0
Article Tier 2 Human Health Effects Sign in to save

Low-density polyethylene microplastics partially alleviate the ecotoxicological effects induced by cadmium exposure on the earthworm Eisenia fetida

Soil Ecology Letters 2024 9 citations

AI summary Read the abstract

A controlled soil experiment found that low-density polyethylene microplastics combined with cadmium did not worsen cadmium toxicity to earthworms and actually alleviated cadmium-induced DNA damage in coelomocytes, while LDPE alone had minimal effects on earthworm survival or reproduction. This counterintuitive finding suggests microplastic-metal interactions in soil are complex and not always additive, complicating risk assessments for contaminated agricultural soils.

Cadmium (Cd) can accumulate in the food chain, with serious impacts on human health and safety. Microplastics (MPs) such as low-density polyethylene (LDPE) should be considered not only as a single pollutant but also as a carrier of other pollutants. In this study, we investigated the joint effects of 30% LDPE and 313 mg kg−1 Cd on mortality, growth, reproduction, microstructure, DNA damage, oxidative stress, and mRNA levels in the earthworm Eisenia fetida. We found that 313 mg kg−1 Cd inhibited growth and reproduction and damaged the microstructures of the skin and intestine. Meanwhile, LDPE had no effect on the mortality, growth, or cocoon production of earthworms. Moreover, it did not increase the mortality, growth, or inhibition of cocoon production caused by Cd and instead alleviated the DNA damage in coelomocytes caused by Cd treatment. Finally, it did not alter the accumulation of Cd in the worms. These indicators can be used for toxicity safety assessment and soil ecological risk assessment of LDPE and Cd cooccurrence in soil.

More Papers Like This

Article Tier 2

Polypropylene microplastics alter the cadmium adsorption capacity on different soil solid fractions

AI summary Read the abstract

Researchers found that polypropylene microplastics reduce soil's ability to bind the toxic heavy metal cadmium, with the effect varying by soil composition and microplastic aging — suggesting that microplastic contamination could indirectly increase the risk of heavy metals leaching into groundwater.

Article Tier 2

Interactive behavior of cadmium ions onto polyethylene microplastics in aquatic system

AI summary Read the abstract

Researchers examined how polyethylene microplastics absorb and release cadmium, a toxic heavy metal, in freshwater conditions, finding that acidic environments can cause near-complete release of cadmium back into the water. This raises concern that microplastics carrying heavy metals could deliver those toxins to aquatic organisms through their digestive systems.

Article Tier 2

Effects of Micro-Nanoplastics Exposure to Earthworms in the Soil System

AI summary Read the abstract

Researchers investigated how micro- and nanoplastic exposure affects earthworms in soil systems, examining toxicity mechanisms and interactions with co-occurring heavy metals and other contaminants. The findings indicate that MNP contamination can impair soil productivity and earthworm health, threatening the foundation of terrestrial food webs.

Article Tier 2

Polylactic acid microplastics and polyhydroxyalkanoate microplastics affect cadmium mobility by regulating sediment geochemical properties

AI summary Read the abstract

A 60-day sediment incubation study showed that biodegradable microplastics (PLA and PHA) lowered sediment pH and organic matter content, shifting cadmium into more mobile acid-soluble chemical forms and increasing its bioavailability—with smaller particle sizes and higher concentrations having the greatest effect. The finding challenges the assumption that biodegradable plastics are environmentally safe, revealing that even these alternatives can amplify heavy metal toxicity in contaminated sediments and pose compounded risks to aquatic life and food safety.

Meta Analysis Tier 1

Meta-analysis reveals contrasting effects of biodegradable and conventional microplastics on earthworm fitness, physiology, and gut microbiota

AI summary Read the abstract

A large analysis of over 100 studies found that both regular plastic pollution and "biodegradable" plastics harm earthworms, shrinking their survival, growth, and gut bacteria, while causing cell damage from oxidative stress. The key takeaway: switching to biodegradable plastics doesn't actually protect these important soil creatures, so it's not a guilt-free fix. Since earthworms keep soil healthy for growing our food, this matters for the whole food chain, including us, and it's a reminder that "biodegradable" labels don't always mean "harmless."

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.

Email me about

Share this paper