants in the area of Civitavecchia (northern coast of Rome), dominated by cement production, three large thermoelectric power plants, numerous chemical and metallurgical plants emitting both dust and gaseous pollutants into the atmosphere, there is a significantly higher incidence of asthma, allergies and hypertension compared to children living outside industrial areas [29].
Similar results were observed in the works of Paciência et al., Pierangeli and Bozzola et al. [5, 30, 31].
Our analysis of the incidence of bronchial asthma depending on the place of school attendance showed statistically significant differences between individual students attending selected schools in the city of Bielsko-Biala as a city that is diverse in terms of industrialization.
Conclusions
The occurrence of bronchial asthma among students of Primary School No. 29 named after Janusz Korczak and Primary School No. 32 named after Ludwik Warynski is closely related to their place of residence and attendance at schools in the industrial zones of the city (Komorowice and Wapienica), as opposed to the other schools studied (outside the industrial zones).
Based on the data obtained, it can be presumed that in the study area, the occurrence of asthma in children is influenced by the emission of harmful dust and gases from industrial plants, although no analysis of the annual average selected air pollutants in the area of the city of Bielsko-Biala has been carried out. It is also important to take significant actions to reduce air pollution from road transport, implement new respiratory technologies in industrial populations, and invest in ecological fuels and energy sources. Consequently, this should lead to a reduction in the severity of asthma symptoms in children suffering from asthma and at the same time reduce the risk of new cases of the disease.
