This programme of research aimed to define and characterise environmental risk factors (ERFs) associated with drownings in the UK, addressing Step 2 of the World Health Organization’s Drowning Prevention Implementation Guide (2017). It was hypothesised that ERFs would differ by drowning circumstances, including location (coastal vs. inland) and intent (unintentional vs. intentional). Four iterative studies were conducted. First, a systematic literature review identified global ERFs and established an operational definition for an ERF related to drowning. Second, a UK-focused expert consensus refined and validated this definition as “any natural or built physical factor that increases the likelihood of water-related injury and can be influenced by the social, cultural, and economic environment.” Experts identified leading ERFs for drownings in the UK, including natural factors (e.g., cold water, heat waves, adverse currents) and built features (e.g., alcohol outlets, bridges). The third and fourth studies validated and expanded these ERFs through site surveys documenting environmental factors at priority drowning locations, along with geospatial analyses within these locations to assess key points of interest and socioeconomic factors known to influence health outcomes. Cold water, adverse currents, and alcohol outlets emerged as leading ERFs across all drowning circumstances. On-premises alcohol outlets were a predictor for unintentional drownings, while elevated surfaces like bridges and cliffs were linked to intentional drownings. Coastal drownings were primarily influenced by natural factors (e.g., steep banks, moving water), while inland cases involved both built (e.g., bridges, alcohol outlets) and natural features (e.g., deep water, cold water). Notably, areas with higher socioeconomic status were associated with higher rates of unintentional drownings, possibly due to greater exposure or visitation. Further investigation into individual-level factors and movement patterns is required. These findings support the hypothesis that ERFs differ by location and intent, emphasising the need for policies and strategies that address these differences and mitigate the associated risks.
