Our new paper by Katalin Lukács et al. has recently been published in Journal of Environmental Management.
The citation of the paper is:
Lukács, K., Kiss, R., Tóth, Á., Godó, L., Deák, B., Valkó, O. (2025): Effects of laundry washing on germination of cloth-dispersed seeds depends on washing intensity not on detergent type. Journal of Environmental Management 375: 124345. https://doi.org/10.1016/j.jenvman.2025.124345
It is an open access paper that can be freely downloaded from the journal's homepage (please
click here).
In this study, we investigated a simple, everyday process - laundry washing. This seems a bit odd, why ecologists study this process - but our study revealed that indeed, it can have very interesting effects on the dispersal of plant species :)
What is the importance of our clothing in the dispersal of plant species? Unintentional human-vectored dispersal (HVD) is a special form of epizoochory, in which the seed dispersal vectors are humans, with seeds attaching to clothing or footwear during various outdoor activities. Due to the increasing human mobility, large quantities of seeds can be spread over long distances on a daily basis. It is important to emphasize, that, to date, mostly weeds and invasive species have been documented as capable of spreading on clothing. Despite HVD is part of everyday life, most people remain unaware of this phenomenon. In many cases, people do not pay attention to clean their clothes from seeds or may not even notice their presence. Unnoticed seeds on clothes can end up in washing machines regularly.
We designed a large experiment to study the effect of laundry washing on the germination potential of cloth-dispersed seeds, with particular attention to the effects of detergents and washing intensity. Since in our earlier study (
Valkó et al. 2020 NeoBiota) we did not find a significant effect of detergent type, we sought to investigate this topic further to identify whether a specific detergent could significantly reduce the germination potential of cloth-dispersed seeds. To this end, we selected detergents based on their chemical composition, to represent the main types of detergents used in households (ranging from natural detergents to synthetic ones with varying concentrations of surfactants, enzymes, and soap). We aimed to cover the full spectrum of the detergent types and washing intensities most commonly used in households, and we had in total 21 treatment combinations.
The main idea of our experiment and the design of the treatments.
The findings show that most seeds remain viable after typical household washing, even at common temperatures and wide range of detergent types, highlighting a largely overlooked vector of plant dispersal. These results provided critical insights into the unintentional spread of plant species through human-vectored dispersal via clothing, a pathway that has received limited attention so far. Since most of the plants that are capable of cloth-dispersal are weeds and invasive species, the results have important implications for management. We emphasize the need for targeted biosecurity measures, especially among those working outdoors, to mitigate the spread of invasive species. The results also offer actionable strategies for environmental management by integrating behavioral changes and public awareness to reduce the environmental impact of human-vectored dispersal. According to our questionnaire survey, raising awareness is especially important for nature conservation professionals who are among the most important potential vectors.
Abstract
Unintentional human-vectored seed dispersal (HVD) occurs when the seed dispersal vectors are humans, and the seeds are attached to clothing or footwear during various outdoor activities. Since most plant species spread by HVD are invasives or weeds, the process can have globally relevant adverse environmental effects due to the growing global tourism industry. Here we evaluated whether the germination capacity of seeds can be reduced by laundry washing treatments used in households, in order to decrease the chance of unintended dispersal of plant species by clothing. We experimentally tested the effects of seven types of detergents with different chemical composition and three washing intensities in a full factorial design on the germination capacity of 18 plant species. Washing at high intensity (60 0C) significantly decreased the germination capacity in 15 species, probably due to high temperatures and longer exposure times. Washing at low (30 0C) and medium intensities (40 0C) had no effect. Detergent type affected the germination capacity of only three species. The findings underscore the importance of laundry washing in seed dispersal, since the low and medium washing intensities and detergent types that are commonly used in households do not decrease the germination capacity of the cloth-dispersed seeds. We urge addressing the spread of HVD-dispersed seeds through combined biosecurity measures. Self-regulation, such as removing of seeds from clothes and disposing them properly, is crucial. Informing outdoor workers, who play the largest role in HVD, can encourage small behavioural changes to decrease the adverse effects of this process.
The graphical summary of the study in the graphical abstract.
