Assessing the toxicity of recycled rubber and bio-rubber leachates on marine plankton

The impacts of microplastics on the marine environment have become a significant concern in the last decades. Specifically, microplastics can leach additives that may be toxic to aquatic organisms. However, little information is available on the effects of leachates from recycled rubber crumbs and their biodegradable alternatives (bio-rubbers). This study estimates the acute toxicity of leachates from various rubber crumbs on the microalga Rhodomonas salina and the planktonic copepod Acartia tonsa. Several endpoints, g̈rowthf̈or R. salina (24 hours of exposure) and ḧatching successänd n̈auplii survivalf̈or A. tonsa (72 hours of exposure), were assessed. A selection of rubber materials (n = 18) was tested, and exposures to different leachate dilutions were conducted with the most toxic leachates to R. salina. Two leachate extraction methods (organic solvent vs. seawater) were compared. The most toxic rubber and the bio-rubber were examined for the copepod tests. The rubber leachates showed a range of median effective concentrations (EC50) from 51.5 to 1088 mg/L. The EC50 values between both extraction methods were of the same order of magnitude. In the copepod tests, hatching success was unaffected. However, recycled black tire crumb caused 100 Also see: https://micro2024.sciencesconf.org/559681/document