Cyclists’ Multiple Environmental Urban Exposures—Comparing Subjective and Objective Measurements

Abstract

Citizens in urban areas are exposed to multiple environmental stressors like noise, heat, and air pollution, with impact on human health. There is a great deal of evidence that connects human health, objective environmental exposure, and place of residence. However, little is known about subjective and objective multiple personal exposures while being mobile. To address this research gap, this paper presents results from a mixed-methods exploratory study with cyclists in the City of Leipzig, Germany. In the summer of 2017, cyclists (n = 66) wore a unique combination of sensors that measured particle number counts (PNC), noise, humidity, temperature, geolocation, and the subjective perception of each exposure on everyday routes for one week (n = 730). A smartphone application was developed to question participants about their perception of subjective exposure. The data were analyzed with three aims: (i) to compare the multiple exposure profiles of the cyclists, (ii) to contrast the objective data and subjective individual perception, and (iii) to examine the role of route decision-making and awareness of health impacts for healthier route choices. The results indicate distinct differences between the exposure profiles of cyclists. Over 80% of the cyclists underestimated their exposure to noise and air pollution. Except for heat, no significant associations between the objective and subjective data were found. This reveals an exposure awareness gap that needs to be considered in urban health planning and risk communication. It is argued that knowledge about health impacts and route characteristics plays a crucial role in decision-making about route choices. The paper concludes with suggestions to harness smart sensing for exposure mitigation and research in health geography.

Risk Perception of Air Pollution: A Systematic Review Focused on Particulate Matter Exposure

“…Another study in 2003 employed ethnographic field methods and semi-structured interviews to ask community members to identify salient risks from industrial pollution and examine whether and how perceptions differed across occupational groups (industrial workers, commercial and service sector workers, and farmers) in a Futian community [ 72 ]. A study in Malaysia included university students [ 46 ] and in a Leipzig University study, a collective of cyclists wore a unique combination of sensors that measured the particle number counts (PNC), noise, humidity, temperature, and geolocation [ 43 ].…”

“…In five articles, measured pollution was not correlated with perception [ 43 , 48 , 56 , 71 , 73 ]. In the study by Ueberham et al [ 43 ], cyclists were not aware of a risk posed by air pollution.…”

“…In five articles, measured pollution was not correlated with perception [ 43 , 48 , 56 , 71 , 73 ]. In the study by Ueberham et al [ 43 ], cyclists were not aware of a risk posed by air pollution. In the study of Reames and Bravo [ 48 ], no association between pollution perception and air pollution exposure was observed and the findings supported the neighborhood stigma theory [ 66 ].…”

Cyclists’ exposure to atmospheric and noise pollution: a systematic literature review

“…In most of these studies, atmospheric pollution and noise do not seem to constitute a major obstacle to the use of the bicycle although a significant number of cyclists feel strongly exposed and state that they experience symptoms (such as respiratory track irritation and cough) after their travel (Tom, Lidia, & Colin, 2015;Ueberham, Schlink, Dijst, & Weiland, 2019). On the basis of a survey with 1402 cyclists in Vancouver (Canada), Winters, Davidson, Kao, and Teschke (2011) discovered that distance from atmospheric and noise pollution constitutes a major motivator for cycling, and this applies to regular, frequent, or occasional cyclists.…”

“…Finally, Ueberham et al (2019)'s study constitutes a unique case that is particularly interesting since it combines objective measures (sensors) and subjective measures (post-trip self-evaluation) for exposure to noise and fine particles for 66 cyclists. The authors conclude that 80% of participants under-estimate their exposure to fine particles and noise, and that no correlation seems to exist between cyclists' perceptions and actual exposure to these two pollutants.…”