Cyclists’ exposure to air and noise pollution within Gothenburg and Mölndal.

Abstract

Travel-related exposure to the surrounding environment remains relatively unknown. Exposure to air and noise pollution are common when cycling within the city, which becomes essential to study as unhealthy concentration can be reached, especially during rush hour traffic. This research focuses on the air and noise exposure within Gothenburg City´s Environmental zone and north of Mölndal. Particulate Matter (PM)2.5, PM10 and LAeq are measured near ground level during and in between rush hour traffic within the period September 2023 to January 2024. Data are sampled through volunteer cyclists within or near the area Medicinareberget. Results show that there is no relation between the nearest PM2.5 and PM10 concentration point to the annual average daily traffic (AADT) year 2018. There is a large variation of concentrations, due to several different factors such as proximity to traffic, topography or the road infrastructure. Concentrations are higher near ground level, especially during morning rush hour traffic, where some concentrations exceed the EU regulation and some of the WHO recommended guidelines. Several factors related to the atmosphere´s conditions or meteorology such as winds and RH percentage affect the pollutants. The planetary boundary layer and the vertical mixing depth could have affected the result. These factors might not be detected at the higher located Femman station that indicate the overall concentration for Gothenburg city. Concentrations differs when comparing to the concentrations near the surface. This indicates that ground level measurements are essential to continue to study, as stations and models might not show a correct representation when focusing on the cyclist´s exposure. Nevertheless, the calculated potential inhaled concentration dose per kilometers, showed that exposure to air pollution is within EU regulation and other recommended guidelines. How harmful it is, depends on the individual itself and further studies should be conducted. Previous studies show that physical activity can overweigh negative health impacts contributed by air pollutions. The method used for this research was feasible when conducting air pollution measurement but is more challenging when analyzing noise pollution exposures. It is suggested to further develop another method to result in a stronger conclusion. In this study, winds and some other minor factors such as rattling noises, studded tires and more can overshadow the reality, making the noise exposure not representative. Levels are overall high and do exceed the Swedish Environmental Protection Agency´s recommended guidelines. No relation could be seen when comparing AADT year 2018 to the nearest LAeq point. However, infrastructure, the surrounding environment and when several local activities are present such as tram activities, bigger roads or construction sites, could be the reason behind the vast variety of concentrations but also increase exposure overall.