0
Article Tier 2 Human Health Effects Sign in to save

Effects of microplastics and their combination with cadmium on Pinus massoniana are dependent on the type of microplastics

Trees Forests and People 2025 1 citation

AI summary Read the abstract

Researchers compared how conventional polyethylene and biodegradable polylactic acid microplastics, alone and combined with cadmium, affect the growth of Masson pine trees. The study found that the effects on tree growth depend significantly on the type of microplastic, suggesting that biodegradable plastics may not necessarily be less harmful to plants than conventional plastics when co-contaminated with heavy metals.

Polymers

The widespread occurrence of microplastics (MPs) in various environments globally often coincides with the presence of toxic heavy metals, leading to co-contamination toxicity in plants. However, the differences between conventional and degradable MPs and their effects on tree responses to heavy metals remain inadequately understood. To address this issue, we conducted a three-factor pot experiment (MP type: polyethylene (PE) and polylactic acid (PLA); dose: 0%, 1% and 10% w/w; cadmium(Cd): (5 mg kg⁻¹)) to investigate the effects of different types of MPs, in combination with Cd on the growth, physiological and biochemical traits of Pinus massoniana seedlings. The results showed that 1% MPs (alone or with Cd) had no significant effect on growth, whereas both high-dose MPs (10%) alone and their co-exposure with Cd significantly reduced seedling biomass and photosynthetic rates. PLA+Cd caused stronger biomass inhibition (51.5% vs. PE+Cd: 34.3%), while PE+Cd suppressed photosynthesis more severely (68.4% vs. PLA+Cd: 52.8%). PE (alone or with Cd) and PLA+Cd triggered oxidative stress, elevating proline (Pro), peroxidase (POD), and superoxide dismutase (SOD) activities, whereas PLA-only increased Pro and POD. Both 10% MPs-only and their co-exposure with Cd significantly reduced non-structural carbohydrates (NSC) in needles. Overall, the effects of MPs and their combination with cadmium on P. massoniana were dependent on the type of MPs, providing significant implications for tree seedling cultivation and forest management in the context of increasing human activities.

More Papers Like This

Article Tier 2

Plant Cadmium Toxicity and Biomarkers Are Differentially Modulated by Degradable and Nondegradable Microplastics in Soil

AI summary Read the abstract

Researchers compared how degradable (polylactic acid) and nondegradable (polypropylene) microplastics affect cadmium toxicity in plants grown in contaminated soil. They found that polypropylene caused greater root growth inhibition, while polylactic acid led to higher levels of cellular stress markers at certain concentrations. The study reveals that both types of microplastics can alter soil chemistry and increase the uptake of heavy metals by crops, but through different mechanisms.

Article Tier 2

Combined effects of microplastics and cadmium on the soil-plant system: Phytotoxicity, Cd accumulation and microbial activity

AI summary Read the abstract

Researchers tested how different microplastic types combined with cadmium affect plant growth and soil health. Aged and biodegradable microplastics increased cadmium uptake in mustard greens more than fresh conventional plastics did. The study also found that microplastics altered soil microbial activity, suggesting that plastic pollution in farmland could change how plants absorb toxic metals from contaminated soil.

Article Tier 2

Microplastics and metals: Microplastics generated from biodegradable polylactic acid mulch reduce bioaccumulation of cadmium in earthworms compared to those generated from polyethylene

AI summary Read the abstract

Researchers compared how microplastics from biodegradable (PLA) and conventional (polyethylene) plastic mulch interact with cadmium, a toxic heavy metal, in soil with earthworms. PLA microplastics absorbed much more cadmium than polyethylene, reducing the amount of this toxic metal available to earthworms. While this suggests biodegradable plastics may offer some protection against heavy metal exposure in contaminated soils, both types still contribute to microplastic pollution.

Article Tier 2

Microplastic dilemma: Assessing the unexpected trade-offs between biodegradable and non-biodegradable forms on plant health, cadmium uptake, and sediment microbial ecology

AI summary Read the abstract

This study compared the environmental effects of biodegradable and conventional plastic microplastics in contaminated sediments, finding that biodegradable plastics actually caused more oxidative stress and greater changes to soil bacteria than conventional plastics. Both types helped plant roots absorb more of the toxic metal cadmium. The surprising finding that biodegradable plastics may pose higher ecological risks challenges the assumption that they are always a safer alternative.

Article Tier 2

Effects of microplastics on cadmium accumulation by rice and arbuscular mycorrhizal fungal communities in cadmium-contaminated soil

AI summary Read the abstract

Researchers studied how three types of microplastics interact with cadmium contamination in rice paddies, examining effects on plant growth, metal uptake, and soil fungal communities. They found that while microplastics generally increased cadmium availability in soil, they actually decreased cadmium accumulation in rice tissues. Notably, biodegradable polylactic acid microplastics caused more harm to plant growth and soil communities than conventional plastic types, challenging the assumption that biodegradable plastics are always safer.

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