Freshwater Harmful Algal Blooms and Health: Awareness, Behaviors, Perceptions, and Communication Preferences Among U.S. Adults.

Freshwater harmful algal blooms (HABs) are a growing health risk for children, adults, and their dogs. To inform more effective illness prevention strategies, this study examined awareness, behaviors, perceptions, and communication preferences related to health and HABs. Four focus groups were conducted in March 2024 with U.S. adults who frequent freshwater bodies (e.g., lakes, rivers) for recreation. Focus group participants, who included dog owners and parents of children or teenagers, reported moderate awareness of HABs and perceived low personal risk from HAB exposure. When deciding if to enter bodies of water, most individuals relied on sensory cues more than official recommendations such as water advisories. In general, participants reported trusting officials and following water advisories if they saw them. They preferred timely information that described HABs using simple terms and information available through multiple channels. Public health practitioners can consider the insights we gained from the focus group participants to inform future audience research, HAB risk communication, and illness prevention.