# Exposure to NO\({}_{2}\) and PM\({}_{2.5}\) While Commuting: Utility of Low-Cost Sensor
## 1 Introduction  
The study of the effects of the environmental environment on the environment  
## 1 Introduction  
Physical activity is essential in preventing noncommunicable diseases in developed countries [1]. Compared to recreational physical activities, which require an individual to allocate time, utilitarian bicycling during commuting specifically enables physical activities with daily and necessary routines. Almost all commuter cycling falls into the'moderate intensity' category of exercise, with an energy expenditure of approximately 4 MET (metabolic equivalent of task), or 5-8 times the energy expenditure at rest [2]. This level is about twice as intensive as walking and offers near-continuous activity. Cycling for transportation has many health-related advantages. According to [PERSON] [3], cycling for 3 h per week results in a relative risk of 0.72, with a 28% reduction in all-cause mortality compared to non-cyclists. Results presented by [PERSON] et al. [4] suggest that occasional cycling for transportation (less than 3 days/week) may not be able to generate significant benefits on mental well-being. However, regular bicycling for transportation (3 days/week or more) may reduce mental distress and boost life satisfaction. An excellent example is Sweden, where 19.2% of the working population meets the WHO's global health recommendations, including moderate- to vigorous-intensity physical activity performed at least 30-60 min per day and more than 150 min of moderate-intensity activity per week [5], just through their bicycle commutes to work [6]. In Poland, 83% of the population knows how to ride a bike, which is more than the 63% global average. In total, 69% own one, and 44% use it at least once a week. However, Poles treat cycling as a sports activity rather than the primary mode of transport for a 2 km distance (18%) [7]. Despite Poles being more and more willing to implement eco-friendly solutions to their lifestyles, in the matter of transport, the changes go slower [8]. According to a report by the Polish Ministry of Climate and Environment conducted in March 2022, \"Which mode of transport do you use most often to get to work?\", 47% of compatriots indicated the car. In comparison, survey results from 1995 and 2005 [9] stated a similar share in 1995, while in 2005, the car was the most frequent mode of transport for 78% of respondents from Polish districts with a high level of mobility. According to the Parliament of the European Union (EU), the transport sector's most serious challenge is significantly reducing its emissions and becoming more sustainable [10]. Among activities aimed at reducing air pollutant emissions from the transport sector at the regional and local scales, the extension of cycling infrastructure and promotion in cities are mentioned. When people choose to ride bikes instead of driving cars, they contribute to reducing the emissions of pollutants from vehicles. Promoting cycling for health reasons implies that the health benefits of cycling should outweigh the risks of cycling. Bikes do not emit pollutants. Therefore, society may benefit from a shift from private car use to bicycle use, making them a zero-emission mode of transportation. Bikes are recommended as an active transport mode, reducing air pollution. However, it is essential to note that disadvantages to individuals may occur. For example, the risks of being involved in traffic accidents increase [2]. Additionally, in areas with high levels of air pollution, cycling can expose people to higher levels of pollutants due to increased respiration rates. For automobile traffic, the characteristic pollutants are NO\({}_{2}\) and PM\({}_{2.5}\)[11]. Both are derived from combustion processes and increase oxidative stress [12]. NO\({}_{2}\) is often treated as a surrogate for PM [13,14]. On the other hand, 14% to 27% of the measured secondary PM\({}_{2.5}\) is generated from the NOx set of reactions [15,16].