As urban landscapes continue to grapple with the escalating impacts of climate change, public fountains have emerged as indispensable oases of relief and social interaction. These water features, numbering over 100,000 globally and drawing approximately three billion visitors each year, transcend their ornamental appeal by functioning as vital urban cooling centers. However, a groundbreaking editorial recently published in Carbon Research unveils a troubling paradox: the very mist that refreshes city dwellers may harbor unseen threats to public health.
Leading this inquiry is Professor Xiaohui Liu of the Key Laboratory of Marine Environment and Ecology under the Ministry of Education and the College of Environmental Science and Engineering at Ocean University of China. Liu’s team exposes an urgent yet overlooked hazard tied to the aerosolization processes inherent in fountain operation. While fountains mitigate the intensifying urban heat island effect, they inadvertently facilitate the dispersion of microscopic pathogens and toxic chemicals into the air, creating airborne cocktails that penetrate deep into human respiratory systems.
Central to this risk is the increasing use of alternative water sources such as reclaimed wastewater and harvested rainwater in fountain systems, driven by stringent water conservation policies. These waters possess heightened chemical and biological complexity compared to traditional potable water supplies. During fountain operation, high-pressure mechanisms generate microdroplets and aerosols, which do more than simply disperse water—they concentrate pollutants. This phenomenon results in airborne contaminant levels that can surpass those found in the water itself by several orders of magnitude.
Particularly alarming is the enrichment of pathogenic microorganisms in aerosolized fountain waters. Reclaimed water often contains Legionella bacteria, the causative agent behind Legionnaires’ disease, a severe form of pneumonia. Data from the 2025 outbreak of Legionnaires’ disease in New York City vividly illustrates the capability of these aerosols to traverse urban environments, instigating public health emergencies. Alongside biological agents, chemical contaminants such as perfluoroalkyl acids (PFAS) have been detected at concentrations in the air thousands of times greater than their aqueous counterparts, intensifying inhalation risks.
The process is further complicated by environmental factors prevalent in peak summer months. Intense sunlight, elevated temperatures, and dynamic wind patterns catalyze chemical transformations of these airborne contaminants. Secondary reactions can produce highly reactive and toxic byproducts, exacerbating their impact on human health upon inhalation. These photochemical and thermally driven reactions convert relatively stable pollutants into volatile intermediates, amplifying their toxicity and persistence in the urban atmosphere.
Demographic data underscores the vulnerability of certain populations to these risks, with children constituting nearly 30% of all fountain visitors. Their physiological characteristics, including higher respiratory rates relative to body mass, coupled with frequent direct contact and unintentional ingestion of fountain waters, make them disproportionately susceptible to adverse health outcomes. Manifestations can range from mild dermatitis to severe immunological respiratory disorders, necessitating urgent protective measures.
The fountain installation industry is expanding at an annual rate of 3.5%, a trajectory that, while enhancing urban livability, simultaneously magnifies potential public health threats due to the lack of harmonized water quality regulations and aerosol safety protocols. Current maintenance practices often overlook aerosol dynamics, leaving a regulatory vacuum that could precipitate widespread epidemics linked to fountain usage.
To counter this emerging threat, Professor Liu and colleagues advocate for an integrated and proactive four-pronged strategy. First, stringent and regular monitoring of water quality must encompass both chemical contaminants and microbial pathogens to ensure early detection and mitigation. Second, engineering innovations are imperative to redesign fountain systems to curtail unnecessary aerosol production without compromising their cooling efficacy. Third, transparent public health advisories should be systematically issued when water quality parameters deviate from safe thresholds. Finally, comprehensive public education campaigns are essential to differentiate decorative water use from safe interactive play, empowering citizens with knowledge to minimize exposure risks.
This multifaceted approach underscores the necessity of cross-sector collaboration involving academic researchers, municipal authorities, public health agencies, and fountain operators. Only through coordinated action can we reconcile the dual imperatives of urban cooling and public safety. As urbanization intensifies and climate pressures mount, the role of fountains as sustainable, health-promoting infrastructure hinges on addressing these hidden hazards with scientific rigor and policy foresight.
Fountains will remain integral to the urban fabric, offering respite and communal engagement amid sweltering cityscapes. Yet, as illuminated by this editorial, their sustainability is contingent upon rigorous attention to aerosolized pollutants. This emerging field of research impels us to rethink how we engineer, monitor, and interact with water features, ensuring that their benefits do not come at the cost of public health.
The findings communicated by Professor Xiaohui Liu and the Ocean University of China research team thus serve as a clarion call to the global community. Protecting millions of urban dwellers—from children to the elderly—requires embedding health considerations into the very design and management frameworks of public fountains. Only then can these gleaming urban jewels truly shine as beacons of safe and resilient city living.
Subject of Research: Environmental health risks related to aerosolized pathogens and chemical pollutants in public fountains.
Article Title: Spotlight the public health risks of fountains.
News Publication Date: 26-Jan-2026.
Web References:
References:
Liu, X., Wang, R., Han, M. et al. Spotlight the public health risks of fountains. Carbon Res. 5, 10 (2026).
Keywords: Aquatic ecosystems, Environmental health, Water quality, Water pollution, Water.
