intro background air

https://bioone.org/journals/environmental-health-insights/volume-16/issue-1/11786302221123563/The-Publics-Perceptions-of-Air-Pollution-Whats-in-a-Name/10.1177/11786302221123563.full

Introduction
Air pollution is alongside climate change one of the biggest environmental threats to human health.1 According to the WHO, 91% of the world’s population lives in places where ambient air pollution levels exceed WHO guideline limits.2 Despite improvements in air quality over the past 3 decades, exposure to air pollution is estimated to cause 7 million premature deaths, and results in the loss of millions more healthy years of life.1

There is indeed growing evidence for a negative effect of air pollution on health and well-being. Many studies provide solid evidence of an association between high concentrations of air pollution and mortality3 or other health outcomes, such as increased ischaemic heart disease, strokes, infections of the lower respiratory tract, asthma or chronic obstructive pulmonary disease4 and mental health indicators, such as psychological stress, symptoms of depression or suicide.5ndash;9 Brain damage caused by air pollution seems to be associated with dementia and with weakened cognitive functioning throughout the life course.10,11 Exposure to air pollutants has potentially harmful effects from the earliest stages of life with negative effects on pregnancies as well as long-term effects that affect susceptibility to disease later in life.12

Given this growing evidence of a negative impact on health and quality of life, there is generally an increasing interest in fighting air pollution at the global, regional and local level. It is therefore important to figure out what air pollution is exactly about.

Air pollution obviously has an ontologically objective existence, but the way in which people come to know and make sense of it, is highly contextual, subjective and therefore far from universal.13 Air pollution in the public’s mind is often different from air pollution as defined by the scientific community. Truth claims of scientists are evidence-based and therefore more convincing for policy makers. However, from a policy perspective, definitions and perceptions of the public need to be considered as well as they define the margins for possible policy action to a large extent. Perceptions being influenced by the social, economic and political context, by knowledge and evolving insights, they will differ between people and contexts. The ambition of this paper is to make a taxonomy of definitions, perceptions and associations that go along with air pollution among Brussels’ citizens.

Background
Why does one’s perception about air pollution matter? Relationships between environmental exposure (eg, air pollution) and physical and mental health (eg, respiratory effects) are mediated by perceptions of the ‘exposure’ (eg, air quality).14 Risk perceptions – or more exactly the there out resulting attitudes – play thus a crucial role in the public’s response to environmental exposure15 and in its response to the sources of the exposure. These attitudes impact health both in a direct and an indirect way. In a direct way, high risk perceptions might constitute a cognitive antecedent of a stress reaction negatively impacting upon mental health16,17 or on the other hand, when risks are underestimated, people might not take appropriate measures to protect themselves which impacts on their physical health. Attitudes resulting from risk perceptions also mediate the potentially harmful human health effects of air pollution in a more indirect way since they might result in behavioural changes and support measures aiming to decrease air pollution thereby mitigating air pollution and its negative health impact. Public awareness and realistic perceptions of the health risks associated with air pollution are therefore key in improving public health and in creating public support for policy measures aimed at reducing air pollution.

In order to develop successful prevention and alleviation strategies, understanding risk perceptions is key. Risk perceptions can be defined as involving ‘people’s beliefs, attitudes, judgements and feelings, as well as the wider cultural and social dispositions they adopt towards hazards and their benefits’.18 Key in shaping a health risk perception, is the definition and identification of air pollution. Indeed, if air pollution is not recognised as such, one will not act upon it.14 These reactions might consist of (individual) behavioural changes, impacting heath directly through protective measures or indirectly through behaviours that reduce levels of air pollution at a personal level (eg, changes in car use). Risk awareness is also crucial for citizens to engage in collective action (eg, through different forms or degrees of activism and to support/call for policy initiatives initiated by local, regional or national governments).7,13 Therefore, understanding how individuals perceive air pollution, is crucial for combating it and to improve public health.

