It has been proven that outdoor and indoor air pollutants can cause adverse health effects and are able to promote the onset of atopic diseases. The current manuscript is focused on methodological issues. The aim of the study is to determine the effect of air pollution, urban environment, and urban heat islands (UHIs) on the occurrence of respiratory diseases including allergic rhinitis, asthma and wheezing in preschool children. The study group consists of 276 five-year-old children attending randomly selected kindergartens in the urban and rural areas of the Łódź Voivodeship. The questionnaire including data on the child’s state of health and socio-economic data will be filled by the caregivers. The children will undergo skin prick testing and the measurement of volatile organic compounds in exhaled breath. The key components of air pollution – particulate matter (PM) will be measured by personal meters. The PM sampling planned in the study will take 12 h for PM_2.5 and for PM₁₀ alike. Data on the level of outdoor air pollution will be collected based on the results obtained from air monitoring stations. The impact of air pollution, UHIs and the environment on the respiratory system and the presence of allergies in children, including chronic respiratory diseases, will be assessed. The project results will provide a scientific basis for the development of preventive programs in the population of children in the Łódź Voivodeship, adapted to the real health needs of society. Int J Occup Med Environ Health. 2021;34(4):453–60