We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Influence of microplastics on the bioconcentration of organic contaminants in fish: Is the “Trojan horse” effect a matter of concern?
AI summary Read the abstract
Researchers tested whether microplastic ingestion increases the bioconcentration of hydrophobic organic chemicals in zebrafish, examining the so-called 'Trojan horse' effect. They found that exposure to contaminated polyethylene microplastics did not significantly increase chemical accumulation in fish compared to waterborne exposure alone. The study suggests that for these chemicals, direct water exposure remains the dominant uptake pathway, and the microplastic carrier effect may be less concerning than previously thought.
Microplastics (MPs) have been shown to act as sorbent phases and thus carriers of organic chemicals in the aquatic environment. Therefore, concerns exist that MP ingestion increases the uptake and accumulation of organic chemicals by aquatic organisms. However, it is unclear if this pathway is relevant compared to other exposure pathways. Here we compared the bioconcentration capacity of two hydrophobic organic chemicals (i.e., chlorpyrifos and hexachlorobenzene) in a freshwater fish (Danio rerio) when exposed to chemicals through water only and in combination with contaminated polyethylene MPs. Additionally, a suite of biomarker analyses (acetylcholine esterase, glutathione S-transferase, alkaline phosphatase, catalase) was carried out to test whether MPs can enhance the toxic stress caused by chemicals. Two 14-day semi-static experiments (one for each chemical) were carried out with adult fish. Each experiment consisted of (1) a control treatment (no chemicals, no MPs); (2) a treatment in which fish were exposed to chlorpyrifos or hexachlorobenzene only through water; (3) a treatment in which fish were exposed to the chemicals through water and contaminated polyethylene MPs (100 mg MP/L). Two additional treatments were included for the biomarker analysis. These contained MPs at two different concentrations (5 and 100 mg MP/L) but no chemicals. The presence of contaminated MPs in contaminated water did not enhance but rather decreased the bioconcentration of both chemicals in fish compared to the treatment that contained contaminated water in absence of MPs. This was more pronounced for hexachlorobenzene, which is more hydrophobic than chlorpyrifos. Enzyme activity levels in fish were only significantly altered in the presence of MPs for alkaline phosphatase. This study indicates that MP presence in freshwater ecosystems is not expected to increase the risks associated with chemical bioconcentration in aquatic organisms and that other exposure pathways (i.e., uptake via respiration, skin permeability) may be of higher importance.
More Papers Like This
Determination of Bisphenol Compounds and the Bioaccumulation after Co-Exposure with Polyethylene Microplastics in Zebrafish
AI summary Read the abstract
Researchers developed a method to measure how bisphenol A and bisphenol S accumulate in zebrafish tissues when microplastics are also present. They found that microplastics increased the accumulation of these hormone-disrupting chemicals in fish tissues, with BPA building up more than BPS. The evidence indicates that microplastics can act as carriers that enhance the uptake of harmful chemicals by aquatic organisms.
Rethinking the relevance of microplastics as vector for anthropogenic contaminants: Adsorption of toxicants to microplastics during exposure in a highly polluted stream - Analytical quantification and assessment of toxic effects in zebrafish (Danio rerio)
AI summary Read the abstract
Researchers exposed microplastics in a highly polluted stream to assess their role as contaminant vectors, then tested effects on zebrafish, finding that naturally contaminated microplastics had limited additional toxicity compared to the polluted water itself.
Effects of pristine or contaminated polyethylene microplastics on zebrafish development
AI summary Read the abstract
Researchers examined the effects of both pristine and pollutant-contaminated polyethylene microplastics on zebrafish development through chronic exposure. The study assessed how microplastics, both alone and as carriers of adsorbed organic pollutants, affect developing fish. The findings provide new insights into how contaminated microplastics may create additional routes for toxic compounds to enter aquatic food webs.
Potentiation of polycyclic aromatic hydrocarbon uptake in zebrafish embryos by nanoplastics
AI summary Read the abstract
Nanoplastics present in the environment were found to enhance the uptake of polycyclic aromatic hydrocarbons (PAHs) in zebrafish embryos, suggesting that plastic particles can act as a "Trojan horse" that increases exposure to other toxic pollutants. This combined toxicity effect raises important concerns about the true health risks of microplastic contamination.
Combined effects of microplastics and chemical contaminants on the organ toxicity of zebrafish ( Danio rerio )
AI summary Read the abstract
Researchers studied the combined effects of microplastics and chemical contaminants like PCBs and methylmercury on zebrafish organs over three weeks of exposure. They found that microplastics carrying adsorbed contaminants produced the most significant effects, particularly on the liver, compared to either microplastics or contaminants alone. The results indicate that microplastics may act as carriers that increase the delivery of harmful chemicals to organisms' tissues.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.