Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Oct 17.
doi: 10.1007/s00330-025-11984-5. Online ahead of print.

Effect of distributing urine-collection bags on contrast-material load in wastewater

Ben J A Janssen  1   2 , Frank M Zijta  2   3   4 , Natasja Fraters  5 , Ad de Man  5 , Sandra Malagon  5 , Saba Rafi  1 , Henrius P Raat  6 , Ankie Hersbach  2 , Joachim E Wildberger  2   3 , Estelle C Nijssen  7   8
Affiliations

Effect of distributing urine-collection bags on contrast-material load in wastewater

Ben J A Janssen et al. Eur Radiol. .

Abstract

Objectives: Contrast materials (CM) are ubiquitous in modern clinical practice. Metabolically inert and excreted in urine, treatment plants (WWTP) have difficulty removing CM from wastewater and CM increasingly emerge as environmental contaminants. This study evaluates the effect of urine-collection bag (UCB) distribution on corresponding CM load in WWTP influent.

Materials and methods: This prospective observational multicenter study includes patients scheduled for contrast-material-enhanced computed tomography (iodine-CM) or magnetic resonance imaging (gadolinium-CM) at an academic and a regional hospital. At each centre, data were collected over a 3-week control-period and a 3-week intervention-period with standard-clinical-care UCB distribution (4pp). Control and intervention were compared for cumulative iodine- and gadolinium-CM-loads in WWTP influent using linear regression analysis, corrected for administered CM. Compliance was evaluated in interviews with consenting patients; results were used to estimate achievable UCB-distribution effects.

Results: UCB were distributed to 69.1% (1188/1719) eligible patients, and had a statistically significant effect on WWTP influent CM-loads: intervention versus control -17.4% iopromide [F(1,37) = 54.7, p < 0.001, η2 = 0.60; R2 = 0.966]; -14.8% ioversol [F(1,37) = 154.5, p < 0.001, η2 = 0.82; R2 = 0.989]; -7.2% gadolinium at the academic hospital [F(1,37) = 43.3, p < 0.001, η2 = 0.54, R2 = 0.967]; -33.2% gadolinium at the regional hospital [F(1,37) = 1.13, p = 0.296, η2 = 0.03]. Interviews were conducted with 47.0% (558/1188) patients: 92.1% (514/558) reported using UCB, and they used 89.2% (1834/2056) of the UCB they were provided with. Compliance-based estimates were: achievable compliance 29.9% to 43.6%, interceptable CM 26.7% to 38.9%.

Conclusion: UCB distribution had a significant but small impact on reducing wastewater CM-loads. Compliance data overestimate UCB-distribution effect, which underscores the importance of wastewater measurements when evaluating mitigation strategies.

Key points: Question Contrast materials (CM) increasingly emerge as environmental contaminants; because treatment plants are currently unable to remove CM from wastewater, the effects of urine-collection-bag distribution are evaluated. Findings Standard-care urine-collection-bag distribution after CT and MRI led to small but significant CM-load reductions in wastewater; compliance data, however, led to sizeable overestimation of (achievable) effects. Clinical relevance Urine-collection bag distribution had a significant but small impact on reducing contrast materials in wastewater. Most studies only include compliance data, but results show these overestimate impact, underscoring the importance of contrast-load measurements when evaluating mitigation strategies.

Keywords: Computed tomography; Contrast media; Environmental pollutants; Magnetic resonance imaging.

PubMed Disclaimer

Conflict of interest statement

Compliance with ethical standards. Guarantor: The scientific guarantor of this publication is Ben Janssen. Conflict of interest: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. Statistics and biometry: No complex statistical methods were necessary for this paper. Informed consent: Written informed consent was obtained for compliance data collection. Ethical approval: Institutional Review Board approval was obtained (METC azM/UM 2022-3265). Study subjects or cohorts overlap: Not applicable. Methodology: Prospective Observational Performed at multiple institutions

References

    1. Organisation for Economic Cooperation and Development (2024) Data set on medical technology availability. Available via https://data-explorer.oecd.org/ . Accessed 28 Jul 2025
    1. van der Molen AJ, Dekkers IA, Geenen RWF et al (2024) Waiting times between examinations with intravascularly administered contrast media: a review of contrast media pharmacokinetics and updated ESUR Contrast Media Safety Committee guidelines. Eur Radiol 34:2512–2523 - DOI - PubMed
    1. Rogowska J, Olkowska E, Ratajczyk W, Wolska L (2018) Gadolinium as a new emerging contaminant of aquatic environments. Environ Toxicol Chem 37:1523–1534 - DOI - PubMed
    1. Sengar A, Vijayanandan A (2021) Comprehensive review on iodinated X-ray contrast media: complete fate, occurrence, and formation of disinfection byproducts. Sci Total Environ 769:144846 - DOI - PubMed
    1. Bringas A, Bringas E, Ibanez R, San Roman MF (2024) Tracing gadolinium levels throughout wastewater treatment: insights from a yearly assessment in northern Spain. Sci Total Environ 48:174819 - DOI

LinkOut - more resources