From a review of qualitative research on air pollution perceptions we learn that qualitative research about the topic remains fairly scarce and most often neglects how air pollution is defined by the public and which mental schemes are employed to categorise an element as being air pollution or not.13

What we learn from the existing body of research on the topic, is that the public and scientists define air pollution differently. The scientific community focuses on specific pollutants derived from multiple sources; the public rarely refers to specific pollutants and rather emphasises the sources of air pollution. In their study on pupils’ knowledge of air pollution in Greece, Dimitriou and Christidou19 observed that the majority of respondents referred to specific air pollutants as ‘smoke’, ‘exhaust-gases’ or ‘harmful substances’, without making any distinction between the different substances found in the air.

Knowledge about air pollution sources differs between experts and the public. The public often associates air pollution sources with odour. In the Nairobi slums, for instance, smelly drainage channels and toilets were frequently cited as a source of air pollution.20 Similarly, respondents in Beijing21 mentioned garbage as a source of air pollution thereby considering odour as the clue connecting garbage with air pollution.

What people categorise as being air pollution is very much culturally defined. In a community in California, smoke caused by wildland fire was perceived as air pollution.22 On the contrary, in a study on open burning of municipal solid waste (MSW-burning) in India, respondents expressed the belief that smoke from ceremonial fire is a purifier when good fuel is used.23 When asked explicitly if smoke from MSW-burning also purifies, there was consensus that it was not purifying, but polluting. The ‘pure’ character of ceremonial fire smoke relative to MSW-burning smoke was explained through the fuel used for the burning. In a community in Australia, the presentation of wood smoke as natural and the idea that wood heating is a traditional source of warmth counteracts the strong association of pollution with modernity and ‘artificial’ sources of energy (Reeve, Scott, Hine and Bhullar, 2013).24 Obviously, the classification of elements as contributing to air pollution is context-dependent. People refer to sources of pollution that are part of their daily lives and the society they live in. Respondents from a London study for instance indicated cars, buses, heavy goods vehicles and pollen as the most significant causes of air pollution,25 while respondents in a poor neighbourhood in Nairobi mostly pointed to road dust, industrial areas and burning trash.26 In sum, definitions of air pollution and elements identified as air pollution are not universal: they differ between experts and the public and between different populations in different contexts.

Study aim and research questions
In this qualitative study, we aim at identifying the beliefs, attitudes, judgements and feelings that the public in the Brussels-Capital Region has about ambient air pollution. Our main research question is: How does the public (in Brussels) perceive air pollution?

This question (see Figure 1) crystallises into 4 sub-questions that approach the topic of perception each from a different but complementary angle:

How does the public define air pollution? (cognition)

Which associations does air pollution evoke in the public? (intuition)

Which elements are perceived by the public as being air pollution and why? (mental schemes)

Is perceived air pollution also seen as problematic by the public? (ethic)

We consider it relevant to investigate whether air pollution is problematized by the respondents as people can only be mobilised or stimulated to fight air pollution if they recognise it to be problematic. This research aims to enrich the limited body of qualitative research on health risk perception of air pollution. It is to our knowledge the first research investigating how air pollution is defined and identified by the public. The richness of the research lies in the different angles from which the study of ‘perception’ is approached and the detailed and complementary information that results thereout.

Figure 1.
Schematic overview of the research questions and how they relate to the main research question.

10.1177_11786302221123563-fig1.tif
First, we present the results related to the definitions of air pollution given by our respondents. The definition question was designed to come to the essence of air pollution through a cognitive way of thinking stimulating the respondent to be concise, to the point and synthetic. To explore the sentimental dimension of respondent’s perceptions in a more intuitive way, an association exercise was done to invite the respondent to think in an open-minded way. The categorisations exercise intended to explore the symbolic dimension of air pollution through mental schemes handed by the respondent. Mental schemas are cognitive structures or mental representations that allows people to categorise knowledge about the world. These schemas help to simplify interactions with the world. In this paper, we focus more specifically on object schemas.27,28 Expressing claims about the problematisation of air pollution encompasses a more ethical dimension through the values expressed towards the problematic character of air pollution. Both ‘feeling’ and ‘thinking’ are touched upon through these 4 questions by means of conscious and more unconscious processes. The insights gained from this research should contribute to the field of environmental epidemiology through a better understanding of how ‘the public’ perceives air pollution.