Tire particles and its leachates: Impact on antibiotic resistance genes in coastal sediments

Waste rubber - Black pollution reframed as a global issue: Ecological challenges and sustainability initiatives

In contrast to "white pollution" originating from waste plastics, waste rubber is often referred to as "black pollution." The quantity and variety of waste rubber are increasing at an alarming rate, with a considerable fraction entering the global ecosystem via various pathways. This study presents the first critical review of waste rubber research with a focus on the risks associated with toxicant discharge and existing problems in waste rubber disposal, management, and recycling practices. We aim to obtain a comprehensive understanding of current research, particularly regarding the ecological impacts of these wastes, highlight major gaps, and propose the most significant research directions. A total of 192 studies published in journals were critically analysed. The importance of conducting long-term and large-scale experiments and developing efficient waste rubber recycling systems is also emphasised. This study highlights the need to address the challenges posed by waste rubber pollution and offers insights and references for undertaking ecological risk assessments and understanding the mechanisms underlying toxicant behaviour. Suggestions and countermeasures are proposed with ecosystem sustainability as the ultimate goal. Further long-term, comprehensive, and systematic research in this area is required.

Effects of tire-road wear particles on the adsorption of tetracycline by aquatic sediments

Tire-road wear particles (TRWPs) are formed by friction between the tire and the road. TRWPs are ubiquitous across the globe, especially in sediments. However, the possible effects of TRWPs on tetracycline (TC) in aquatic sediments are unknown. To investigate the potential role of TRWPs as carriers of co-pollutants, this study investigated the pore surface properties and TC adsorption behavior of TRWP-contaminated sediments and explored the TC behavior in water sediments, as well as the role of aging processes and TRWPs abundance. The results showed that the surface morphology of TRWP-contaminated sediments changed and the adsorption capacity of sediments to TC increased. The TC adsorption capacity of sediments contaminated by 2% TRWPs increased from 3.15 to 3.48 mg/g. Moreover, the surface physical and chemical properties of TRWPs after UV aging changed, which further increased the TC adsorption capacity. The TC adsorption capacity of the sediments contaminated by aged TRWPs increased from 3.48 to 3.65 mg/g. Changing the proportion of aged TRWPs, we found that the adsorption capacity of sediments contaminated by different proportions of TRWPs for TC was 2% > 1% > 0.5% > 4% > blank sediment. These results may contribute to predicting the potential environmental risks of TRWPs in aquatic sediments.

Long-term application of organic fertilizer prompting the dispersal of antibiotic resistance genes and their health risks in the soil plastisphere

Microplastic (MP) pollution is a rapidly growing global environmental concern that has led to the emergence of a new environmental compartment, the plastisphere, which is a hotspot for the accumulation of antibiotic resistance genes (ARGs) and human bacterial pathogens (HBPs). However, studies on the effects of long-term organic fertilizer application on the dispersal of ARGs and virulence factor genes (VFGs) in the plastisphere of farmland soil have been limited. Here, we performed a field culture experiment by burying nylon bags filled with MPs in paddy soil that had been treated with different fertilizers for over 30 years to explore the changes of ARGs and VFGs in soil plastisphere. Our results show that the soil plastisphere amplified the ARG and VFG pollution caused by organic fertilization by 1.5 and 1.4 times, respectively. And it also led to a 2.7-fold increase in the risk of horizontal gene transfer. Meanwhile, the plastisphere tended to promote deterministic process in the community assembly of HBPs, with an increase of 1.4 times. Network analysis found a significant correlation between ARGs, VFGs, and bacteria in plastisphere. Correlation analysis highlight the important role of mobile genetic elements (MGEs) and bacterial communities in shaping the abundance of ARGs and VFGs, respectively. Our findings provide new insights into the health risk associated with the soil plastisphere due ARGs and VFGs derived from organic fertilizers.