Since 2016, social media companies and news providers have come under pressure to tackle the spread of political mis- and dis-information (MDI) online. However, despite evidence that online health MDI (on the web, on social media, and within mobile apps) also has negative real-world effects, there has been a lack of comparable action by either online service providers or state-sponsored public health bodies.

This research project focuses on why this is the case. Specifically, it seeks to answer three questions:

• Why has so little has been done to control the flow of, and exposure to, health MDI online?
• How might more robust action be justified?
• What specific, newly-justified actions are needed to curb the flow of, and exposure to, online health MDI?

In particular, the project focuses on the influence of four ethical concerns: paternalism, autonomy, freedom of speech, and pluralism, and four arguments against using these concerns as a reason not to intervene: (i) education is necessary but insufficient to curb the circulation of health MDI; (ii) there is precedent for state control of internet content in other domains; (iii) network dynamics adversely affect the spread of accurate health information; and (iv) that justice is best served by protecting those susceptible to inaccurate health information.

Finally, the project looks at how these arguments can be used as a reason for classifying the quality of the infosphere as a social determinant of health, thus making its protection a public health responsibility.