Response to letter from de Boer et al

We read the letter of de Boer and colleagues with interest. The authors propose that our analysis of Dutch media coverage of the risks of rubber granulate has provided a one‐sided view of the scientific assessment or acceptability of these risks. In this reply we will elucidate why we believe that this critique is misdirected to a large extent.

Our study aimed to gain insights into the role of the media in changing public perceptions (amplification and attenuation) of modern health risks, by studying newspaper coverage of the health risks posed by practicing sports on fields with rubber granulate (or crumb rubber). The study of media representations of risk and their potential effects is central to the field of health communication. Crucial to mention here is that media reports on the risk of rubber granulate are our key materials, that we analyzed through scientifically validated procedures. In their letter, de Boer et al. pinpoint several other aspects that are also relevant to the scientific study of risk, such as the assessment and acceptability of health risks in general, and the risks of rubber granulate in particular. For example, they propose that “Standard risk assessment methodologies […] do not take account of newer approaches to understanding cancer etiology”. Although interesting, this is another field of research.

In our paper we reflect on media representations and public perceptions of the health risks of rubber granulate against the backdrop of reassuring risk appraisals or judgements from renowned and trusted knowledge institutes, such as Health Protection Schotland (2017), National Institute for Public Health and the Environment (RIVM) (2017), New York State Department of Environmental Conservation and New York State Department of Health (2009), and Norwegian Institute of Public Health and Radium Hospital Norway (2006). The more recent report from ECHA, published after the media coverage studied in our paper, reaches a similar conclusion as abovementioned studies, namely that, despite the several uncertainties in available knowledge, they “[…] found no reason to advise people against playing sports on synthetic turf containing recycled rubber granules as infill material. This advice is based on ECHA's evaluation that there is a very low level of concern from exposure to substances found in the granules” (European Chemicals Agency (ECHA), 2017, p. 5).

De Boer et al criticize our paper for ‘underplaying’ the scientific controversy around the risks posed by rubber granulate. We acknowledge that there is scientific discussion about the risks posed by practicing sports on fields with rubber granulate in the wider scientific community. Indeed, opposing scientific opinions were also observed in the results from our analyses of the media coverage, to which some of the authors of the de Boer et al.’s letter also contributed. We also agree with these authors that more insights into the nature and extent of scientific debate could provide a valuable context to our analysis of media coverage and public perceptions. While we acknowledge the presence of scientific discussions about the assessment and acceptability of the risks posed by rubber granulate, we do not take a stand within this particular discussion, which takes place outside our field of expertise. Nevertheless, we thank de Boer and colleagues for elucidating the nature of the scientific discussion within their field of research, addressing the assumptions underlying risk assessments, the application of policy‐based risk limits, and the potential health effects due to combined exposures.

The authors also raise another interesting point about the use of safety statements in risk communication to the public. The authors state that safety statements undermine public confidence in governments and their advisors, and they are surprised that we did not comment on the use of the safety statement provided by the RIVM with regard to practicing sports on fields with rubber granulate. While the goal of our paper was not to evaluate such statements, but rather to provide a generalizable account of media representations of the risk of rubber granulate, we agree with the authors that, overall, risk communicators need to be cautious with using safety statements in risk communication. Risk communicators are faced with a complex task. They aim to convey complex scientific risk knowledge to the public in a way that is transparent with regard to scientific nuance and uncertainties but also understandable and applicable in people's daily life (Fischhoff, 2012; Frewer, 2004). Stating that a product is safe is understandable and applicable to the public, but needs contextualization to be also transparent. In our opinion, most important in this discussion about safety statements in risk communication is that communicators need to stress what they mean when they use the word ‘safe’, and how scientists have reached such a conclusion. This way, risk communication messages can be transparent, understandable and applicable for the public.

The authors raised some other points. They argue that we focused insufficiently on other potential elements of societal and media discussions about modern risks, such as trade‐offs between economic and health interests, and the industrial lobby in risk policy decisions. We want to reiterate our previous point here, that we analyzed recurring themes that occurred in national newspaper articles about rubber granulate, and these two themes were not central in the media reports. We do not rule out that the themes played an underlying role in both the scientific and societal discussion about the risks posed by rubber granulate, but this is, again, outside the scope of our paper. To put it differently, with our method we only analyze what is made explicit in the media. Often, scientific and societal discussions about the evidence of and uncertainties about risks are intrinsically more about trade‐offs between values and interest about the acceptability of risks (Clahsen et al., 2020; Kinzig & Starrett, 2003; Zehr, 2016). It is important to understand the nature of disagreements between scientists and stakeholders about the weighting and interpretation of uncertainties on the one hand and the weighting of different interests and values on the other hand. Both of these aspects are important in judgements about the acceptability of risks. Public engagement and multi‐stakeholder discussions might contribute to a shared perception of the acceptability of risks.

Finally, the authors point out that we have confused hazard with risk, a distinction that was in fact highly central in our manuscript. We specifically argued that the strong emphasis on the presence of hazardous substances in rubber granulate, while providing limited contextualization of the probability of health effects to occur due to exposure to these substances, might be one aspect in the newspaper coverage that could have amplified public perceptions of risk. And we recommend public health authorities to be very clear about this distinction. The argument from the authors for our suggested confusion between hazard and risk may be rooted in linguistically diverging interpretations of the phrase “supposed hazardous substances”. “Supposed” might be read as “pretended” or “alleged”, which was probably the interpretation by the authors of the letter. “Supposed” however can also be read as “believed” or “considered probable or certain”, which is the interpretation that we intended. It was certainly not our intention to suggest that rubber granulate does not contain hazardous substances. And we are certain that, aside from this connotation that got lost in interpretation, our manuscript does not give reason to think so.

We want to thank de Boer and colleagues for their interest in our paper, and hope that this exchange of ideas has added to the reader's understanding of scientific and public discussions about modern risks, and the risks posed by practicing sports on fields with rubber granulate in particular.