Air and noise pollution: A state-of-the-art review of causal health outcomes

Air and noise pollution have in the medical literature been shown to have large negative health effects. However, the findings might exhibit the problem of endogeneity, i.e. that they are not causal. While literature focusing on causal relationships in the area has grown in the last decades, a comprehensive overview has not been performed in recent years. This study aims to provide a state-of-the-art review of the causal relationship between air and noise pollution and health outcomes by summarizing the findings from international peer-reviewed articles, as well as informing the reader of the methodological challenges in the field and knowledge gaps in the literature. In addition, we will contribute by comparing the economic literature regarding both air and noise pollution. To achieve these aims, we conducted a review of existing international literature. This review identified previous research linking air and noise pollution to health outcomes, focusing on causal estimations using primarily quasi-experimental settings. The empirical findings show that air pollution can be linked to several health outcomes, e.g., increased mortality, emergency room visits, and hospitalization, through different risk pathways. The number of studies focused on noise pollution are significantly fewer, with individual studies also finding negative health effects, e.g., sleeping problems, hypertension, and increased medication and healthcare utilization. The evaluation of air and noise pollution differs primarily in temporal aspects and the source of variation used.